Amazon Elastic Compute Cloud User Guide For Linux Instances

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Amazon Elastic
Compute Cloud
User Guide for Linux Instances

Amazon Elastic Compute Cloud
User Guide for Linux Instances

Amazon Elastic Compute Cloud: User Guide for Linux Instances
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Amazon Elastic Compute Cloud
User Guide for Linux Instances

Table of Contents
What Is Amazon EC2? .................................................................................................................. 1
Features of Amazon EC2 ....................................................................................................... 1
How to Get Started with Amazon EC2 ..................................................................................... 2
Related Services ................................................................................................................... 2
Accessing Amazon EC2 ......................................................................................................... 3
Pricing for Amazon EC2 ........................................................................................................ 3
PCI DSS Compliance ............................................................................................................ 4
Instances and AMIs .............................................................................................................. 4
Instances ..................................................................................................................... 5
AMIs ........................................................................................................................... 6
Regions and Availability Zones ............................................................................................... 7
Region and Availability Zone Concepts ............................................................................ 7
Available Regions ......................................................................................................... 8
Regions and Endpoints .................................................................................................. 9
Describing Your Regions and Availability Zones ................................................................ 9
Specifying the Region for a Resource ............................................................................ 11
Launching Instances in an Availability Zone .................................................................... 12
Migrating an Instance to Another Availability Zone ............................................................ 13
Root Device Volume ............................................................................................................ 14
Root Device Storage Concepts ..................................................................................... 14
Choosing an AMI by Root Device Type .......................................................................... 16
Determining the Root Device Type of Your Instance ......................................................... 17
Changing the Root Device Volume to Persist .................................................................. 17
Setting Up .................................................................................................................................. 19
Sign Up for AWS ................................................................................................................ 19
Create an IAM User ............................................................................................................ 19
Create a Key Pair ............................................................................................................... 21
Create a Virtual Private Cloud (VPC) ..................................................................................... 23
Create a Security Group ...................................................................................................... 23
Getting Started ........................................................................................................................... 26
Overview ............................................................................................................................ 26
Prerequisites ...................................................................................................................... 27
Step 1: Launch an Instance .................................................................................................. 27
Step 2: Connect to Your Instance .......................................................................................... 28
Step 3: Clean Up Your Instance ............................................................................................ 29
Next Steps ......................................................................................................................... 30
Best Practices ............................................................................................................................ 31
Tutorials ..................................................................................................................................... 33
Tutorial: Installing a LAMP Web Server on Amazon Linux .......................................................... 33
Related Topics ............................................................................................................ 42
Tutorial: Hosting a WordPress Blog ....................................................................................... 42
Prerequisites .............................................................................................................. 43
Install WordPress ........................................................................................................ 43
Next Steps ................................................................................................................. 50
Help! My Public DNS Name Changed and now my Blog is Broken ...................................... 50
Tutorial: Configure Apache Web Server on Amazon Linux to use SSL/TLS ................................... 51
Prerequisites .............................................................................................................. 52
Step 1: Enable SSL/TLS on the Server .......................................................................... 52
Step 2: Obtain a CA-signed Certificate ........................................................................... 54
Step 3: Test and Harden the Security Configuration .......................................................... 57
Troubleshooting .......................................................................................................... 60
Tutorial: Increase the Availability of Your Application ................................................................ 60
Prerequisites .............................................................................................................. 61
Scale and Load Balance Your Application ....................................................................... 61
Test Your Load Balancer .............................................................................................. 63

Amazon Elastic Compute Cloud
User Guide for Linux Instances

Tutorial: Remotely Manage Your Instances ............................................................................. 64
Launch a New Instance ............................................................................................... 64
Grant Your User Account Access to SSM ....................................................................... 65
Install the SSM Agent .................................................................................................. 65
Send a Command Using the EC2 Console ...................................................................... 67
Send a Command Using the AWS CLI ........................................................................... 68
Amazon Machine Images ............................................................................................................. 69
Using an AMI ..................................................................................................................... 69
Creating Your Own AMI ....................................................................................................... 70
Buying, Sharing, and Selling AMIs ......................................................................................... 70
Deregistering Your AMI ........................................................................................................ 70
Amazon Linux ..................................................................................................................... 70
AMI Types ......................................................................................................................... 71
Launch Permissions .................................................................................................... 71
Storage for the Root Device ......................................................................................... 71
Virtualization Types ............................................................................................................. 74
Finding a Linux AMI ............................................................................................................ 75
Finding a Linux AMI Using the Amazon EC2 Console ....................................................... 75
Finding an AMI Using the AWS CLI ............................................................................... 76
Shared AMIs ...................................................................................................................... 76
Finding Shared AMIs ................................................................................................... 77
Making an AMI Public .................................................................................................. 78
Sharing an AMI with Specific AWS Accounts ................................................................... 80
Using Bookmarks ........................................................................................................ 81
Guidelines for Shared Linux AMIs .................................................................................. 81
Paid AMIs .......................................................................................................................... 85
Selling Your AMI ......................................................................................................... 86
Finding a Paid AMI ..................................................................................................... 86
Purchase a Paid AMI ................................................................................................... 87
Getting the Product Code for Your Instance .................................................................... 87
Using Paid Support ..................................................................................................... 88
Bills for Paid and Supported AMIs ................................................................................. 88
Managing Your AWS Marketplace Subscriptions .............................................................. 88
Creating an Amazon EBS-Backed Linux AMI ........................................................................... 89
Overview of Creating Amazon EBS-Backed AMIs ............................................................. 89
Creating a Linux AMI from an Instance ........................................................................... 90
Creating a Linux AMI from a Snapshot ........................................................................... 91
Creating an Instance Store-Backed Linux AMI ......................................................................... 92
Overview of the Creation Process for Instance Store-Backed AMIs ...................................... 93
Prerequisites .............................................................................................................. 93
Setting Up the AMI Tools ............................................................................................. 94
Creating an AMI from an Instance Store-Backed Instance ................................................ 120
Converting to an Amazon EBS-Backed AMI .................................................................. 129
AMIs with Encrypted Snapshots ........................................................................................... 132
AMI Scenarios Involving Encrypted EBS Snapshots ........................................................ 133
Copying an AMI ................................................................................................................ 135
Copying an AMI You Own .......................................................................................... 136
Copying an AMI Across AWS Accounts ........................................................................ 136
Copying an AMI Across Regions ................................................................................. 136
Copying to Encrypt .................................................................................................... 137
AMI Copying Scenarios .............................................................................................. 138
Copying an AMI Using the Console or Command Line .................................................... 139
Stopping a Pending AMI Copy Operation ...................................................................... 140
Deregistering Your AMI ...................................................................................................... 140
Cleaning Up Your Amazon EBS-Backed AMI ................................................................. 141
Cleaning Up Your Instance Store-Backed AMI ............................................................... 142
Amazon Linux ................................................................................................................... 142
Finding the Amazon Linux AMI .................................................................................... 143

Amazon Elastic Compute Cloud
User Guide for Linux Instances

Launching and Connecting to an Amazon Linux Instance ................................................. 143
Identifying Amazon Linux AMI Images .......................................................................... 143
Included AWS Command Line Tools ............................................................................ 144
cloud-init ............................................................................................................. 145
Repository Configuration ............................................................................................. 146
Adding Packages ...................................................................................................... 147
Accessing Source Packages for Reference ................................................................... 147
Developing Applications .............................................................................................. 148
Instance Store Access ................................................................................................ 148
Product Life Cycle ..................................................................................................... 148
Security Updates ....................................................................................................... 148
Support .................................................................................................................... 149
User Provided Kernels ....................................................................................................... 149
HVM AMIs (GRUB) .................................................................................................... 149
Paravirtual AMIs (PV-GRUB) ....................................................................................... 150
Instances .................................................................................................................................. 156
Instance Types .................................................................................................................. 156
Available Instance Types ............................................................................................ 157
Hardware Specifications ............................................................................................. 158
Virtualization Types .................................................................................................... 158
Networking and Storage Features ................................................................................ 158
Instance Limits .......................................................................................................... 159
T2 Instances ............................................................................................................. 160
C4 Instances ............................................................................................................ 163
GPU Instances .......................................................................................................... 166
I2 Instances .............................................................................................................. 169
D2 Instances ............................................................................................................ 170
HI1 Instances ............................................................................................................ 173
HS1 Instances .......................................................................................................... 174
T1 Micro Instances .................................................................................................... 175
X1 Instances ............................................................................................................. 187
Resizing Instances ..................................................................................................... 189
Instance Purchasing Options ............................................................................................... 193
Determining the Instance Lifecycle ............................................................................... 193
Reserved Instances ................................................................................................... 194
Scheduled Instances .................................................................................................. 215
Spot Instances .......................................................................................................... 219
Dedicated Hosts ........................................................................................................ 264
Instance Lifecycle .............................................................................................................. 275
Instance Launch ........................................................................................................ 275
Instance Stop and Start (Amazon EBS-backed instances only) ......................................... 276
Instance Reboot ........................................................................................................ 276
Instance Retirement ................................................................................................... 276
Instance Termination .................................................................................................. 276
Differences Between Reboot, Stop, and Terminate ......................................................... 277
Launch ..................................................................................................................... 278
Connect ................................................................................................................... 289
Stop and Start .......................................................................................................... 299
Reboot ..................................................................................................................... 302
Retire ....................................................................................................................... 303
Terminate ................................................................................................................. 305
Recover ................................................................................................................... 310
Configure Instances ........................................................................................................... 311
Common Configuration Scenarios ................................................................................ 311
Managing Software .................................................................................................... 312
Managing Users ........................................................................................................ 320
Processor State Control .............................................................................................. 322
Setting the Time ........................................................................................................ 326

Amazon Elastic Compute Cloud
User Guide for Linux Instances

Changing the Hostname ............................................................................................. 330
Setting Up Dynamic DNS ........................................................................................... 332
Running Commands at Launch .................................................................................... 334
Instance Metadata and User Data ................................................................................ 337
Remotely Manage Your Instances ........................................................................................ 352
Components and Concepts ......................................................................................... 352
Prerequisites ............................................................................................................. 355
Installing the SSM Agent ............................................................................................ 357
Delegating Access ..................................................................................................... 365
Setting Up Run Command On Managed Instances ......................................................... 371
Executing Commands ................................................................................................ 374
Viewing Command Output .......................................................................................... 377
Creating SSM Documents ........................................................................................... 378
Sharing SSM Documents ............................................................................................ 381
Walkthroughs ............................................................................................................ 387
Cancelling a Command .............................................................................................. 394
Monitoring Commands ................................................................................................ 394
Troubleshooting Run Command ................................................................................... 404
Importing and Exporting Virtual Machines .............................................................................. 406
Monitoring ................................................................................................................................ 407
Automated and Manual Monitoring ....................................................................................... 409
Automated Monitoring Tools ........................................................................................ 409
Manual Monitoring Tools ............................................................................................ 410
Best Practices for Monitoring ............................................................................................... 410
Monitoring the Status of Your Instances ................................................................................ 411
Instance Status Checks .............................................................................................. 411
Scheduled Events ...................................................................................................... 415
Monitoring Your Instances Using CloudWatch ........................................................................ 419
Enable Detailed Monitoring ......................................................................................... 419
List Available Metrics ................................................................................................. 421
Get Statistics for Metrics ............................................................................................. 426
Graph Metrics ........................................................................................................... 441
Create a CloudWatch Alarm ........................................................................................ 444
Create Alarms That Stop, Terminate, Reboot, or Recover an Instance ................................ 450
Monitoring Memory and Disk Metrics .................................................................................... 471
Prerequisites ............................................................................................................. 472
Getting Started .......................................................................................................... 474
mon-put-instance-data.pl ............................................................................................. 475
mon-get-instance-stats.pl ............................................................................................ 477
Viewing Your Custom Metrics in the Console ................................................................. 479
Network and Security ................................................................................................................. 480
Key Pairs ......................................................................................................................... 481
Creating Your Key Pair Using Amazon EC2 .................................................................. 482
Importing Your Own Key Pair to Amazon EC2 ............................................................... 482
Retrieving the Public Key for Your Key Pair on Linux ...................................................... 484
Retrieving the Public Key for Your Key Pair on Windows ................................................. 485
Verifying Your Key Pair's Fingerprint ............................................................................ 485
Deleting Your Key Pair ............................................................................................... 486
Connecting to Your Linux Instance if You Lose Your Private Key ....................................... 486
Security Groups ................................................................................................................ 489
Security Groups for EC2-Classic .................................................................................. 490
Security Groups for EC2-VPC ..................................................................................... 490
Security Group Rules ................................................................................................. 491
Default Security Groups .............................................................................................. 492
Custom Security Groups ............................................................................................. 493
Creating a Security Group .......................................................................................... 494
Describing Your Security Groups ................................................................................. 495
Adding Rules to a Security Group ................................................................................ 495

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User Guide for Linux Instances

Deleting Rules from a Security Group ........................................................................... 496
Deleting a Security Group ........................................................................................... 496
API and Command Overview ...................................................................................... 497
Controlling Access ............................................................................................................. 498
Network Access to Your Instance ................................................................................ 498
Amazon EC2 Permission Attributes .............................................................................. 498
IAM and Amazon EC2 ............................................................................................... 498
IAM Policies ............................................................................................................. 500
IAM Roles ................................................................................................................ 536
Network Access ........................................................................................................ 541
Amazon VPC .................................................................................................................... 543
Benefits of Using a VPC ............................................................................................. 543
Differences Between EC2-Classic and EC2-VPC ............................................................ 544
Sharing and Accessing Resources Between EC2-Classic and EC2-VPC ............................. 546
Instance Types Available Only in a VPC ....................................................................... 548
Amazon VPC Documentation ...................................................................................... 548
Supported Platforms .................................................................................................. 549
ClassicLink ............................................................................................................... 550
Migrating from EC2-Classic to a VPC ........................................................................... 560
Instance IP Addressing ...................................................................................................... 570
Private IP Addresses and Internal DNS Hostnames ........................................................ 571
Public IP Addresses and External DNS Hostnames ........................................................ 572
Elastic IP Addresses .................................................................................................. 573
Amazon DNS Server .................................................................................................. 573
IP Address Differences Between EC2-Classic and EC2-VPC ............................................ 573
Determining Your Public, Private, and Elastic IP Addresses .............................................. 574
Assigning a Public IP Address ..................................................................................... 575
Multiple Private IP Addresses ...................................................................................... 576
Elastic IP Addresses .......................................................................................................... 581
Elastic IP Address Basics ........................................................................................... 581
Elastic IP Address Differences for EC2-Classic and EC2-VPC .......................................... 582
Working with Elastic IP Addresses ............................................................................... 584
Using Reverse DNS for Email Applications .................................................................... 587
Elastic IP Address Limit .............................................................................................. 587
Elastic Network Interfaces ................................................................................................... 588
Private IP Addresses Per Network Interface Per Instance Type ......................................... 589
Public IP Addresses for Network Interfaces ................................................................... 591
Creating a Management Network ................................................................................. 591
Use Network and Security Appliances in Your VPC ........................................................ 592
Creating Dual-homed Instances with Workloads/Roles on Distinct Subnets ......................... 592
Create a Low Budget High Availability Solution .............................................................. 592
Monitoring IP Traffic on Your Network Interface .............................................................. 593
Best Practices for Configuring Elastic Network Interfaces ................................................. 593
Configuring Your Network Interface Using ec2-net-utils .................................................... 593
Creating an Elastic Network Interface ........................................................................... 594
Deleting an Elastic Network Interface ........................................................................... 595
Viewing Details about an Elastic Network Interface ......................................................... 595
Attaching an Elastic Network Interface When Launching an Instance ................................. 596
Attaching an Elastic Network Interface to a Stopped or Running Instance ........................... 597
Detaching an Elastic Network Interface from an Instance ................................................. 598
Changing the Security Group of an Elastic Network Interface ............................................ 598
Changing the Source/Destination Checking of an Elastic Network Interface ......................... 599
Associating an Elastic IP Address with an Elastic Network Interface ................................... 599
Disassociating an Elastic IP Address from an Elastic Network Interface .............................. 600
Changing Termination Behavior for an Elastic Network Interface ....................................... 600
Adding or Editing a Description for an Elastic Network Interface ........................................ 601
Adding or Editing Tags for an Elastic Network Interface ................................................... 601
Placement Groups ............................................................................................................. 602

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Amazon Elastic Compute Cloud
User Guide for Linux Instances

Placement Group Limitations .......................................................................................
Launching Instances into a Placement Group ................................................................
Deleting a Placement Group .......................................................................................
Network MTU ....................................................................................................................
Jumbo Frames (9001 MTU) ........................................................................................
Path MTU Discovery ..................................................................................................
Check the Path MTU Between Two Hosts .....................................................................
Check and Set the MTU on your Amazon EC2 Instance ..................................................
Troubleshooting .........................................................................................................
Enhanced Networking ........................................................................................................
Enhanced Networking Types .......................................................................................
Enabling Enhanced Networking on Your Instance ...........................................................
Enabling Enhanced Networking: Intel 82599 VF .............................................................
Enabling Enhanced Networking: ENA ...........................................................................
Troubleshoooting ENA ................................................................................................
Storage ....................................................................................................................................
Amazon EBS ....................................................................................................................
Features of Amazon EBS ...........................................................................................
EBS Volumes ...........................................................................................................
EBS Snapshots .........................................................................................................
EBS Optimization ......................................................................................................
EBS Encryption .........................................................................................................
EBS Performance ......................................................................................................
Instance Store ...................................................................................................................
Instance Store Lifetime ...............................................................................................
Instance Store Volumes .............................................................................................
Add Instance Store Volumes .......................................................................................
SSD Instance Store Volumes ......................................................................................
Instance Store Swap Volumes .....................................................................................
Optimizing Disk Performance ......................................................................................
Amazon S3 ......................................................................................................................
Amazon S3 and Amazon EC2 .....................................................................................
Instance Volume Limits ......................................................................................................
Linux-Specific Volume Limits .......................................................................................
Windows-Specific Volume Limits ..................................................................................
Bandwidth vs Capacity ...............................................................................................
Device Naming ..................................................................................................................
Available Device Names .............................................................................................
Device Name Considerations ......................................................................................
Block Device Mapping ........................................................................................................
Block Device Mapping Concepts ..................................................................................
AMI Block Device Mapping .........................................................................................
Instance Block Device Mapping ...................................................................................
Using Public Data Sets ......................................................................................................
Public Data Set Concepts ...........................................................................................
Finding Public Data Sets ............................................................................................
Creating a Public Data Set Volume from a Snapshot .......................................................
Attaching and Mounting the Public Data Set Volume .......................................................
Resources and Tags ..................................................................................................................
Resource Locations ...........................................................................................................
Resource IDs ....................................................................................................................
Working with Longer IDs ............................................................................................
Controlling Access to Longer ID Settings ......................................................................
Listing and Filtering Your Resources ....................................................................................
Advanced Search ......................................................................................................
Listing Resources Using the Console ...........................................................................
Filtering Resources Using the Console .........................................................................
Listing and Filtering Using the CLI and API ...................................................................

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Amazon Elastic Compute Cloud
User Guide for Linux Instances

Tagging Your Resources .................................................................................................... 751
Tag Basics ............................................................................................................... 752
Tag Restrictions ........................................................................................................ 753
Tagging Your Resources for Billing .............................................................................. 754
Working with Tags Using the Console .......................................................................... 755
Working with Tags Using the CLI or API ....................................................................... 760
Service Limits ................................................................................................................... 760
Viewing Your Current Limits ........................................................................................ 761
Requesting a Limit Increase ........................................................................................ 762
Usage Reports .................................................................................................................. 762
Available Reports ...................................................................................................... 762
Getting Set Up for Usage Reports ................................................................................ 762
Granting IAM Users Access to the Amazon EC2 Usage Reports ....................................... 764
Instance Usage ......................................................................................................... 764
Reserved Instance Utilization ...................................................................................... 767
Troubleshooting ......................................................................................................................... 773
Launching Your Instance .................................................................................................... 773
Getting the Reason for Instance Termination ................................................................. 774
Connecting to Your Instance ............................................................................................... 774
Error connecting to your instance: Connection timed out .................................................. 775
Error: User key not recognized by server ...................................................................... 776
Error: Host key not found, Permission denied (publickey), or Authentication failed,
permission denied ..................................................................................................... 777
Error: Unprotected Private Key File .............................................................................. 778
Error: Server refused our key or No supported authentication methods available .................. 778
Error using MindTerm on Safari Browser ....................................................................... 779
Error Using Mac OS X RDP Client ............................................................................... 779
Cannot Ping Instance ................................................................................................. 779
Stopping Your Instance ...................................................................................................... 779
Terminating Your Instance .................................................................................................. 781
Delayed Instance Termination ..................................................................................... 781
Terminated Instance Still Displayed .............................................................................. 781
Automatically Launch or Terminate Instances ................................................................ 781
Instance Recovery Failures ................................................................................................. 781
Failed Status Checks ......................................................................................................... 782
Initial Steps .............................................................................................................. 782
Retrieving System Logs .............................................................................................. 783
Troubleshooting System Log Errors for Linux-Based Instances ......................................... 783
Out of memory: kill process ........................................................................................ 784
ERROR: mmu_update failed (Memory management update failed) .................................... 785
I/O error (Block device failure) ..................................................................................... 786
IO ERROR: neither local nor remote disk (Broken distributed block device) ......................... 787
request_module: runaway loop modprobe (Looping legacy kernel modprobe on older Linux
versions) .................................................................................................................. 788
"FATAL: kernel too old" and "fsck: No such file or directory while trying to open /dev" (Kernel
and AMI mismatch) .................................................................................................... 789
"FATAL: Could not load /lib/modules" or "BusyBox" (Missing kernel modules) ...................... 789
ERROR Invalid kernel (EC2 incompatible kernel) ............................................................ 791
request_module: runaway loop modprobe (Looping legacy kernel modprobe on older Linux
versions) .................................................................................................................. 792
fsck: No such file or directory while trying to open... (File system not found) ........................ 793
General error mounting filesystems (Failed mount) ......................................................... 794
VFS: Unable to mount root fs on unknown-block (Root filesystem mismatch) ....................... 796
Error: Unable to determine major/minor number of root device... (Root file system/device
mismatch) ................................................................................................................. 797
XENBUS: Device with no driver... ................................................................................ 798
... days without being checked, check forced (File system check required) .......................... 798
fsck died with exit status... (Missing device) ................................................................... 799

Amazon Elastic Compute Cloud
User Guide for Linux Instances

GRUB prompt (grubdom>) ..........................................................................................
Bringing up interface eth0: Device eth0 has different MAC address than expected, ignoring.
(Hard-coded MAC address) .........................................................................................
Unable to load SELinux Policy. Machine is in enforcing mode. Halting now. (SELinux
misconfiguration) .......................................................................................................
XENBUS: Timeout connecting to devices (Xenbus timeout) ..............................................
Instance Capacity ..............................................................................................................
Error: InsufficientInstanceCapacity ................................................................................
Error: InstanceLimitExceeded ......................................................................................
Getting Console Output and Rebooting Instances ...................................................................
Instance Reboot ........................................................................................................
Instance Console Output ............................................................................................
Capture a Screenshot of an Unreachable Instance .........................................................
Instance Recovery When a Host Computer Fails ............................................................
My Instance is Booting from the Wrong Volume .....................................................................
Making API Requests .................................................................................................................
Document History ......................................................................................................................
AWS Glossary ..........................................................................................................................

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Amazon Elastic Compute Cloud
User Guide for Linux Instances
Features of Amazon EC2

What Is Amazon EC2?
Amazon Elastic Compute Cloud (Amazon EC2) provides scalable computing capacity in the Amazon
Web Services (AWS) cloud. Using Amazon EC2 eliminates your need to invest in hardware up front,
so you can develop and deploy applications faster. You can use Amazon EC2 to launch as many or as
few virtual servers as you need, configure security and networking, and manage storage. Amazon EC2
enables you to scale up or down to handle changes in requirements or spikes in popularity, reducing
your need to forecast traffic.
For more information about cloud computing, see What is Cloud Computing?

Features of Amazon EC2
Amazon EC2 provides the following features:
• Virtual computing environments, known as instances
• Preconfigured templates for your instances, known as Amazon Machine Images (AMIs), that
package the bits you need for your server (including the operating system and additional software)
• Various configurations of CPU, memory, storage, and networking capacity for your instances, known
as instance types
• Secure login information for your instances using key pairs (AWS stores the public key, and you
store the private key in a secure place)
• Storage volumes for temporary data that's deleted when you stop or terminate your instance, known
as instance store volumes
• Persistent storage volumes for your data using Amazon Elastic Block Store (Amazon EBS), known
as Amazon EBS volumes
• Multiple physical locations for your resources, such as instances and Amazon EBS volumes, known
as regions and Availability Zones
• A firewall that enables you to specify the protocols, ports, and source IP ranges that can reach your
instances using security groups
• Static IP addresses for dynamic cloud computing, known as Elastic IP addresses
• Metadata, known as tags, that you can create and assign to your Amazon EC2 resources
• Virtual networks you can create that are logically isolated from the rest of the AWS cloud, and that
you can optionally connect to your own network, known as virtual private clouds (VPCs)
For more information about the features of Amazon EC2, see the Amazon EC2 product page.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
How to Get Started with Amazon EC2

For more information about running your website on AWS, see Websites & Website Hosting.

How to Get Started with Amazon EC2
The first thing you need to do is get set up to use Amazon EC2. After you are set up, you are ready to
complete the Getting Started tutorial for Amazon EC2. Whenever you need more information about a
feature of Amazon EC2, you can read the technical documentation.

Get Up and Running
• Setting Up with Amazon EC2 (p. 19)
• Getting Started with Amazon EC2 Linux Instances (p. 26)

Basics
• Instances and AMIs (p. 4)
• Regions and Availability Zones (p. 7)
• Instance Types (p. 156)
• Tags (p. 751)

Networking and Security
• Amazon EC2 Key Pairs (p. 481)
• Security Groups (p. 489)
• Elastic IP Addresses (p. 581)
• Amazon EC2 and Amazon VPC (p. 543)

Storage
• Amazon EBS (p. 634)
• Instance Store (p. 715)

Working with Linux Instances
• Tutorial: Installing a LAMP Web Server on Amazon Linux (p. 33)
• Tutorial: Configure Apache Web Server on Amazon Linux to use SSL/TLS (p. 51)
• Getting Started with AWS: Hosting a Web App for Linux
If you have questions about whether AWS is right for you, contact AWS Sales. If you have technical
questions about Amazon EC2, use the Amazon EC2 forum.

Related Services
You can provision Amazon EC2 resources, such as instances and volumes, directly using Amazon
EC2. You can also provision Amazon EC2 resources using other services in AWS. For more
information, see the following documentation:
• Auto Scaling User Guide

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Accessing Amazon EC2

• AWS CloudFormation User Guide
• AWS Elastic Beanstalk Developer Guide
• AWS OpsWorks User Guide
To automatically distribute incoming application traffic across multiple instances, use Elastic Load
Balancing. For more information, see Elastic Load Balancing User Guide.
To monitor basic statistics for your instances and Amazon EBS volumes, use Amazon CloudWatch.
For more information, see the Amazon CloudWatch Developer Guide.
To monitor the calls made to the Amazon EC2 API for your account, including calls made by the
AWS Management Console, command line tools, and other services, use AWS CloudTrail. For more
information, see the AWS CloudTrail User Guide.
To get a managed relational database in the cloud, use Amazon Relational Database Service (Amazon
RDS) to launch a database instance. Although you can set up a database on an EC2 instance,
Amazon RDS offers the advantage of handling your database management tasks, such as patching
the software, backing up, and storing the backups. For more information, see Amazon Relational
Database Service Developer Guide.

Accessing Amazon EC2
Amazon EC2 provides a web-based user interface, the Amazon EC2 console. If you've signed up for
an AWS account, you can access the Amazon EC2 console by signing into the AWS Management
Console and selecting EC2 from the console home page.
If you prefer to use a command line interface, you have the following options:
AWS Command Line Interface (CLI)
Provides commands for a broad set of AWS products, and is supported on Windows, Mac, and
Linux. To get started, see AWS Command Line Interface User Guide. For more information about
the commands for Amazon EC2, see ec2 in the AWS Command Line Interface Reference.
AWS Tools for Windows PowerShell
Provides commands for a broad set of AWS products for those who script in the PowerShell
environment. To get started, see the AWS Tools for Windows PowerShell User Guide. For more
information about the cmdlets for Amazon EC2, see the AWS Tools for Windows PowerShell
Reference.
Amazon EC2 provides a Query API. These requests are HTTP or HTTPS requests that use the HTTP
verbs GET or POST and a Query parameter named Action. For more information about the API
actions for Amazon EC2, see Actions in the Amazon EC2 API Reference.
If you prefer to build applications using language-specific APIs instead of submitting a request over
HTTP or HTTPS, AWS provides libraries, sample code, tutorials, and other resources for software
developers. These libraries provide basic functions that automate tasks such as cryptographically
signing your requests, retrying requests, and handling error responses, making it is easier for you to
get started. For more information, see AWS SDKs and Tools.

Pricing for Amazon EC2
When you sign up for AWS, you can get started with Amazon EC2 for free using the AWS Free Tier.
Amazon EC2 provides the following purchasing options for instances:

Amazon Elastic Compute Cloud
User Guide for Linux Instances
PCI DSS Compliance

On-Demand instances
Pay for the instances that you use by the hour, with no long-term commitments or up-front
payments.
Reserved Instances
Make a low, one-time, up-front payment for an instance, reserve it for a one- or three-year term,
and pay a significantly lower hourly rate for these instances.
Spot instances
Specify the maximum hourly price that you are willing to pay to run a particular instance type. The
Spot price fluctuates based on supply and demand, but you never pay more than the maximum
price you specified. If the Spot price moves higher than your maximum price, Amazon EC2 shuts
down your Spot instances.
For a complete list of charges and specific prices for Amazon EC2, see Amazon EC2 Pricing.
To calculate the cost of a sample provisioned environment, see AWS Economics Center.
To see your bill, go to your AWS Account Activity page. Your bill contains links to usage reports that
provide details about your bill. To learn more about AWS account billing, see AWS Account Billing.
If you have questions concerning AWS billing, accounts, and events, contact AWS Support.
For an overview of Trusted Advisor, a service that helps you optimize the costs, security, and
performance of your AWS environment, see AWS Trusted Advisor.

PCI DSS Compliance
Amazon EC2 supports the processing, storage, and transmission of credit card data by a merchant or
service provider, and has been validated as being compliant with Payment Card Industry (PCI) Data
Security Standard (DSS). For more information about PCI DSS, including how to request a copy of the
AWS PCI Compliance Package, see PCI DSS Level 1.

Instances and AMIs
An Amazon Machine Image (AMI) is a template that contains a software configuration (for example,
an operating system, an application server, and applications). From an AMI, you launch an instance,
which is a copy of the AMI running as a virtual server in the cloud. You can launch multiple instances of
an AMI, as shown in the following figure.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Instances

Your instances keep running until you stop or terminate them, or until they fail. If an instance fails, you
can launch a new one from the AMI.

Instances
You can launch different types of instances from a single AMI. An instance type essentially determines
the hardware of the host computer used for your instance. Each instance type offers different compute
and memory capabilities. Select an instance type based on the amount of memory and computing
power that you need for the application or software that you plan to run on the instance. For more
information about the hardware specifications for each Amazon EC2 instance type, see Amazon EC2
Instances.
After you launch an instance, it looks like a traditional host, and you can interact with it as you would
any computer. You have complete control of your instances; you can use sudo to run commands that
require root privileges.
Your AWS account has a limit on the number of instances that you can have running. For more
information about this limit, and how to request an increase, see How many instances can I run in
Amazon EC2 in the Amazon EC2 General FAQ.

Storage for Your Instance
The root device for your instance contains the image used to boot the instance. For more information,
see Amazon EC2 Root Device Volume (p. 14).
Your instance may include local storage volumes, known as instance store volumes, which you
can configure at launch time with block device mapping. For more information, see Block Device
Mapping (p. 731). After these volumes have been added to and mapped on your instance, they are
available for you to mount and use. If your instance fails, or if your instance is stopped or terminated,
the data on these volumes is lost; therefore, these volumes are best used for temporary data. For
important data, you should use a replication strategy across multiple instances in order to keep your
data safe, or store your persistent data in Amazon S3 or Amazon EBS volumes. For more information,
see Storage (p. 633).

Security Best Practices
• Use AWS Identity and Access Management (IAM) to control access to your AWS resources,
including your instances. You can create IAM users and groups under your AWS account, assign
security credentials to each, and control the access that each has to resources and services in AWS.
For more information, see Controlling Access to Amazon EC2 Resources (p. 498).
• Restrict access by only allowing trusted hosts or networks to access ports on your instance.
For example, you can restrict SSH access by restricting incoming traffic on port 22. For more
information, see Amazon EC2 Security Groups for Linux Instances (p. 489).
• Review the rules in your security groups regularly, and ensure that you apply the principle of least
privilege—only open up permissions that you require. You can also create different security groups
to deal with instances that have different security requirements. Consider creating a bastion security
group that allows external logins, and keep the remainder of your instances in a group that does not
allow external logins.
• Disable password-based logins for instances launched from your AMI. Passwords can be found or
cracked, and are a security risk. For more information, see Disable Password-Based Remote Logins
for Root (p. 82). For more information about sharing AMIs safely, see Shared AMIs (p. 76).

Stopping, Starting, and Terminating Instances
Stopping an instance

Amazon Elastic Compute Cloud
User Guide for Linux Instances
AMIs

When an instance is stopped, the instance performs a normal shutdown, and then transitions to a
stopped state. All of its Amazon EBS volumes remain attached, and you can start the instance again
at a later time.
You are not charged for additional instance hours while the instance is in a stopped state. A full
instance hour will be charged for every transition from a stopped state to a running state, even if this
happens multiple times within a single hour. If the instance type was changed while the instance was
stopped, you will be charged the rate for the new instance type after the instance is started. All of the
associated Amazon EBS usage of your instance, including root device usage, is billed using typical
Amazon EBS prices.
When an instance is in a stopped state, you can attach or detach Amazon EBS volumes. You can also
create an AMI from the instance, and you can change the kernel, RAM disk, and instance type.
Terminating an instance
When an instance is terminated, the instance performs a normal shutdown, then the attached Amazon
EBS volumes are deleted unless the volume's deleteOnTermination attribute is set to false. The
instance itself is also deleted, and you can't start the instance again at a later time.
To prevent accidental termination, you can disable instance termination. If you do so, ensure that
the disableApiTermination attribute is set to true for the instance. To control the behavior
of an instance shutdown, such as shutdown -h in Linux or shutdown in Windows, set the
instanceInitiatedShutdownBehavior instance attribute to stop or terminate as desired.
Instances with Amazon EBS volumes for the root device default to stop, and instances with instancestore root devices are always terminated as the result of an instance shutdown.
For more information, see Instance Lifecycle (p. 275).

AMIs
Amazon Web Services (AWS) publishes many Amazon Machine Images (AMIs) that contain common
software configurations for public use. In addition, members of the AWS developer community have
published their own custom AMIs. You can also create your own custom AMI or AMIs; doing so
enables you to quickly and easily start new instances that have everything you need. For example, if
your application is a website or a web service, your AMI could include a web server, the associated
static content, and the code for the dynamic pages. As a result, after you launch an instance from this
AMI, your web server starts, and your application is ready to accept requests.
All AMIs are categorized as either backed by Amazon EBS, which means that the root device for an
instance launched from the AMI is an Amazon EBS volume, or backed by instance store, which means
that the root device for an instance launched from the AMI is an instance store volume created from a
template stored in Amazon S3.
The description of an AMI indicates the type of root device (either ebs or instance store). This is
important because there are significant differences in what you can do with each type of AMI. For more
information about these differences, see Storage for the Root Device (p. 71).

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Regions and Availability Zones

Regions and Availability Zones
Amazon EC2 is hosted in multiple locations world-wide. These locations are composed of regions
and Availability Zones. Each region is a separate geographic area. Each region has multiple, isolated
locations known as Availability Zones. Amazon EC2 provides you the ability to place resources, such
as instances, and data in multiple locations. Resources aren't replicated across regions unless you do
so specifically.
Amazon operates state-of-the-art, highly-available data centers. Although rare, failures can occur that
affect the availability of instances that are in the same location. If you host all your instances in a single
location that is affected by such a failure, none of your instances would be available.
Contents
• Region and Availability Zone Concepts (p. 7)
• Available Regions (p. 8)
• Regions and Endpoints (p. 9)
• Describing Your Regions and Availability Zones (p. 9)
• Specifying the Region for a Resource (p. 11)
• Launching Instances in an Availability Zone (p. 12)
• Migrating an Instance to Another Availability Zone (p. 13)

Region and Availability Zone Concepts
Each region is completely independent. Each Availability Zone is isolated, but the Availability Zones
in a region are connected through low-latency links. The following diagram illustrates the relationship
between regions and Availability Zones.

Amazon EC2 resources are either global, tied to a region, or tied to an Availability Zone. For more
information, see Resource Locations (p. 743).

Regions
Each Amazon EC2 region is designed to be completely isolated from the other Amazon EC2 regions.
This achieves the greatest possible fault tolerance and stability.
When you view your resources, you'll only see the resources tied to the region you've specified. This
is because regions are isolated from each other, and we don't replicate resources across regions
automatically.
When you launch an instance, you must select an AMI that's in the same region. If the AMI is in
another region, you can copy the AMI to the region you're using. For more information, see Copying an
AMI (p. 135).

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Available Regions

All communication between regions is across the public Internet. Therefore, you should use the
appropriate encryption methods to protect your data. Data transfer between regions is charged at the
Internet data transfer rate for both the sending and the receiving instance. For more information, see
Amazon EC2 Pricing - Data Transfer.

Availability Zones
When you launch an instance, you can select an Availability Zone or let us choose one for you. If you
distribute your instances across multiple Availability Zones and one instance fails, you can design your
application so that an instance in another Availability Zone can handle requests.
You can also use Elastic IP addresses to mask the failure of an instance in one Availability Zone by
rapidly remapping the address to an instance in another Availability Zone. For more information, see
Elastic IP Addresses (p. 581).
An Availability Zone is represented by a region code followed by a letter identifier; for example, useast-1a. To ensure that resources are distributed across the Availability Zones for a region, we
independently map Availability Zones to identifiers for each account. For example, your Availability
Zone us-east-1a might not be the same location as us-east-1a for another account. There's no
way for you to coordinate Availability Zones between accounts.
As Availability Zones grow over time, our ability to expand them can become constrained. If this
happens, we might restrict you from launching an instance in a constrained Availability Zone unless
you already have an instance in that Availability Zone. Eventually, we might also remove the
constrained Availability Zone from the list of Availability Zones for new customers. Therefore, your
account might have a different number of available Availability Zones in a region than another account.
You can list the Availability Zones that are available to your account. For more information, see
Describing Your Regions and Availability Zones (p. 9).

Available Regions
Your account determines the regions that are available to you. For example:
• An AWS account provides multiple regions so that you can launch Amazon EC2 instances in
locations that meet your requirements. For example, you might want to launch instances in Europe to
be closer to your European customers or to meet legal requirements.
• An AWS GovCloud (US) account provides access to the AWS GovCloud (US) region. For more
information, see AWS GovCloud (US) Region.
• An Amazon AWS account provides access to the China (Beijing) region.
The following table lists the regions provided by an AWS account. Note that you can't describe or
access additional regions from an AWS account, such as AWS GovCloud (US) or China (Beijing).
Code

Name

us-east-1

US East (N. Virginia)

us-west-2

US West (Oregon)

us-west-1

US West (N. California)

eu-west-1

EU (Ireland)

eu-central-1

EU (Frankfurt)

ap-southeast-1

Asia Pacific (Singapore)

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User Guide for Linux Instances
Regions and Endpoints

Code

Name

ap-northeast-1

Asia Pacific (Tokyo)

ap-southeast-2

Asia Pacific (Sydney)

ap-northeast-2

Asia Pacific (Seoul)

ap-south-1

Asia Pacific (Mumbai)

sa-east-1

South America (São Paulo)

For more information, see AWS Global Infrastructure.
The number and mapping of Availability Zones per region may vary between AWS accounts. To get a
list of the Availability Zones that are available to your account, you can use the Amazon EC2 console
or the command line interface. For more information, see Describing Your Regions and Availability
Zones (p. 9).

Regions and Endpoints
When you work with an instance using the command line interface or API actions, you must specify
its regional endpoint. For more information about the regions and endpoints for Amazon EC2, see
Regions and Endpoints in the Amazon Web Services General Reference.
For more information about endpoints and protocols in AWS GovCloud (US), see AWS GovCloud (US)
Endpoints in the AWS GovCloud (US) User Guide.

Describing Your Regions and Availability Zones
You can use the Amazon EC2 console or the command line interface to determine which regions and
Availability Zones are available for your account. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).

To find your regions and Availability Zones using the Amazon EC2 console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

From the navigation bar, view the options in the region selector.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Describing Your Regions and Availability Zones

Your Availability Zones are listed on the dashboard under Service Health, under Availability
Zone Status.

To find your regions and Availability Zones using the command line
1.

Use the describe-regions command as follows to describe your regions.
$ aws ec2 describe-regions
{

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Specifying the Region for a Resource
"Regions": [
{
"Endpoint": "ec2.us-east-1.amazonaws.com",
"RegionName": "us-east-1"
},
{
"Endpoint": "ec2.ap-southeast-1.amazonaws.com",
"RegionName": "ap-southeast-1"
},
{
"Endpoint": "ec2.ap-southeast-2.amazonaws.com",
"RegionName": "ap-southeast-2"
},
...
]
}

Use the describe-availability-zones command as follows to describe your Availability Zones within
the us-east-1 region.
$ aws ec2 describe-availability-zones --region us-east-1
{
"AvailabilityZones": [
{
"State": "available",
"RegionName": "us-east-1",
"Messages": [],
"ZoneName": "us-east-1b"
},
{
"State": "available",
"RegionName": "us-east-1",
"Messages": [],
"ZoneName": "us-east-1c"
},
{
"State": "available",
"RegionName": "us-east-1",
"Messages": [],
"ZoneName": "us-east-1d"
}
]
}

Alternatively, you can use the following AWS Tools for Windows PowerShell commands: GetEC2Region and Get-EC2AvailabilityZone.

Specifying the Region for a Resource
Every time you create an Amazon EC2 resource, you can specify the region for the resource. You can
specify the region for a resource using the AWS Management Console or the command line.

Note
Some AWS resources might not be available in all regions and Availability Zones. Ensure
that you can create the resources you need in the desired regions or Availability Zone before
launching an instance in a specific Availability Zone.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Launching Instances in an Availability Zone

To specify the region for a resource using the console
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
Use the region selector in the navigation bar.

To specify the default region using the command line
You can set the value of an environment variable to the desired regional endpoint (for example,
https://ec2.us-west-1.amazonaws.com):
• AWS_DEFAULT_REGION (AWS CLI)
• Set-AWSDefaultRegion (AWS Tools for Windows PowerShell)
Alternatively, you can use the --region (AWS CLI) or -Region (AWS Tools for Windows
PowerShell) command line option with each individual command. For example, --region uswest-1.
For more information about the endpoints for Amazon EC2, see Amazon Elastic Compute Cloud
Endpoints.

Launching Instances in an Availability Zone
When you launch an instance, select a region that puts your instances closer to specific customers, or
meets the legal or other requirements you have. By launching your instances in separate Availability
Zones, you can protect your applications from the failure of a single location.
When you launch an instance, you can optionally specify an Availability Zone in the region that you
are using. If you do not specify an Availability Zone, we select one for you. When you launch your

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Migrating an Instance to Another Availability Zone

initial instances, we recommend that you accept the default Availability Zone, because this enables
us to select the best Availability Zone for you based on system health and available capacity. If you
launch additional instances, only specify an Availability Zone if your new instances must be close to, or
separated from, your running instances.

To specify an Availability Zone for your instance using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

On the dashboard, choose Launch Instance.

Follow the directions for the wizard. On the Configure Instance Details page, do the following:
• [EC2-Classic] Select one of the Availability Zone options from the list, or select No Preference
to enable us to select the best one for you.

• [EC2-VPC] Select one of the subnet options from the list, or select No preference (default
subnet in any Availability Zone) to enable us to select the best one for you.

To specify an Availability Zone for your instance using the AWS CLI
You can use the run-instances command with one of the following options:
• [EC2-Classic] --placement
• [EC2-VPC] --subnet-id

To specify an Availability Zone for your instance using the AWS Tools for Windows
PowerShell
You can use the New-EC2Instance command with one of the following options:
• [EC2-Classic] -AvailabilityZone
• [EC2-VPC] -SubnetId

Migrating an Instance to Another Availability
Zone
If you need to, you can migrate an instance from one Availability Zone to another. For example, if you
are trying to modify the instance type of your instance and we can't launch an instance of the new
instance type in the current Availability Zone, you could migrate the instance to an Availability Zone
where we can launch an instance of that instance type.
The migration process involves creating an AMI from the original instance, launching an instance in the
new Availability Zone, and updating the configuration of the new instance, as shown in the following
procedure.

To migrate an instance to another Availability Zone
1.

Create an AMI from the instance. The procedure depends on the operating system and the
type of root device volume for the instance. For more information, see the documentation that
corresponds to your operating system and root device volume:

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Root Device Volume

• Creating an Amazon EBS-Backed Linux AMI (p. 89)
• Creating an Instance Store-Backed Linux AMI (p. 92)
• Creating an Amazon EBS-Backed Windows AMI
• Creating an Instance Store-Backed Windows AMI
2.

[EC2-VPC] If you need to preserve the private IP address of the instance, you must delete the
subnet in the current Availability Zone and then create a subnet in the new Availability Zone with
the same IP address range as the original subnet. Note that you must terminate all instances in a
subnet before you can delete it. Therefore, you should move all instances in the current subnet to
the new subnet.

Launch an instance from the AMI that you just created, specifying the new Availability Zone or
subnet. You can use the same instance type as the original instance, or select a new instance
type. For more information, see Launching Instances in an Availability Zone (p. 12).

If the original instance has an associated Elastic IP address, associate it with the new instance.
For more information, see Disassociating an Elastic IP Address and Reassociating it with a
Different Instance (p. 585).

If the original instance is a Reserved Instance, change the Availability Zone for your reservation. (If
you also changed the instance type, you can also change the instance type for your reservation.)
For more information, see Submitting Modification Requests (p. 213).

(Optional) Terminate the original instance. For more information, see Terminating an
Instance (p. 306).

Amazon EC2 Root Device Volume
When you launch an instance, the root device volume contains the image used to boot the instance.
When we introduced Amazon EC2, all AMIs were backed by Amazon EC2 instance store, which
means the root device for an instance launched from the AMI is an instance store volume created
from a template stored in Amazon S3. After we introduced Amazon EBS, we introduced AMIs that are
backed by Amazon EBS. This means that the root device for an instance launched from the AMI is an
Amazon EBS volume created from an Amazon EBS snapshot. You can choose between AMIs backed
by Amazon EC2 instance store and AMIs backed by Amazon EBS. We recommend that you use AMIs
backed by Amazon EBS, because they launch faster and use persistent storage.
Topics
• Root Device Storage Concepts (p. 14)
• Choosing an AMI by Root Device Type (p. 16)
• Determining the Root Device Type of Your Instance (p. 17)
• Changing the Root Device Volume to Persist (p. 17)

Root Device Storage Concepts
You can launch an instance from one of two types of AMIs: an instance store-backed AMI or an
Amazon EBS-backed AMI. The description of an AMI includes which type of AMI it is; you'll see the
root device referred to in some places as either ebs (for Amazon EBS-backed) or instance store
(for instance store-backed). This is important because there are significant differences between what
you can do with each type of AMI. For more information about these differences, see Storage for the
Root Device (p. 71).
Instance Store-backed Instances
Instances that use instance stores for the root device automatically have instance store volumes
available, with one serving as the root device volume. When an instance is launched, the image that

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Root Device Storage Concepts

is used to boot the instance is copied to the root volume (typically sda1). Any data on the instance
store volumes persists as long as the instance is running, but this data is deleted when the instance is
terminated (instance store-backed instances do not support the Stop action) or if it fails (such as if an
underlying drive has issues).

After an instance store-backed instance fails or terminates, it cannot be restored. If you plan to use
Amazon EC2 instance store-backed instances, we highly recommend that you distribute the data on
your instance stores across multiple Availability Zones. You should also back up the data on your
instance store volumes to persistent storage on a regular basis.
For more information, see Amazon EC2 Instance Store (p. 715).
Amazon EBS-backed Instances
Instances that use Amazon EBS for the root device automatically have an Amazon EBS volume
attached. When you launch an Amazon EBS-backed instance, we create an Amazon EBS volume for
each Amazon EBS snapshot referenced by the AMI you use. You can optionally use other Amazon
EBS volumes or instance store volumes.

An Amazon EBS-backed instance can be stopped and later restarted without affecting data stored
in the attached volumes. There are various instance– and volume-related tasks you can do when an
Amazon EBS-backed instance is in a stopped state. For example, you can modify the properties of the
instance, you can change the size of your instance or update the kernel it is using, or you can attach
your root volume to a different running instance for debugging or any other purpose.
By default, the root device volume and the other Amazon EBS volumes attached when you launch an
Amazon EBS-backed instance are automatically deleted when the instance terminates. For information
about how to change this behavior when you launch an instance, see Changing the Root Device
Volume to Persist (p. 17).
By default, any Amazon EBS volumes that you attach to a running instance are detached with their
data intact when the instance terminates. You can attach a detached volume to any running instance.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Choosing an AMI by Root Device Type

If an Amazon EBS-backed instance fails, you can restore your session by following one of these
methods:
• Stop and then start again (try this method first).
• Automatically snapshot all relevant volumes and create a new AMI. For more information, see
Creating an Amazon EBS-Backed Linux AMI (p. 89).
• Attach the volume to the new instance by following these steps:
1. Create a snapshot of the root volume.
2. Register a new AMI using the snapshot.
3. Launch a new instance from the new AMI.
4. Detach the remaining Amazon EBS volumes from the old instance.
5. Reattach the Amazon EBS volumes to the new instance.

Choosing an AMI by Root Device Type
The AMI that you specify when you launch your instance determines the type of root device volume
that your instance has.

To choose an Amazon EBS-backed AMI using the console
1.

Open the Amazon EC2 console.

In the navigation pane, click AMIs.

From the filter lists, select the image type (such as Public images). In the search bar click
Platform to select the operating system (such as Amazon Linux), and Root Device Type to
select EBS images.

(Optional) To get additional information to help you make your choice, click the Show/Hide
Columns icon, update the columns to display, and click Close.

Choose an AMI and write down its AMI ID.

To choose an instance store-backed AMI using the console
1.

Open the Amazon EC2 console.

In the navigation pane, click AMIs.

From the filter lists, select the image type (such as Public images). In the search bar, click
Platform to select the operating system (such as Amazon Linux), and Root Device Type to
select Instance store.

(Optional) To get additional information to help you make your choice, click the Show/Hide
Columns icon, update the columns to display, and click Close.

Choose an AMI and write down its AMI ID.

To verify the type of the root device volume of an AMI using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• describe-images (AWS CLI)
• Get-EC2Image (AWS Tools for Windows PowerShell)

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Determining the Root Device Type of Your Instance

Determining the Root Device Type of Your
Instance
To determine the root device type of an instance using the console
1.

Open the Amazon EC2 console.

2.
3.

In the navigation pane, click Instances, and select the instance.
Check the value of Root device type in the Description tab as follows:
• If the value is ebs, this is an Amazon EBS-backed instance.
• If the value is instance store, this is an instance store-backed instance.

To determine the root device type of an instance using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• describe-instances (AWS CLI)
• Get-EC2Instance (AWS Tools for Windows PowerShell)

Changing the Root Device Volume to Persist
By default, the root device volume for an AMI backed by Amazon EBS is deleted when the instance
terminates. To change the default behavior, set the DeleteOnTermination attribute to false using
a block device mapping.

Changing the Root Volume to Persist Using the Console
Using the console, you can change the DeleteOnTermination attribute when you launch an
instance. To change this attribute for a running instance, you must use the command line.

To change the root device volume of an instance to persist at launch using the console
1.
2.

Open the Amazon EC2 console.
From the Amazon EC2 console dashboard, click Launch Instance.

3.
4.
5.

On the Choose an Amazon Machine Image (AMI) page, choose the AMI to use and click Select.
Follow the wizard to complete the Choose an Instance Type and Configure Instance Details
pages.
On the Add Storage page, deselect the Delete On Termination check box for the root volume.

Complete the remaining wizard pages, and then click Launch.

You can verify the setting by viewing details for the root device volume on the instance's details pane.
Next to Block devices, click the entry for the root device volume. By default, Delete on termination is
True. If you change the default behavior, Delete on termination is False.

Changing the Root Volume of an Instance to Persist Using
the AWS CLI
Using the AWS CLI, you can change the DeleteOnTermination attribute when you launch an
instance or while the instance is running. The root device is typically /dev/sda1 (Linux) or xvda
(Windows).

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Changing the Root Device Volume to Persist

Example at Launch
Use the run-instances command to preserve the root volume by including a block device mapping that
sets its DeleteOnTermination attribute for to false.
$ aws ec2 run-instances --image-id ami-1a2b3c4d --block-device-mappings
'[{"DeviceName":"/dev/sda1","Ebs":{"DeleteOnTermination":false}}]' other
parameters...

You can confirm that DeleteOnTermination is false by using the describe-instances command
and looking for the BlockDeviceMappings entry for /dev/sda1 in the command output, as shown
here.
...
"BlockDeviceMappings": [
{
"DeviceName": "/dev/sda1",
"Ebs": {
"Status": "attached",
"DeleteOnTermination": false,
"VolumeId": "vol-1234567890abcdef0",
"AttachTime": "2013-07-19T02:42:39.000Z"
}
}
...

Example While the Instance is Running
Use the modify-instance-attribute command to preserve the root volume by including a block device
mapping that sets its DeleteOnTermination attribute to false.
$ aws ec2 modify-instance-attribute --instance-id i-1234567890abcdef0
--block-device-mappings '[{"DeviceName":"/dev/sda1","Ebs":
{"DeleteOnTermination":false}}]'

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Sign Up for AWS

Setting Up with Amazon EC2
If you've already signed up for Amazon Web Services (AWS), you can start using Amazon EC2
immediately. You can open the Amazon EC2 console, click Launch Instance, and follow the steps in
the launch wizard to launch your first instance.
If you haven't signed up for AWS yet, or if you need assistance launching your first instance, complete
the following tasks to get set up to use Amazon EC2:
1. Sign Up for AWS (p. 19)
2. Create an IAM User (p. 19)
3. Create a Key Pair (p. 21)
4. Create a Virtual Private Cloud (VPC) (p. 23)
5. Create a Security Group (p. 23)

Sign Up for AWS
When you sign up for Amazon Web Services (AWS), your AWS account is automatically signed up for
all services in AWS, including Amazon EC2. You are charged only for the services that you use.
With Amazon EC2, you pay only for what you use. If you are a new AWS customer, you can get started
with Amazon EC2 for free. For more information, see AWS Free Tier.
If you have an AWS account already, skip to the next task. If you don't have an AWS account, use the
following procedure to create one.

To create an AWS account
1.
2.

Open http://aws.amazon.com/, and then choose Create an AWS Account.
Follow the online instructions.
Part of the sign-up procedure involves receiving a phone call and entering a PIN using the phone
keypad.

Note your AWS account number, because you'll need it for the next task.

Create an IAM User
Services in AWS, such as Amazon EC2, require that you provide credentials when you access them,
so that the service can determine whether you have permission to access its resources. The console

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Create an IAM User

requires your password. You can create access keys for your AWS account to access the command
line interface or API. However, we don't recommend that you access AWS using the credentials for
your AWS account; we recommend that you use AWS Identity and Access Management (IAM) instead.
Create an IAM user, and then add the user to an IAM group with administrative permissions or and
grant this user administrative permissions. You can then access AWS using a special URL and the
credentials for the IAM user.
If you signed up for AWS but have not created an IAM user for yourself, you can create one using the
IAM console. If you aren't familiar with using the console, see Working with the AWS Management
Console for an overview.

To create a group for administrators
1.

In the navigation pane, choose Groups, and then choose Create New Group.

For Group Name, type a name for your group, such as Administrators, and then choose Next
Step.

In the list of policies, select the check box next to the AdministratorAccess policy. You can use
the Filter menu and the Search box to filter the list of policies.

Choose Next Step, and then choose Create Group.

Your new group is listed under Group Name.

To create an IAM user for yourself, add the user to the administrators group, and create
a password for the user
1.

In the navigation pane, choose Users, and then choose Create New Users.

In box 1, type a user name.

Clear the check box next to Generate an access key for each user.

Choose Create.

In the list of users, choose the name (not the check box) of the user you just created. You can use
the Search box to search for the user name.

Choose the Groups tab and then choose Add User to Groups.

Select the check box next to the administrators group. Then choose Add to Groups.

Choose the Security Credentials tab. Under Sign-In Credentials, choose Manage Password.

Select Assign a custom password. Then type a password in the Password and Confirm
Password boxes. When you are finished, choose Apply.

To sign in as this new IAM user, sign out of the AWS console, then use the following URL, where
your_aws_account_id is your AWS account number without the hyphens (for example, if your AWS
account number is 1234-5678-9012, your AWS account ID is 123456789012):
https://your_aws_account_id.signin.aws.amazon.com/console/

Enter the IAM user name (not your email address) and password that you just created. When you're
signed in, the navigation bar displays "your_user_name @ your_aws_account_id".
If you don't want the URL for your sign-in page to contain your AWS account ID, you can create an
account alias. From the IAM console, click Dashboard in the navigation pane. From the dashboard,
click Customize and enter an alias such as your company name. To sign in after you create an
account alias, use the following URL:

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Create a Key Pair
https://your_account_alias.signin.aws.amazon.com/console/

To verify the sign-in link for IAM users for your account, open the IAM console and check under IAM
users sign-in link on the dashboard.
For more information about IAM, see IAM and Amazon EC2 (p. 498).

Create a Key Pair
AWS uses public-key cryptography to secure the login information for your instance. A Linux instance
has no password; you use a key pair to log in to your instance securely. You specify the name of the
key pair when you launch your instance, then provide the private key when you log in using SSH.
If you haven't created a key pair already, you can create one using the Amazon EC2 console. Note that
if you plan to launch instances in multiple regions, you'll need to create a key pair in each region. For
more information about regions, see Regions and Availability Zones (p. 7).

To create a key pair
1.

From the AWS dashboard, choose EC2 to open the Amazon EC2 console.

From the navigation bar, select a region for the key pair. You can select any region that's available
to you, regardless of your location. However, key pairs are specific to a region; for example, if you
plan to launch an instance in the US West (Oregon) Region, you must create a key pair for the
instance in the US West (Oregon) Region.

In the navigation pane, under NETWORK & SECURITY, click Key Pairs.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Create a Key Pair

Tip
The navigation pane is on the left side of the console. If you do not see the pane, it might
be minimized; click the arrow to expand the pane. You may have to scroll down to see the
Key Pairs link.

Click Create Key Pair.

Enter a name for the new key pair in the Key pair name field of the Create Key Pair dialog box,
and then click Create. Choose a name that is easy for you to remember, such as your IAM user
name, followed by -key-pair, plus the region name. For example, me-key-pair-uswest2.

The private key file is automatically downloaded by your browser. The base file name is the name
you specified as the name of your key pair, and the file name extension is .pem. Save the private
key file in a safe place.

Important
This is the only chance for you to save the private key file. You'll need to provide the
name of your key pair when you launch an instance and the corresponding private key
each time you connect to the instance.
8.

If you will use an SSH client on a Mac or Linux computer to connect to your Linux instance, use
the following command to set the permissions of your private key file so that only you can read it.
$ chmod 400 your_user_name-key-pair-region_name.pem

For more information, see Amazon EC2 Key Pairs (p. 481).
To connect to your instance using your key pair
To connect to your Linux instance from a computer running Mac or Linux, you'll specify the .pem file to
your SSH client with the -i option and the path to your private key. To connect to your Linux instance
from a computer running Windows, you can use either MindTerm or PuTTY. If you plan to use PuTTY,
you'll need to install it and use the following procedure to convert the .pem file to a .ppk file.

(Optional) To prepare to connect to a Linux instance from Windows using PuTTY
1.

Download and install PuTTY from http://www.chiark.greenend.org.uk/~sgtatham/putty/. Be sure to
install the entire suite.

Start PuTTYgen (for example, from the Start menu, click All Programs > PuTTY > PuTTYgen).

Under Type of key to generate, select SSH-2 RSA.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Create a Virtual Private Cloud (VPC)

Click Load. By default, PuTTYgen displays only files with the extension .ppk. To locate your
.pem file, select the option to display files of all types.

Select the private key file that you created in the previous procedure and click Open. Click OK to
dismiss the confirmation dialog box.

Click Save private key. PuTTYgen displays a warning about saving the key without a passphrase.
Click Yes.
Specify the same name for the key that you used for the key pair. PuTTY automatically adds the
.ppk file extension.

Create a Virtual Private Cloud (VPC)
Amazon VPC enables you to launch AWS resources into a virtual network that you've defined. If
you have a default VPC, you can skip this section and move to the next task, Create a Security
Group (p. 23). To determine whether you have a default VPC, see Supported Platforms in the
Amazon EC2 Console (p. 549). Otherwise, you can create a nondefault VPC in your account using
the steps below.

Important
If your account supports EC2-Classic in a region, then you do not have a default VPC in that
region. T2 instances must be launched into a VPC.

To create a nondefault VPC
1.
2.
3.

Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.
From the navigation bar, select a region for the VPC. VPCs are specific to a region, so you should
select the same region in which you created your key pair.
On the VPC dashboard, click Start VPC Wizard.

On the Step 1: Select a VPC Configuration page, ensure that VPC with a Single Public Subnet
is selected, and click Select.

On the Step 2: VPC with a Single Public Subnet page, enter a friendly name for your VPC in
the VPC name field. Leave the other default configuration settings, and click Create VPC. On the
confirmation page, click OK.

For more information about Amazon VPC, see What is Amazon VPC? in the Amazon VPC User Guide.

Create a Security Group
Security groups act as a firewall for associated instances, controlling both inbound and outbound
traffic at the instance level. You must add rules to a security group that enable you to connect to your
instance from your IP address using SSH. You can also add rules that allow inbound and outbound
HTTP and HTTPS access from anywhere.
Note that if you plan to launch instances in multiple regions, you'll need to create a security group in
each region. For more information about regions, see Regions and Availability Zones (p. 7).
Prerequisites
You'll need the public IP address of your local computer, which you can get using a service. For
example, we provide the following service: http://checkip.amazonaws.com/. To locate another service

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Create a Security Group

that provides your IP address, use the search phrase "what is my IP address." If you are connecting
through an Internet service provider (ISP) or from behind a firewall without a static IP address, you
need to find out the range of IP addresses used by client computers.

To create a security group with least privilege
1.

Open the Amazon EC2 console.

Tip
Alternatively, you can use the Amazon VPC console to create a security group. However,
the instructions in this procedure don't match the Amazon VPC console. Therefore, if
you switched to the Amazon VPC console in the previous section, either switch back to
the Amazon EC2 console and use these instructions, or use the instructions in Set Up a
Security Group for Your VPC in the Amazon VPC Getting Started Guide.
2.

From the navigation bar, select a region for the security group. Security groups are specific to a
region, so you should select the same region in which you created your key pair.

Click Security Groups in the navigation pane.

Click Create Security Group.

Enter a name for the new security group and a description. Choose a name that is easy for you to
remember, such as your IAM user name, followed by _SG_, plus the region name. For example,
me_SG_uswest2.

In the VPC list, select your VPC. If you have a default VPC, it's the one that is marked with an
asterisk (*).

Note
If your account supports EC2-Classic, select the VPC that you created in the previous
task.
7.

On the Inbound tab, create the following rules (click Add Rule for each new rule), and then click
Create:

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Create a Security Group

• Select HTTP from the Type list, and make sure that Source is set to Anywhere (0.0.0.0/0).
• Select HTTPS from the Type list, and make sure that Source is set to Anywhere (0.0.0.0/0).
• Select SSH from the Type list. In the Source box, ensure Custom is selected, and specify
the public IP address of your computer or network in CIDR notation. To specify an individual
IP address in CIDR notation, add the routing prefix /32. For example, if your IP address is
203.0.113.25, specify 203.0.113.25/32. If your company allocates addresses from a
range, specify the entire range, such as 203.0.113.0/24.

Caution
For security reasons, we don't recommend that you allow SSH access from all IP
addresses (0.0.0.0/0) to your instance, except for testing purposes and only for a
short time.
For more information, see Amazon EC2 Security Groups for Linux Instances (p. 489).

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Overview

Getting Started with Amazon EC2
Linux Instances

Let's get started with Amazon Elastic Compute Cloud (Amazon EC2) by launching, connecting to, and
using a Linux instance. An instance is a virtual server in the AWS cloud. With Amazon EC2, you can
set up and configure the operating system and applications that run on your instance.
When you sign up for AWS, you can get started with Amazon EC2 for free using the AWS Free Tier. If
you created your AWS account less than 12 months ago, and have not already exceeded the free tier
benefits for Amazon EC2, it will not cost you anything to complete this tutorial, because we help you
select options that are within the free tier benefits. Otherwise, you'll incur the standard Amazon EC2
usage fees from the time that you launch the instance until you terminate the instance (which is the
final task of this tutorial), even if it remains idle.
Contents
• Overview (p. 26)
• Prerequisites (p. 27)
• Step 1: Launch an Instance (p. 27)
• Step 2: Connect to Your Instance (p. 28)
• Step 3: Clean Up Your Instance (p. 29)
• Next Steps (p. 30)

Overview
The instance is an Amazon EBS-backed instance (meaning that the root volume is an EBS volume).
You can either specify the Availability Zone in which your instance runs, or let Amazon EC2 select an
Availability Zone for you. When you launch your instance, you secure it by specifying a key pair and
security group. When you connect to your instance, you must specify the private key of the key pair
that you specified when launching your instance.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Prerequisites

Tasks
To complete this tutorial, perform the following tasks:
1. Launch an Instance (p. 27)
2. Connect to Your Instance (p. 28)
3. Clean Up Your Instance (p. 29)

Related Tutorials
• If you'd prefer to launch a Windows instance, see this tutorial in the Amazon EC2 User Guide for
Windows Instances: Getting Started with Amazon EC2 Windows Instances.
• If you'd prefer to use the command line, see this tutorial in the AWS Command Line Interface User
Guide: Using Amazon EC2 through the AWS CLI.

Prerequisites
Before you begin, be sure that you've completed the steps in Setting Up with Amazon EC2 (p. 19).

Step 1: Launch an Instance
You can launch a Linux instance using the AWS Management Console as described in the following
procedure. This tutorial is intended to help you launch your first instance quickly, so it doesn't cover all
possible options. For more information about the advanced options, see Launching an Instance.

To launch an instance
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
From the console dashboard, choose Launch Instance.

The Choose an Amazon Machine Image (AMI) page displays a list of basic configurations,
called Amazon Machine Images (AMIs), that serve as templates for your instance. Select the HVM
edition of the Amazon Linux AMI. Notice that this AMI is marked "Free tier eligible."

On the Choose an Instance Type page, you can select the hardware configuration of your
instance. Select the t2.micro type, which is selected by default. Notice that this instance type is
eligible for the free tier.

Note
T2 instances, such as t2.micro, must be launched into a VPC. If your AWS account
supports EC2-Classic and you do not have a VPC in the selected region, the launch

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Step 2: Connect to Your Instance

wizard creates a VPC for you and you can continue to the next step. Otherwise, the
Review and Launch button is disabled and you must choose Next: Configure Instance
Details and follow the directions to select a subnet.
5.

Choose Review and Launch to let the wizard complete the other configuration settings for you.

On the Review Instance Launch page, under Security Groups, you'll see that the wizard created
and selected a security group for you. You can use this security group, or alternatively you can
select the security group that you created when getting set up using the following steps:
a.

Choose Edit security groups.

On the Configure Security Group page, ensure that Select an existing security group is
selected.

Select your security group from the list of existing security groups, and then choose Review
and Launch.

On the Review Instance Launch page, choose Launch.

When prompted for a key pair, select Choose an existing key pair, then select the key pair that
you created when getting set up.
Alternatively, you can create a new key pair. Select Create a new key pair, enter a name for the
key pair, and then choose Download Key Pair. This is the only chance for you to save the private
key file, so be sure to download it. Save the private key file in a safe place. You'll need to provide
the name of your key pair when you launch an instance and the corresponding private key each
time you connect to the instance.

Caution
Don't select the Proceed without a key pair option. If you launch your instance without a
key pair, then you can't connect to it.
When you are ready, select the acknowledgement check box, and then choose Launch
Instances.
9.

A confirmation page lets you know that your instance is launching. Choose View Instances to
close the confirmation page and return to the console.

10. On the Instances screen, you can view the status of the launch. It takes a short time for an
instance to launch. When you launch an instance, its initial state is pending. After the instance
starts, its state changes to running and it receives a public DNS name. (If the Public DNS
column is hidden, choose the Show/Hide icon in the top right corner of the page and then select
Public DNS.)
11. It can take a few minutes for the instance to be ready so that you can connect to it. Check that
your instance has passed its status checks; you can view this information in the Status Checks
column.

Step 2: Connect to Your Instance
There are several ways to connect to a Linux instance. In this procedure, you'll connect using your
browser. Alternatively, you can connect using PuTTY or an SSH client. It's also assumed that you
followed the steps earlier and launched an instance from an Amazon Linux AMI, which has a specific
user name. Other Linux distributions may use a different user name. For more information, see
Connecting to Your Linux Instance from Windows Using PuTTY (p. 293) or Connecting to Your Linux
Instance Using SSH (p. 289).

Important
You can't connect to your instance unless you launched it with a key pair for which you have
the .pem file and you launched it with a security group that allows SSH access. If you can't
connect to your instance, see Troubleshooting Connecting to Your Instance (p. 774) for
assistance.
28

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Step 3: Clean Up Your Instance

To connect to your Linux instance using a web browser
1.

You must have Java installed and enabled in the browser. If you don't have Java already, you can
contact your system administrator to get it installed, or follow the steps outlined in the following
pages: Install Java and Enable Java in your web browser.
From the Amazon EC2 console, choose Instances in the navigation pane.

Select the instance, and then choose Connect.

4.
5.

Choose A Java SSH client directly from my browser (Java required).
Amazon EC2 automatically detects the public DNS name of your instance and populates Public
DNS for you. It also detects the key pair that you specified when you launched the instance.
Complete the following, and then choose Launch SSH Client.
a.

In User name, enter ec2-user.

In Private key path, enter the fully qualified path to your private key (.pem) file, including the
key pair name.

(Optional) Choose Store in browser cache to store the location of the private key in your
browser cache. This enables Amazon EC2 to detect the location of the private key in
subsequent browser sessions, until you clear your browser's cache.

If necessary, choose Yes to trust the certificate, and choose Run to run the MindTerm client.

If this is your first time running MindTerm, a series of dialog boxes asks you to accept the license
agreement, confirm setup for your home directory, and confirm setup of the known hosts directory.
Confirm these settings.
A dialog prompts you to add the host to your set of known hosts. If you do not want to store the
host key information on your local computer, choose No.
A window opens and you are connected to your instance.

8.
9.

Note
If you chose No in the previous step, you'll see the following message, which is expected:
Verification of server key disabled in this session.

Step 3: Clean Up Your Instance
After you've finished with the instance that you created for this tutorial, you should clean up by
terminating the instance. If you want to do more with this instance before you clean up, see Next
Steps (p. 30).

Important
Terminating an instance effectively deletes it; you can't reconnect to an instance after you've
terminated it.
If you launched an instance that is not within the AWS Free Tier, you'll stop incurring charges for that
instance as soon as the instance status changes to shutting down or terminated. If you'd like
to keep your instance for later, but not incur charges, you can stop the instance now and then start it
again later. For more information, see Stopping Instances.

To terminate your instance
1.
2.
3.

In the navigation pane, choose Instances. In the list of instances, select the instance.
Choose Actions, then Instance State, and then choose Terminate.
Choose Yes, Terminate when prompted for confirmation.
Amazon EC2 shuts down and terminates your instance. After your instance is terminated, it
remains visible on the console for a short while, and then the entry is deleted.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Next Steps

Next Steps
After you start your instance, you might want to try some of the following exercises:
• Configure a CloudWatch alarm to notify you if your usage exceeds the Free Tier. For more
information, see Create a Billing Alarm in the AWS Billing and Cost Management User Guide.
• Add an EBS volume. For more information, see Creating an Amazon EBS Volume (p. 650) and
Attaching an Amazon EBS Volume to an Instance (p. 654).
• Install the LAMP stack. For more information, see Tutorial: Installing a LAMP Web Server on
Amazon Linux (p. 33).

Amazon Elastic Compute Cloud
User Guide for Linux Instances

Best Practices for Amazon EC2
This checklist is intended to help you get the maximum benefit from and satisfaction with Amazon EC2.

Security and Network
• Manage access to AWS resources and APIs using identity federation, IAM users, and IAM roles.
Establish credential management policies and procedures for creating, distributing, rotating, and
revoking AWS access credentials. For more information, see IAM Best Practices in the IAM User
Guide.
• Implement the least permissive rules for your security group. For more information, see Security
Group Rules (p. 491).
• Regularly patch, update, and secure the operating system and applications on your instance. For
more information about updating Amazon Linux, see Managing Software on Your Linux Instance. For
more information about updating your Windows instance, see Updating Your Windows Instance in
the Amazon EC2 User Guide for Windows Instances.
• Launch your instances into a VPC instead of EC2-Classic. Note that if you created your AWS
account after 2013-12-04, we automatically launch your instances into a VPC. For more information
about the benefits, see Amazon EC2 and Amazon Virtual Private Cloud (p. 543).

Storage
• Understand the implications of the root device type for data persistence, backup, and recovery. For
more information, see Storage for the Root Device (p. 71).
• Use separate Amazon EBS volumes for the operating system versus your data. Ensure that the
volume with your data persists after instance termination. For more information, see Preserving
Amazon EBS Volumes on Instance Termination (p. 308).
• Use the instance store available for your instance to store temporary data. Remember that the data
stored in instance store is deleted when you stop or terminate your instance. If you use instance
store for database storage, ensure that you have a cluster with a replication factor that ensures fault
tolerance.

Resource Management
• Use instance metadata and custom resource tags to track and identify your AWS resources. For
more information, see Instance Metadata and User Data (p. 337) and Tagging Your Amazon EC2
Resources (p. 751).
• View your current limits for Amazon EC2. Plan to request any limit increases in advance of the time
that you'll need them. For more information, see Amazon EC2 Service Limits (p. 760).

Amazon Elastic Compute Cloud
User Guide for Linux Instances

Backup and Recovery
• Regularly back up your instance using Amazon EBS snapshots (p. 685) or a backup tool.
• Deploy critical components of your application across multiple Availability Zones, and replicate your
data appropriately.
• Design your applications to handle dynamic IP addressing when your instance restarts. For more
information, see Amazon EC2 Instance IP Addressing (p. 570).
• Monitor and respond to events. For more information, see Monitoring Amazon EC2 (p. 407).
• Ensure that you are prepared to handle failover. For a basic solution, you can manually attach a
network interface or Elastic IP address to a replacement instance. For more information, see Elastic
Network Interfaces (ENI) (p. 588). For an automated solution, you can use Auto Scaling. For more
information, see the Auto Scaling User Guide.
• Regularly test the process of recovering your instances and Amazon EBS volumes if they fail.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Tutorial: Installing a LAMP
Web Server on Amazon Linux

Tutorials for Amazon EC2
Instances Running Linux

The following tutorials show you how to perform common tasks using EC2 instances running Linux.
Tutorials
• Tutorial: Installing a LAMP Web Server on Amazon Linux (p. 33)
• Tutorial: Hosting a WordPress Blog with Amazon Linux (p. 42)
• Tutorial: Configure Apache Web Server on Amazon Linux to use SSL/TLS (p. 51)
• Tutorial: Increase the Availability of Your Application on Amazon EC2 (p. 60)
• Tutorial: Remotely Manage Your Amazon EC2 Instances (p. 64)

Tutorial: Installing a LAMP Web Server on
Amazon Linux
The following procedures help you install the Apache web server with PHP and MySQL support on
your Amazon Linux instance (sometimes called a LAMP web server or LAMP stack). You can use this
server to host a static website or deploy a dynamic PHP application that reads and writes information
to a database.
Prerequisites
This tutorial assumes that you have already launched an instance with a public DNS name that is
reachable from the Internet. For more information, see Step 1: Launch an Instance (p. 27). You must
also have configured your security group to allow SSH (port 22), HTTP (port 80), and HTTPS (port 443)
connections. For more information about these prerequisites, see Setting Up with Amazon EC2 (p. 19).

Important
If you are trying to set up a LAMP web server on an Ubuntu instance, this tutorial will not work
for you. These procedures are intended for use with Amazon Linux. For more information

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Tutorial: Installing a LAMP
Web Server on Amazon Linux
about other distributions, see their specific documentation. For information about LAMP web
servers on Ubuntu, see the Ubuntu community documentation ApacheMySQLPHP topic.

To install and start the LAMP web server on Amazon Linux
1.

Connect to your instance (p. 28).

To ensure that all of your software packages are up to date, perform a quick software update on
your instance. This process may take a few minutes, but it is important to make sure you have the
latest security updates and bug fixes.

Note
The -y option installs the updates without asking for confirmation. If you would like to
examine the updates before installing, you can omit this option.
[ec2-user ~]$ sudo yum update -y

Now that your instance is current, you can install the Apache web server, MySQL, and PHP
software packages. Use the yum install command to install multiple software packages and all
related dependencies at the same time.
[ec2-user ~]$ sudo yum install -y httpd24 php56 mysql55-server php56mysqlnd

Start the Apache web server.
[ec2-user ~]$ sudo service httpd start
Starting httpd:

[

]

Use the chkconfig command to configure the Apache web server to start at each system boot.
[ec2-user ~]$ sudo chkconfig httpd on

Tip
The chkconfig command does not provide any confirmation message when you
successfully enable a service. You can verify that httpd is on by running the following
command.
[ec2-user ~]$ chkconfig --list httpd
httpd
0:off
1:off
2:on

3:on

4:on

5:on

6:off

Here, httpd is on in runlevels 2, 3, 4, and 5 (which is what you want to see).
6.

Test your web server. In a web browser, enter the public DNS address (or the public IP address)
of your instance; you should see the Apache test page. You can get the public DNS for your
instance using the Amazon EC2 console (check the Public DNS column; if this column is hidden,
choose Show/Hide and select Public DNS).

Tip
If you are unable to see the Apache test page, check that the security group you are
using contains a rule to allow HTTP (port 80) traffic. For information about adding an HTTP
rule to your security group, see Adding Rules to a Security Group (p. 495).

Important
If you are not using Amazon Linux, you may also need to configure the firewall on your
instance to allow these connections. For more information about how to configure the
firewall, see the documentation for your specific distribution.
34

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Tutorial: Installing a LAMP
Web Server on Amazon Linux

Note
This test page appears only when there is no content in /var/www/html. When you add
content to the document root, your content appears at the public DNS address of your
instance instead of this test page.
Apache httpd serves files that are kept in a directory called the Apache document root. The Amazon
Linux Apache document root is /var/www/html, which is owned by root by default.
[ec2-user ~]$ ls -l /var/www
total 16
drwxr-xr-x 2 root root 4096 Jul 12 01:00 cgi-bin
drwxr-xr-x 3 root root 4096 Aug 7 00:02 error
drwxr-xr-x 2 root root 4096 Jan 6 2012 html
drwxr-xr-x 3 root root 4096 Aug 7 00:02 icons

To allow ec2-user to manipulate files in this directory, you need to modify the ownership and
permissions of the directory. There are many ways to accomplish this task; in this tutorial, you add a
www group to your instance, and you give that group ownership of the /var/www directory and add
write permissions for the group. Any members of that group will then be able to add, delete, and modify
files for the web server.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Tutorial: Installing a LAMP
Web Server on Amazon Linux

To set file permissions
1.

Add the www group to your instance.
[ec2-user ~]$ sudo groupadd www

Add your user (in this case, ec2-user) to the www group.
[ec2-user ~]$ sudo usermod -a -G www ec2-user

Important

You need to log out and log back in to pick up the new group. You can use the exit
command, or close the terminal window.
Log out and then log back in again, and verify your membership in the www group.
a.

Log out.
[ec2-user ~]$ exit

Reconnect to your instance, and then run the following command to verify your membership in
the www group.
[ec2-user ~]$ groups
ec2-user wheel www

Change the group ownership of /var/www and its contents to the www group.
[ec2-user ~]$ sudo chown -R root:www /var/www

Change the directory permissions of /var/www and its subdirectories to add group write
permissions and to set the group ID on future subdirectories.
[ec2-user ~]$ sudo chmod 2775 /var/www
[ec2-user ~]$ find /var/www -type d -exec sudo chmod 2775 {} \;

Recursively change the file permissions of /var/www and its subdirectories to add group write
permissions.
[ec2-user ~]$ find /var/www -type f -exec sudo chmod 0664 {} \;

Now ec2-user (and any future members of the www group) can add, delete, and edit files in the
Apache document root. Now you are ready to add content, such as a static website or a PHP
application.
(Optional) Secure your web server
A web server running the HTTP protocol provides no transport security for the data that it sends or
receives. When you connect to an HTTP server using a web browser, the URLs that you enter, the
content of web pages that you receive, and the contents (including passwords) of any HTML forms that
you submit are all visible to eavesdroppers anywhere along the network pathway. The best practice for
securing your web server is to install support for HTTPS (HTTP Secure), which protects your data with
SSL/TLS encryption.
For information about enabling HTTPS on your server, see Tutorial: Configure Apache Web Server on
Amazon Linux to use SSL/TLS.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Tutorial: Installing a LAMP
Web Server on Amazon Linux

To test your LAMP web server
If your server is installed and running, and your file permissions are set correctly, your ec2-user
account should be able to create a simple PHP file in the /var/www/html directory that will be
available from the Internet.
1.

Create a simple PHP file in the Apache document root.
[ec2-user ~]$ echo "" > /var/www/html/phpinfo.php

Tip
If you get a "Permission denied" error when trying to run this command, try logging
out and logging back in again to pick up the proper group permissions that you configured
in To set file permissions (p. 36).
2.

In a web browser, enter the URL of the file you just created. This URL is the public DNS address
of your instance followed by a forward slash and the file name. For example:
http://my.public.dns.amazonaws.com/phpinfo.php

You should see the PHP information page:

Note
If you do not see this page, verify that the /var/www/html/phpinfo.php file was
created properly in the previous step. You can also verify that all of the required packages
were installed with the following command (the package versions in the second column
do not need to match this example output):
[ec2-user ~]$ sudo yum list installed httpd24 php56 mysql55-server
php56-mysqlnd
Loaded plugins: priorities, update-motd, upgrade-helper
959 packages excluded due to repository priority protections
Installed Packages

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Tutorial: Installing a LAMP
Web Server on Amazon Linux
httpd24.x86_64
2.4.16-1.62.amzn1
@amzn-main
mysql55-server.x86_64
5.5.45-1.9.amzn1
@amzn-main
php56.x86_64
5.6.13-1.118.amzn1
@amzn-main
php56-mysqlnd.x86_64
5.6.13-1.118.amzn1
@amzn-main

If any of the required packages are not listed in your output, install them with the sudo
yum install package command.
3.

Delete the phpinfo.php file. Although this can be useful information to you, it should not be
broadcast to the Internet for security reasons.
[ec2-user ~]$ rm /var/www/html/phpinfo.php

To secure the MySQL server
The default installation of the MySQL server has several features that are great for testing
and development, but they should be disabled or removed for production servers. The
mysql_secure_installation command walks you through the process of setting a root password and
removing the insecure features from your installation. Even if you are not planning on using the MySQL
server, performing this procedure is a good idea.
1.

Start the MySQL server.
[ec2-user ~]$ sudo service mysqld start
Initializing MySQL database: Installing MySQL system tables...
OK
Filling help tables...
OK
To start mysqld at boot time you have to copy
support-files/mysql.server to the right place for your system
PLEASE REMEMBER TO SET A PASSWORD FOR THE MySQL root USER !
...
Starting mysqld:

[

]

Run mysql_secure_installation.
[ec2-user ~]$ sudo mysql_secure_installation

When prompted, enter a password for the root account.
i.

Enter the current root password. By default, the root account does not have a
password set, so press Enter.

ii.

Type Y to set a password, and enter a secure password twice. For more information
about creating a secure password, see http://www.pctools.com/guides/password/. Make
sure to store this password in a safe place.

Note
Setting a root password for MySQL is only the most basic measure for securing
your database. When you build or install a database-driven application, you
38

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Tutorial: Installing a LAMP
Web Server on Amazon Linux
typically create a database service user for that application and avoid using the
root account for anything but database administration.

Type Y to remove the anonymous user accounts.

Type Y to disable remote root login.

Type Y to remove the test database.

Type Y to reload the privilege tables and save your changes.

(Optional) Stop the MySQL server if you do not plan to use it right away. You can restart the server
when you need it again.
[ec2-user ~]$ sudo service mysqld stop
Stopping mysqld:

[

]

(Optional) If you want the MySQL server to start at every boot, enter the following command.
[ec2-user ~]$ sudo chkconfig mysqld on

You should now have a fully functional LAMP web server. If you add content to the Apache document
root at /var/www/html, you should be able to view that content at the public DNS address for your
instance.

(Optional) Install phpMyAdmin
phpMyAdmin is a web-based database management tool that you can use to view and edit the MySQL
databases on your EC2 instance. Follow the steps below to install and configure phpMyAdmin on your
Amazon Linux instance.

Important
We do not recommend using phpMyAdmin to access a LAMP server unless you have enabled
SSL/TLS in Apache; otherwise, your database administrator password and other data will be
transmitted insecurely across the Internet. For information about configuring a secure web
server on an EC2 instance, see Tutorial: Configure Apache Web Server on Amazon Linux to
use SSL/TLS.
1.

Enable the Extra Packages for Enterprise Linux (EPEL) repository from the Fedora project on your
instance.
[ec2-user ~]$ sudo yum-config-manager --enable epel

Install the phpMyAdmin package.
[ec2-user ~]$ sudo yum install -y phpMyAdmin

Note
Answer y to import the GPG key for the EPEL repository when prompted.
3.

Configure your phpMyAdmin installation to allow access from your local machine. By default,
phpMyAdmin only allows access from the server that it is running on, which is not very useful
because Amazon Linux does not include a web browser.
a.

Find your local IP address by visiting a service such as whatismyip.com.

Edit the /etc/httpd/conf.d/phpMyAdmin.conf file and replace the server IP
address (127.0.0.1) with your local IP address with the following command, replacing
your_ip_address with the local IP address that you identified in the previous step.
39

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Tutorial: Installing a LAMP
Web Server on Amazon Linux
[ec2-user ~]$ sudo sed -i -e 's/127.0.0.1/your_ip_address/g' /etc/
httpd/conf.d/phpMyAdmin.conf

Restart the Apache web server to pick up the new configuration.
[ec2-user ~]$ sudo service httpd restart
Stopping httpd:
Starting httpd:

OK
OK

]
]

[
[

OK
OK

]
]

Restart the MySQL server to pick up the new configuration.
[ec2-user ~]$ sudo service mysqld restart
Stopping mysqld:
Starting mysqld:

[
[

In a web browser, enter the URL of your phpMyAdmin installation. This URL is the public DNS
address of your instance followed by a forward slash and phpmyadmin. For example:
http://my.public.dns.amazonaws.com/phpmyadmin

You should see the phpMyAdmin login page:

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Tutorial: Installing a LAMP
Web Server on Amazon Linux

Note
If you get a 403 Forbidden error, verify that you have set the correct IP address in the /
etc/httpd/conf.d/phpMyAdmin.conf file. You can see what IP address the Apache
server is actually getting your requests from by viewing the Apache access log with the
following command:
[ec2-user ~]$ sudo tail -n 1 /var/log/httpd/access_log | awk
'{ print $1 }'

Amazon Elastic Compute Cloud
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Related Topics
205.251.233.48

Repeat Step 3.b (p. 39), replacing the incorrect address that you previously entered
with the address returned here; for example:
[ec2-user ~]$ sudo sed -i -e 's/previous_ip_address/205.251.233.48/
g' /etc/httpd/conf.d/phpMyAdmin.conf

After you've replaced the IP address, restart the httpd service with Step 4 (p. 40).
7.

Log into your phpMyAdmin installation with the root user name and the MySQL root password
you created earlier. For more information about using phpMyAdmin, see the phpMyAdmin User
Guide.

Related Topics
For more information on transferring files to your instance or installing a WordPress blog on your web
server, see the following topics:
• Transferring Files to Your Linux Instance Using WinSCP (p. 296)
• Transferring Files to Linux Instances from Linux Using SCP (p. 291)
• Tutorial: Hosting a WordPress Blog with Amazon Linux (p. 42)
For more information about the commands and software used in this topic, see the following web
pages:
• Apache web server: http://httpd.apache.org/
• MySQL database server: http://www.mysql.com/
• PHP programming language: http://php.net/
• The chmod command: https://en.wikipedia.org/wiki/Chmod
• The chown command: https://en.wikipedia.org/wiki/Chown
If you are interested in registering a domain name for your web server, or transferring an existing
domain name to this host, see Creating and Migrating Domains and Subdomains to Amazon Route 53
in the Amazon Route 53 Developer Guide.

Tutorial: Hosting a WordPress Blog with
Amazon Linux
The following procedures will help you install, configure, and secure a WordPress blog on your
Amazon Linux instance.

Important
These procedures are intended for use with Amazon Linux. For more information about other
distributions, see their specific documentation. Many steps in this tutorial do not work on
Ubuntu instances. For help installing WordPress on an Ubuntu instance, see WordPress in the
Ubuntu documentation.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Prerequisites

Prerequisites
This tutorial assumes that you have launched an Amazon Linux instance with a functional web server
with PHP and MySQL support by following all of the steps in Tutorial: Installing a LAMP Web Server
on Amazon Linux (p. 33). This tutorial also has steps for configuring a security group to allow HTTP
and HTTPS traffic, as well as several steps to ensure that file permissions are set properly for your
web server. If you have not already done so, see Tutorial: Installing a LAMP Web Server on Amazon
Linux (p. 33) to meet these prerequisites and then return to this tutorial to install WordPress. For
information about adding rules to your security group, see Adding Rules to a Security Group (p. 495).
We strongly recommend that you associate an Elastic IP address (EIP) to the instance you are using
to host a WordPress blog. This prevents the public DNS address for your instance from changing and
breaking your installation. If you own a domain name and you want to use it for your blog, you can
update the DNS record for the domain name to point to your EIP address (for help with this, contact
your domain name registrar). You can have one EIP address associated with a running instance at no
charge. For more information, see Elastic IP Addresses (p. 581).
If you don't already have a domain name for your blog, you can register a domain name with Amazon
Route 53 and associate your instance's EIP address with your domain name. For more information,
see Registering Domain Names Using Amazon Route 53 in the Amazon Route 53 Developer Guide.

Install WordPress
This tutorial is a good introduction to using Amazon EC2 in that you have full control over a web server
that hosts your WordPress blog, which is not typical with a traditional hosting service. Of course, that
means that you are responsible for updating the software packages and maintaining security patches
for your server as well. For a more automated WordPress installation that does not require direct
interaction with the web server configuration, the AWS CloudFormation service provides a WordPress
template that can also get you started quickly. For more information, see Getting Started in the AWS
CloudFormation User Guide. If you'd prefer to host your WordPress blog on a Windows instance, see
Deploying a WordPress Blog on Your Amazon EC2 Windows Instance in the Amazon EC2 User Guide
for Windows Instances.

To download and unzip the WordPress installation package
1.

Download the latest WordPress installation package with the wget command. The following
command should always download the latest release.
[ec2-user ~]$ wget https://wordpress.org/latest.tar.gz
--2013-08-09 17:19:01-- https://wordpress.org/latest.tar.gz
Resolving wordpress.org (wordpress.org)... 66.155.40.249, 66.155.40.250
Connecting to wordpress.org (wordpress.org)|66.155.40.249|:443...
connected.
HTTP request sent, awaiting response... 200 OK
Length: 4028740 (3.8M) [application/x-gzip]
Saving to: latest.tar.gz
100%[======================================>] 4,028,740
0.2s

20.1MB/s

2013-08-09 17:19:02 (20.1 MB/s) - latest.tar.gz saved [4028740/4028740]

Unzip and unarchive the installation package. The installation folder is unzipped to a folder called
wordpress.
[ec2-user ~]$ tar -xzf latest.tar.gz
[ec2-user ~]$ ls

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Install WordPress
latest.tar.gz

wordpress

To create a MySQL user and database for your WordPress installation
Your WordPress installation needs to store information, such as blog post entries and user comments,
in a database. This procedure helps you create a database for your blog and a user that is authorized
to read and save information to that database.
1.

Start the MySQL server.
[ec2-user ~]$ sudo service mysqld start

Log in to the MySQL server as the root user. Enter your MySQL root password when prompted;
this may be different than your root system password, or it may even be empty if you have not
secured your MySQL server.

Important
If you have not secured your MySQL server yet, it is very important that you do so. For
more information, see To secure the MySQL server (p. 38).
[ec2-user ~]$ mysql -u root -p
Enter password:

Create a user and password for your MySQL database. Your WordPress installation uses these
values to communicate with your MySQL database. Enter the following command, substituting a
unique user name and password.
mysql> CREATE USER 'wordpress-user'@'localhost' IDENTIFIED BY
'your_strong_password';
Query OK, 0 rows affected (0.00 sec)

Make sure that you create a strong password for your user. Do not use the single quote character
( ' ) in your password, because this will break the preceding command. For more information about
creating a secure password, go to http://www.pctools.com/guides/password/. Do not reuse an
existing password, and make sure to store this password in a safe place.
Create your database. Give your database a descriptive, meaningful name, such as wordpressdb.

Note
The punctuation marks surrounding the database name in the command below are
called backticks. The backtick (`) key is usually located above the Tab key on a standard
keyboard. Backticks are not always required, but they allow you to use otherwise illegal
characters, such as hyphens, in database names.
mysql> CREATE DATABASE `wordpress-db`;
Query OK, 1 row affected (0.01 sec)

Grant full privileges for your database to the WordPress user that you created earlier.
mysql> GRANT ALL PRIVILEGES ON `wordpress-db`.* TO "wordpressuser"@"localhost";
Query OK, 0 rows affected (0.00 sec)

Flush the MySQL privileges to pick up all of your changes.
mysql> FLUSH PRIVILEGES;

Amazon Elastic Compute Cloud
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Install WordPress
Query OK, 0 rows affected (0.01 sec)

Exit the mysql client.
mysql> exit
Bye

To create and edit the wp-config.php file
The WordPress installation folder contains a sample configuration file called wp-configsample.php. In this procedure, you copy this file and edit it to fit your specific configuration.
1.

Copy the wp-config-sample.php file to a file called wp-config.php. This creates a new
configuration file and keeps the original sample file intact as a backup.
[ec2-user ~]$ cd wordpress/
[ec2-user wordpress]$ cp wp-config-sample.php wp-config.php

Edit the wp-config.php file with your favorite text editor (such as nano or vim) and enter values
for your installation. If you do not have a favorite text editor, nano is much easier for beginners to
use.
[ec2-user wordpress]$ nano wp-config.php

Find the line that defines DB_NAME and change database_name_here to the database
name that you created in Step 4 (p. 44) of To create a MySQL user and database for your
WordPress installation (p. 44).
define('DB_NAME', 'wordpress-db');

Find the line that defines DB_USER and change username_here to the database user that
you created in Step 3 (p. 44) of To create a MySQL user and database for your WordPress
installation (p. 44).
define('DB_USER', 'wordpress-user');

Find the line that defines DB_PASSWORD and change password_here to the strong password
that you created in Step 3 (p. 44) of To create a MySQL user and database for your
WordPress installation (p. 44).
define('DB_PASSWORD', 'your_strong_password');

Find the section called Authentication Unique Keys and Salts. These KEY and
SALT values provide a layer of encryption to the browser cookies that WordPress users store
on their local machines. Basically, adding long, random values here makes your site more
secure. Visit https://api.wordpress.org/secret-key/1.1/salt/ to randomly generate a set of
key values that you can copy and paste into your wp-config.php file. To paste text into a
PuTTY terminal, place the cursor where you want to paste the text and right-click your mouse
inside the PuTTY terminal.
For more information about security keys, go to http://codex.wordpress.org/Editing_wpconfig.php#Security_Keys.

Note
The values below are for example purposes only; do not use these values for your
installation.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Install WordPress
define('AUTH_KEY',
' #U$$+[RXN8:b^-L 0(WU_+ c+WFkI~c]o]-bHw+)/
Aj[wTwSiZ)Y |;
(^[Iw]Pi+LG#A4R?7N`YB3');
define('NONCE_KEY',
'P(g62HeZxEes|LnI^i=H,[XwK9I&[2s|:?0N}VJM
%?;v2v]v+;+^9eXUahg@::Cj');
define('AUTH_SALT',
'C$DpB4Hj[JK:?{ql`sRVa:{:7yShy(9A@5wg
+`JJVb1fk%_-Bx*M4(qc[Qg%JT!h');
define('SECURE_AUTH_SALT', 'd!uRu#}+q#{f$Z?Z9uFPG.${+S{n~1M&
%@~gL>U>NV.|Y
%Ug4#I^*LVd9QeZ^&XmK|e(76miC+&W&+^0P/');
define('NONCE_SALT',
'-97r*V/cgxLmp?Zy4zUU4r99QQ_rGs2LTd%P;|
_e1tS)8_B/,.6[=UK.

#
# Possible values for the Options directive are "None", "All",
# or any combination of:
#
Indexes Includes FollowSymLinks SymLinksifOwnerMatch ExecCGI
MultiViews
#
# Note that "MultiViews" must be named *explicitly* --- "Options All"
# doesn't give it to you.
#
# The Options directive is both complicated and important. Please see
# http://httpd.apache.org/docs/2.4/mod/core.html#options
# for more information.
#
Options Indexes FollowSymLinks
#
# AllowOverride controls what directives may be placed in .htaccess
files.
# It can be "All", "None", or any combination of the keywords:
#
Options FileInfo AuthConfig Limit
#
AllowOverride None
#
# Controls who can get stuff from this server.
#
Require all granted

Change the AllowOverride None line in the above section to read AllowOverride All.

Note
There are multiple AllowOverride lines in this file; be sure you change the line in the
section.
AllowOverride All

Save the file and exit your text editor.

To fix file permissions for the Apache web server
Some of the available features in WordPress require write access to the Apache document root (such
as uploading media though the Administration screens). The web server runs as the apache user, so
you need to add that user to the www group that was created in the LAMP web server tutorial (p. 33).

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Install WordPress

Add the apache user to the www group.
[ec2-user wordpress]$ sudo usermod -a -G www apache

Change the file ownership of /var/www and its contents to the apache user.
[ec2-user wordpress]$ sudo chown -R apache /var/www

Change the group ownership of /var/www and its contents to the www group.
[ec2-user wordpress]$ sudo chgrp -R www /var/www

Change the directory permissions of /var/www and its subdirectories to add group write
permissions and to set the group ID on future subdirectories.
[ec2-user wordpress]$ sudo chmod 2775 /var/www
[ec2-user wordpress]$ find /var/www -type d -exec sudo chmod 2775 {} \;

Recursively change the file permissions of /var/www and its subdirectories to add group write
permissions.
[ec2-user wordpress]$ find /var/www -type f -exec sudo chmod 0664 {} \;

Restart the Apache web server to pick up the new group and permissions.
[ec2-user wordpress]$ sudo service httpd restart
Stopping httpd:
Starting httpd:

[
[

OK
OK

]
]

To run the WordPress installation script
1.

Use the chkconfig command to ensure that the httpd and mysqld services start at every system
boot.
[ec2-user wordpress]$ sudo chkconfig httpd on
[ec2-user wordpress]$ sudo chkconfig mysqld on

Verify that the MySQL server (mysqld) is running.
[ec2-user wordpress]$ sudo service mysqld status
mysqld (pid 4746) is running...

If the mysqld service is not running, start it.
[ec2-user wordpress]$ sudo service mysqld start
Starting mysqld:

Verify that your Apache web server (httpd) is running.
[ec2-user wordpress]$ sudo service httpd status
httpd (pid 502) is running...

If the httpd service is not running, start it.
48

[

]

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Install WordPress
[ec2-user wordpress]$ sudo service httpd start
Starting httpd:

[

]

In a web browser, enter the URL of your WordPress blog (either the public DNS address for your
instance, or that address followed by the blog folder). You should see the WordPress installation
screen.
http://my.public.dns.amazonaws.com

Enter the remaining installation information into the WordPress installation wizard.
Field

Value

Site Title

Enter a name for your WordPress site.

Username

Enter a name for your WordPress
administrator. For security purposes, you
should choose a unique name for this user,
because it will be more difficult to exploit than
the default user name, admin.

Password

Enter a strong password, and then enter it
again to confirm. Do not reuse an existing
password, and make sure to store this
password in a safe place.

Your E-mail

Enter the email address you want to use for
notifications.

Click Install WordPress to complete the installation.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Next Steps

Congratulations, you should now be able to log into your WordPress blog and start posting entries.

Next Steps
After you have tested your initial WordPress blog, consider updating its configuration.
Use a Custom Domain Name
If you have a domain name associated with your EC2 instance's EIP address, you can configure
your blog to use that name instead of the EC2 public DNS address. For more information, see http://
codex.wordpress.org/Changing_The_Site_URL.
Configure Your Blog
You can configure your blog to use different themes and plugins to offer a more personalized
experience for your readers. However, sometimes the installation process can backfire, causing you
to lose your entire blog. We strongly recommend that you create a backup Amazon Machine Image
(AMI) of your instance before attempting to install any themes or plugins so you can restore your blog if
anything goes wrong during installation. For more information, see Creating Your Own AMI (p. 70).
Increase Capacity
If your WordPress blog becomes popular and you need more compute power or storage, consider the
following steps:
• Expand the storage space on your instance. For more information, see Expanding the Storage
Space of an EBS Volume on Linux (p. 671).
• Move your MySQL database to Amazon RDS to take advantage of the service's ability to scale
automatically.
• Migrate to a larger instance type. For more information, see Resizing Your Instance (p. 189).
• Add additional instances. For more information, see Tutorial: Increase the Availability of Your
Application on Amazon EC2 (p. 60).
Learn More about WordPress
For information about WordPress, see the WordPress Codex help documentation at http://
codex.wordpress.org/. For more information about troubleshooting your installation, go to http://
codex.wordpress.org/Installing_WordPress#Common_Installation_Problems. For information about
making your WordPress blog more secure, go to http://codex.wordpress.org/Hardening_WordPress.
For information about keeping your WordPress blog up-to-date, go to http://codex.wordpress.org/
Updating_WordPress.

Help! My Public DNS Name Changed and now
my Blog is Broken
Your WordPress installation is automatically configured using the public DNS address for your
EC2 instance. If you stop and restart the instance, the public DNS address changes (unless it is
associated with an Elastic IP address) and your blog will not work anymore because it references
resources at an address that no longer exists (or is assigned to another EC2 instance). A more detailed
description of the problem and several possible solutions are outlined in http://codex.wordpress.org/
Changing_The_Site_URL.
If this has happened to your WordPress installation, you may be able to recover your blog with the
procedure below, which uses the wp-cli command line interface for WordPress.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Tutorial: Configure Apache Web Server
on Amazon Linux to use SSL/TLS

To change your WordPress site URL with the wp-cli
1.
2.

Connect to your EC2 instance with SSH.
Note the old site URL and the new site URL for your instance. The old site URL is likely the public
DNS name for your EC2 instance when you installed WordPress. The new site URL is the current
public DNS name for your EC2 instance. If you are not sure of your old site URL, you can use curl
to find it with the following command.
[ec2-user ~]$ curl localhost | grep wp-content

You should see references to your old public DNS name in the output, which will look like this (old
site URL in red):

Download the wp-cli with the following command.
[ec2-user ~]$ curl -O https://raw.githubusercontent.com/wp-cli/builds/ghpages/phar/wp-cli.phar

Search and replace the old site URL in your WordPress installation with the following command.
Substitute the old and new site URLs for your EC2 instance and the path to your WordPress
installation (usually /var/www/html or /var/www/html/blog).
[ec2-user ~]$ php wp-cli.phar search-replace 'old_site_url' 'new_site_url'
--path=/path/to/wordpress/installation --skip-columns=guid

In a web browser, enter the new site URL of your WordPress blog to verify that the site is working
properly again. If it is not, see http://codex.wordpress.org/Changing_The_Site_URL and http://
codex.wordpress.org/Installing_WordPress#Common_Installation_Problems for more information.

Tutorial: Configure Apache Web Server on
Amazon Linux to use SSL/TLS
Secure Sockets Layer/Transport Layer Security (SSL/TLS) creates an encrypted channel between
a web server and web client that protects data in transit from being eavesdropped on. This tutorial
explains how to add support manually for SSL/TLS on a single instance of Amazon Linux running
Apache web server. The AWS Certificate Manager, not discussed here, is a good option as well,
especially if you need to manage several domains or will be offering commercial-grade services.

Note
For historical reasons, web encryption is often referred to as simply SSL. While web browsers
still support SSL, its successor protocol TLS is considered to be less vulnerable to attack.
Amazon Linux disables SSL version 2 by default, and this tutorial recommends disabling SSL
version 3 as well, as described below. For more information about the proposed updated
encryption standard, go to RFC7568.

Important
These procedures are intended for use with Amazon Linux. If you are trying to set up a LAMP
web server on an instance of a different distribution, this tutorial will not work for you. For
information about LAMP web servers on Ubuntu, go to the Ubuntu community documentation
ApacheMySQLPHP topic. For information about Red Hat Enterprise Linux, go to the Customer
Portal topic Web Servers.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Prerequisites

Topics
• Prerequisites (p. 52)
• Step 1: Enable SSL/TLS on the Server (p. 52)
• Step 2: Obtain a CA-signed Certificate (p. 54)
• Step 3: Test and Harden the Security Configuration (p. 57)
• Troubleshooting (p. 60)

Prerequisites
Before you begin this tutorial, complete the following steps:
• Launch an Amazon Linux instance. For more information, see Step 1: Launch an Instance (p. 27).
• Configure your security group to allow SSH (port 22), HTTP (port 80), and HTTPS (port 443)
connections. For more information, see Setting Up with Amazon EC2 (p. 19).
• Install Apache web server. For step-by-step instructions, see Tutorial: Installing a LAMP Web Server
on Amazon Linux (p. 33). Only the http24 package and its dependencies are needed; you can
ignore the instructions involving PHP and MySQL.
• The SSL/TLS public key infrastructure (PKI) relies on the Domain Name System (DNS) to identify
and authenticate web sites. If you plan to use your EC2 instance to host a public web site, you need
to register a domain name for your web server or transfer an existing domain name to your Amazon
EC2 host. Numerous third-party domain registration and DNS hosting services are available for this,
or you may use Amazon Route 53.

Step 1: Enable SSL/TLS on the Server
This procedure takes you through the process of setting up SSL/TLS on Amazon Linux with a selfsigned, digital certificate.

To enable SSL/TLS on a server
1.

Connect to your instance (p. 28) and confirm that Apache is running.
[ec2-user ~]$ sudo service httpd status

If necessary, start Apache.
[ec2-user ~]$ sudo service httpd start

Note
The -y option installs the updates without asking for confirmation. If you would like to
examine the updates before installing, you can omit this option.
[ec2-user ~]$ sudo yum update -y

Now that your instance is current, add SSL/TLS support by installing the Apache module mod_ssl:
[ec2-user ~]$ sudo yum install -y mod24_ssl

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Step 1: Enable SSL/TLS on the Server

Later in this tutorial you will work with three important files that have been installed:
• /etc/httpd/conf.d/ssl.conf
The configuration file for mod_ssl. It contains "directives" telling Apache where to find encryption
keys and certificates, which SSL/TLS protocols to allow, and what encryption algorithms to use.
• /etc/pki/tls/private/localhost.key
An automatically generated, 2048-bit RSA private key for your Amazon EC2 host. During
installation, OpenSSL used this key to generate a self-signed host certificate, and you can also
use it later to generate a certificate signing request (CSR) to submit to a certificate authority
(CA).
• /etc/pki/tls/certs/localhost.crt
An automatically generated, self-signed X.509 certificate for your server host. This certificate is
useful for testing that Apache is properly set up to use SSL/TLS.
The .key and .crt files are both in PEM format, with consists of Base64-encoded ASCII
characters framed by "BEGIN" and "END" lines, as in this abbreviated example of a certificate:
-----BEGIN CERTIFICATE----MIIEazCCA1OgAwIBAgICWxQwDQYJKoZIhvcNAQELBQAwgbExCzAJBgNVBAYTAi0t
MRIwEAYDVQQIDAlTb21lU3RhdGUxETAPBgNVBAcMCFNvbWVDaXR5MRkwFwYDVQQK
DBBTb21lT3JnYW5pemF0aW9uMR8wHQYDVQQLDBZTb21lT3JnYW5pemF0aW9uYWxV
bml0MRkwFwYDVQQDDBBpcC0xNzItMzEtMjAtMjM2MSQwIgYJKoZIhvcNAQkBFhVy
...
z5rRUE/XzxRLBZOoWZpNWTXJkQ3uFYH6s/
sBwtHpKKZMzOvDedREjNKAvk4ws6F0
WanXWehT6FiSZvB4sTEXXJN2jdw8g
+sHGnZ8zCOsclknYhHrCVD2vnBlZJKSZvak
3ZazhBxtQSukFMOnWPP2a0DMMFGYUHOd0BQE8sBJxg==
-----END CERTIFICATE-----

The file names and extensions are a convenience and have no effect on function; you can call a
certificate either cert.crt or cert.pem or certificate.pem, so long as the related directive in
the ssl.conf file uses the same name.

Note
When you replace the default SSL files with your own customized files, be sure that they
are in PEM format.
4.

Restart Apache.
[ec2-user ~]$ sudo service httpd restart

Your Apache web server should now support HTTPS (secure HTTP) over port 443. Test it by
typing the IP address or fully qualified domain name of your EC2 instance into a browser URL
bar with the prefix https://. Because you are connecting to a site with a self-signed, untrusted
certificate, your browser may display a series of warnings.
Override these and proceed to the site. If the default Apache welcome page opens, it means that
you have successfully configured SSL/TLS on your server. All data passing between the browser
and server is now safely encrypted, as signalled by the lock icon in the browser's URL bar.
53

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Step 2: Obtain a CA-signed Certificate

To prevent site visitors from encountering warning screens, you need to obtain a certificate that
not only encrypts, but also publicly authenticates you as the owner of the site.

Step 2: Obtain a CA-signed Certificate
This section describes the process of generating a certificate signing request (CSR) from a private
key, submitting the CSR to a certificate authority (CA), obtaining a signed certificate, and configuring
Apache to use it.
A self-signed SSL/TLS X.509 certificate is cryptologically identical to a CA-signed certificate. The
difference is social, not mathematical; a CA promises to validate, at a minimum, a domain's ownership
before issuing a certificate to an applicant. Each web browser contains a list of CAs trusted by the
browser vendor to do this. An X.509 certificate consists primarily of a public key that corresponds to
your private server key, and a signature by the CA that is cryptographically tied to the public key. When
a browser connects to a web server over HTTPS, the server presents a certificate for the browser to
check against its list of trusted CAs. If the signer is on the list, or accessible through a chain of other
trusted signers, the browser negotiates a fast encrypted data channel with the server and loads the
page.
Certificates generally cost money because of the labor involved in validating the requests, so it pays to
shop around. A list of well-known CAs can be found at dmoz.org. A few CAs, such as StartCom, offer
basic-level ("Class 1") certificates free of charge.
Underlying the certificate is the key. As of 2013, government and industry groups recommend using
a minimum key (modulus) size of 2048 bits for RSA keys. The default modulus size generated by
OpenSSL in Amazon Linux is 2048 bits, which means that the existing auto-generated key is suitable
for use in a CA-signed certificate. An alternative procedure is described below for those who desire a
customized key, for instance, one with a larger modulus or using a different encryption algorithm.

To obtain a CA-signed certificate
1.

Connect to your instance (p. 28) and navigate to /etc/pki/tls/private/. This is the directory where the
server's private key for SSL/TLS is stored. If you prefer to use your existing host key to generate
the CSR, skip to Step 3.

(Optional) Generate a new private key. Here are some sample key configurations. Any of the
resulting keys will work with your web server, but they vary in how (and how much) security they
implement.
1. As a starting point, here is the command to create an RSA key resembling the default host key
on your instance:
[ec2-user ~]$ sudo openssl genrsa -out custom.key 2048

The resulting file, custom.key, is a 2048-bit RSA private key.
2. To create a stronger RSA key with a bigger modulus, use the following command:
[ec2-user ~]$ sudo openssl genrsa -out custom.key 4096

The resulting file, custom.key, is a 4096--bit RSA private key.
3. To create a 4096-bit encrypted RSA key with password protection, use the following command:
[ec2-user ~]$ sudo openssl genrsa -aes128 -passout pass:abcde12345 -out
custom.key 4096

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Step 2: Obtain a CA-signed Certificate

This results in a 4096-bit RSA private key that has been encrypted with the AES-128 cipher.

Important
Encryption provides greater security, but because an encrypted key requires a
password, services depending on it cannot be auto-started. Each time you use this
key, you need to supply the password "abcde12345" over an SSH connection.
4. RSA cryptography can be relatively slow, because its security relies on the difficulty of factoring
the product of two large two prime numbers. However, it is possible to create keys for SSL/TLS
that use non-RSA ciphers. Keys based on the mathematics of elliptic curves are smaller and
faster when delivering an equivalent level of security. Here is an example:
[ec2-user ~]$ sudo openssl ecparam -name prime256v1 -out custom.key genkey

The output in this case is a 256-bit elliptic curve private key using prime256v1, a "named curve"
that OpenSSL supports. Its cryptographic strength is slightly greater than a 2048-bit RSA key,
according to NIST.

Note
Not all CAs provide the same level of support for elliptic-curve-based keys as for RSA
keys.
Make sure that the new private key has highly restrictive permissions (owner root, group root,
read/write for owner only). The commands would be as follows:
[ec2-user ~]$ sudo chown root.root custom.key
[ec2-user ~]$ sudo chmod 600 custom.key
[ec2-user ~]$ ls -al custom.key

The commands above should yield the following result:
-rw------- root root custom.key

After you have created and configured a satisfactory key, you can create a CSR.
3.

Create a CSR using your preferred key; the example below uses private.key:
[ec2-user ~]$ sudo openssl req -new -key private.key -out csr.pem

OpenSSL opens a dialog and prompts you for information shown in the table below. All of the
fields except Common Name are optional for a basic, domain-validated certificate.
Name

Description

Example

Country
Name

The two-letter ISO abbreviation for your
country.

US (=United States)

State or
Province
Name

The name of the state or province where your
organization is located. This name cannot be
abbreviated.

Washington

Locality
Name

The location of your organization, such as a
city.

Seattle

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Step 2: Obtain a CA-signed Certificate

Name

Description

Example

Organization
Name

The full legal name of your organization. Do
not abbreviate your organization name.

Example Corp

Organizational Additional organizational information, if any.
Unit Name

Example Dept

Common
Name

This value must exactly match the web
address that you expect users to type into a
browser. Usually, this means a domain name
with a prefixed host name or alias in the form
www.example.com. In testing with a selfsigned certificate and no DNS resolution,
the common name may consist of the host
name alone. CAs also offer more expensive
certificates that accept wild-card names such
as *.example.com.

www.example.com

Email
Address

The server administrator's email address.

someone@example.com

Finally, OpenSSL prompts you for an optional challenge password. This password applies only
to the CSR and to transactions between you and your CA, so follow the CA's recommendations
about this and the other optional field, optional company name. The CSR challenge password has
no effect on server operation.
The resulting file csr.pem contains your public key, your digital signature of your public key, and
the metadata that you entered.
4.

Submit the CSR to a CA. This usually consists of opening your CSR file in a text editor and
copying the contents into a web form. At this time, you may be asked to supply one or more
subject alternate names (SANs) to be placed on the certificate. If www.example.com is the
common name, then example.com would be a good SAN, and vice versa. A user typing in either
of the listed names would see an error-free connection. If your CA web form allows it, include the
common name in the list of SANs. (Some CAs include it automatically.)
After your request has been approved, you will receive a new host certificate signed by the CA.
You may also be instructed to download an intermediate certificate file that contains additional
certificates needed to complete the CA's chain of trust.

Remove the old self-signed host certificate localhost.crt from the /etc/pki/tls/certs directory
and place the new CA-signed certificate there (along with any intermediate certificates).

Note
There are several ways to upload your new certificate to your EC2 instance, but the most
straightforward and informative way is to open a text editor (vi, nano, notepad, etc.) on
both your local computer and your instance, and then copy and paste the file contents
between them. This way, you will see immediately if there are any permission or path
problems. Be careful, however, not to add any additional lines while copying the contents,
or to change them in any way.
From inside the /etc/pki/tls/certs directory, check that the file ownership, group, and permission
settings match the highly restrictive Amazon Linux defaults (owner root, group root, read/write for
owner only). The commands would be as follows:
[ec2-user certs]$ sudo chown root.root custom.crt
[ec2-user certs]$ sudo chmod 600 custom.crt
[ec2-user certs]$ ls -al custom.crt

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Step 3: Test and Harden the Security Configuration

The commands above should yield the following result:
-rw------- root root custom.crt

The permissions for the intermediate certificate file are less stringent (owner root, group root,
owner can write, world can read). The commands would be:
[ec2-user certs]$ sudo chown root.root intermediate.crt
[ec2-user certs]$ sudo chmod 644 intermediate.crt
[ec2-user certs]$ ls -al intermediate.crt

The commands above should yield the following result:
-rw-r--r-- root root intermediate.crt

The file name of the new CA-signed certificate (custom.crt in this example) probably differs from
the old certificate. Edit /etc/httpd/conf.d/ssl.conf and provide the correct path and file name using
Apache's SSLCertificateFile directive.
SSLCertificateFile /etc/pki/tls/certs/custom.crt

If you received an intermediate certificate file (intermediate.crt in this example), provide its
path and file name using Apache's SSLCACertificateFile directive.
SSLCACertificateFile /etc/pki/tls/certs/intermediate.crt

Save /etc/httpd/conf.d/ssl.conf and restart Apache.
[ec2-user ~]$ sudo service httpd restart

Step 3: Test and Harden the Security
Configuration
After your SSL/TLS is operational and exposed to the public, you should test how secure it really is.
This is easy to do using online services such as Qualys SSL Labs, which performs a free and thorough
analysis of your security setup. Based on the results, you may decide to harden the default security
configuration by controlling which protocols you accept, which ciphers you prefer, and which you
exclude. For more information, see how Qualys formulates its scores.

Important
Real-world testing is crucial to the security of your server. Small configuration errors may
lead to serious security breaches and loss of data. Because recommended security practices
change constantly in response to research and emerging threats, periodic security audits are
essential to good server administration.
On the Qualys SSL Labs site, type the fully qualified domain name of your server, in the form
www.example.com. After about two minutes, you will receive a grade (from A to F) for your site and a
detailed breakdown of the findings. The table below summarizes the report for a domain with settings
identical to the default Apache configuration on Amazon Linux:
Overall rating

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Step 3: Test and Harden the Security Configuration

Certificate

100%

Protocol support

90%

Key exchange

90%

Cipher strength

90%

The report shows that the configuration is mostly sound, with acceptable ratings for certificate, protocol
support, key exchange, and cipher strength issues. However, the report also flags three vulnerabilities
that are responsible for lowering the overall grade and should be addressed:
• POODLE vulnerability: The POODLE attack, discovered in 2014, exploits a weakness in SSL
version 3 that allows an attacker to impersonate a web site. The fix is straightforward: Disable SSL
version 3 support on the server. In the configuration file /etc/httpd/conf.d/ssl.conf, comment out the
following by typing "#" at the beginning of the line:
SSLProtocol all -SSLv2

Then, add the following directive:
SSLProtocol -SSLv2 -SSLv3 +TLSv1 +TLSv1.1 +TLSv1.2

In addition to explicitly disabling SSL version 2, this command also disables SSL version 3 (the
one flagged by the security audit) and explicitly allows all currently existing versions of TLS. The
server will now refuse to accept encrypted connections with clients using anything except TLS. The
verbose wording in the directive communicates more clearly, to a human reader, what the server is
configured to do.
• RC4 cipher support: A cipher is the mathematical core of an encryption algorithm. RC4, a fast
cipher used to encrypt SSL/TLS data-streams, is known to have several serious weaknesses. The fix
is to disable RC4 support in ssl.conf, which we'll do as part of the fix in the next case.
• Missing support for forward secrecy: Forward secrecy is a feature of protocols that encrypt
using temporary (ephemeral) session keys derived from the private key. This means in practice that
attackers cannot decrypt HTTPS data even if they possess a web server's long-term private key. The
web browsers that make up Qualys's list of "reference browsers" all support forward secrecy.
The fix for both RC4 and forward secrecy issues is to customize Apache's list of permitted and
forbidden ciphers, and to enforce a preference for strong ciphers over weaker ones. This requires
two configuration changes.
In the configuration file /etc/httpd/conf.d/ssl.conf, find the section with commented-out examples
for configuring SSLCipherSuite, comment out (but keep) the current list, and add the following
directive:

Note
Though shown here on several lines for readability, the entire directive must be on a single
line without spaces between the cipher names.
SSLCipherSuite ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCMSHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:
ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSAAES128-SHA256:ECDHE-ECDSA-AES128-SHA256:

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Step 3: Test and Harden the Security Configuration
AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES:!
aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:
!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA

These ciphers are a subset of the much longer list of supported ciphers in OpenSSL. They were
selected and ordered according to the following criteria:
1. Support for forward secrecy
2. Strength
3. Speed
4. Specific ciphers before cipher families
5. Allowed ciphers before denied ciphers
Note that the high-ranking ciphers have ECDHE in their names, for Elliptic Curve Diffie-Hellman
Ephemeral ; the ephemeral indicates forward secrecy. Also, RC4 is now among the forbidden
ciphers near the end.
We recommend that you use an explicit list of ciphers instead relying on defaults or terse directives
whose content isn't visible.

Important
The cipher list shown here is just one of many possible lists; for instance, you might want to
optimize a list for speed rather than forward secrecy.
If you anticipate a need to support older clients, you can allow the DES-CBC3-SHA cipher
suite.
Finally, each update to OpenSSL introduces new ciphers and deprecates old ones. Keep
your EC2 Amazon Linux instance up to date, watch for security announcements from
OpenSSL, and be alert to reports of new security exploits in the technical press. For more
information, see Predefined SSL Security Policies for Elastic Load Balancing in the Elastic
Load Balancing User Guide.
Uncomment the following line by removing the "#":
#SSLHonorCipherOrder on

This command forces the server to prefer high-ranking ciphers, including (in this case) those that
support forward secrecy. With this directive turned on, the server tries to establish a strongly secure
connection before falling back to allowed ciphers with lesser security.
Restart Apache after saving the edited configuration file.
If you test the domain again on Qualys SSL Labs, you should see that the vulnerabilities are gone and
the summary looks something like this:
Overall rating

Certificate

100%

Protocol support

95%

Key exchange

90%

Cipher strength

90%

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Troubleshooting

Troubleshooting
• My Apache webserver won't start unless I supply a password.
This is expected behavior if you installed an encrypted, password-protected, private server key.
You can strip the key of its encryption and password. Assuming you have a private encrypted RSA
key called custom.key in the default directory, and that the passphrase on it is abcde12345, run
the following commands on your EC2 instance to generate an unencrypted version of this key:
[ec2-user ~]$ cd /etc/pki/tls/private/
[ec2-user private]$ sudo cp custom.key custom.key.bak
[ec2-user private]$ sudo openssl rsa -in custom.key -passin pass:abcde12345
-out custom.key.nocrypt
[ec2-user private]$ sudo mv custom.key.nocrypt custom.key
[ec2-user private]$ sudo chown root.root custom.key
[ec2-user private]$ sudo chmod 600 custom.key
[ec2-user private]$ sudo service httpd restart

Apache should now start without prompting you for a password.

Tutorial: Increase the Availability of Your
Application on Amazon EC2
Suppose that you start out running your app or website on a single EC2 instance, and over time,
traffic increases to the point that you require more than one instance to meet the demand. You can
launch multiple EC2 instances from your AMI and then use Elastic Load Balancing to distribute
incoming traffic for your application across these EC2 instances. This increases the availability of your
application. Placing your instances in multiple Availability Zones also improves the fault tolerance in
your application. If one Availability Zone experiences an outage, traffic is routed to the other Availability
Zone.
You can use Auto Scaling to maintain a minimum number of running instances for your application
at all times. Auto Scaling can detect when your instance or application is unhealthy and replace it
automatically to maintain the availability of your application. You can also use Auto Scaling to scale
your Amazon EC2 capacity up or down automatically based on demand, using criteria that you specify.
In this tutorial, we use Auto Scaling with Elastic Load Balancing to ensure that you maintain a specified
number of healthy EC2 instances behind your load balancer. Note that these instances do not need
public IP addresses, because traffic goes to the load balancer and is then routed to the instances. For
more information, see Auto Scaling and Elastic Load Balancing.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Prerequisites

Contents
• Prerequisites (p. 61)
• Scale and Load Balance Your Application (p. 61)
• Test Your Load Balancer (p. 63)

Prerequisites
This tutorial assumes that you have already done the following:
1.
2.
3.

If you don't have a default virtual private cloud (VPC), create a VPC with one public subnet in two
or more Availability Zones. For more information, see Create a Virtual Private Cloud (VPC) (p. 23).
Launch an instance in the VPC.
Connect to the instance and customize it. For example, you can install software and applications,
copy data, and attach additional EBS volumes. For information about setting up a web server on
your instance, see Tutorial: Installing a LAMP Web Server on Amazon Linux (p. 33).
Test your application on your instance to ensure that your instance is configured correctly.

Create a custom Amazon Machine Image (AMI) from your instance. For more information, see
Creating an Amazon EBS-Backed Linux AMI (p. 89) or Creating an Instance Store-Backed
Linux AMI (p. 92).

6.
7.

(Optional) Terminate the instance if you no longer need it.
Create an IAM role that grants your application the access to AWS that it needs. For more
information, see Creating an IAM Role Using the Console (p. 538).

Scale and Load Balance Your Application
Use the following procedure to create a load balancer, create a launch configuration for your instances,
create an Auto Scaling group with two or more instances, and associate the load balancer with the
Auto Scaling group.

To scale and load-balance your application
1.
2.
3.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, under LOAD BALANCING, click Load Balancers.
Click Create Load Balancer.

On the Define Load Balancer page, do the following:

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Scale and Load Balance Your Application

Enter a name for the load balancer in Load Balancer name. For example, my-lb.

Select your VPC from Create LB Inside.

Leave the default for Listener Configuration, which is an HTTP listener.

If you selected a nondefault VPC, you are prompted to select subnets under Select Subnets.
Click the icon in the Action column for each of your two public subnets.

Click Next: Assign Security Groups.

On the Assign Security Groups page, do the following:
a.

Click Create a new security group.

Enter a name and description for your security group. This new security group contains a rule
that allows traffic to the port for your HTTP listener.

Click Next: Configure Security Settings.

On the Configure Security Settings page, click Next: Configure Health Check to continue to
the next page, as we are not creating an HTTPS load balancer.

On the Configure Health Check page, do the following:
a.

Leave Ping Protocol and Ping Port at their default values.

Set Ping Path to /. This sends queries to your default page, whether it is named
index.html or something else.

Click Next: Add EC2 Instances.

On the Add EC2 Instances page, click Next: Add Tags to continue to the next page, as we'll use
Auto Scaling to add EC2 instances to the load balancer.

On the Add Tags page, add any tags that you need, and then click Review and Create.

10. On the Review page, review your settings and then click Create. After the load balancer is
created, click Close.
11. In the navigation pane, under AUTO SCALING, click Launch Configurations.
•

If you are new to Auto Scaling, you see a welcome page. Click Create Auto Scaling group to
start the Create Auto Scaling Group wizard, and then click Create launch configuration.

•

Otherwise, click Create launch configuration.

12. On the Choose AMI page, select the My AMIs tab, and then select the AMI that you created in
Prerequisites (p. 61).
13. On the Choose Instance Type page, select an instance type, and then click Next: Configure
details.
14. On the Configure details page, do the following:
a.

In Name, enter a name for your launch configuration (for example, my-launch-config).

From IAM role, select the IAM role that you created in Prerequisites (p. 61).

(Optional) If you need to run a startup script, expand Advanced Details and enter the script in
User data.

Click Skip to review.

15. On the Review page, click Edit security groups. You can select an existing security group or
create a new one. This security group must allow HTTP traffic and health checks from the load
balancer. If your instances will have public IP addresses, you can optionally allow SSH traffic if you
need to connect to the instances. When you are finished, click Review.
16. On the Review page, click Create launch configuration.
17. When prompted, select an existing key pair, create a new key pair, or proceed without a key pair.
Click the acknowledgment check box, and then click Create launch configuration.
18. After the launch configuration is created, you must create an Auto Scaling group.
•

If you are new to Auto Scaling and you are using the Create Auto Scaling group wizard, you
are taken to the next step automatically.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Test Your Load Balancer

•

Otherwise, click Create an Auto Scaling group using this launch configuration.

19. On the Configure Auto Scaling group details page, do the following:
a.

Enter a name for the Auto Scaling group. For example, my-asg.

In Group size, enter the number of instances in the text box (for example, 2). Note that
we recommend that you maintain approximately the same number of instances in each
Availability Zone.

Select your VPC from Network and your two public subnets from Subnet.

Expand Advanced Details. Select Receive traffic from Elastic Load Balancer(s). Select
your load balancer from the text field.

Click Next: Configure scaling policies.

20. On the Configure scaling policies page, click Review, as we will simply let Auto Scaling
maintain the group at the specified size. Note that later on, you can manually scale this Auto
Scaling group, configure the group to scale on a schedule, or configure the group to scale based
on demand.
21. On the Review page, click Create Auto Scaling group.
22. After the group is created, click Close.

Test Your Load Balancer
First, verify that Auto Scaling has launched your instances and that they are ready. From the Auto
Scaling Groups page, select your Auto Scaling group and then select the Instances tab.

Initially, your instances are in the Pending state. When their states are InService, they are ready for
use.
Next, verify that your instances are registered with the load balancer and ready to receive traffic from
the load balancer. From the Load Balancers page, select your load balancer and then select the
Instances tab.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Tutorial: Remotely Manage Your Instances

If the state of your instances is OutOfService, it's possible that they are still registering. When their
states are InService, they are ready for use. After your instances are ready, you can test your load
balancer as follows.

To test your load balancer
1.

From the Load Balancers page, select your load balancer.

On the Description tab, locate the DNS name. This name has the following form:
my-lb-xxxxxxxxxx.us-west-2.elb.amazonaws.com

In a web browser, paste the DNS name for the load balancer into the address bar and press Enter.
You'll see your website displayed.

Tutorial: Remotely Manage Your Amazon EC2
Instances
This tutorial shows you how to remotely manage an Amazon EC2 instance using Amazon Elastic
Compute Cloud (Amazon EC2) Run Command from your local machine. In this tutorial, you will learn
how to do the following tasks:
• Launch a new instance that is configured for Run Command.
• Configure your user account for Run Command.
• Use Run Command to send a command from your local machine and retrieve a list of services
running on the instance.
This tutorial includes procedures for executing commands using either the Amazon EC2 console or
AWS Command Line Interface.

Note
With Run Command, you can also manage your servers and virtual machines (VMs) in your
on-premises environment or in an environment provided by other cloud providers. For more
information, see Setting Up Run Command On Managed Instances (p. 371).

Launch a New Instance
Instances require an AWS Identity and Access Management (IAM) role that enables the instance to
communicate with Amazon EC2 Simple Systems Manager (SSM). You must assign the IAM role when

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Grant Your User Account Access to SSM

you create the new instance. You can't assign a role to an instance that is already running. For existing
instances, you must create an image of the instance, launch an instance from that image, and assign
the IAM role as you launch the instance. For more information, see Creating an Amazon EBS-Backed
Linux AMI.

To create an instance that uses an SSM-supported role
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
Select a supported region.

Choose Launch Instance and select a Linux Amazon Machine Image (AMI).

Choose your instance type and then choose Next: Configure Instance Details.

5.
6.

In Auto-assign Public IP, choose Enable.
Beside IAM role choose Create new IAM role. The IAM console opens in a new tab.
a.

Choose Create New Role.

In Step 1: Set Role Name, enter a name that identifies this role as a Run Command role.

In Step 2: Select Role Type, choose Amazon EC2 Role for Simple Systems Manager. The
system skips Step 3: Establish Trust because this is a managed policy.

In Step 4: Attach Policy, choose AmazonEC2RoleforSSM.

e.
f.

Choose Next Step, and then choose Create Role.
Close the tab with the IAM console.

In the Amazon EC2 console, choose the Refresh button beside Create New IAM role.

8.
9.

From IAM role, choose the role you just created.
Complete the wizard to launch the new instance. Make a note of the instance ID. You will need to
specify this ID later in this tutorial.

Grant Your User Account Access to SSM
Your user account must be configured to communicate with the SSM API. Use the following procedure
to attach a managed IAM policy to your user account that grants you full access to SSM API actions.

To create the IAM policy for your user account
1.

3.
4.

Open the Identity and Access Management (IAM) console at https://console.aws.amazon.com/
iam/.
In the navigation pane, choose Policies. (If this is your first time using IAM, choose Get Started,
and then choose Create Policy.)
In the Filter field, type AmazonSSMFullAccess and press Enter.
Select the check box next to AmazonSSMFullAccess and then choose Policy Actions, Attach.

On the Attach Policy page, choose your user account and then choose Attach Policy.

Install the SSM Agent
The SSM agent processes Run Command requests and configures the instances that are specified
in the request. You must manually install the agent using the procedure for your version of Linux.
The following procedure describes how to install the agent on Red Hat Enterprise Linux (RHEL). For
information about how to install the agent on Ubuntu, Amazon Linux or CentOS, see Manually Install
the SSM Agent on EC2 Instances (p. 359).

To install the SSM agent on Red Hat Enterprise Linux
1.

Connect to your RHEL instance and create a temporary directory on the instance.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Install the SSM Agent
mkdir /tmp/ssm

Use one of the following commands to download the SSM installer to the temporary directory.
Replace region with one of the AWS Regions where SSM is available. To avoid cross-region
data transfer costs for the download, specify the region of your EC2 instance.
64-Bit
curl https://amazon-ssm-region.s3.amazonaws.com/latest/linux_amd64/amazonssm-agent.rpm -o /tmp/ssm/amazon-ssm-agent.rpm

32-Bit
curl https://amazon-ssm-region.s3.amazonaws.com/latest/linux_386/amazonssm-agent.rpm -o /tmp/ssm/amazon-ssm-agent.rpm

Run the SSM installer.
sudo yum install -y /tmp/ssm/amazon-ssm-agent.rpm

Run one of the following commands to determine if the SSM agent is running. The command
should return "amazon-ssm-agent is running."
RHEL 7.x
sudo systemctl status amazon-ssm-agent

RHEL 6.x
sudo status amazon-ssm-agent

Execute the following commands if the previous command returned "amazon-ssm-agent is
stopped."
a.

Start the service.
RHEL 7.x
sudo systemctl start amazon-ssm-agent

RHEL 6.x
sudo start amazon-ssm-agent

Check the status of the agent.
RHEL 7.x
sudo systemctl status amazon-ssm-agent

RHEL 6.x

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Send a Command Using the EC2 Console
sudo status amazon-ssm-agent

Send a Command Using the EC2 Console
Use the following procedure to list all services running on the instance by using Run Command from
the Amazon EC2 console.
1.

In the Amazon EC2 console choose Command History in the navigation pane, and then choose
Run a command.

In the Command document list, choose AWS-RunShellScript.

Choose Select instances, and then choose the instance you just created. If you do not see the
instance, verify that you are currently in the same region as the instance you created. Also verify
that you configured the IAM role and trust policies correctly as described earlier in this topic.

In the Commands field, type service --status-all. You can specify a Working Directory
and Execution Timeout, if you want. The Execution Timeout is the number of seconds the SSM
agent will attempt to run the command before it is considered to have failed. We recommend
entering a comment in the Comments field. A comment will help you identify the command in the
list of pending commands and make it easier to view the output.

In the Timeout (seconds) field, type the number of seconds Run Command should attempt to
reach instances before an instance is considered unreachable and the command execution fails.

Choose Run to execute the command simultaneously on the selected instances. Run Command
displays a status screen.

Choose View result.

Choose the command invocation for the command you just ran.

Choose the Output tab, and then choose View Output.

10. The system displays the output in your browser. If the output is longer than 2500 characters, only
the first 2500 characters are shown and the rest is truncated. You could view the full output by
specifying an Amazon S3 bucket before executing the command.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Send a Command Using the AWS CLI

Send a Command Using the AWS CLI
Use the following procedure to list all services running on the instance by using Run Command in the
AWS CLI.

To execute a command
1.

On your local computer, download the latest version of the AWS Command Line Interface (AWS
CLI).

Open the AWS CLI on your local computer and execute the following command to specify your
credentials and the region.
aws configure

The system prompts you to specify the following.
AWS Access Key ID [None]: key
AWS Secret Access Key [None]: key
Default region name [None]: region, for example us-east-1
Default output format [None]: ENTER

Execute the following command to retrieve the services running on the instance.
aws ssm send-command --document-name "AWS-RunShellScript" --comment
"listing services" --instance-ids "Instance-ID" --parameters
commands="service --status-all" --region us-west-2 --output text

The command returns a command ID, which you will use to view the results.
The following command returns the output of the original Send-SSMCommand. The output is
truncated after 2500 characters. To view the full list of services, you would need to specify an
Amazon S3 bucket in the command using the --output-s3-bucket-name bucket_name parameter.
aws ssm list-command-invocations --command-id "command ID" --details

For more examples of how to execute commands using Run Command with the AWS CLI and the
AWS Management Console, see Amazon EC2 Run Command Walkthroughs (p. 387). For more
information about Run Command, see Remotely Manage Your Instances (p. 352).
For videos, see AWS Instructional Videos and Labs.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Using an AMI

Amazon Machine Images (AMI)

An Amazon Machine Image (AMI) provides the information required to launch an instance, which is a
virtual server in the cloud. You specify an AMI when you launch an instance, and you can launch as
many instances from the AMI as you need. You can also launch instances from as many different AMIs
as you need.
An AMI includes the following:
• A template for the root volume for the instance (for example, an operating system, an application
server, and applications)
• Launch permissions that control which AWS accounts can use the AMI to launch instances
• A block device mapping that specifies the volumes to attach to the instance when it's launched

Using an AMI
The following diagram summarizes the AMI lifecycle. After you create and register an AMI, you can use
it to launch new instances. (You can also launch instances from an AMI if the AMI owner grants you
launch permissions.) You can copy an AMI to the same region or to different regions. When you are
finished launching instance from an AMI, you can deregister the AMI.

You can search for an AMI that meets the criteria for your instance. You can search for AMIs provided
by AWS or AMIs provided by the community. For more information, see AMI Types (p. 71) and
Finding a Linux AMI (p. 75).

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Creating Your Own AMI

When you are connected to an instance, you can use it just like you use any other server.
For information about launching, connecting, and using your instance, see Amazon EC2
Instances (p. 156).

Creating Your Own AMI
You can customize the instance that you launch from a public AMI and then save that configuration as
a custom AMI for your own use. Instances that you launch from your AMI use all the customizations
that you've made.
The root storage device of the instance determines the process you follow to create an AMI. The root
volume of an instance is either an Amazon EBS volume or an instance store volume. For information,
see Amazon EC2 Root Device Volume (p. 14).
To create an Amazon EBS-backed AMI, see Creating an Amazon EBS-Backed Linux AMI (p. 89).
To create an instance store-backed AMI, see Creating an Instance Store-Backed Linux AMI (p. 92).
To help categorize and manage your AMIs, you can assign custom tags to them. For more information,
see Tagging Your Amazon EC2 Resources (p. 751).

Buying, Sharing, and Selling AMIs
After you create an AMI, you can keep it private so that only you can use it, or you can share it with a
specified list of AWS accounts. You can also make your custom AMI public so that the community can
use it. Building a safe, secure, usable AMI for public consumption is a fairly straightforward process,
if you follow a few simple guidelines. For information about how to create and use shared AMIs, see
Shared AMIs (p. 76).
You can purchase an AMIs from a third party, including AMIs that come with service contracts from
organizations such as Red Hat. You can also create an AMI and sell it to other Amazon EC2 users. For
more information about buying or selling AMIs, see Paid AMIs (p. 85).

Deregistering Your AMI
You can deregister an AMI when you have finished with it. After you deregister an AMI, you can't use it
to launch new instances. For more information, see Deregistering Your AMI (p. 140).

Amazon Linux
The Amazon Linux AMI is a supported and maintained Linux image provided by AWS. The following
are some of the features of Amazon Linux:
• A stable, secure, and high-performance execution environment for applications running on Amazon
EC2.
• Provided at no additional charge to Amazon EC2 users.
• Repository access to multiple versions of MySQL, PostgreSQL, Python, Ruby, Tomcat, and many
more common packages.
• Updated on a regular basis to include the latest components, and these updates are also made
available in the yum repositories for installation on running instances.

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User Guide for Linux Instances
AMI Types

• Includes packages that enable easy integration with AWS services, such as the AWS CLI, Amazon
EC2 API and AMI tools, the Boto library for Python, and the Elastic Load Balancing tools.
For more information, see Amazon Linux (p. 142).

AMI Types
You can select an AMI to use based on the following characteristics:
• Region (see Regions and Availability Zones (p. 7))
• Operating system
• Architecture (32-bit or 64-bit)
• Launch Permissions (p. 71)
• Storage for the Root Device (p. 71)

Launch Permissions
The owner of an AMI determines its availability by specifying launch permissions. Launch permissions
fall into the following categories.
Launch
Permission

Description

public

The owner grants launch permissions to all AWS accounts.

explicit

The owner grants launch permissions to specific AWS accounts.

implicit

The owner has implicit launch permissions for an AMI.

Amazon and the Amazon EC2 community provide a large selection of public AMIs. For more
information, see Shared AMIs (p. 76). Developers can charge for their AMIs. For more information,
see Paid AMIs (p. 85).

Storage for the Root Device
All AMIs are categorized as either backed by Amazon EBS or backed by instance store. The former
means that the root device for an instance launched from the AMI is an Amazon EBS volume created
from an Amazon EBS snapshot. The latter means that the root device for an instance launched
from the AMI is an instance store volume created from a template stored in Amazon S3. For more
information, see Amazon EC2 Root Device Volume (p. 14).
This section summarizes the important differences between the two types of AMIs. The following table
provides a quick summary of these differences.
Characteristic

Amazon EBS-Backed

Amazon Instance Store-Backed

Boot time

Usually less than 1 minute

Usually less than 5 minutes

Size limit

16 TiB

10 GiB

Root device volume

Amazon EBS volume

Instance store volume

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Storage for the Root Device

Characteristic

Amazon EBS-Backed

Amazon Instance Store-Backed

Data persistence

By default, the root volume
is deleted when the instance
terminates.* Data on any other
Amazon EBS volumes persists after
instance termination by default.
Data on any instance store volumes
persists only during the life of the
instance.

Data on any instance store volumes
persists only during the life of the
instance. Data on any Amazon EBS
volumes persists after instance
termination by default.

Upgrading

The instance type, kernel, RAM
disk, and user data can be changed
while the instance is stopped.

Instance attributes are fixed for the
life of an instance.

Charges

You're charged for instance usage,
Amazon EBS volume usage, and
storing your AMI as an Amazon
EBS snapshot.

You're charged for instance usage
and storing your AMI in Amazon S3.

AMI creation/bundling

Uses a single command/call

Requires installation and use of AMI
tools

Stopped state

Can be placed in stopped state
where instance is not running,
but the root volume is persisted in
Amazon EBS

Cannot be in stopped state;
instances are running or terminated

* By default, Amazon EBS-backed instance root volumes have the DeleteOnTermination flag set to
true. For information about how to change this flag so that the volume persists after termination, see
Changing the Root Device Volume to Persist (p. 17).

Determining the Root Device Type of Your AMI
To determine the root device type of an AMI using the console
1.

Open the Amazon EC2 console.

In the navigation pane, click AMIs, and select the AMI.

Check the value of Root Device Type in the Details tab as follows:
• If the value is ebs, this is an Amazon EBS-backed AMI.
• If the value is instance store, this is an instance store-backed AMI.

To determine the root device type of an AMI using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• describe-images (AWS CLI)
• Get-EC2Image (AWS Tools for Windows PowerShell)

Stopped State
You can stop an Amazon EBS-backed instance, but not an Amazon EC2 instance store-backed
instance. Stopping causes the instance to stop running (its status goes from running to stopping

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Storage for the Root Device

to stopped). A stopped instance persists in Amazon EBS, which allows it to be restarted. Stopping
is different from terminating; you can't restart a terminated instance. Because Amazon EC2 instance
store-backed AMIs can't be stopped, they're either running or terminated. For more information
about what happens and what you can do while an instance is stopped, see Stop and Start Your
Instance (p. 299).

Default Data Storage and Persistence
Instances that use an instance store volume for the root device automatically have instance store
available (the root volume contains the root partition and you can store additional data). Any data
on an instance store volume is deleted when the instance fails or terminates (except for data on the
root device). You can add persistent storage to your instance by attaching one or more Amazon EBS
volumes.
Instances that use Amazon EBS for the root device automatically have an Amazon EBS volume
attached. The volume appears in your list of volumes like any other. The instances don't use any
available instance store volumes by default. You can add instance storage or additional Amazon EBS
volumes using a block device mapping. For more information, see Block Device Mapping (p. 731).
For information about what happens to the instance store volumes when you stop an instance, see
Stop and Start Your Instance (p. 299).

Boot Times
Amazon EBS-backed AMIs launch faster than Amazon EC2 instance store-backed AMIs. When you
launch an Amazon EC2 instance store-backed AMI, all the parts have to be retrieved from Amazon
S3 before the instance is available. With an Amazon EBS-backed AMI, only the parts required to boot
the instance need to be retrieved from the snapshot before the instance is available. However, the
performance of an instance that uses an Amazon EBS volume for its root device is slower for a short
time while the remaining parts are retrieved from the snapshot and loaded into the volume. When
you stop and restart the instance, it launches quickly, because the state is stored in an Amazon EBS
volume.

AMI Creation
To create Linux AMIs backed by instance store, you must create an AMI from your instance on the
instance itself using the Amazon EC2 AMI tools.
AMI creation is much easier for AMIs backed by Amazon EBS. The CreateImage API action creates
your Amazon EBS-backed AMI and registers it. There's also a button in the AWS Management
Console that lets you create an AMI from a running instance. For more information, see Creating an
Amazon EBS-Backed Linux AMI (p. 89).

How You're Charged
With AMIs backed by instance store, you're charged for AMI storage and instance usage. With AMIs
backed by Amazon EBS, you're charged for volume storage and usage in addition to the AMI and
instance usage charges.
With Amazon EC2 instance store-backed AMIs, each time you customize an AMI and create a
new one, all of the parts are stored in Amazon S3 for each AMI. So, the storage footprint for each
customized AMI is the full size of the AMI. For Amazon EBS-backed AMIs, each time you customize an
AMI and create a new one, only the changes are stored. So the storage footprint for subsequent AMIs
you customize after the first is much smaller, resulting in lower AMI storage charges.
When an Amazon EBS-backed instance is stopped, you're not charged for instance usage; however,
you're still charged for volume storage. We charge a full instance hour for every transition from a
stopped state to a running state, even if you transition the instance multiple times within a single hour.
For example, let's say the hourly instance charge for your instance is $0.10. If you were to run that
instance for one hour without stopping it, you would be charged $0.10. If you stopped and restarted

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Virtualization Types

that instance twice during that hour, you would be charged $0.30 for that hour of usage (the initial
$0.10, plus 2 x $0.10 for each restart).

Linux AMI Virtualization Types
Linux Amazon Machine Images use one of two types of virtualization: paravirtual (PV) or hardware
virtual machine (HVM). The main difference between PV and HVM AMIs is the way in which they boot
and whether they can take advantage of special hardware extensions (CPU, network, and storage) for
better performance.
For the best performance, we recommend that you use current generation instance types and HVM
AMIs when you launch your instances. For more information about current generation instance types,
see the Amazon EC2 Instances detail page. If you are using previous generation instance types and
would like to upgrade, see Upgrade Paths.
For information about the types of the Amazon Linux AMI recommended for each instance type, see
the Amazon Linux AMI Instance Types detail page.
HVM AMIs
HVM AMIs are presented with a fully virtualized set of hardware and boot by executing the master
boot record of the root block device of your image. This virtualization type provides the ability to run an
operating system directly on top of a virtual machine without any modification, as if it were run on the
bare-metal hardware. The Amazon EC2 host system emulates some or all of the underlying hardware
that is presented to the guest.
Unlike PV guests, HVM guests can take advantage of hardware extensions that provide fast access
to the underlying hardware on the host system. For more information on CPU virtualization extensions
available in Amazon EC2, see Intel Virtualization Technology on the Intel website. HVM AMIs are
required to take advantage of enhanced networking and GPU processing. In order to pass through
instructions to specialized network and GPU devices, the OS needs to be able to have access to
the native hardware platform; HVM virtualization provides this access. For more information, see
Enhanced Networking (p. 608) and Linux GPU Instances (p. 166).
All current generation instance types support HVM AMIs. The CC2, CR1, HI1, and HS1 previous
generation instance types support HVM AMIs.
To find an HVM AMI, verify that the virtualization type of the AMI is set to hvm, using the console or the
describe-images command.
PV AMIs
PV AMIs boot with a special boot loader called PV-GRUB, which starts the boot cycle and then chain
loads the kernel specified in the menu.lst file on your image. Paravirtual guests can run on host
hardware that does not have explicit support for virtualization, but they cannot take advantage of
special hardware extensions such as enhanced networking or GPU processing. Historically, PV
guests had better performance than HVM guests in many cases, but because of enhancements in
HVM virtualization and the availability of PV drivers for HVM AMIs, this is no longer true. For more
information about PV-GRUB and its use in Amazon EC2, see User Provided Kernels (p. 149).
The C3 and M3 current generation instance types support PV AMIs. The C1, HI1, HS1, M1, M2, and
T1 previous generation instance types support PV AMIs.
To find a PV AMI, verify that the virtualization type of the AMI is set to paravirtual, using the
console or the describe-images command.
PV on HVM
Paravirtual guests traditionally performed better with storage and network operations than HVM guests
because they could leverage special drivers for I/O that avoided the overhead of emulating network

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Finding a Linux AMI

and disk hardware, whereas HVM guests had to translate these instructions to emulated hardware.
Now these PV drivers are available for HVM guests, so operating systems that cannot be ported to run
in a paravirtualized environment (such as Windows) can still see performance advantages in storage
and network I/O by using them. With these PV on HVM drivers, HVM guests can get the same, or
better, performance than paravirtual guests.

Finding a Linux AMI
Before you can launch an instance, you must select an AMI to use. As you select an AMI, consider the
following requirements you might have for the instances that you'll launch:
• The region
• The operating system
• The architecture: 32-bit (i386) or 64-bit (x86_64)
• The root device type: Amazon EBS or instance store
• The provider: Amazon Web Services, Oracle, IBM, Microsoft, or the community
If you need to find a Windows AMI, see Finding a Windows AMI in the Amazon EC2 User Guide for
Windows Instances.
Contents
• Finding a Linux AMI Using the Amazon EC2 Console (p. 75)
• Finding an AMI Using the AWS CLI (p. 76)

Finding a Linux AMI Using the Amazon EC2
Console
You can find Linux AMIs using the Amazon EC2 console. You can search through all available AMIs
using the Images page, or select from commonly used AMIs on the Quick Launch tab when you use
the console to launch an instance.

To find a Linux AMI using the Images page
1.
2.
3.
4.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
From the navigation bar, select a region. You can select any region that's available to you,
regardless of your location. This is the region in which you'll launch your instance.
In the navigation pane, choose AMIs.
(Optional) Use the Filter options to scope the list of displayed AMIs to see only the AMIs that
interest you. For example, to list all Linux AMIs provided by AWS, select Public images. Choose
the Search bar and select Owner from the menu, then select Amazon images. Choose the
Search bar again to select Platform and then the operating system from the list provided.
(Optional) Choose the Show/Hide Columns icon to select which image attributes to display, such
as the root device type. Alternatively, you can select an AMI from the list and view its properties in
the Details tab.
Before you select an AMI, it's important that you check whether it's backed by instance store or by
Amazon EBS and that you are aware of the effects of this difference. For more information, see
Storage for the Root Device (p. 71).
To launch an instance from this AMI, select it and then choose Launch. For more information
about launching an instance using the console, see Launching Your Instance from an
AMI (p. 281). If you're not ready to launch the instance now, write down the AMI ID
(ami-xxxxxxxx) for later.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Finding an AMI Using the AWS CLI

To find a Linux AMI when you launch an instance
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

From the console dashboard, choose Launch Instance.

On the Choose an Amazon Machine Image (AMI) page, on the Quick Start tab, select from one
of the commonly used AMIs in the list. If you don't see the AMI that you need, select the AWS
Marketplace or Community AMIs tab to find additional AMIs.

Finding an AMI Using the AWS CLI
You can use command line parameters to list only the types of AMIs that interest you. For example,
you can use the describe-images command as follows to find public AMIs owned by you or Amazon.
$ aws ec2 describe-images --owners self amazon

Add the following filter to the previous command to display only AMIs backed by Amazon EBS:
--filters "Name=root-device-type,Values=ebs"

After locating an AMI that meets your needs, write down its ID (ami-xxxxxxxx). You can use this AMI
to launch instances. For more information, see Launching an Instance Using the AWS CLI in the AWS
Command Line Interface User Guide.

Shared AMIs
A shared AMI is an AMI that a developer created and made available for other developers to use. One
of the easiest ways to get started with Amazon EC2 is to use a shared AMI that has the components
you need and then add custom content. You can also create your own AMIs and share them with
others.
You use a shared AMI at your own risk. Amazon can't vouch for the integrity or security of AMIs shared
by other Amazon EC2 users. Therefore, you should treat shared AMIs as you would any foreign code
that you might consider deploying in your own data center and perform the appropriate due diligence.
We recommend that you get an AMI from a trusted source. If you have questions or observations about
a shared AMI, use the AWS forums.
Amazon's public images have an aliased owner, which appears as amazon in the account field. This
enables you to find AMIs from Amazon easily. Other users can't alias their AMIs.
For information about creating an AMI, see Creating an Instance Store-Backed Linux AMI or Creating
an Amazon EBS-Backed Linux AMI . For more information about building, delivering, and maintaining
your applications on the AWS Marketplace, see the AWS Marketplace User Guide and AWS
Marketplace Seller Guide.
Contents
• Finding Shared AMIs (p. 77)
• Making an AMI Public (p. 78)
• Sharing an AMI with Specific AWS Accounts (p. 80)
• Using Bookmarks (p. 81)
• Guidelines for Shared Linux AMIs (p. 81)

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Finding Shared AMIs

Finding Shared AMIs
You can use the Amazon EC2 console or the command line to find shared AMIs.

Finding a Shared AMI (Console)
To find a shared private AMI using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose AMIs.

In the first filter, choose Private images. All AMIs that have been shared with you are listed. To
granulate your search, choose the Search bar and use the filter options provided in the menu.

To find a shared public AMI using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose AMIs.

In the first filter, choose Public images. To granulate your search, choose the Search bar and use
the filter options provided in the menu.

Use filters to list only the types of AMIs that interest you. For example, choose Owner : and then
choose Amazon images to display only Amazon's public images.

Finding a Shared AMI (Command Line)
To find a shared public AMI using the command line tools
Use the describe-images command (AWS CLI) to list AMIs. You can scope the list to the types of AMIs
that interest you, as shown in the following examples.
The following command lists all public AMIs using the --executable-users option. This list includes
any public AMIs that you own.
$ aws ec2 describe-images --executable-users all

The following command lists the AMIs for which you have explicit launch permissions. This list
excludes any such AMIs that you own.
$ aws ec2 describe-images --executable-users self

The following command lists the AMIs owned by Amazon. Amazon's public AMIs have an aliased
owner, which appears as amazon in the account field. This enables you to find AMIs from Amazon
easily. Other users can't alias their AMIs.
$ aws ec2 describe-images --owners amazon

The following command lists the AMIs owned by the specified AWS account.
$ aws ec2 describe-images --owners 123456789012

To reduce the number of displayed AMIs, use a filter to list only the types of AMIs that interest you. For
example, use the following filter to display only EBS-backed AMIs.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Making an AMI Public
--filters "Name=root-device-type,Values=ebs"

Alternatively, you can use the following AWS Tools for Windows PowerShell command: GetEC2Image.

Using Shared AMIs
Before you use a shared AMI, take the following steps to confirm that there are no pre-installed
credentials that would allow unwanted access to your instance by a third party and no pre-configured
remote logging that could transmit sensitive data to a third party. Check the documentation for the
Linux distribution used by the AMI for information about improving the security of the system.
To ensure that you don't accidentally lose access to your instance, we recommend that you initiate
two SSH sessions and keep the second session open until you've removed credentials that you don't
recognize and confirmed that you can still log into your instance using SSH.
1. Identify and disable any unauthorized public SSH keys. The only key in the file should be the key
you used to launch the AMI. The following command locates authorized_keys files:
$ sudo find / -name "authorized_keys" -print -exec cat {} \;

2. Disable password-based authentication for the root user. Open the ssh_config file and edit the
PermitRootLogin line as follows:
PermitRootLogin without-password

Alternatively, you can disable the ability to log into the instance as root:
PermitRootLogin No

Restart the sshd service.
3. Check whether there are any other user accounts that are able to log in to your instance. Accounts
with superuser privileges are particularly dangerous. Remove or lock the password of any unknown
accounts.
4. Check for open ports that you aren't using and running network services listening for incoming
connections.
5. To prevent preconfigured remote logging, you should delete the existing configuration file and restart
the rsyslog service. For example:
$ sudo rm /etc/
rsyslog.config
$ sudo service rsyslog restart

6. Verify that all cron jobs are legitimate.
If you discover a public AMI that you feel presents a security risk, contact the AWS security team. For
more information, see the AWS Security Center.

Making an AMI Public
Amazon EC2 enables you to share your AMIs with other AWS accounts. You can allow all AWS
accounts to launch the AMI (make the AMI public), or only allow a few specific accounts to launch the
78

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Making an AMI Public

AMI (see Sharing an AMI with Specific AWS Accounts (p. 80)). You are not billed when your AMI is
launched by other AWS accounts; only the accounts launching the AMI are billed.
AMIs are a regional resource. Therefore, sharing an AMI makes it available in that region. To make an
AMI available in a different region, copy the AMI to the region and then share it. For more inforamation,
see Copying an AMI (p. 135).
To avoid exposing sensitive data when you share an AMI, read the security considerations in
Guidelines for Shared Linux AMIs (p. 81) and follow the recommended actions.

Note
If an AMI has a product code, you can't make it public. You must share the AMI with only
specific AWS accounts.

Sharing an AMI with all AWS Accounts (Console)
After you make an AMI public, it is available in Community AMIs when you launch an instance
in the same region using the console. Note that it can take a short while for an AMI to appear in
Community AMIs after you make it public. It can also take a short while for an AMI to be removed
from Community AMIs after you make it private again.

To share a public AMI using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose AMIs.

Select your AMI from the list, and then choose Actions, Modify Image Permissions.

Choose Public and choose Save.

Sharing an AMI with all AWS Accounts (Command Line)
Each AMI has a launchPermission property that controls which AWS accounts, besides the
owner's, are allowed to use that AMI to launch instances. By modifying the launchPermission
property of an AMI, you can make the AMI public (which grants launch permissions to all AWS
accounts) or share it with only the AWS accounts that you specify.
You can add or remove account IDs from the list of accounts that have launch permissions for an
AMI. To make the AMI public, specify the all group. You can specify both public and explicit launch
permissions.
To make an AMI public
Use the modify-image-attribute command (AWS CLI) as follows to add the all group to the
launchPermission list for the specified AMI.
$ aws ec2 modify-image-attribute --image-id ami-12345678 --launch-permission
"{\"Add\":[{\"Group\":\"all\"}]}"

To verify the launch permissions of the AMI, use the following describe-image-attribute command.
$ aws ec2 describe-image-attribute --image-id ami-12345678 --attribute
launchPermission

(Optional) To make the AMI private again, remove the all group from its launch permissions. Note
that the owner of the AMI always has launch permissions and is therefore unaffected by this command.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Sharing an AMI with Specific AWS Accounts
$ aws ec2 modify-image-attribute --image-id ami-12345678 --launch-permission
"{\"Remove\":[{\"Group\":\"all\"}]}"

Alternatively, you can use the following AWS Tools for Windows PowerShell commands: EditEC2ImageAttribute and Get-EC2ImageAttribute.

Sharing an AMI with Specific AWS Accounts
You can share an AMI with specific AWS accounts without making the AMI public. All you need are the
AWS account IDs.
AMIs are a regional resource. Therefore, sharing an AMI makes it available in that region. To make an
AMI available in a different region, copy the AMI to the region and then share it. For more information,
see Copying an AMI (p. 135).

Sharing an AMI (Console)
To grant explicit launch permissions using the console
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose AMIs.

3.
4.

Select your AMI in the list, and then choose Actions, Modify Image Permissions.
Specify the AWS account number of the user with whom you want to share the AMI in the AWS
Account Number field, then choose Add Permission.

To share this AMI with multiple users, repeat the above step until you have added all the required
users.
To allow create volume permissions for snapshots, select Add "create volume" permissions to
the following associated snapshots when creating permissions.

Note

You do not need to share the Amazon EBS snapshots that an AMI references in order to
share the AMI. Only the AMI itself needs to be shared; the system automatically provides
the instance access to the referenced Amazon EBS snapshots for the launch.
Choose Save when you are done.

Sharing an AMI (Command Line)
Use the modify-image-attribute command (AWS CLI) to share an AMI as shown in the following
examples.
To grant explicit launch permissions
The following command grants launch permissions for the specified AMI to the specified AWS account.
$ aws ec2 modify-image-attribute --image-id ami-12345678 --launch-permission
"{\"Add\":[{\"UserId\":\"123456789012\"}]}"

To remove launch permissions for an account
The following command removes launch permissions for the specified AMI from the specified AWS
account:
$ aws ec2 modify-image-attribute --image-id ami-12345678 --launch-permission
"{\"Remove\":[{\"UserId\":\"123456789012\"}]}"

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Using Bookmarks

To remove all launch permissions
The following command removes all public and explicit launch permissions from the specified AMI.
Note that the owner of the AMI always has launch permissions and is therefore unaffected by this
command.
$ aws ec2 reset-image-attribute --image-id ami-12345678 --attribute
launchPermission

Alternatively, you can use the following AWS Tools for Windows PowerShell command: EditEC2ImageAttribute.

Using Bookmarks
If you have created a public AMI, or shared an AMI with another AWS user, you can create a bookmark
that allows a user to access your AMI and launch an instance in their own account immediately. This
is an easy way to share AMI references, so users don't have to spend time finding your AMI in order to
use it.
Note that your AMI must be public, or you must have shared it with the user to whom you want to send
the bookmark.

To create a bookmark for your AMI
1.

Type a URL with the following information, where is the region in which your AMI
resides, and is the ID of the AMI:
https://console.aws.amazon.com/ec2/v2/home?
region=#LaunchInstanceWizard:ami=

For example, this URL launches an instance from the ami-12345678 AMI in the us-east-1 region:
https://console.aws.amazon.com/ec2/v2/home?region=useast-1#LaunchInstanceWizard:ami=ami-12345678

2.
3.

Distribute the link to users who want to use your AMI.
To use a bookmark, choose the link or copy and paste it into your browser. The launch wizard
opens, with the AMI already selected.

Guidelines for Shared Linux AMIs
Use the following guidelines to reduce the attack surface and improve the reliability of the AMIs you
create.

Note
No list of security guidelines can be exhaustive. Build your shared AMIs carefully and take
time to consider where you might expose sensitive data.
Topics
• Update the AMI Tools at Boot Time (p. 82)
• Disable Password-Based Remote Logins for Root (p. 82)
• Disable Local Root Access (p. 83)
• Remove SSH Host Key Pairs (p. 83)
• Install Public Key Credentials (p. 83)

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Guidelines for Shared Linux AMIs

• Disabling sshd DNS Checks (Optional) (p. 84)
• Identify Yourself (p. 84)
• Protect Yourself (p. 85)
If you are building AMIs for AWS Marketplace, see Building AMIs for AWS Marketplace for guidelines,
policies and best practices.
For additional information about sharing AMIs safely, see the following articles:
• How To Share and Use Public AMIs in A Secure Manner
• Public AMI Publishing: Hardening and Clean-up Requirements

Update the AMI Tools at Boot Time
For AMIs backed by instance store, we recommend that your AMIs download and upgrade the Amazon
EC2 AMI creation tools during startup. This ensures that new AMIs based on your shared AMIs have
the latest AMI tools.
For Amazon Linux, add the following to /etc/rc.local:
# Update the Amazon EC2 AMI tools
echo " + Updating EC2 AMI tools"
yum update -y aws-amitools-ec2
echo " + Updated EC2 AMI tools"

Use this method to automatically update other software on your image.

Note
When deciding which software to automatically update, consider the amount of WAN traffic
that the update will generate (your users will be charged for it) and the risk of the update
breaking other software on the AMI.
For other distributions, make sure you have the latest AMI tools.

Disable Password-Based Remote Logins for Root
Using a fixed root password for a public AMI is a security risk that can quickly become known. Even
relying on users to change the password after the first login opens a small window of opportunity for
potential abuse.
To solve this problem, disable password-based remote logins for the root user.

To disable password-based remote logins for root
1.

Open the /etc/ssh/sshd_config file with a text editor and locate the following line:
#PermitRootLogin yes

Change the line to:
PermitRootLogin without-password

The location of this configuration file might differ for your distribution, or if you are not running
OpenSSH. If this is the case, consult the relevant documentation.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Guidelines for Shared Linux AMIs

Disable Local Root Access
When you work with shared AMIs, a best practice is to disable direct root logins. To do this, log into
your running instance and issue the following command:
[ec2-user ~]$ sudo passwd -l root

Note
This command does not impact the use of sudo.

Remove SSH Host Key Pairs
If you plan to share an AMI derived from a public AMI, remove the existing SSH host key pairs located
in /etc/ssh. This forces SSH to generate new unique SSH key pairs when someone launches an
instance using your AMI, improving security and reducing the likelihood of "man-in-the-middle" attacks.
Remove all of the following key files that are present on your system.
• ssh_host_dsa_key
• ssh_host_dsa_key.pub
• ssh_host_key
• ssh_host_key.pub
• ssh_host_rsa_key
• ssh_host_rsa_key.pub
• ssh_host_ecdsa_key
• ssh_host_ecdsa_key.pub
• ssh_host_ed25519_key
• ssh_host_ed25519_key.pub
You can securely remove all of these files with the following command.
[ec2-user ~]$ sudo shred -u /etc/ssh/*_key /etc/ssh/*_key.pub

Warning
Secure deletion utilities such as shred may not remove all copies of a file from your storage
media. Hidden copies of files may be created by journalling file systems (including Amazon
Linux default ext4), snapshots, backups, RAID, and temporary caching. For more information
see the shred documentation.

Important
If you forget to remove the existing SSH host key pairs from your public AMI, our routine
auditing process notifies you and all customers running instances of your AMI of the potential
security risk. After a short grace period, we mark the AMI private.

Install Public Key Credentials
After configuring the AMI to prevent logging in using a password, you must make sure users can log in
using another mechanism.
Amazon EC2 allows users to specify a public-private key pair name when launching an instance. When
a valid key pair name is provided to the RunInstances API call (or through the command line API
tools), the public key (the portion of the key pair that Amazon EC2 retains on the server after a call
to CreateKeyPair or ImportKeyPair) is made available to the instance through an HTTP query
against the instance metadata.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Guidelines for Shared Linux AMIs

To log in through SSH, your AMI must retrieve the key value at boot and append it to /root/.ssh/
authorized_keys (or the equivalent for any other user account on the AMI). Users can launch
instances of your AMI with a key pair and log in without requiring a root password.
Many distributions, including Amazon Linux and Ubuntu, use the cloud-init package to inject public
key credentials for a configured user. If your distribution does not support cloud-init, you can add
the following code to a system start-up script (such as /etc/rc.local) to pull in the public key you
specified at launch for the root user.
if [ ! -d /root/.ssh ] ; then
mkdir -p /root/.ssh
chmod 700 /root/.ssh
fi
# Fetch public key using HTTP
curl http://169.254.169.254/latest/meta-data/public-keys/0/openssh-key > /
tmp/my-key
if [ $? -eq 0 ] ; then
cat /tmp/my-key >> /root/.ssh/authorized_keys
chmod 700 /root/.ssh/authorized_keys
rm /tmp/my-key
fi

This can be applied to any user account; you do not need to restrict it to root.

Note
Rebundling an instance based on this AMI includes the key with which it was launched. To
prevent the key's inclusion, you must clear out (or delete) the authorized_keys file or
exclude this file from rebundling.

Disabling sshd DNS Checks (Optional)
Disabling sshd DNS checks slightly weakens your sshd security. However, if DNS resolution fails, SSH
logins still work. If you do not disable sshd checks, DNS resolution failures prevent all logins.

To disable sshd DNS checks
1. Open the /etc/ssh/sshd_config file with a text editor and locate the following line:
#UseDNS yes

2. Change the line to:
UseDNS no

Note
The location of this configuration file can differ for your distribution or if you are not running
OpenSSH. If this is the case, consult the relevant documentation.

Identify Yourself
Currently, there is no easy way to know who provided a shared AMI, because each AMI is represented
by an account ID.
We recommend that you post a description of your AMI, and the AMI ID, in the Amazon EC2 forum.
This provides a convenient central location for users who are interested in trying new shared AMIs.
You can also post the AMI to the Amazon Machine Images (AMIs) page.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Paid AMIs

Protect Yourself
The previous sections described how to make your shared AMIs safe, secure, and usable for the users
who launch them. This section describes guidelines to protect yourself from the users of your AMI.
We recommend against storing sensitive data or software on any AMI that you share. Users who
launch a shared AMI might be able to rebundle it and register it as their own. Follow these guidelines to
help you to avoid some easily overlooked security risks:
• We recommend using the --exclude directory option on ec2-bundle-vol to skip any
directories and subdirectories that contain secret information that you would not like to include
in your bundle. In particular, exclude all user-owned SSH public/private key pairs and SSH
authorized_keys files when bundling the image. The Amazon public AMIs store these in /
root/.ssh for the root account, and /home/user_name/.ssh/ for regular user accounts. For
more information, see ec2-bundle-vol (p. 99).
• Always delete the shell history before bundling. If you attempt more than one bundle upload in the
same AMI, the shell history contains your secret access key. The following example should be the
last command executed before bundling from within the instance.
[ec2-user ~]$ shred -u ~/.*history

Warning
The limitations of shred described in the warning above apply here as well.
Be aware that bash writes the history of the current session to the disk on exit. If you log out
of your instance after deleting ~/.bash_history, and then log back in, you will find that
~/.bash_history has been re-created and contains all of the commands executed during
your previous session.
Other programs besides bash also write histories to disk, Use caution and remove or
exclude unnecessary dot-files and dot-directories.
• Bundling a running instance requires your private key and X.509 certificate. Put these and other
credentials in a location that is not bundled (such as the instance store).

Paid AMIs
A paid AMI is an AMI that you can purchase from a developer.
Amazon EC2 integrates with AWS Marketplace, enabling developers to charge other Amazon EC2
users for the use of their AMIs or to provide support for instances.
The AWS Marketplace is an online store where you can buy software that runs on AWS; including
AMIs that you can use to launch your EC2 instance. The AWS Marketplace AMIs are organized into
categories, such as Developer Tools, to enable you to find products to suit your requirements. For
more information about AWS Marketplace, see the AWS Marketplace site.
Launching an instance from a paid AMI is the same as launching an instance from any other AMI. No
additional parameters are required. The instance is charged according to the rates set by the owner of
the AMI, as well as the standard usage fees for the related web services; for example, the hourly rate
for running a m1.small instance type in Amazon EC2. The owner of the paid AMI can confirm whether
a specific instance was launched using that paid AMI.

Important
Amazon DevPay is no longer accepting new sellers or products. AWS Marketplace is now
the single, unified e-commerce platform for selling software and services through AWS. For
information about how to deploy and sell software from AWS Marketplace, see Selling on
AWS Marketplace. AWS Marketplace supports AMIs backed by Amazon EBS.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Selling Your AMI

Topics
• Selling Your AMI (p. 86)
• Finding a Paid AMI (p. 86)
• Purchase a Paid AMI (p. 87)
• Getting the Product Code for Your Instance (p. 87)
• Using Paid Support (p. 88)
• Bills for Paid and Supported AMIs (p. 88)
• Managing Your AWS Marketplace Subscriptions (p. 88)

Selling Your AMI
You can sell your AMI using AWS Marketplace. AWS Marketplace offers an organized shopping
experience. Additionally, AWS Marketplace also supports AWS features such as Amazon EBS-backed
AMIs, Reserved Instances, and Spot instances.
For information about how to sell your AMI on AWS Marketplace, see Selling on AWS Marketplace.

Finding a Paid AMI
There are several ways that you can find AMIs that are available for you to purchase. For example, you
can use AWS Marketplace, the Amazon EC2 console, or the command line. Alternatively, a developer
might let you know about a paid AMI themselves.

Finding a Paid AMI Using the Console
To find a paid AMI using the console
1.
2.
3.

Open the Amazon EC2 console.
In the navigation pane, click AMIs.
Select Public images from the first Filter list. Click the Search bar and select Product Code, then
Marketplace. Click the Search bar again, select Platform and then choose the operating system
from the list.

Finding a Paid AMI Using AWS Marketplace
To find a paid AMI using AWS Marketplace
1.

Open AWS Marketplace.

2.
3.

Enter the name of the operating system in the search box, and click Go.
To scope the results further, use one of the categories or filters.

Each product is labeled with its product type: either AMI or Software as a Service.

Finding a Paid AMI Using the Command Line
You can find a paid AMI using the describe-images command (AWS CLI) as follows.
$

aws ec2 describe-images --owners aws-marketplace

This command returns numerous details that describe each AMI, including the product code for a paid
AMI. The output from describe-images includes an entry for the product code like the following:

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Purchase a Paid AMI
"ProductCodes": [
{
"ProductCodeId": "product_code",
"ProductCodeType": "marketplace"
}
],

Alternatively, you can use the following AWS Tools for Windows PowerShell command: GetEC2Image.

Purchase a Paid AMI
You must sign up for (purchase) a paid AMI before you can launch an instance using the AMI.
Typically a seller of a paid AMI presents you with information about the AMI, including its price and a
link where you can buy it. When you click the link, you're first asked to log into AWS, and then you can
purchase the AMI.

Purchasing a Paid AMI Using the Console
You can purchase a paid AMI by using the Amazon EC2 launch wizard. For more information, see
Launching an AWS Marketplace Instance (p. 287).

Subscribing to a Product Using AWS Marketplace
To use the AWS Marketplace, you must have an AWS account. To launch instances from AWS
Marketplace products, you must be signed up to use the Amazon EC2 service, and you must be
subscribed to the product from which to launch the instance. There are two ways to subscribe to
products in the AWS Marketplace:
• AWS Marketplace website: You can launch preconfigured software quickly with the 1-Click
deployment feature.
• Amazon EC2 launch wizard: You can search for an AMI and launch an instance directly from the
wizard. For more information, see Launching an AWS Marketplace Instance (p. 287).

Purchasing a Paid AMI From a Developer
The developer of a paid AMI can enable you to purchase a paid AMI that isn't listed in AWS
Marketplace. The developer provides you with a link that enables you to purchase the product through
Amazon. You can sign in with your Amazon.com credentials and select a credit card that's stored in
your Amazon.com account to use when purchasing the AMI.

Getting the Product Code for Your Instance
You can retrieve the AWS Marketplace product code for your instance using its instance metadata. For
more information about retrieving metadata, see Instance Metadata and User Data (p. 337).
To retrieve a product code, use the following query:
$ GET http://169.254.169.254/latest/meta-data/product-codes

If the instance has a product code, Amazon EC2 returns it. For example:
774F4FF8

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Using Paid Support

Using Paid Support
Amazon EC2 also enables developers to offer support for software (or derived AMIs). Developers
can create support products that you can sign up to use. During sign-up for the support product, the
developer gives you a product code, which you must then associate with your own AMI. This enables
the developer to confirm that your instance is eligible for support. It also ensures that when you run
instances of the product, you are charged according to the terms for the product specified by the
developer.

Important
You can't use a support product with Reserved Instances. You always pay the price that's
specified by the seller of the support product.
To associate a product code with your AMI, use one of the following commands, where ami_id is the ID
of the AMI and product_code is the product code:
• modify-image-attribute (AWS CLI)
$ aws ec2 modify-image-attribute --image-id ami_id --product-codes
"product_code"

• Edit-EC2ImageAttribute (AWS Tools for Windows PowerShell)
C:\> Edit-EC2ImageAttribute -ImageId ami_id -ProductCode product_code

After you set the product code attribute, it cannot be changed or removed.

Bills for Paid and Supported AMIs
At the end of each month, you receive an email with the amount your credit card has been charged
for using any paid or supported AMIs during the month. This bill is separate from your regular Amazon
EC2 bill. For more information, see Paying For AWS Marketplace Products.

Managing Your AWS Marketplace Subscriptions
On the AWS Marketplace website, you can check your subscription details, view the vendor's usage
instructions, manage your subscriptions, and more.

To check your subscription details
1.
2.
3.
4.

Log in to the AWS Marketplace.
Click Your Account.
Click Manage Your Software Subscriptions.
All your current subscriptions are listed. Click Usage Instructions to view specific instructions for
using the product, for example, a user name for connecting to your running instance.

To cancel an AWS Marketplace subscription
1.

Ensure that you have terminated any instances running from the subscription.
a.
b.
c.

Open the Amazon EC2 console.
In the navigation pane, click Instances.
Select the instance, click Actions, select Instance State, and select Terminate. When
prompted, click Yes, Terminate.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Creating an Amazon EBS-Backed Linux AMI

2.
3.

Log in to the AWS Marketplace, and click Your Account, then Manage Your Software
Subscriptions.
Click Cancel subscription. You are prompted to confirm your cancellation.

Note
After you've canceled your subscription, you are no longer able to launch any instances
from that AMI. To use that AMI again, you need to resubscribe to it, either on the AWS
Marketplace website, or through the launch wizard in the Amazon EC2 console.

Creating an Amazon EBS-Backed Linux AMI
To create an Amazon EBS-backed Linux AMI, start from an instance that you've launched from an
existing Amazon EBS-backed Linux AMI. After you've customized the instance to suit your needs,
create and register a new AMI, which you can use to launch new instances with these customizations.
For more information about creating an Amazon EBS-backed Windows AMI, see Creating an Amazon
EBS-Backed Windows AMI in the Amazon EC2 User Guide for Windows Instances.
The procedures described below work for Amazon EC2 instances backed by encrypted Amazon EBS
volumes (including the root volume) as well as for unencrypted volumes.
The AMI creation process is different for instance store-backed AMIs. For more information about the
differences between Amazon EBS-backed and instance store-backed instances, and how to determine
the root device type for your instance, see Storage for the Root Device (p. 71). For more information
about creating an instance store-backed Linux AMI, see Creating an Instance Store-Backed Linux
AMI (p. 92).

Overview of Creating Amazon EBS-Backed AMIs
First, launch an instance from an AMI that's similar to the AMI that you'd like to create. You can
connect to your instance and customize it. When the instance is configured correctly, ensure data
integrity by stopping the instance before you create an AMI, then create the image. When you create
an Amazon EBS-backed AMI, we automatically register it for you.
Amazon EC2 powers down the instance before creating the AMI to ensure that everything on the
instance is stopped and in a consistent state during the creation process. If you're confident that your
instance is in a consistent state appropriate for AMI creation, you can tell Amazon EC2 not to power
down and reboot the instance. Some file systems, such as XFS, can freeze and unfreeze activity,
making it safe to create the image without rebooting the instance.
During the AMI-creation process, Amazon EC2 creates snapshots of your instance's root volume
and any other EBS volumes attached to your instance. If any volumes attached to the instance are
encrypted, the new AMI only launches successfully on instances that support Amazon EBS encryption.
For more information, see Amazon EBS Encryption (p. 695).
Depending on the size of the volumes, it can take several minutes for the AMI-creation process to
complete (sometimes up to 24 hours).You may find it more efficient to create snapshots of your
volumes prior to creating your AMI. This way, only small, incremental snapshots need to be created
when the AMI is created, and the process completes more quickly (the total time for snapshot creation
remains the same). For more information, see Creating an Amazon EBS Snapshot (p. 686).
After the process completes, you have a new AMI and snapshot created from the root volume of the
instance. When you launch an instance using the new AMI, we create a new EBS volume for its root
volume using the snapshot. Both the AMI and the snapshot incur charges to your account until you
delete them. For more information, see Deregistering Your AMI (p. 140).
If you add instance-store volumes or EBS volumes to your instance in addition to the root device
volume, the block device mapping for the new AMI contains information for these volumes, and

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Creating a Linux AMI from an Instance

the block device mappings for instances that you launch from the new AMI automatically contain
information for these volumes. The instance-store volumes specified in the block device mapping for
the new instance are new and don't contain any data from the instance store volumes of the instance
you used to create the AMI. The data on EBS volumes persists. For more information, see Block
Device Mapping (p. 731).

Creating a Linux AMI from an Instance
You can create an AMI using the AWS Management Console or the command line. The following
diagram summarizes the process for creating an Amazon EBS-backed AMI from a running EC2
instance. Start with an existing AMI, launch an instance, customize it, create a new AMI from it, and
finally launch an instance of your new AMI. The steps in the following diagram match the steps in the
procedure below.

To create an AMI from an instance using the console
1.

Select an appropriate EBS-backed AMI to serve as a starting point for your new AMI, and
configure it as needed prior to launch. For more information, see Launching an Instance (p. 279).

Choose Launch to launch an instance of the EBS-backed AMI that you've selected. Accept
the default values as you step through the wizard. For more information, see Launching an
Instance (p. 279).

While the instance is running, connect to it.
You can perform any of the following actions on your instance to customize it for your needs:
• Install software and applications
• Copy data
• Reduce start time by deleting temporary files, defragmenting your hard drive, and zeroing out
free space
• Attach additional Amazon EBS volumes
(Optional) Create snapshots of all the volumes attached to your instance. For more information
about creating snapshots, see Creating an Amazon EBS Snapshot (p. 686).
In the navigation pane, choose Instances and select your instance. Choose Actions, Image, and
Create Image.

Tip
If this option is disabled, your instance isn't an Amazon EBS-backed instance.
4.

In the Create Image dialog box, specify values for the following fields, and then choose Create
Image.
Name
A unique name for the image.
Description
(Optional) A description of the image, up to 255 characters.
90

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User Guide for Linux Instances
Creating a Linux AMI from a Snapshot

By default, Amazon EC2 shuts down the instance, takes snapshots of any attached volumes,
creates and registers the AMI, and then reboots the instance. Choose No reboot if you don't want
your instance to be shut down.

Warning
If you choose No reboot, we can't guarantee the file system integrity of the created
image.
You can modify the root volume, Amazon EBS volumes, and instance store volumes as follows:
• To change the size of the root volume, locate the Root volume in the Type column, and fill in
the Size field.
• To suppress an Amazon EBS volume specified by the block device mapping of the AMI used to
launch the instance, locate the EBS volume in the list and choose Delete.
• To add an Amazon EBS volume, choose Add New Volume, Type, and EBS, and fill in the
fields. When you then launch an instance from your new AMI, these additional volumes are
automatically attached to the instance. Empty volumes must be formatted and mounted.
Volumes based on a snapshot must be mounted.
• To suppress an instance store volume specified by the block device mapping of the AMI used to
launch the instance, locate the volume in the list and choose Delete.
• To add an instance store volume, choose Add New Volume, Type, and Instance Store, and
select a device name from the Device list. When you launch an instance from your new AMI,
these additional volumes are automatically initialized and mounted. These volumes don't contain
data from the instance store volumes of the running instance from which you based your AMI.
5.

While your AMI is being created, you can choose AMIs in the navigation pane to view its status.
Initially this will be pending. After a few minutes the status should change to available.
(Optional) Choose Snapshots in the navigation pane to view the snapshot that was created for
the new AMI. When you launch an instance from this AMI, we use this snapshot to create its root
device volume.

Launch an instance from your new AMI. For more information, see Launching an
Instance (p. 279).

The new running instance contains all of the customizations you applied in previous steps.

To create an AMI from an instance using the command
line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• create-image (AWS CLI)
• New-EC2Image (AWS Tools for Windows PowerShell)

Creating a Linux AMI from a Snapshot
If you have a snapshot of the root device volume of an instance, you can create an AMI from this
snapshot using the AWS Management Console or the command line.

Important
Some Linux distributions, such as Red Hat Enterprise Linux (RHEL) and SUSE Linux
Enterprise Server (SLES), use the Amazon EC2 billingProduct code associated with an
AMI to verify subscription status for package updates. Creating an AMI from an EBS snapshot

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User Guide for Linux Instances
Creating an Instance Store-Backed Linux AMI

does not maintain this billing code, and subsequent instances launched from such an AMI will
not be able to connect to package update infrastructure.
Similarly, although you can create a Windows AMI from a snapshot, you can't successfully
launch an instance from the AMI.
In general, AWS advises against manually creating AMIs from snapshots.
For more information about creating Windows AMIs or AMIs for Linux operating systems
that must retain AMI billing codes to work properly, see Creating a Linux AMI from an
Instance (p. 90).

To create an AMI from a snapshot using the console
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, under Elastic Block Store, choose Snapshots.

Choose the snapshot and choose Actions, Create Image.

In the Create Image from EBS Snapshot dialog box, complete the fields to create your AMI,
then choose Create. If you're re-creating a parent instance, then choose the same options as the
parent instance.
• Architecture: Choose i386 for 32-bit or x86_64 for 64-bit.
• Root device name: Enter the appropriate name for the root volume. For more information, see
Device Naming on Linux Instances (p. 729).
• Virtualization type: Choose whether instances launched from this AMI use paravirtual
(PV) or hardware virtual machine (HVM) virtualization. For more information, see Linux AMI
Virtualization Types (p. 74).
• (PV virtualization type only) Kernel ID and RAM disk ID: Choose the AKI and ARI from the lists.
If you choose the default AKI or don't choose an AKI, you'll be required to specify an AKI every
time you launch an instance using this AMI. In addition, your instance may fail the health checks
if the default AKI is incompatible with the instance.
• (Optional) Block Device Mappings: Add volumes or expand the default size of the root volume
for the AMI. For more information about resizing the file system on your instance for a larger
volume, see Extending a Linux File System (p. 673).

To create an AMI from a snapshot using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• register-image (AWS CLI)
• Register-EC2Image (AWS Tools for Windows PowerShell)

Creating an Instance Store-Backed Linux AMI
To create an instance store-backed Linux AMI, start from an instance that you've launched from an
existing instance store-backed Linux AMI. After you've customized the instance to suit your needs,
bundle the volume and register a new AMI, which you can use to launch new instances with these
customizations.
If you need to create an instance store-backed Windows AMI, see Creating an Instance Store-Backed
Windows AMI in the Amazon EC2 User Guide for Windows Instances.
The AMI creation process is different for instance store-backed AMIs. For more information about the
differences between Amazon EBS-backed and instance store-backed instances, and how to determine
the root device type for your instance, see Storage for the Root Device (p. 71). If you need to create
an Amazon EBS-backed Linux AMI, see Creating an Amazon EBS-Backed Linux AMI (p. 89).

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Overview of the Creation Process
for Instance Store-Backed AMIs

Overview of the Creation Process for Instance
Store-Backed AMIs
The following diagram summarizes the process of creating an AMI from an instance store-backed
instance.

First, launch an instance from an AMI that's similar to the AMI that you'd like to create. You can
connect to your instance and customize it. When the instance is set up the way you want it, you
can bundle it. It takes several minutes for the bundling process to complete. After the process
completes, you have a bundle, which consists of an image manifest (image.manifest.xml) and
files (image.part.xx) that contain a template for the root volume. Next you upload the bundle to your
Amazon S3 bucket and then register your AMI.
When you launch an instance using the new AMI, we create the root volume for the instance using
the bundle that you uploaded to Amazon S3. The storage space used by the bundle in Amazon
S3 incurs charges to your account until you delete it. For more information, see Deregistering Your
AMI (p. 140).
If you add instance store volumes to your instance in addition to the root device volume, the block
device mapping for the new AMI contains information for these volumes, and the block device
mappings for instances that you launch from the new AMI automatically contain information for these
volumes. For more information, see Block Device Mapping (p. 731).

Prerequisites
Before you can create an AMI, you must complete the following tasks:
• Install the AMI tools. For more information, see Setting Up the AMI Tools (p. 94).
• Install the AWS CLI. For more information, see Getting Set Up with the AWS Command Line
Interface.
• Ensure that you have an Amazon S3 bucket for the bundle. To create an Amazon S3 bucket, open
the Amazon S3 console and click Create Bucket.

Note
You can also use the AWS CLI mb command to create a bucket.
• Ensure that you have the following credentials:
• Your AWS account ID. To find your AWS account ID number in the AWS Management Console,
click on Support in the navigation bar in the upper-right, and then click Support Center. Your
currently signed in account ID appears below the Support menu.
• An X.509 certificate and corresponding private key. If you need to create an X.509 certificate, see
Managing Signing Certificates (p. 115). The X.509 certificate and private key are used to encrypt
and decrypt your AMI.
• Your AWS account access key ID and secret access key. For more information, see Creating,
Modifying, and Viewing Access Keys in the IAM User Guide.

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User Guide for Linux Instances
Setting Up the AMI Tools

• Connect to your instance and customize it. For example, you can install software and applications,
copy data, delete temporary files, and modify the Linux configuration.
Topics
• Setting Up the AMI Tools (p. 94)
• Creating an AMI from an Instance Store-Backed Amazon Linux Instance (p. 120)
• Creating an AMI from an Instance Store-Backed Ubuntu Instance (p. 124)
• Converting your Instance Store-Backed AMI to an Amazon EBS-Backed AMI (p. 129)

Setting Up the AMI Tools
You can use the AMI tools to create and manage instance store-backed Linux AMIs. To use the tools,
you must install them on your Linux instance. The AMI tools are available as both an RPM and as
a .zip file for Linux distributions that don't support RPM. For more information, see Amazon EC2 AMI
Tools.

Note
The AMI tools are supported on instance store-backed Linux instances only. To create an
Amazon EBS-backed AMI, use the create-image AWS CLI command instead. To create an
instance store-backed Windows AMI, see Creating an Instance Store-Backed Windows AMI.

To set up the AMI tools using the RPM
1.

Install Ruby using the package manager for your Linux distribution, such as yum. For example:
$ sudo yum install -y ruby

Download the RPM file using a tool such as wget or curl. For example:
$ sudo wget http://s3.amazonaws.com/ec2-downloads/ec2-ami-tools.noarch.rpm

Install the RPM using the following command.
$ sudo yum install ec2-ami-tools.noarch.rpm

Verify your AMI tools installation with the following command.
$ ec2-ami-tools-version

Note
If you receive a load error such as cannot load such file -- ec2/amitools/
version (LoadError), complete the next step to add the location of your AMI tools
installation to your RUBYLIB path.
5.

(Optional) If you received an error in the previous step, add the location of your AMI tools
installation to your RUBYLIB path.
a.

Run the following command to determine the paths to add.
$ rpm -qil ec2-ami-tools | grep ec2/amitools/version
/usr/lib/ruby/site_ruby/ec2/amitools/version.rb
/usr/lib64/ruby/site_ruby/ec2/amitools/version.rb

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Setting Up the AMI Tools

In the above example, the missing file from the previous load error is located at /usr/lib/
ruby/site_ruby and /usr/lib64/ruby/site_ruby.
b.

Add the locations from the previous step to your RUBYLIB path.
$ export RUBYLIB=$RUBYLIB:/usr/lib/ruby/site_ruby:/usr/lib64/ruby/
site_ruby

Verify your AMI tools installation with the following command.
$ ec2-ami-tools-version

To set up the AMI tools using the .zip file
1.

Install Ruby and unzip using the package manager for your Linux distribution, such as apt-get. For
example:
$ sudo apt-get update -y && sudo apt-get install -y ruby unzip

Download the .zip file using a tool such as wget or curl. For example:
$ wget http://s3.amazonaws.com/ec2-downloads/ec2-ami-tools.zip

Unzip the files into a suitable installation directory, such as /usr/local/ec2.
$ sudo mkdir -p /usr/local/ec2
$ sudo unzip ec2-ami-tools.zip -d /usr/local/ec2

Notice that the .zip file contains a folder ec2-ami-tools-x.x.x, where x.x.x is the version number of
the tools (for example, ec2-ami-tools-1.5.7).
4.

Set the EC2_AMITOOL_HOME environment variable to the installation directory for the tools. For
example:
$ export EC2_AMITOOL_HOME=/usr/local/ec2/ec2-ami-tools-x.x.x

Add the tools to your PATH environment variable. For example:
$ export PATH=$EC2_AMITOOL_HOME/bin:$PATH

You can verify your AMI tools installation with the following command.
$ ec2-ami-tools-version

AMI Tool Commands
You can use the following commands with the AMI tools to create and manage instance store-backed
Linux AMIs. To set up the tools, see Setting Up the AMI Tools (p. 94).
Topics
• ec2-ami-tools-version (p. 96)
• ec2-bundle-image (p. 96)

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Setting Up the AMI Tools

• ec2-bundle-vol (p. 99)
• ec2-delete-bundle (p. 104)
• ec2-download-bundle (p. 106)
• ec2-migrate-manifest (p. 108)
• ec2-unbundle (p. 110)
• ec2-upload-bundle (p. 111)
• Common Options for AMI Tools (p. 115)

ec2-ami-tools-version
Description
Describes the version of the AMI tools.

Syntax
ec2-ami-tools-version

Options
This command has no parameters.

Output
The version information.

Example
This example command displays the version information for the AMI tools that you're using.
$ ec2-ami-tools-version
1.5.2 20071010

ec2-bundle-image
Description
Creates an instance store-backed Linux AMI from an operating system image created in a loopback
file.

Syntax
ec2-bundle-image -c path -k path -u account -i path [-d path] [--ec2cert
path] [-r architecture] [--productcodes code1,code2,...] [-B mapping] [-p
prefix]

Options
Option

Description

-c, --cert path

The user's PEM encoded RSA public key certificate file.
Required: Yes
Example: -c certHKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem

-k, --privatekey path

The path to a PEM-encoded RSA key file. You'll need to
specify this key to unbundle this bundle, so keep it in a safe

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User Guide for Linux Instances
Setting Up the AMI Tools

Option

Description
place. Note that the key doesn't have to be registered to
your AWS account.
Required: Yes
Example: -k pkHKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem

-u, --user account

The user's AWS account ID without dashes.
Required: Yes
Example: -u 111122223333

-i, --image path

The path to the image to bundle.
Required: Yes
Example: -i /var/spool/my-image/version-2/
debian.img

-d, --destination path

The directory in which to create the bundle.
Default: /tmp
Required: No
Example: -d /media/ephemeral0

--ec2cert path

The path to the Amazon EC2 X.509 public key certificate
used to encrypt the image manifest.
The us-gov-west-1 and cn-north-1 regions use a
non-default public key certificate and the path to that
certificate must be specified with this option. The path to
the certificate varies based on the installation method of the
AMI tools. For Amazon Linux, the certificates are located at
/opt/aws/amitools/ec2/etc/ec2/amitools/. If you
installed the AMI tools from the RPM or ZIP file in Setting
Up the AMI Tools (p. 94), the certificates are located at
$EC2_AMITOOL_HOME/etc/ec2/amitools/.
Default: varies, depending on the tools
Required: Only for the us-gov-west-1 and cn-north-1
regions.
Example: --ec2cert $EC2_AMITOOL_HOME/etc/ec2/
amitools/cert-ec2.pem

-r, --arch architecture

Image architecture. If you don't provide the architecture on
the command line, you'll be prompted for it when bundling
starts.
Valid values: i386 | x86_64
Required: No
Example: -r x86_64

--productcodes code1,code2,... Product codes to attach to the image at registration time,
separated by commas.
Required: No
Example: --productcodes 1234abcd

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User Guide for Linux Instances
Setting Up the AMI Tools

Option

Description

-B, --block-device-mapping
mapping

Defines how block devices are exposed to an instance of
this AMI if its instance type supports the specified device.
Specify a comma-separated list of key-value pairs,
where each key is a virtual name and each value is the
corresponding device name. Virtual names include the
following:
• ami—The root file system device, as seen by the
instance
• root—The root file system device, as seen by the kernel
• swap—The swap device, as seen by the instance
• ephemeralN—The Nth instance store volume
Required: No
Example: --block-devicemapping ami=sda1,root=/dev/
sda1,ephemeral0=sda2,swap=sda3
Example: --block-device-mapping ami=0,root=/
dev/dsk/c0d0s0,ephemeral0=1

-p, --prefix prefix

The filename prefix for bundled AMI files.
Default: The name of the image file. For example, if the
image path is /var/spool/my-image/version-2/
debian.img, then the default prefix is debian.img.
Required: No
Example: -p my-image-is-special

--kernel kernel_id

Deprecated. Use register-image to set the kernel.
Required: No
Example: --kernel aki-ba3adfd3

--ramdisk ramdisk_id

Deprecated. Use register-image to set the RAM disk if
required.
Required: No
Example: --ramdisk ari-badbad00

Common options

For options common to most of the AMI Tools, see
Common Options for AMI Tools (p. 115).

Output
Status messages describing the stages and status of the bundling process.

Example
This example creates a bundled AMI from an operating system image that was created in a loopback
file.
$ ec2-bundle-image -k pk-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem -c certHKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem -u 111122223333 -i image.img -d bundled/
-r x86_64
Please specify a value for arch [i386]:

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Setting Up the AMI Tools
Bundling image file...
Splitting bundled/image.gz.crypt...
Created image.part.00
Created image.part.01
Created image.part.02
Created image.part.03
Created image.part.04
Created image.part.05
Created image.part.06
Created image.part.07
Created image.part.08
Created image.part.09
Created image.part.10
Created image.part.11
Created image.part.12
Created image.part.13
Created image.part.14
Generating digests for each part...
Digests generated.
Creating bundle manifest...
ec2-bundle-image complete.

ec2-bundle-vol
Description
Creates an instance store-backed Linux AMI by compressing, encrypting, and signing a copy of the
root device volume for the instance.
Amazon EC2 attempts to inherit product codes, kernel settings, RAM disk settings, and block device
mappings from the instance.
By default, the bundle process excludes files that might contain sensitive information. These files
include *.sw, *.swo, *.swp, *.pem, *.priv, *id_rsa*, *id_dsa* *.gpg, *.jks, */.ssh/
authorized_keys, and */.bash_history. To include all of these files, use the --no-filter
option. To include some of these files, use the --include option.
For more information, see Creating an Instance Store-Backed Linux AMI.

Syntax
ec2-bundle-vol -c path -k path -u account [-d path] [--ec2cert path] [r architecture] [--productcodes code1,code2,...] [-B mapping] [--all] [-e
directory1,directory2,...] [-i file1,file2,...] [--no-filter] [-p prefix] [s size] [--[no-]inherit] [-v volume] [-P type] [-S script] [--fstab path] [-generate-fstab] [--grub-config path]

Options
Option

Description

-c, --cert path

The user's PEM encoded RSA public key certificate file.
Required: Yes
Example: -c certHKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem

-k, --privatekey path

The path to the user's PEM-encoded RSA key file.
Required: Yes

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Setting Up the AMI Tools

Option

Description
Example: -k pkHKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem

-u, --user account

The user's AWS account ID without dashes.
Required: Yes
Example: -u 111122223333

-d, --destination destination

The directory in which to create the bundle.
Default: /tmp
Required: No
Example: -d /var/run/my-bundle

--ec2cert path

-r, --arch architecture

The image architecture. If you don't provide this on the
command line, you'll be prompted to provide it when the
bundling starts.
Valid values: i386 | x86_64
Required: No
Example: -r x86_64

--productcodes code1,code2,... Product codes to attach to the image at registration time,
separated by commas.
Required: No
Example: --productcodes 1234abcd

100

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Setting Up the AMI Tools

Option

Description

-B, --block-device-mapping
mapping

-a, --all

Bundle all directories, including those on remotely mounted
file systems.
Required: No
Example: -a

-e, --exclude
directory1,directory2,...

A list of absolute directory paths and files to exclude from
the bundle operation. This parameter overrides the -all option. When exclude is specified, the directories and
subdirectories listed with the parameter will not be bundled
with the volume.
Required: No
Example: Assuming the mount point of the volume is -v /
foo, and you want to exclude directories /foo/bar and /foo/
baz, specify -e /bar,/baz.

-i, --include file1,file2,... A list of files to include in the bundle operation. The
specified files would otherwise be excluded from the AMI
because they might contain sensitive information.
Required: No
Example: If the volume mount point is /mnt/myvol/ and
you want to include the file /mnt/myvol/foo/bar.pem,
specify -i /foo/bar.pem.
--no-filter

If specified, we won't exclude files from the AMI because
they might contain sensitive information.
Required: No
Example: --no-filter

-p, --prefix prefix

The file name prefix for bundled AMI files.
Default: image
Required: No
Example: -p my-image-is-special

101

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Setting Up the AMI Tools

Option

Description

-s, --size size

The size, in MB (1024 * 1024 bytes), of the image file to
create. The maximum size is 10240 MB.
Default: 10240
Required: No
Example: -s 2048

--[no-]inherit

Indicates whether the image should inherit the instance's
metadata (the default is to inherit). Bundling fails if you
enable --inherit but the instance metadata is not
accessible.
Required: No
Example: --inherit

-v, --volume volume

The absolute path to the mounted volume from which to
create the bundle.
Default: The root directory (/)
Required: No
Example: -v /mnt/my-customized-ami

-P, --partition type

Indicates whether the disk image should use a partition
table. If you don't specify a partition table type, the default
is the type used on the parent block device of the volume, if
applicable, otherwise the default is gpt.
Valid values: mbr | gpt | none
Required: No
Example: --partition gpt

-S, --script script

A customization script to be run right before bundling. The
script must expect a single argument, the mount point of
the volume.
Required: No

--fstab path

The path to the fstab to bundle into the image. If this is not
specified, Amazon EC2 bundles /etc/fstab.
Required: No
Example: --fstab /etc/fstab

--generate-fstab

Bundles the volume using an Amazon EC2-provided fstab.
Required: No
Example: --generate-fstab

--grub-config

The path to an alternate grub configuration file to
bundle into the image. By default, ec2-bundle-vol
expects either /boot/grub/menu.lst or /boot/
grub/grub.conf to exist on the cloned image. This
option allows you to specify a path to an alternative grub
configuration file, which will then be copied over the
defaults (if present).
Required: No
Example: --grub-config /path/to/grub.conf

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Option

Description

--kernel kernel_id

Deprecated. Use register-image to set the kernel.
Required: No
Example: --kernel aki-ba3adfd3

--ramdisk ramdisk_id

Deprecated. Use register-image to set the RAM disk if
required.
Required: No
Example: --ramdisk ari-badbad00

Common options

For options common to most of the AMI tools, see Common
Options for AMI Tools (p. 115).

Output
Status messages describing the stages and status of the bundling.

Example
This example creates a bundled AMI by compressing, encrypting and signing a snapshot of the local
machine's root file system.
$ ec2-bundle-vol -d /mnt -k pk-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem -c certHKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem -u 111122223333 -r x86_64
Copying / into the image file /mnt/image...
Excluding:
sys
dev/shm
proc
dev/pts
proc/sys/fs/binfmt_misc
dev
media
mnt
proc
sys
tmp/image
mnt/img-mnt
1+0 records in
1+0 records out
mke2fs 1.38 (30-Jun-2005)
warning: 256 blocks unused.
Splitting /mnt/image.gz.crypt...
Created image.part.00
Created image.part.01
Created image.part.02
Created image.part.03
...
Created image.part.22
Created image.part.23
Generating digests for each part...
Digests generated.
Creating bundle manifest...
Bundle Volume complete.

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ec2-delete-bundle
Description
Deletes the specified bundle from Amazon S3 storage. After you delete a bundle, you can't launch
instances from the corresponding AMI.

Syntax
ec2-delete-bundle -b bucket -a access_key_id -s secret_access_key [-t token]
[--url url] [--region region] [--sigv version] [-m path] [-p prefix] [-clear] [--retry] [-y]

Options
Option

Description

-b, --bucket bucket

The name of the Amazon S3 bucket containing the bundled
AMI, followed by an optional '/'-delimited path prefix
Required: Yes
Example: -b myawsbucket/ami-001

-a, --access-key access_key_id The AWS access key ID. Before you specify a value for this
option, review and follow the guidance in Best Practices for
Managing AWS Access Keys.
Required: Yes
Example: -a AKIAIOSFODNN7EXAMPLE
-s, --secret-key
secret_access_key

The AWS secret access key. Before you specify a value
for this option, review and follow the guidance in Best
Practices for Managing AWS Access Keys.
Required: Yes
Example: -s wJalrXUtnFEMI/K7MDENG/
bPxRfiCYEXAMPLEKEY

-t, --delegation-token token

The delegation token to pass along to the AWS request.
For more information, see Using Temporary Security
Credentials.
Required: Only when you are using temporary security
credentials.
Default: The value of the AWS_DELEGATION_TOKEN
environment variable (if set).
Example: -t AQoDYXdzEJr...

--region region

The region to use in the request signature.
Default: us-east-1
Required: Conditional
Condition: Required if using signature version 4
Example: --region eu-west-1

--sigv version

The signature version to use when signing the request.
Valid values: 2 | 4
Default: 4
Required: No
Example: --sigv 2

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Option

Description

-m, --manifest path

The path to the manifest file.
Required: Conditional
Condition: You must specify --prefix or --manifest.
Example: -m /var/spool/my-first-bundle/
image.manifest.xml

-p, --prefix prefix

The bundled AMI filename prefix. Provide the entire prefix.
For example, if the prefix is image.img, use -p image.img
and not -p image.
Required: Conditional
Condition: You must specify --prefix or --manifest.
Example: -p image.img

--clear

Deletes the Amazon S3 bucket if it's empty after deleting
the specified bundle.
Required: No
Example: --clear

--retry

Automatically retries on all Amazon S3 errors, up to five
times per operation.
Required: No
Example: --retry

-y, --yes

Automatically assumes the answer to all prompts is yes.
Required: No
Example: -y

Common options

For options common to most of the AMI tools, see Common
Options for AMI Tools (p. 115).

Output
Amazon EC2 displays status messages indicating the stages and status of the delete process.

Example
This example deletes a bundle from Amazon S3.
$ ec2-delete-bundle -b myawsbucket -a your_access_key_id s your_secret_access_key
Deleting files:
myawsbucket/image.manifest.xml
myawsbucket/image.part.00
myawsbucket/image.part.01
myawsbucket/image.part.02
myawsbucket/image.part.03
myawsbucket/image.part.04
myawsbucket/image.part.05
myawsbucket/image.part.06
Continue? [y/n]
y
Deleted myawsbucket/image.manifest.xml
Deleted myawsbucket/image.part.00
Deleted myawsbucket/image.part.01

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Deleted myawsbucket/image.part.02
Deleted myawsbucket/image.part.03
Deleted myawsbucket/image.part.04
Deleted myawsbucket/image.part.05
Deleted myawsbucket/image.part.06
ec2-delete-bundle complete.

ec2-download-bundle
Description
Downloads the specified instance store-backed Linux AMIs from Amazon S3 storage.

Syntax
ec2-download-bundle -b bucket -a access_key_id -s secret_access_key -k path
[--url url] [--region region] [--sigv version] [-m file] [-p prefix] [-d
directory] [--retry]

Options
Option

Description

-b, --bucket bucket

The name of the Amazon S3 bucket where the bundle is
located, followed by an optional '/'-delimited path prefix.
Required: Yes
Example: -b myawsbucket/ami-001

-k, --privatekey path

The private key used to decrypt the manifest.
Required: Yes
Example: -k pkHKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem

--url url

The Amazon S3 service URL.
Default: https://s3.amazonaws.com
Required: No
Example: --url https://s3.example.com

--region region

The region to use in the request signature.
Default: us-east-1
Required: Conditional
Condition: Required if using signature version 4
Example: --region eu-west-1

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Option

Description

--sigv version

The signature version to use when signing the request.
Valid values: 2 | 4
Default: 4
Required: No
Example: --sigv 2

-m, --manifest file

The name of the manifest file (without the path). We
recommend that you specify either the manifest (-m) or a
prefix (-p).
Required: No
Example: -m my-image.manifest.xml

-p, --prefix prefix

The filename prefix for the bundled AMI files.
Default: image
Required: No
Example: -p my-image

-d, --directory directory

The directory where the downloaded bundle is saved. The
directory must exist.
Default: The current working directory.
Required: No
Example: -d /tmp/my-downloaded-bundle

--retry

Automatically retries on all Amazon S3 errors, up to five
times per operation.
Required: No
Example: --retry

Common options

For options common to most of the AMI tools, see Common
Options for AMI Tools (p. 115).

Output
Status messages indicating the various stages of the download process are displayed.

Example
This example creates the bundled directory (using the Linux mkdir command) and downloads the
bundle from the myawsbucket Amazon S3 bucket.
$ mkdir bundled
$ ec2-download-bundle -b myawsbucket/bundles/bundle_name -m
image.manifest.xml -a your_access_key_id -s your_secret_access_key -k pkHKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem -d mybundle
Downloading manifest image.manifest.xml from myawsbucket to mybundle/
image.manifest.xml ...
Downloading part image.part.00 from myawsbucket/bundles/bundle_name to
mybundle/image.part.00 ...
Downloaded image.part.00 from myawsbucket
Downloading part image.part.01 from myawsbucket/bundles/bundle_name to
mybundle/image.part.01 ...
Downloaded image.part.01 from myawsbucket

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Downloading part image.part.02 from myawsbucket/bundles/bundle_name
mybundle/image.part.02 ...
Downloaded image.part.02 from myawsbucket
Downloading part image.part.03 from myawsbucket/bundles/bundle_name
mybundle/image.part.03 ...
Downloaded image.part.03 from myawsbucket
Downloading part image.part.04 from myawsbucket/bundles/bundle_name
mybundle/image.part.04 ...
Downloaded image.part.04 from myawsbucket
Downloading part image.part.05 from myawsbucket/bundles/bundle_name
mybundle/image.part.05 ...
Downloaded image.part.05 from myawsbucket
Downloading part image.part.06 from myawsbucket/bundles/bundle_name
mybundle/image.part.06 ...
Downloaded image.part.06 from myawsbucket

ec2-migrate-manifest
Description
Modifies an instance store-backed Linux AMI (for example, its certificate, kernel, and RAM disk) so that
it supports a different region.

Syntax
ec2-migrate-manifest -c path -k path -m path {(-a access_key_id s secret_access_key --region region) | (--no-mapping)} [--ec2cert
ec2_cert_path] [--kernel kernel-id] [--ramdisk ramdisk_id]

Options
Option

Description

-c, --cert path

The user's PEM encoded RSA public key certificate file.
Required: Yes
Example: -c certHKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem

-k, --privatekey path

The path to the user's PEM-encoded RSA key file.
Required: Yes
Example: -k pkHKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem

--manifest path

The path to the manifest file.
Required: Yes
Example: --manifest my-ami.manifest.xml

-a, --access-key
access_key_id

The AWS access key ID. Before you specify a value for this
option, review and follow the guidance in Best Practices for
Managing AWS Access Keys.
Required: Conditional
Condition: Required if using automatic mapping.
Example: -a AKIAIOSFODNN7EXAMPLE

-s, --secret-key
secret_access_key

The AWS secret access key. Before you specify a value
for this option, review and follow the guidance in Best
Practices for Managing AWS Access Keys.

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Option

Description
Required: Conditional
Condition: Required if using automatic mapping.
Example: -s wJalrXUtnFEMI/K7MDENG/
bPxRfiCYEXAMPLEKEY

--region region

The region to look up in the mapping file.
Condition: Required if using automatic mapping.
Required: Conditional
Example: --region eu-west-1

--no-mapping

Disables automatic mapping of kernels and RAM disks.
During migration, Amazon EC2 replaces the kernel and
RAM disk in the manifest file with a kernel and RAM disk
designed for the destination region. Unless the --nomapping parameter is given, ec2-migrate-bundle
might use the DescribeRegions and DescribeImages
operations to perform automated mappings.
Required: Conditional
Condition: Required if you're not providing the -a, -s, and
--region options (which are used for automatic mapping).

--ec2cert path

The path to the Amazon EC2 X.509 public key certificate
used to encrypt the image manifest.
The us-gov-west-1 and cn-north-1 regions use a
non-default public key certificate and the path to that
certificate must be specified with this option. The path to
the certificate varies based on the installation method of the
AMI tools. For Amazon Linux, the certificates are located
at /opt/aws/amitools/ec2/etc/ec2/amitools/. If
you installed the AMI tools from the ZIP file in Setting Up
the AMI Tools (p. 94), the certificates are located at
$EC2_AMITOOL_HOME/etc/ec2/amitools/.
Default: varies, depending on the tools
Required: Only for the us-gov-west-1 and cn-north-1
regions.
Example: --ec2cert $EC2_AMITOOL_HOME/etc/ec2/
amitools/cert-ec2.pem

--kernel kernel_id

The ID of the kernel to select.

Important
We recommend that you use PV-GRUB instead of
kernels and RAM disks. For more information, see
PV-GRUB.
Required: No
Example: --kernel aki-ba3adfd3

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Option

Description

--ramdisk ramdisk_id

The ID of the RAM disk to select.

Important
We recommend that you use PV-GRUB instead of
kernels and RAM disks. For more information, see
PV-GRUB.
Required: No
Example: --ramdisk ari-badbad00
Common options

For options common to most of the AMI tools, see Common
Options for AMI Tools (p. 115).

Output
Status messages describing the stages and status of the bundling process.

Example
This example copies the AMI specified in the my-ami.manifest.xml manifest from the US to the EU.
$ ec2-migrate-manifest --manifest my-ami.manifest.xml --cert
cert-HKZYKTAIG2ECMXYIBH3HXV4ZBZQ55CLO.pem --privatekey pkHKZYKTAIG2ECMXYIBH3HXV4ZBZQ55CLO.pem --region eu-west-1
Backing up manifest...
Successfully migrated my-ami.manifest.xml It is now suitable for use in euwest-1.

ec2-unbundle
Description
Re-creates the bundle from an instance store-backed Linux AMI.

Syntax
ec2-unbundle -k path -m path [-s source_directory] [-d destination_directory]

Options
Option

Description

-k, --privatekey path

The path to your PEM-encoded RSA key file.
Required: Yes
Example: -k $HOME/pk-234242example.pem

-m, --manifest path

The path to the manifest file.
Required: Yes
Example: -m /var/spool/my-first-bundle/
Manifest

-s, --source source_directory

The directory containing the bundle.
Default: The current directory.
Required: No
Example: -s /tmp/my-bundled-image

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Option

Description

-d, --destination
destination_directory

The directory in which to unbundle the AMI. The destination
directory must exist.
Default: The current directory.
Required: No
Example: -d /tmp/my-image

Common options

For options common to most of the AMI tools, see Common
Options for AMI Tools (p. 115).

Example
This Linux and UNIX example unbundles the AMI specified in the image.manifest.xml file.
$ mkdir unbundled
$ ec2-unbundle -m mybundle/image.manifest.xml -k pkHKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem -s mybundle -d unbundled
$ ls -l unbundled
total 1025008
-rw-r--r-- 1 root root 1048578048 Aug 25 23:46 image.img

Output
Status messages indicating the various stages of the unbundling process are displayed.

ec2-upload-bundle
Description
Uploads the bundle for an instance store-backed Linux AMI to Amazon S3 and sets the appropriate
ACLs on the uploaded objects. For more information, see Creating an Instance Store-Backed Linux
AMI.

Syntax
ec2-upload-bundle -b bucket -a access_key_id -s secret_access_key [-t token]
-m path [--url url] [--region region] [--sigv version] [--acl acl] [-d
directory] [--part part] [--retry] [--skipmanifest]

Options
Option

Description

-b, --bucket bucket

The name of the Amazon S3 bucket in which to store the
bundle, followed by an optional '/'-delimited path prefix. If
the bucket doesn't exist, it's created if the bucket name is
available.
Required: Yes
Example: -b myawsbucket/bundles/ami-001

-a, --access-key access_key_id Your AWS access key ID. Before you specify a value
for this option, review and follow the guidance in Best
Practices for Managing AWS Access Keys.
Required: Yes
Example: -a AKIAIOSFODNN7EXAMPLE

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Option

Description

-s, --secret-key
secret_access_key

Your AWS secret access key. Before you specify a value
for this option, review and follow the guidance in Best
Practices for Managing AWS Access Keys.
Required: Yes
Example: -s wJalrXUtnFEMI/K7MDENG/
bPxRfiCYEXAMPLEKEY

-t, --delegation-token token

-m, --manifest path

The path to the manifest file. The manifest file is created
during the bundling process and can be found in the
directory containing the bundle.
Required: Yes
Example: -m image.manifest.xml

--url url

Deprecated. Use the --region option instead unless
your bucket is constrained to the EU location (and not euwest-1). The --location flag is the only way to target
that specific location restraint.
The Amazon S3 endpoint service URL.
Default: https://s3.amazonaws.com
Required: No
Example: --url https://s3.example.com

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Option

Description

--region region

The region to use in the request signature for the
destination Amazon S3 bucket.
• If the bucket doesn't exist and you don't specify a region,
the tool creates the bucket without a location constraint
(in us-east-1).
• If the bucket doesn't exist and you specify a region, the
tool creates the bucket in the specified region.
• If the bucket exists and you don't specify a region, the
tool uses the bucket's location.
• If the bucket exists and you specify us-east-1 as the
region, the tool uses the bucket's actual location without
any error message, any existing matching files are overwritten.
• If the bucket exists and you specify a region (other than
us-east-1) that doesn't match the bucket's actual
location, the tool exits with an error.
If your bucket is constrained to the EU location (and not
eu-west-1), use the --location flag instead. The
--location flag is the only way to target that specific
location restraint.
Default: us-east-1
Required: Conditional
Condition: Required if using signature version 4
Example: --region eu-west-1

--sigv version

The signature version to use when signing the request.
Valid values: 2 | 4
Default: 4
Required: No
Example: --sigv 2

--acl acl

The access control list policy of the bundled image.
Valid values: public-read | aws-exec-read
Default: aws-exec-read
Required: No
Example: --acl public-read

-d, --directory directory

The directory containing the bundled AMI parts.
Default: The directory containing the manifest file (see the m option).
Required: No
Example: -d /var/run/my-bundle

--part part

Starts uploading the specified part and all subsequent
parts.
Required: No
Example: --part 04

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Option

Description

--retry

Automatically retries on all Amazon S3 errors, up to five
times per operation.
Required: No
Example: --retry

--skipmanifest

Does not upload the manifest.
Required: No
Example: --skipmanifest

--location location

Deprecated. Use the --region option instead, unless
your bucket is constrained to the EU location (and not euwest-1). The --location flag is the only way to target
that specific location restraint.
The location constraint of the destination Amazon S3
bucket. If the bucket exists and you specify a location that
doesn't match the bucket's actual location, the tool exits
with an error. If the bucket exists and you don't specify a
location, the tool uses the bucket's location. If the bucket
doesn't exist and you specify a location, the tool creates the
bucket in the specified location. If the bucket doesn't exist
and you don't specify a location, the tool creates the bucket
without a location constraint (in us-east-1).
Default: If --region is specified, the location is set to that
specified region. If --region is not specified, the location
defaults to us-east-1.
Required: No
Example: --location eu-west-1

Common options

For options common to most of the AMI tools, see Common
Options for AMI Tools (p. 115).

Output
Amazon EC2 displays status messages that indicate the stages and status of the upload process.

Example
This example uploads the bundle specified by the image.manifest.xml manifest.
$ ec2-upload-bundle -b myawsbucket/bundles/bundle_name -m image.manifest.xml
-a your_access_key_id -s your_secret_access_key
Creating bucket...
Uploading bundled image parts to the S3 bucket myawsbucket ...
Uploaded image.part.00
Uploaded image.part.01
Uploaded image.part.02
Uploaded image.part.03
Uploaded image.part.04
Uploaded image.part.05
Uploaded image.part.06
Uploaded image.part.07
Uploaded image.part.08
Uploaded image.part.09
Uploaded image.part.10

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Uploaded image.part.11
Uploaded image.part.12
Uploaded image.part.13
Uploaded image.part.14
Uploading manifest ...
Uploaded manifest.
Bundle upload completed.

Common Options for AMI Tools
Most of the commands described in this section accept the set of optional parameters described in the
following table.
Option

Description

--help, -h

Displays the help message.

--version

Displays the version and copyright notice.

--manual

Displays the manual entry.

--batch

Runs in batch mode, suppressing interactive prompts.

--debug

Displays debugging information that may be useful when
troubleshooting problems.

Managing Signing Certificates
This section describes how to create and manage signing certificates; also known as X.509 certificates.
These certificates are required for certain AMI tool commands.

Important
Amazon EC2 originally supported the SOAP protocol for making service calls, and SOAPbased calls use a signing certificate in order to digitally sign the requests. However, support
for SOAP in Amazon EC2 is deprecated (see SOAP Requests), and you should use HTTP
query requests instead. For more information, see Making API Requests.
Each user can have two certificates for the purposes of credential rotation.

Note
You can give your users permission to list and manage their own certificates. For more
information, see Allow Users to Manage Their Own Passwords, Access Keys, and Signing
Certificate in the IAM User Guide.
Topics
• Creating a User Signing Certificate (p. 115)
• Managing a User Signing Certificate (p. 119)

Creating a User Signing Certificate
If you need a signing certificate, you must first obtain one, and then upload it to AWS. There is no
Amazon EC2 API action to create signing certificates, so you must use a third-party tool such as
OpenSSL to create the user signing certificate.

Note
Although you can use the security credentials page in the AWS Management Console to
create an X.509 certificate, that method is only for the AWS account root credentials. You

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can't upload a certificate generated using the console for individual Amazon EC2 users.
Instead, use the process described in the next sections.
To create a signing certificate, you must do the following:
• Install and configure OpenSSL.
• Create a private key.
• Generate a certificate using the private key.
• Upload the certificate to AWS.

Install and Configure OpenSSL
Creating and uploading a certificate requires a tool that supports the SSL and TLS protocols. OpenSSL
is an open-source tool that provides the basic cryptographic functions necessary to create an RSA
token and sign it with your private key. If you don't already have OpenSSL installed, follow these
instructions.

To install OpenSSL on Linux and UNIX
1.

Go to OpenSSL: Source, Tarballs (http://www.openssl.org/source/).

Download the latest source and build the package.

To install OpenSSL on Windows
1.
2.

Go to Binaries (https://wiki.openssl.org/index.php/Binaries).
Choose the appropriate OpenSSL for Windows option.
A new page displays with links to the Windows downloads.

If it is not already installed on your system, select the Microsoft Visual C++ 2008
Redistributables link appropriate for your environment and click Download. Follow the
instructions provided by the Microsoft Visual C++ 2008 Redistributable Setup Wizard.

Note

If you are not sure if the Microsoft Visual C++ 2008 Redistributable package is already
installed on your system, you can try installing OpenSSL first. The OpenSSL installer
displays an error if the Microsoft Visual C++ 2008 Redistributable package is not yet
installed. Make sure you install the architecture (32-bit or 64-bit) that matches the version
of OpenSSL that you install.
After you have installed the Microsoft Visual C++ 2008 Redistributable package, select the
appropriate version of the OpenSSL binaries for your environment and save the file locally. Launch
the OpenSSL Setup Wizard.
Follow the instructions described in the OpenSSL Setup Wizard.

Before you use OpenSSL commands, you must configure the operating system so that it has
information about the location where OpenSSL is installed.

To configure OpenSSL on Linux or Unix
1.

At the command line, set the OpenSSL_HOME variable to the location of the OpenSSL installation:
export OpenSSL_HOME=path_to_your_OpenSSL_installation

Set the path to include the OpenSSL installation:
export PATH=$PATH:$OpenSSL_HOME/bin

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Note
Any changes you make to environment variables using the export command are valid
only for the current session. You can make persistent changes to the environment
variables by setting them using your shell configuration file. For more information, see the
documentation for your operating system.

To configure OpenSSL on Windows
1.

Open a Command Prompt window.

Set the OpenSSL_HOME variable to the location of the OpenSSL installation:
set OpenSSL_HOME=path_to_your_OpenSSL_installation

Set the OpenSSL_CONF variable to the location of the configuration file in your OpenSSL
installation:
set OpenSSL_CONF=path_to_your_OpenSSL_installation\bin\openssl.cfg

Set the path to include the OpenSSL installation:
set Path=%Path%;%OpenSSL_HOME%\bin

Note
Any changes you make to Windows environment variables in a Command Prompt
window are valid only for the current command line session. You can make persistent
changes to the environment variables by setting them as system properties. The exact
procedures depends on what version of Windows you're using. For more information, see
the Windows documentation.

Create a Private Key
You need a unique private key that you use when generating the user signing certificate.

To create a private key
1.

At the command line, use the openssl genrsa command with the following syntax:
openssl genrsa 2048 > private-key.pem

For private-key.pem, specify your own file name. In the example, 2048 represents 2048-bit
encryption. AWS also supports 1024-bit and 4096-bit encryption. We recommend that you create a
2048-bit or 4096-bit RSA key.
2.

If you will be using the certificate to authenticate CLI commands for Auto Scaling, CloudWatch, or
Elastic Load Balancing, generate the certificate in PKCS8 format using the following command:
openssl pkcs8 -topk8 -nocrypt -inform PEM -in private-key.pem out private-key-in-PKCS8-format.pem

Create the User Signing Certificate
You can now create a user signing certificate.

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To create a user signing certificate
•

Use the openssl req command with the following syntax:
openssl req -new -x509 -nodes -sha256 -days 365 -key private-key.pem outform PEM -out certificate.pem

For private-key.pem, use the .pem file that you generated in a previous procedure. For
certificate.pem, use the name of a file into which you want the certificate to be generated.
The certificate must be in .pem format. For security, we recommend using either SHA-256, as in
this example, or SHA-512 as your hash algorithm.
In this example, the -days 365 switch specifies that the certificate is good for 365 days. For
information about the other switches, enter openssl req -h at the command line.
OpenSSL displays a message similar to the following:
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a
DN.
There are quite a few fields but you can leave some blank.
For some fields there will be a default value.
If you enter '.', the field will be left blank.

Because you're creating a user signing certificate (not a server certificate), you can leave all the
values blank when you're prompted. These values are used by the certificate authority (CA) to help
authenticate the server certificate. However, because user signing certificates are uploaded in an
authenticated session, AWS does not need any information in the certificate for further validation,
and requires only the public-private key pair.
The .pem file contains the certificate value that you can copy and paste during the upload procedure
that follows.

Upload the User Signing Certificate
You can upload a signing certificate using the console, API, or CLI.

To upload a signing certificate for a user using the console
1.

Open the Identity and Access Management (IAM) console at https://console.aws.amazon.com/
iam/.

In the navigation pane, click Users.

Click the name of the user for whom you want to upload the certificate, and then open the
Security Credentials section. You may have to scroll down to see this section.

Click Manage Signing Certificates.

Click Upload Signing Certificate in the lower part of the page.

Using a text editor, open the .pem file that contains the user signing certificate that you created
using OpenSSL, as described earlier in this section, and copy the contents of the .pem file.

Paste the contents of the user's signing certificate into the Certificate Body field, and then click
Upload Signing Certificate.

Note
After the certificate has been uploaded, it cannot be retrieved, its contents cannot be
viewed, and it cannot be reused.
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To upload a certificate (CLI and API)
• upload-signing-certificate (AWS CLI)
• UploadSigningCertificate (IAM API)

Note
Use a POST request when uploading a signing certificate because of the certificate's size.

Managing a User Signing Certificate
You can manage a signing certificate using the console, API, or CLI.
As with access keys, each certificate can have a status of either Active or Inactive. By default,
the status is Active when you upload the certificate. When you upload the certificate, it returns a
certificate ID that you can save for your records. You can list the IDs for the user's certificates. You can
delete a certificate at any time.

To modify or delete a signing certificate for a user
1.

Open the Identity and Access Management (IAM) console at https://console.aws.amazon.com/
iam/.

In the navigation pane, click Users.

Click the name of the user for whom you want to modify or delete the certificate, and then open the
Security Credentials section.

4.
5.
6.

Click Manage Signing Certificates.
To disable or re-enable a signing certificate, click Make Inactive or Make Active.
To delete a user's signing certificate, click Delete.

To view a list of signing certificates belonging to a user
1.
2.
3.

Open the Identity and Access Management (IAM) console at https://console.aws.amazon.com/
iam/.
In the navigation pane, click Users, and then click the name of the user whose signing certificate
you want to view.
In the Security Credentials section, you can view the signing certificates and the status of
certificates. Users cannot have more than two signing certificates.

Managing a User Signing Certificate (CLI and API)
You can use the AWS CLI or IAM API to manage certificates.

To disable or re-enable a certificate
• update-signing-certificate (AWS CLI)
• UpdateSigningCertificate (IAM API)

To list a user's certificates
• list-signing-certificates (AWS CLI)
• ListSigningCertificates (IAM API)

To delete a certificate
• delete-signing-certificate (AWS CLI)

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• DeleteSigningCertificate (IAM API)

Creating an AMI from an Instance Store-Backed
Instance
The following procedures are for creating an instance store-backed AMI from an instance store-backed
instance. Before you begin, ensure that you've read the Prerequisites (p. 93).
Topics
• Creating an AMI from an Instance Store-Backed Amazon Linux Instance (p. 120)
• Creating an AMI from an Instance Store-Backed Ubuntu Instance (p. 124)

Creating an AMI from an Instance Store-Backed Amazon
Linux Instance
This section describes the creation of an AMI from an Amazon Linux instance. The following
procedures may not work for instances running other Linux distributions. For Ubuntu-specific
procedures, see Creating an AMI from an Instance Store-Backed Ubuntu Instance (p. 124).

To prepare to use the Amazon EC2 AMI Tools (HVM instances only)
1.

The Amazon EC2 AMI tools require GRUB Legacy to boot properly. Use the following command to
install GRUB:
[ec2-user ~]$ sudo yum install -y grub

Install the partition management packages with the following command:
[ec2-user ~]$ sudo yum install -y gdisk kpartx parted

To create an AMI from an instance store-backed Linux instance
This procedure assumes that you have satisfied the prerequisites in Prerequisites (p. 93).
1.

Upload your credentials to your instance. We use these credentials to ensure that only you and
Amazon EC2 can access your AMI.
a.

Create a temporary directory on your instance for your credentials as follows:
[ec2-user ~]$ mkdir /tmp/cert

This enables you to exclude your credentials from the created image.
Copy your X.509 certificate and corresponding private key from your computer to the /tmp/
cert directory on your instance using a secure copy tool such as scp (p. 291). The -i
my-private-key.pem option in the following scp command is the private key you use to
connect to your instance with SSH, not the X.509 private key. For example:
you@your_computer:~ $ scp -i my-private-key.pem /
path/to/pk-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem /
path/to/cert-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem ec2user@ec2-203-0-113-25.compute-1.amazonaws.com:/tmp/cert/

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pk-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem 100% 717
cert-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem 100% 685
00:00

0.7KB/s
00:00
0.7KB/s

Alternatively, because these are plain text files, you can open the certificate and key in a text
editor and copy their contents into new files in /tmp/cert.
2.

Prepare the bundle to upload to Amazon S3 by running the ec2-bundle-vol (p. 99) command
from inside your instance. Be sure to specify the -e option to exclude the directory where your
credentials are stored. By default, the bundle process excludes files that might contain sensitive
information. These files include *.sw, *.swo, *.swp, *.pem, *.priv, *id_rsa*, *id_dsa*
*.gpg, *.jks, */.ssh/authorized_keys, and */.bash_history. To include all of these
files, use the --no-filter option. To include some of these files, use the --include option.

Important
By default, the AMI bundling process creates a compressed, encrypted collection of files
in the /tmp directory that represents your root volume. If you do not have enough free
disk space in /tmp to store the bundle, you need to specify a different location for the
bundle to be stored with the -d /path/to/bundle/storage option. Some instances
have ephemeral storage mounted at /mnt or /media/ephemeral0 that you can use,
or you can also create (p. 650), attach (p. 654), and mount (p. 655) a new Amazon
EBS volume to store the bundle.
a.

The ec2-bundle-vol command needs to run as root. For most commands, you can use
sudo to gain elevated permissions, but in this case, you should run sudo -E su to keep your
environment variables.
[ec2-user ~]$ sudo -E su

Note that bash prompt now identifies you as the root user, and that the dollar sign has been
replaced by a hash tag, signalling that you are in a root shell:
[root ec2-user]#

To create the AMI bundle, run the ec2-bundle-vol (p. 99) command with the following
parameters:
-c
Path and filename for RSA certificate
-k
Path and filename for RSA certificate private key
--partition
Partition type: mbr, gpt, or none. AMI s from HVM instances will not boot without this.
-r
CPU architecture: i386 or x86_64. You can check this by running the arch command.
-u
Your AWS user account ID
-e
Comma-separated list of directories to exclude from the created image.
-d
If default directory /tmp has insufficient space to accommodate the bundle, this provides
the path to a directory with sufficient space.
For more information on this command and its available options, see ec2-bundlevol (p. 99).
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The following is a sample command:
[root ec2-user]# $EC2_AMITOOL_HOME/bin/ec2-bundle-vol -k /tmp/
cert/pk-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem -c /tmp/cert/certHKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem -u your_aws_account_id -r x86_64
-e /tmp/cert --partition gpt

It can take a few minutes to create the image. When this command completes, your /
tmp (or non-default) directory contains the bundle (image.manifest.xml, plus multiple
image.part.xx files).
c.

Exit from the root shell.
[root ec2-user]# exit

(Optional) Edit the block device mappings in the image.manifest.xml file for your AMI. Instance
store-backed AMIs can only specify instance store volumes in the block device mapping when the
AMI is created, and these mappings are specified in the image.manifest.xml file. For more
information, see Block Device Mapping (p. 731).

Note
This step is required only if you wish to add one or more additional instance store
volumes on your AMI.
a.

Create a backup of your image.manifest.xml file.
[ec2-user ~]$ sudo cp /tmp/image.manifest.xml /tmp/
image.manifest.xml.bak

Reformat the image.manifest.xml file so that it is easier to read and edit.
[ec2-user ~]$ sudo xmllint --format /tmp/image.manifest.xml.bak >
sudo /tmp/image.manifest.xml

Edit the block device mappings in image.manifest.xml with a text editor. The example
below shows a new entry for the ephemeral1 instance store volume.

ami
sda

ephemeral0
sdb

ephemeral1
sdc

root
/dev/sda1

Save the image.manifest.xml file and exit your text editor.
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To upload your bundle to Amazon S3, run the ec2-upload-bundle (p. 111) command with the
following parameters.

-b
Location of S3 bucket: my-s3-bucket/bundle_folder/bundle_name. Note that if the
bucket and folder path does not exist, the command creates it.
-m
Path to image.manifest.xml. If you specified a path with -d /path/to/bundle/storage
in Step 2 (p. 121), use that same path with this parameter.
-a
Your AWS account access key ID
-s
Your AWS account secret access key
--region
If you intend to register your AMI in a region other than US East (N. Virginia), you must specify
both the target region with the --region option and a bucket path that already exists in the
target region or a unique bucket path that can be created in the target region.
For more information on this command and its available options, see ec2-uploadbundle (p. 111).
The following is a sample command:
[ec2-user ~]$ ec2-upload-bundle -b my-s3-bucket/bundle_folder/bundle_name
-m /tmp/image.manifest.xml -a your_access_key_id s your_secret_access_key

(Optional) After the bundle is uploaded to Amazon S3, you can remove the bundle from the /tmp
directory on the instance using the following rm command:

Note
If you specified a path with the -d /path/to/bundle/storage option in Step
2 (p. 121), use that same path below, instead of /tmp.
[ec2-user ~]$ sudo rm /tmp/image.manifest.xml /tmp/image.part.* /tmp/image

To register your AMI , run the register-image AWS CLI command with the following parameters.
--image-location
my-s3-bucket/bundle_folder/bundle_name/image.manifest.xml
--name
A name for the AMI
--virtualization-type
Possible values are hvm and paravirtual.
--region
If you previously specified a region for the ec2-upload-bundle (p. 111) command, specify
that region again for this command.
For more information on this command and its available options, see register-image in the AWS
Command Line Interface Reference.
The following is a sample command:

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[ec2-user ~]$ aws ec2 register-image --image-location my-s3bucket/bundle_folder/bundle_name/image.manifest.xml --name AMI_name -virtualization-type hvm

Creating an AMI from an Instance Store-Backed Ubuntu
Instance
This section describes the creation of an AMI from an Ubuntu Linux instance. The following procedures
may not work for instances running other Linux distributions. For procedures specific to Amazon Linux,
see Creating an AMI from an Instance Store-Backed Amazon Linux Instance (p. 120).

To prepare to use the Amazon EC2 AMI Tools (HVM instances only)
The Amazon EC2 AMI tools require GRUB Legacy to boot properly. However, Ubuntu is configured to
use GRUB 2. You must check to see that your instance uses GRUB Legacy, and if not, you need to
install and configure it.
HVM instances also require partitioning tools to be installed for the AMI tools to work properly.
1.

GRUB Legacy (version 0.9x or less) must be installed on your instance. Check to see if GRUB
Legacy is present and install it if necessary.
a.

Check the version of your GRUB installation.
ubuntu:~$ grub-install --version
grub-install (GRUB) 1.99-21ubuntu3.10

In this example, the GRUB version is greater than 0.9x, so GRUB Legacy must be installed.
Proceed to Step 1.b (p. 124). If GRUB Legacy is already present, you can skip to Step
2 (p. 124).
b.

Install the grub package using the following command.
ubuntu:~$ sudo apt-get install -y grub

Verify that your instance is using GRUB Legacy.
ubuntu:~$ grub --version
grub (GNU GRUB 0.97)

Install the following partition management packages using the package manager for your
distribution.
• gdisk (some distributions may call this package gptfdisk instead)
• kpartx
• parted
Use the following command.
ubuntu:~$ sudo apt-get install -y gdisk kpartx parted

Check the kernel parameters for yourinstance.

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ubuntu:~$ cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-3.2.0-54-virtual root=UUID=4f392932-ed93-4f8faee7-72bc5bb6ca9d ro console=ttyS0 xen_emul_unplug=unnecessary

Note the options following the kernel and root device parameters: ro, console=ttyS0, and
xen_emul_unplug=unnecessary. Your options may differ.
4.

Check the kernel entries in /boot/grub/menu.lst.
ubuntu:~$ grep ^kernel /boot/grub/menu.lst
kernel /boot/vmlinuz-3.2.0-54-virtual root=LABEL=cloudimg-rootfs ro
console=hvc0
kernel /boot/vmlinuz-3.2.0-54-virtual root=LABEL=cloudimg-rootfs ro
single
kernel /boot/memtest86+.bin

Note that the console parameter is pointing to hvc0 instead of ttyS0 and that the
xen_emul_unplug=unnecessary parameter is missing. Again, your options may differ.
5.

Edit the /boot/grub/menu.lst file with your favorite text editor (such as vim or nano) to
change the console and add the parameters you identified earlier to the boot entries.
title
Ubuntu 12.04.3 LTS, kernel 3.2.0-54-virtual
root
(hd0)
kernel
/boot/vmlinuz-3.2.0-54-virtual root=LABEL=cloudimg-rootfs
ro console=ttyS0 xen_emul_unplug=unnecessary
initrd
/boot/initrd.img-3.2.0-54-virtual
title
Ubuntu 12.04.3 LTS, kernel 3.2.0-54-virtual (recovery
mode)
root
(hd0)
kernel
/boot/vmlinuz-3.2.0-54-virtual root=LABEL=cloudimg-rootfs
ro single console=ttyS0 xen_emul_unplug=unnecessary
initrd
/boot/initrd.img-3.2.0-54-virtual
title
root
kernel

Ubuntu 12.04.3 LTS, memtest86+
(hd0)
/boot/memtest86+.bin

Verify that your kernel entries now contain the correct parameters.
ubuntu:~$ grep ^kernel /boot/grub/menu.lst
kernel /boot/vmlinuz-3.2.0-54-virtual root=LABEL=cloudimg-rootfs ro
console=ttyS0 xen_emul_unplug=unnecessary
kernel /boot/vmlinuz-3.2.0-54-virtual root=LABEL=cloudimg-rootfs ro
single console=ttyS0 xen_emul_unplug=unnecessary
kernel /boot/memtest86+.bin

(For Ubuntu 14.04 and later only) Starting with Ubuntu 14.04, instance store backed Ubuntu AMIs
use a GPT partition table and a separate EFI partition mounted at /boot/efi. The ec2-bundlevol command will not bundle this boot partition, so you need to comment out the /etc/fstab
entry for the EFI partition as shown in the following example.
LABEL=cloudimg-rootfs
/
#LABEL=UEFI
/boot/efi

ext4
vfat

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defaults
defaults

0 0
0 0

/dev/xvdb
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/mnt
auto
defaults,nobootwait,comment=cloudconfig 0

To create an AMI from an instance store-backed Linux instance
This procedure assumes that you have satisfied the prerequisites in Prerequisites (p. 93).
1.

Upload your credentials to your instance. We use these credentials to ensure that only you and
Amazon EC2 can access your AMI.
a.

Create a temporary directory on your instance for your credentials as follows:
ubuntu:~$ mkdir /tmp/cert

This enables you to exclude your credentials from the created image.
b.

Copy your X.509 certificate and private key from your computer to the /tmp/cert directory
on your instance, using a secure copy tool such as scp (p. 291). The -i my-privatekey.pem option in the following scp command is the private key you use to connect to your
instance with SSH, not the X.509 private key. For example:
you@your_computer:~ $ scp -i my-private-key.pem /
path/to/pk-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem /
path/to/cert-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem ec2user@ec2-203-0-113-25.compute-1.amazonaws.com:/tmp/cert/
pk-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem 100% 717
0.7KB/s
00:00
cert-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem 100% 685
0.7KB/s
00:00

Alternatively, because these are plain text files, you can open the certificate and key in a text
editor and copy their contents into new files in /tmp/cert.
2.

Note that bash prompt now identifies you as the root user, and that the dollar sign has been
replaced by a hash tag, signalling that you are in a root shell:
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root@ubuntu:#

To create the AMI bundle, run the ec2-bundle-vol (p. 99) command with the following
parameters.
-c
Path and filename for RSA certificate
-k
Path and filename for RSA certificate private key
--partition
Partition type: mbr, gpt, or none. For Ubuntu 14.04 and later HVM instances, add the
--partition mbr flag to bundle the boot instructions properly; otherwise, your newlycreated AMI will not boot.
-r
CPU architecture: i386 or x86_64. You can check this by running the arch command.
-u
Your AWS user account ID
-e
Comma-separated list of directories to exclude from the created image.
-d
If default directory /tmp has insufficient space to accommodate the bundle, this provides
the path to a directory with sufficient space.
For more information on this command and its available options, see ec2-bundlevol (p. 99).
The following is a sample command:
root@ubuntu:# $EC2_AMITOOL_HOME/bin/ec2-bundle-vol -k /tmp/
cert/pk-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem -c /tmp/cert/certHKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem -u your_aws_account_id -r x86_64
-e /tmp/cert --partition gpt

It can take a few minutes to create the image. When this command completes, your tmp
directory contains the bundle (image.manifest.xml, plus multiple image.part.xx files).
c.

Exit from the root shell.
root@ubuntu:# exit

Note
This step is required only if you wish to add one or more additional instance store
volumes on your AMI.
a.

Create a backup of your image.manifest.xml file.
ubuntu:~$ sudo cp /tmp/image.manifest.xml /tmp/image.manifest.xml.bak

Reformat the image.manifest.xml file so that it is easier to read and edit.
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ubuntu:~$ sudo xmllint --format /tmp/image.manifest.xml.bak > /tmp/
image.manifest.xml

Edit the block device mappings in image.manifest.xml with a text editor. The example
below shows a new entry for the ephemeral1 instance store volume.

ami
sda

ephemeral0
sdb

ephemeral1
sdc

root
/dev/sda1

d.
4.

Save the image.manifest.xml file and exit your text editor.

To upload your bundle to Amazon S3, run the ec2-upload-bundle (p. 111) command with the
following parameters.
-b
Location of S3 bucket: my-s3-bucket/bundle_folder/bundle_name. Note that if the
bucket and folder path does not exist, the command creates it.
-m
Path to image.manifest.xml. If you specified a path with -d /path/to/bundle/storage
in Step 2 (p. 126), use that same path in this parameter.
-a
Your AWS account access key ID
-s
Your AWS account secret access key
--region
If you intend to register your AMI in a region other than US East (N. Virginia), you must specify
both the target region with the --region option and a bucket path that already exists in the
target region or a unique bucket path that can be created in the target region.
For more information on this command and its available options, see ec2-uploadbundle (p. 111).
The following is a sample command:
ubuntu:~$ ec2-upload-bundle -b my-s3-bucket/bundle_folder/bundle_name -m /
tmp/image.manifest.xml -a your_access_key_id -s your_secret_access_key

(Optional) After the bundle is uploaded to Amazon S3, you can remove the bundle from the /tmp
directory on the instance using the following rm command:

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Note
If you specified a path with the -d /path/to/bundle/storage option in Step
2 (p. 126), use that same path below, instead of /tmp.
ubuntu:~$ sudo rm /tmp/image.manifest.xml /tmp/image.part.* /tmp/image

To register your AMI, run the register-image AWS CLI command with the following parameters.
Path to manifest
my-s3-bucket/bundle_folder/bundle_name/image.manifest.xml
-n
A name for the AMI
--virtualization-type
Possible values are hvm and paravirtual.
--region
If you previously specified a region for the ec2-upload-bundle (p. 111) command, specify
that region again for this command.
For more information on this command and its available options, see register-image in the AWS
Command Line Interface Reference.
The following is a sample command:
ubuntu:~$ aws ec2 register-image my-s3-bucket/bundle_folder/bundle_name/
image.manifest.xml --name AMI_name --virtualization-type hvm

(For Ubuntu 14.04 and later only) Uncomment the EFI entry in /etc/fstab; otherwise, your
running instance will not be able to reboot.

Converting your Instance Store-Backed AMI to
an Amazon EBS-Backed AMI
You can convert an instance store-backed Linux AMI that you own to an Amazon EBS-backed Linux
AMI.

Important
You can't convert an instance store-backed Windows AMI to an Amazon EBS-backed
Windows AMI and you cannot convert an AMI that you do not own.

To convert an instance store-backed AMI to an Amazon EBS-backed AMI
1.

Launch an Amazon Linux instance from an Amazon EBS-backed AMI. For more information, see
Launching an Instance (p. 279). Amazon Linux instances have the AWS CLI and AMI tools preinstalled.

Upload the X.509 private key that you used to bundle your instance store-backed AMI to your
instance. We use this key to ensure that only you and Amazon EC2 can access your AMI.
a.

Create a temporary directory on your instance for your X.509 private key as follows:
[ec2-user ~]$ mkdir /tmp/cert

Copy your X.509 private key from your computer to the /tmp/cert directory on your
instance, using a secure copy tool such as scp (p. 291). The my-private-key parameter
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in the following command is the private key you use to connect to your instance with SSH. For
example:
you@your_computer:~ $ scp -i my-private-key.pem /
path/to/pk-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem ec2user@ec2-203-0-113-25.compute-1.amazonaws.com:/tmp/cert/
pk-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem 100% 717
0.7KB/s

00:00

Set environment variables for your AWS access key and secret key.
[ec2-user ~]$ export AWS_ACCESS_KEY_ID=your_access_key_id
[ec2-user ~]$ export AWS_SECRET_ACCESS_KEY=your_secret_access_key

Prepare an Amazon EBS volume for your new AMI.
a.

Create an empty Amazon EBS volume in the same Availability Zone as your instance using
the create-volume command. Note the volume ID in the command output.

Important
This Amazon EBS volume must be the same size or larger than the original instance
store root volume.
[ec2-user ~]$ aws ec2 create-volume --size 10 --region us-west-2 -availability-zone us-west-2b

Attach the volume to your Amazon EBS-backed instance using the attach-volume command.
[ec2-user ~]$ aws ec2 attach-volume --volumeif volume_id --instanceid instance_id --device /dev/sdb --region us-west-2

Create a folder for your bundle.
[ec2-user ~]$ mkdir /tmp/bundle

Download the bundle for your instance store-based AMI to /tmp/bundle using the ec2download-bundle (p. 106) command.
[ec2-user ~]$ ec2-download-bundle -b my-s3bucket/bundle_folder/bundle_name -m image.manifest.xml -a
$AWS_ACCESS_KEY -s $AWS_SECRET_KEY --privatekey /path/to/pkHKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem -d /tmp/bundle

Reconstitute the image file from the bundle using the ec2-unbundle (p. 110) command.
a.

Change directories to the bundle folder.
[ec2-user ~]$ cd /tmp/bundle/

Run the ec2-unbundle (p. 110) command.
[ec2-user bundle]$ ec2-unbundle -m image.manifest.xml --privatekey /
path/to/pk-HKZYKTAIG2ECMXYIBH3HXV4ZBEXAMPLE.pem

Copy the files from the unbundled image to the new Amazon EBS volume.
[ec2-user bundle]$ sudo dd if=/tmp/bundle/image of=/dev/sdb bs=1M

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Probe the volume for any new partitions that were unbundled.
[ec2-user bundle]$ sudo partprobe /dev/sdb

10. List the block devices to find the device name to mount.
[ec2-user bundle]$ lsblk
NAME
MAJ:MIN RM SIZE
/dev/sda
202:0
0
8G
##/dev/sda1 202:1
0
8G
/dev/sdb
202:80
0 10G
##/dev/sdb1 202:81
0 10G

RO TYPE MOUNTPOINT
0 disk
0 part /
0 disk
0 part

In this example, the partition to mount is /dev/sdb1, but your device name will likely be different.
If your volume is not partitioned, then the device to mount will be similar to /dev/sdb (without a
device partition trailing digit).
11. Create a mount point for the new Amazon EBS volume and mount the volume.
[ec2-user bundle]$ sudo mkdir /mnt/ebs
[ec2-user bundle]$ sudo mount /dev/sdb1 /mnt/ebs

12. Open the /etc/fstab file on the EBS volume with your favorite text editor (such as vim or nano)
and remove any entries for instance store (ephemeral) volumes. Because the Amazon EBS
volume is mounted on /mnt/ebs, the fstab file is located at /mnt/ebs/etc/fstab.
[ec2-user bundle]$ sudo nano /mnt/ebs/etc/fstab
#
LABEL=/
/
ext4
defaults,noatime 1
1
tmpfs
/dev/shm
tmpfs
defaults
0
0
devpts
/dev/pts
devpts gid=5,mode=620 0
0
sysfs
/sys
sysfs
defaults
0
0
proc
/proc
proc
defaults
0
0
/dev/sdb
/media/ephemeral0
auto
defaults,comment=cloudconfig
0
2

In this example, the last line should be removed.
13. Unmount the volume and detach it from the instance.
[ec2-user bundle]$ sudo umount /mnt/ebs
[ec2-user bundle]$ aws ec2 detach-volume --volume-id volume_id -region us-west-2

14. Create an AMI from the new Amazon EBS volume as follows.
a.

Create a snapshot of the new Amazon EBS volume.
[ec2-user bundle]$ aws ec2 create-snapshot --region us-west-2 -description "your_snapshot_description" --volume-id volume_id

Check to see that your snapshot is complete.
[ec2-user bundle]$ aws ec2 describe-snapshots --region us-west-2 -snapshot-id snapshot_id

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Identify the processor architecture, virtualization type, and the kernel image (aki) used on
the original AMI with the describe-images command. You need the AMI ID of the original
instance store-backed AMI for this step.
[ec2-user bundle]$ aws ec2 describe-images --region us-west-2 --imageid ami-id --output text
IMAGES x86_64 amazon/amzn-ami-pv-2013.09.2.x86_64-s3 ami-8ef297be
amazon available public machine aki-fc8f11cc instance-store
paravirtual xen

In this example, the architecture is x86_64 and the kernel image ID is aki-fc8f11cc. Use
these values in the following step. If the output of the above command also lists an ari ID,
take note of that as well.
d.

Register your new AMI with the snapshot ID of your new Amazon EBS volume and the values
from the previous step. If the previous command output listed an ari ID, include that in the
following command with --ramdisk-id ari_id.
[ec2-user bundle]$ aws ec2 register-image --region uswest-2 --name your_new_ami_name --block-device-mappings
Ebs={SnapshotId=snapshot_id} --virtualization-type hvm --architecture
x86_64 --kernel-id aki-fc8f11cc

15. (Optional) After you have tested that you can launch an instance from your new AMI, you can
delete the Amazon EBS volume that you created for this procedure.
$ aws ec2 delete-volume --volume-id volume_id

AMIs with Encrypted Snapshots
AMIs that are backed by Amazon EBS snapshots can take advantage of Amazon EBS encryption.
Snapshots of both data and root volumes can be encrypted and attached to an AMI.
EC2 instances with encrypted volumes are launched from AMIs in the same way as other instances.
The CopyImage action can be used to create an AMI with encrypted snapshots from an AMI with
unencrypted snapshots. By default, CopyImage preserves the encryption status of source snapshots
when creating destination copies. However, you can configure the parameters of the copy process to
also encrypt the destination snapshots.
Snapshots can be encrypted with either your default AWS Key Management Service customer master
key (CMK), or with a custom key that you specify. You must in all cases have permission to use the
selected key. If you have an AMI with encrypted snapshots, you can choose to re-encrypt them with a
different encryption key as part of the CopyImage action. CopyImage accepts only one key at a time
and encrypts all of an image's snapshots (whether root or data) to that key. However, it is possible to
manually build an AMI with snapshots encrypted to multiple keys.
Support for creating AMIs with encrypted snapshots is accessible through the Amazon EC2 console,
Amazon EC2 API, or the AWS CLI.
The encryption parameters of CopyImage are available in all regions where AWS KMS is available.

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AMI Scenarios Involving Encrypted EBS
Snapshots
You can copy an AMI and simultaneously encrypt its associated EBS snapshots using the AWS
Management Console or the command line.

Copying an AMI with an Encrypted Data Snapshot
In this scenario, an EBS-backed AMI has an unencrypted root snapshot and an encrypted data
snapshot, shown in step 1. The CopyImage action is invoked in step 2 without encryption parameters.
As a result, the encryption status of each snapshot is preserved, so that the destination AMI, in step
3, is also backed by an unencrypted root snapshot and an encrypted data snapshot. Though the
snapshots contain the same data, they are distinct from each other and you will incur storage costs for
the snapshots in both AMIs, as well as charges for any instances you launch from either AMI.

You can perform a simple copy such as this using either the Amazon EC2 console or the command
line. For more information, see Copying an AMI (p. 135).

Copying an AMI Backed by An Encrypted Root Snapshot
In this scenario, an Amazon EBS-backed AMI has an encrypted root snapshot, shown in step 1. The
CopyImage action is invoked in step 2 without encryption parameters. As a result, the encryption
status of the snapshot is preserved, so that the destination AMI, in step 3, is also backed by an
encrypted root snapshot. Though the root snapshots contain identical system data, they are distinct
from each other and you will incur storage costs for the snapshots in both AMIs, as well as charges for
any instances you launch from either AMI.

You can perform a simple copy such as this using either the Amazon EC2 console or the command
line. For more information, see Copying an AMI (p. 135).

Creating an AMI with Encrypted Root Snapshot from an
Unencrypted AMI
In this scenario, an Amazon EBS-backed AMI has an unencrypted root snapshot, shown in step 1, and
an AMI is created with an encrypted root snapshot, shown in step 3. The CopyImage action in step 2
is invoked with two encryption parameters, including the choice of a CMK. As a result, the encryption
status of the root snapshot changes, so that the target AMI is backed by a root snapshot containing the

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same data as the source snapshot, but encrypted using the specified key. You will incur storage costs
for the snapshots in both AMIs, as well as charges for any instances you launch from either AMI.

You can perform a copy and encrypt operation such as this using either the Amazon EC2 console or
the command line. For more information, see Copying an AMI (p. 135).

Creating an AMI with an Encrypted Root Snapshot from a
Running Instance
In this scenario, an AMI is created from a running EC2 instance. The running instance in step 1 has
an encrypted root volume, and the created AMI in step 3 has a root snapshot encrypted to the same
key as the source volume. The CreateImage action has exactly the same behavior whether or not
encryption is present.

You can create an AMI from a running Amazon EC2 instance (with or without encrypted volumes)
using either the Amazon EC2 console or the command line. For more information, see Creating an
Amazon EBS-Backed Linux AMI (p. 89).

Creating an AMI with Unique CMKs for Each Encrypted
Snapshot
This scenario starts with an AMI backed by a root-volume snapshot (encrypted to key #1), and finishes
with an AMI that has two additional data-volume snapshots attached (encrypted to key #2 and key #3).
The CopyImage action cannot apply more than one encryption key in a single operation. However, you
can create an AMI from an instance that has multiple attached volumes encrypted to different keys.
The resulting AMI has snapshots encrypted to those keys and any instance launched from this new
AMI also has volumes encrypted to those keys.
The steps of this example procedure correspond to the following diagram.
1. Start with the source AMI backed by vol. #1 (root) snapshot, which is encrypted with key #1.
2. Launch an EC2 instance from the source AMI.
3. Create EBS volumes vol. #2 (data) and vol. #3 (data), encrypted to key #2 and key #3 respectively.
4. Attach the encrypted data volumes to the EC2 instance.

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5. The EC2 instance now has an encrypted root volume as well as two encrypted data volumes, all
using different keys.
6. Use the CreateImage action on the EC2 instance.
7. The resulting target AMI contains encrypted snapshots of the three EBS volumes, all using different
keys.

You can carry out this procedure using either the Amazon EC2 console or the command line. For more
information, see the following topics:
• Launch Your Instance (p. 278)
• Creating an Amazon EBS-Backed Linux AMI (p. 89).
• Amazon EBS Volumes (p. 636)
• AWS Key Management in the AWS Key Management Service Developer Guide

Copying an AMI
You can copy an Amazon Machine Image (AMI) within or across an AWS region using the AWS
Management Console, the command line, or the Amazon EC2 API, all of which support the
CopyImage action. Both Amazon EBS-backed AMIs and instance store-backed AMIs can be copied.
Copying a source AMI results in an identical but distinct target AMI with its own unique identifier. In
the case of an Amazon EBS-backed AMI, each of its backing snapshots is, by default, copied to an
identical but distinct target snapshot. (The one exception is when you choose to encrypt the snapshot,
as described below.) The source AMI can be changed or deregistered with no effect on the target AMI.
The reverse is also true.
There are no charges for copying an AMI. However, standard storage and data transfer rates apply.
AWS does not copy launch permissions, user-defined tags, or Amazon S3 bucket permissions from the
source AMI to the new AMI. After the copy operation is complete, you can apply launch permissions,
user-defined tags, and Amazon S3 bucket permissions to the new AMI.

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Copying an AMI You Own
You can copy any AMI that belongs to your AWS account using the CopyImage action. This includes
AMIs with encrypted snapshots and encrypted AMIs.

Copying an AMI Across AWS Accounts
You can copy an AMI across AWS accounts. This includes AMIs with encrypted snapshots, but does
not include encrypted AMIs.
The owner of the account must grant read permissions on the storage that backs the AMI, whether it is
an associated EBS snapshot (for an Amazon EBS-backed AMI) or an associated Amazon S3 bucket
( for an instance-store-backed AMI). To allow other accounts to copy your AMIs, you must grant read
permissions on your associated snapshot or bucket using the Amazon EBS or Amazon S3 access
management tools.
When an AMI is copied, the owner of the source AMI is charged standard Amazon EBS or Amazon S3
transfer fees, and the owner of the target AMI is charged for storage in the destination region.

Limits
• You can't copy an encrypted AMI between accounts. Instead, if the underlying snapshot and
encryption key have been shared with you, you can copy the snapshot to another account while reencrypting it with a key of your own, and then register this privately owned snapshot as a new AMI.
• You can't directly copy an AMI that has a billingProduct code associated with it. This includes
Windows AMIs and other AMIs from the AWS Marketplace that are owned and shared by another
AWS account. To create a private copy of an AMI that has a billingProduct code associated with
it, we recommend the following procedure:
1. Launch an EC2 instance in the target account using the shared AMI.
2. Create an image from the new instance.
The result will be a private AMI that you own and can customize like any other AMI you own. For
example, if you have created a private copy of an EBS-backed AMI, you can use CopyImage to
create an AMI with an encrypted root volume. For more information, see Creating an Amazon EBSBacked Linux AMI (p. 89).

Copying an AMI Across Regions
Copying an AMI across geographically diverse regions provides the following benefits:
• Consistent global deployment: Copying an AMI from one region to another enables you to launch
consistent instances based from the same AMI into different regions.
• Scalability: You can more easily design and build world-scale applications that meet the needs of
your users, regardless of their location.
• Performance: You can increase performance by distributing your application, as well as locating
critical components of your application in closer proximity to your users. You can also take
advantage of region-specific features, such as instance types or other AWS services.
• High availability: You can design and deploy applications across AWS regions, to increase
availability.
The following diagram shows the relations among a source AMI and two copied AMIs in different
regions, as well as the EC2 instances launched from each. When you launch an instance from an AMI,
it resides in the same region where the AMI resides. If you make changes to the source AMI and want

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those changes to be reflected in the AMIs in the target regions, you must recopy the source AMI to the
target regions.

When you first copy an instance store-backed AMI to a region, we create an Amazon S3 bucket
for the AMIs copied to that region. All instance store-backed AMIs that you copy to that region are
stored in this bucket. The names of these buckets have the following format: amis-for-accountin-region-hash. For example: amis-for-123456789012-in-us-west-2-yhjmxvp6.

Note
Destination regions are limited to 50 concurrent AMI copies at a time, with no more than 25
of those coming from a single source region. To request an increase to this limit, see Amazon
EC2 Service Limits (p. 760).
Prior to copying an AMI, you must ensure that the contents of the source AMI are updated to support
running in a different region. For example, you should update any database connection strings or
similar application configuration data to point to the appropriate resources. Otherwise, instances
launched from the new AMI in the destination region may still use the resources from the source
region, which can impact performance and cost.

Copying to Encrypt
Encrypting during copying applies only to Amazon EBS-backed AMIs. Because an instance-storebacked AMIs does not rely on snapshots, the CopyImage action cannot be used to change its
encryption status.
The CopyImage action can also be used to create a new AMI backed by encrypted Amazon EBS
snapshots. If you invoke encryption while copying an AMI, each snapshot taken of its associated
Amazon EBS volumes—including the root volume—will be encrypted using a key that you specify.
For more information about using AMIs with encrypted snapshots, see AMIs with Encrypted
Snapshots (p. 132).
By default, the backing snapshot of an AMI will be copied with its original encryption status. Copying
an AMI backed by an unencrypted snapshot will result in an identical target snapshot that is also
unencrypted. If the source AMI is backed by an encrypted snapshot, copying it will result in a target
snapshot encrypted to the specified key. Copying an AMI backed by multiple snaphots preserves
the source encryption status in each target snapshot. For more information about copying AMIs with
multiple snapshots, see AMIs with Encrypted Snapshots (p. 132).
The following table shows encryption support for various scenarios. Note that while it is possible
to copy an unencrypted snapshot to yield an encrypted snapshot, you cannot copy an encrypted
snapshot to yield an unencrypted one.
Scenario

Description

Supported

Unencrypted-to-unencrypted

Yes

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Scenario

Description

Supported

Encrypted-to-encrypted

Yes

Unencrypted-to-encrypted

Yes

Encrypted-to-unencrypted

AMI Copying Scenarios
This section describes basic scenarios for copying AMIs and provides copy procedures using the
Amazon EC2 console and the command line.
Copy an unencrypted source AMI to an unencrypted target AMI
In the simplest case, a copy of an AMI with an unencrypted single backing snapshot is created in the
specified geographical region (not shown).

Note
Although the diagram above shows an AMI with a single backing snapshot, the CopyImage
action also works for AMIs with multiple snapshots. The encryption status of each snapshot
is preserved. This means that an unencrypted snapshot in the source AMI will cause an
unencrypted snapshot to be created in the target AMI, and an encrypted snapshot in the
source AMI will cause an encrypted snapshot to be created in the target AMI.
Copy an encrypted source AMI to an encrypted target AMI
Although this scenario involves encrypted snapshots, it is functionally equivalent to the previous
scenario.

Note
If you apply encryption while copying a multi-snapshot AMI, all of the target snapshots are
encrypted using the specified key or the default key if none is specified. For information about
creating an AMI with multiple snapshots encrypted to multiple keys, see AMIs with Encrypted
Snapshots (p. 132).
Copy an unencrypted source AMI to an encrypted target AMI

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In this last scenario, the CopyImage action changes the encryption status of the destination image,
for instance, by encrypting an unencrypted snapshot, or re-encrypting an encrypted snapshot with
a different key. To apply encryption during the copy, you must supply encryption parameters: an
encryption flag and a key. Volumes created from the target snapshot are accessible only if you
supply this key. For more information about supported encryption scenarios for AMIs, see AMIs with
Encrypted Snapshots (p. 132).

Copying an AMI Using the Console or Command
Line
The steps in the following procedure correspond to the three steps in each scenario diagram. Apart
from the configuration of encryption options, the procedure for implementing the CopyImage action is
identical in all cases.

To copy an AMI using the console
1.

Create or obtain an AMI backed by an Amazon EBS snapshot. For more information, see Creating
an Amazon EBS-Backed Linux AMI (p. 89). A wide variety of AWS-supplied AMIs are available
through the Amazon EC2 console.
From the console navigation bar, select the region that contains the AMI you wish to copy. In the
navigation pane, expand Images and select AMIs to display the list of AMIs available to you in the
selected region.
Select the AMI to copy and choose Actions and Copy AMI.
In the AMI Copy page, set the following fields and choose Copy AMI:
• Destination region: Choose the region into which to copy the AMI.
• Name: Provide a name for the new AMI. You may want to include operating system information
in the name, as we do not provide this information when displaying details about the AMI.
• Description: By default, the description includes information about the source AMI so that you
can distinguish a copy from its original. You can change this description as needed.

• Encryption: Select this field to encrypt the target Amazon EBS snapshots, or to re-encrypt them
using a different key.
• Master Key: The KMS key that will be used to encrypt the target Amazon EBS snapshots if
Encryption has been chosen.
We display a confirmation page to let you know that the copy operation has been initiated and to
provide you with the ID of the new AMI.
To check on the progress of the copy operation immediately, follow the provided link. To check on
the progress later, choose Done, and then when you are ready, use the navigation bar to switch to
the target region (if applicable) and locate your AMI in the list of AMIs.

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The initial status of the target AMI is pending and the operation is complete when the status is
available.
To copy an AMI using the command line
Copying an AMI using the command line requires that you specify both the source and destination
regions. You specify the source region using the --source-region parameter. For the destination
region, you have two options:
• Use the --region parameter.
• Set an environmental variable. For more information, see Configuring the AWS Command Line
Interface.
When you encrypt a target snapshot during copying, you will need to supply two additional parameters:
• A Boolean, --encrypted
• A string, --kms-key-id, providing the master encryption key ID
You can copy an AMI using one of the following commands. For more information about these
command line interfaces, see Accessing Amazon EC2 (p. 3).
• copy-image (AWS CLI)
• Copy-EC2Image (AWS Tools for Windows PowerShell)

Stopping a Pending AMI Copy Operation
You can stop a pending AMI copy using the AWS Management Console or the command line.

To stop an AMI copy operation using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

From the navigation bar, select the destination region from the region selector.

In the navigation pane, choose AMIs.

Select the AMI to stop copying and choose Actions and Deregister.

When asked for confirmation, choose Continue.

To stop an AMI copy operation using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• deregister-image (AWS CLI)
• Unregister-EC2Image (AWS Tools for Windows PowerShell)

Deregistering Your AMI
You can deregister an AMI when you have finished using it. After you deregister an AMI, you can't use
it to launch new instances.

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When you deregister an AMI, it doesn't affect any instances that you've already launched from the
AMI. You'll continue to incur usage costs for these instances. Therefore, if you are finished with these
instances, you should terminate them.
The procedure that you'll use to clean up your AMI depends on whether it is backed by Amazon EBS
or instance store. (Note that the only Windows AMIs that can be backed by instance store are those for
Windows Server 2003.)
Contents
• Cleaning Up Your Amazon EBS-Backed AMI (p. 141)
• Cleaning Up Your Instance Store-Backed AMI (p. 142)

Cleaning Up Your Amazon EBS-Backed AMI
When you deregister an Amazon EBS-backed AMI, it doesn't affect the snapshot that was created for
the root volume of the instance during the AMI creation process. You'll continue to incur storage costs
for this snapshot. Therefore, if you are finished with the snapshot, you should delete it.
The following diagram illustrates the process for cleaning up your Amazon EBS-backed AMI.

To clean up your Amazon EBS-backed AMI
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose AMIs. Select the AMI, and take note of its ID — this can help you
find the correct snapshot in the next step. Choose Actions, and then Deregister. When prompted
for confirmation, choose Continue.
The AMI status is now unavailable.

Note
It may take a few minutes before the console changes the status from available to
unavailable, or removes the AMI from the list altogether. Choose Refresh to refresh
the status.
3.

In the navigation pane, choose Snapshots, and select the snapshot (look for the AMI ID in the
Description column). Choose Actions, and then choose Delete Snapshot. When prompted for
confirmation, choose Yes, Delete.

(Optional) If you are finished with an instance that you launched from the AMI, terminate it. In the
navigation pane, choose Instances. Select the instance, choose Actions, then Instance State,
and then Terminate. When prompted for confirmation, choose Yes, Terminate.

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Cleaning Up Your Instance Store-Backed AMI
When you deregister an instance store-backed AMI, it doesn't affect the files that you uploaded to
Amazon S3 when you created the AMI. You'll continue to incur usage costs for these files in Amazon
S3. Therefore, if you are finished with these files, you should delete them.
The following diagram illustrates the process for cleaning up your instance store-backed AMI.

To clean up your instance store-backed AMI
1.

Deregister the AMI using the deregister-image command as follows.
aws ec2 deregister-image --image-id ami_id

The AMI status is now unavailable.
2.

Delete the bundle in Amazon S3 using the ec2-delete-bundle (p. 104) (AMI tools) command as
follows.
ec2-delete-bundle -b myawsbucket/myami -a your_access_key_id s your_secret_access_key -p image

(Optional) If you are finished with an instance that you launched from the AMI, you can terminate it
using the terminate-instances command as follows.
aws ec2 terminate-instances --instance-ids instance_id

(Optional) If you are finished with the Amazon S3 bucket that you uploaded the bundle to, you
can delete the bucket. To delete an Amazon S3 bucket, open the Amazon S3 console, select the
bucket, choose Actions, and then choose Delete.

Amazon Linux
Amazon Linux is provided by Amazon Web Services (AWS). It is designed to provide a stable, secure,
and high-performance execution environment for applications running on Amazon EC2. It also includes
packages that enable easy integration with AWS, including launch configuration tools and many
popular AWS libraries and tools. AWS provides ongoing security and maintenance updates to all
instances running Amazon Linux.
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Note
The Amazon Linux AMI repository structure is configured to deliver a continuous flow of
updates that allow you to roll from one version of the Amazon Linux AMI to the next. To lock
existing instances to their current version, see Repository Configuration (p. 146).
To launch an Amazon Linux instance, use an Amazon Linux AMI. AWS provides Amazon Linux AMIs
to Amazon EC2 users at no additional cost.
Topics
• Finding the Amazon Linux AMI (p. 143)
• Launching and Connecting to an Amazon Linux Instance (p. 143)
• Identifying Amazon Linux AMI Images (p. 143)
• Included AWS Command Line Tools (p. 144)
• cloud-init (p. 145)
• Repository Configuration (p. 146)
• Adding Packages (p. 147)
• Accessing Source Packages for Reference (p. 147)
• Developing Applications (p. 148)
• Instance Store Access (p. 148)
• Product Life Cycle (p. 148)
• Security Updates (p. 148)
• Support (p. 149)

Finding the Amazon Linux AMI
For a list of the latest Amazon Linux AMIs, see Amazon Linux AMIs.

Launching and Connecting to an Amazon Linux
Instance
After locating your desired AMI, note the AMI ID. You can use the AMI ID to launch and then connect
to your instance.
Amazon Linux does not allow remote root SSH by default. Also, password authentication is disabled to
prevent brute-force password attacks. To enable SSH logins to an Amazon Linux instance, you must
provide your key pair to the instance at launch. You must also set the security group used to launch
your instance to allow SSH access. By default, the only account that can log in remotely using SSH is
ec2-user; this account also has sudo privileges. If you want to enable remote root log in, please be
aware that it is less secure than relying on key pairs and a secondary user.
For information about launching and using your Amazon Linux instance, see Launch Your
Instance (p. 278). For information about connecting to your Amazon Linux instance, see Connecting
to Your Linux Instance (p. 290).

Identifying Amazon Linux AMI Images
Each image contains a unique /etc/image-id that identifies the AMI. This file contains information
about the image.
The following is an example of the /etc/image-id file:

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[ec2-user ~]$ cat /etc/image-id
image_name="amzn-ami-hvm"
image_version="2016.03"
image_arch="x86_64"
image_file="amzn-ami-hvm-2016.03.3.x86_64.ext4.gpt"
image_stamp="72d4-6a2a"
image_date="20160621201058"
recipe_name="amzn ami"
recipe_id="0275ad70-5d13-1d50-a976-482a-73b6-2208-14cb7bc0"

The image_name, image_version, and image_arch items come from the build recipe that Amazon
used to construct the image. The image_stamp is simply a unique random hex value generated
during image creation. The image_date item is in YYYYMMDDhhmmss format, and is the UTC time
of image creation. The recipe_name and recipe_id refer to the name and ID of the build recipe
Amazon used to construct the image, which identifies the current running version of Amazon Linux.
This file will not change as you install updates from the yum repository.
Amazon Linux contains an /etc/system-release file that specifies the current release that is
installed. This file is updated through yum and is part of the system-release RPM.
The following is an example of an /etc/system-release file:
[ec2-user ~]$ cat /etc/system-release
Amazon Linux AMI release 2016.03

Amazon Linux also contains a machine readable version of the /etc/system-release file found in /
etc/system-release-cpe and follows the CPE specification from MITRE (CPE).

Included AWS Command Line Tools
The following popular command line tools for AWS integration and usage have been included in
Amazon Linux or in the default repositories:
• aws-amitools-ec2
• aws-apitools-as
• aws-apitools-cfn
• aws-apitools-ec2
• aws-apitools-elb
• aws-apitools-iam
• aws-apitools-mon
• aws-apitools-rds
• aws-cfn-bootstrap
• aws-cli
• aws-scripts-ses

Note
The minimal versions of Amazon Linux (amzn-ami-minimal-*) do not contain the above
packages; however, they are available in the default yum repositories, and you can install
them with the following command:
[ec2-user ~]$ sudo yum install -y package_name

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Although the aws-apitools-* command line tools are included with every Amazon Linux version, the
aws-cli command line tools provide a standard experience across all Amazon Web Services and will
eventually replace the service-specific tool sets.
For instances launched using IAM roles, a simple script has been included to prepare
AWS_CREDENTIAL_FILE, JAVA_HOME, AWS_PATH, PATH, and product-specific environment variables
after a credential file has been installed to simplify the configuration of these tools.
Also, to allow the installation of multiple versions of the API and AMI tools, we have placed symbolic
links to the desired versions of these tools in /opt/aws, as described here:
/opt/aws/bin
Symbolic links to /bin directories in each of the installed tools directories.
/opt/aws/{apitools|amitools}
Products are installed in directories of the form name-version and a symbolic link name that is
attached to the most recently installed version.
/opt/aws/{apitools|amitools}/name/environment.sh
Used by /etc/profile.d/aws-apitools-common.sh to set product-specific environment
variables, such as EC2_HOME.

cloud-init

The cloud-init package is an open source application built by Canonical that is used to bootstrap
Linux images in a cloud computing environment, such as Amazon EC2. Amazon Linux contains a
customized version of cloud-init. It enables you to specify actions that should happen to your
instance at boot time. You can pass desired actions to cloud-init through the user data fields when
launching an instance. This means you can use common AMIs for many use cases and configure them
dynamically at startup. Amazon Linux also uses cloud-init to perform initial configuration of the
ec2-user account.
For more information about cloud-init, see http://cloudinit.readthedocs.org/en/latest/.
Amazon Linux uses the following cloud-init actions (configurable in /etc/sysconfig/
cloudinit):
• action: INIT (always runs)
• Sets a default locale
• Sets the hostname
• Parses and handles user data
• action: CONFIG_SSH
• Generates host private SSH keys
• Adds a user's public SSH keys to .ssh/authorized_keys for easy login and administration
• action: PACKAGE_SETUP
• Prepares yum repo
• Handles package actions defined in user data
• action: RUNCMD
• Runs a shell command
• action: RUN_USER_SCRIPTS
• Executes user scripts found in user data
• action: CONFIG_MOUNTS
• Mounts ephemeral drives
• action: CONFIG_LOCALE
• Sets the locale in the locale configuration file according to user data

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Supported User-Data Formats
The cloud-init package supports user-data handling of a variety of formats:
• Gzip
• If user-data is gzip compressed, cloud-init decompresses the data and handles it
appropriately.
• MIME multipart
• Using a MIME multipart file, you can specify more than one type of data. For example, you could
specify both a user-data script and a cloud-config type. Each part of the multipart file can be
handled by cloud-init if it is one of the supported formats.
• Base64 decoding
• If user-data is base64-encoded, cloud-init determines if it can understand the decoded data as
one of the supported types. If it understands the decoded data, it decodes the data and handles it
appropriately. If not, it returns the base64 data intact.
• User-Data script
• Begins with #! or Content-Type: text/x-shellscript.
• The script is executed by /etc/init.d/cloud-init-user-scripts during the first boot cycle.
This occurs late in the boot process (after the initial configuration actions are performed).
• Include file
• Begins with #include or Content-Type: text/x-include-url.
• This content is an include file. The file contains a list of URLs, one per line. Each of the URLs is
read, and their content passed through this same set of rules. The content read from the URL can
be gzipped, MIME-multi-part, or plain text.
• Cloud Config Data
• Begins with #cloud-config or Content-Type: text/cloud-config.
• This content is cloud-config data. See the examples for a commented example of supported
configuration formats.
• Cloud Boothook
• Begins with #cloud-boothook or Content-Type: text/cloud-boothook.
• This content is boothook data. It is stored in a file under /var/lib/cloud and then executed
immediately.
• This is the earliest "hook" available. Note that there is no mechanism provided for running it
only one time. The boothook must take care of this itself. It is provided with the instance ID in
the environment variable INSTANCE_ID. Use this variable to provide a once-per-instance set of
boothook data.

Repository Configuration
Beginning with the 2011.09 release of Amazon Linux, Amazon Linux AMIs are treated as snapshots in
time, with a repository and update structure that always gives you the latest packages when you run
yum update -y.
The repository structure is configured to deliver a continuous flow of updates that allow you to roll from
one version of Amazon Linux to the next. For example, if you launch an instance from an older version
of the Amazon Linux AMI (such as 2015.09 or earlier) and run yum update -y, you end up with the
latest packages.
You can disable rolling updates for Amazon Linux by enabling the lock-on-launch feature. The lock-onlaunch feature locks your newly launched instance to receive updates only from the specified release
of the AMI. For example, you can launch a 2015.09 AMI and have it receive only the updates that were
released prior to the 2016.03 AMI, until you are ready to migrate to the 2016.03 AMI. To enable lock-

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on-launch in new instances, launch it with the following user data passed to cloud-init, using either
the Amazon EC2 console or the ec2-run-instances command with the -f flag.

Important
If you lock your AMI to a version of the repositories that is not latest, you will not receive
any further updates. The only way to receive a continuous flow of updates for the Amazon
Linux AMI is to be using the latest AMI, or to be consistently updating your old AMI with the
repositories pointed to latest.
#cloud-config
repo_releasever: 2015.09

To lock existing instances to their current AMI release version
1. Edit /etc/yum.conf.
2. Comment out releasever=latest.
3. Run yum clean all to clear the cache.

Adding Packages
Amazon Linux is designed to be used with online package repositories hosted in each Amazon EC2
region. These repositories provide ongoing updates to packages in the Amazon Linux AMI, as well
as access to hundreds of additional common open source server applications. The repositories are
available in all regions and are accessed using yum update tools, as well as on the Amazon Linux AMI
packages site. Hosting repositories in each region enables us to deploy updates quickly and without
any data transfer charges. The packages can be installed by issuing yum commands, such as the
following example:
[ec2-user ~]$ sudo yum install httpd

Access to the Extra Packages for Enterprise Linux (EPEL) repository is configured, but it is not enabled
by default. EPEL provides third-party packages in addition to those that are in the Amazon Linux
repositories. The third-party packages are not supported by AWS.
If you find that Amazon Linux does not contain an application you need, you can simply install the
application directly on your Amazon Linux instance. Amazon Linux uses RPMs and yum for package
management, and that is likely the simplest way to install new applications. You should always
check to see if an application is available in our central Amazon Linux repository first, because many
applications are available there. These applications can easily be added to your Amazon Linux
instance.
To upload your applications onto a running Amazon Linux instance, use scp or sftp and then
configure the application by logging on to your instance. Your applications can also be uploaded during
the instance launch by using the PACKAGE_SETUP action from the built-in cloud-init package. For
more information, see cloud-init (p. 145).

Important
If your instance is running in a virtual private cloud (VPC), you must attach an Internet
Gateway to the VPC in order to contact the yum repository. For more information, see Internet
Gateways in the Amazon VPC User Guide.

Accessing Source Packages for Reference
You can view the source of packages you have installed on your instance for reference purposes by
using tools provided in Amazon Linux. Source packages are available for all of the packages included

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in Amazon Linux and the online package repository. Simply determine the package name for the
source package you want to install and use the get_reference_source command to view source
within your running instance. For example:
[ec2-user ~]$ get_reference_source -p bash

The following is a sample response:
Requested package: bash
Found package from local RPM database: bash-4.2.46-19.35.amzn1.x86_64
Corresponding source RPM to found package : bash-4.2.46-19.35.amzn1.src.rpm
Are these parameters correct? Please type 'yes' to continue: yes
Source RPM downloaded to: /usr/src/srpm/debug/bash-4.2.46-19.35.amzn1.src.rpm

The source RPM is placed in the /usr/src/srpm/debug directory of your instance. From there, it
can be unpacked, and, for reference, you can view the source tree using standard RPM tools. After you
finish debugging, the package is available for use.

Developing Applications
A full set of Linux development tools is provided in the yum repository for Amazon Linux. To develop
applications on Amazon Linux, select the development tools you need with yum. Alternatively, many
applications developed on CentOS and other similar distributions should run on Amazon Linux.

Instance Store Access
The instance store drive ephemeral0 is mounted in /media/ephemeral0 only on Amazon instance
store-backed AMIs. This is different than many other images that mount the instance store drive under
/mnt.

Product Life Cycle
The Amazon Linux AMI is updated regularly with security and feature enhancements. If you do not
need to preserve data or customizations on your Amazon Linux instances, you can simply relaunch
new instances with the latest Amazon Linux AMI. If you need to preserve data or customizations for
your Amazon Linux instances, you can maintain those instances through the Amazon Linux yum
repositories. The yum repositories contain all the updated packages. You can choose to apply these
updates to your running instances.
Older versions of the AMI and update packages will continue to be available for use, even as new
versions are released. In some cases, if you're seeking support for an older version of Amazon Linux;
through AWS Support, we might ask you to move to newer versions as part of the support process.

Security Updates
Security updates are provided via the Amazon Linux AMI yum repositories as well as via updated
Amazon Linux AMIs. Security alerts are published in the Amazon Linux AMI Security Center. For more
information on AWS security policies or to report a security problem, go to the AWS Security Center.

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Amazon Linux AMIs are configured to download and install security updates at launch time. This is
controlled via a cloud-init setting called repo_upgrade. The following snippet of cloud-init
configuration shows how you can change the settings in the user data text you pass to your instance
initialization:
#cloud-config
repo_upgrade: security

The possible values for the repo_upgrade setting are as follows:
security
Apply outstanding updates that Amazon marks as security updates.
bugfix
Apply updates that Amazon marks as bug fixes. Bug fixes are a larger set of updates, which
include security updates and fixes for various other minor bugs.
all

Apply all applicable available updates, regardless of their classification.
none
Do not apply any updates to the instance on startup.

The default setting for repo_upgrade is security. That is, if you don't specify a different value in
your user data, by default, the Amazon Linux AMI performs the security upgrades at launch for any
packages installed at that time. The Amazon Linux AMI also notifies you of any updates to the installed
packages by listing the number of available updates upon login using the /etc/motd file. To install
these updates, you need to run sudo yum upgrade on the instance.

Support
Support for installation and use of the base Amazon Linux AMI is included through subscriptions to
AWS Support. For more information, see AWS Support.
We encourage you to post any questions you have about Amazon Linux to the Amazon EC2 forum.

User Provided Kernels
If you have a need for a custom kernel on your Amazon EC2 instances, you can start with an AMI that
is close to what you want, compile the custom kernel on your instance, and modify the menu.lst file
to point to the new kernel. This process varies depending on the virtualization type that your AMI uses.
For more information, see Linux AMI Virtualization Types (p. 74).
Contents
• HVM AMIs (GRUB) (p. 149)
• Paravirtual AMIs (PV-GRUB) (p. 150)

HVM AMIs (GRUB)
HVM instance volumes are treated like actual physical disks. The boot process is similar to that of a
bare metal operating system with a partitioned disk and bootloader, which allows it to work with all

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currently supported Linux distributions. The most common bootloader is GRUB, and the following
section describes configuring GRUB to use a custom kernel.

Configuring GRUB for HVM AMIs
The following is an example of a menu.lst configuration file for an HVM AMI. In this example, there
are two kernel entries to choose from: Amazon Linux 2016.03 (the original kernel for this AMI), and
Vanilla Linux 4.7.4 (a newer version of the Vanilla Linux kernel from https://www.kernel.org/).
The Vanilla entry was copied from the original entry for this AMI, and the kernel and initrd paths
were updated to the new locations. The default 0 parameter points the bootloader to the first entry
that it sees (in this case, the Vanilla entry), and the fallback 1 parameter points the bootloader to
the next entry if there is a problem booting the first.
By default, GRUB does not send its output to the instance console because it creates an extra boot
delay. For more information, see Instance Console Output (p. 806). If you are installing a custom
kernel, you should consider enabling GRUB output by deleting the hiddenmenu line and adding
serial and terminal lines to /boot/grub/menu.lst as shown in the example below.

Important
Avoid printing large amounts of debug information during the boot process; the serial console
does not support high rate data transfer.
default=0
fallback=1
timeout=5
serial --unit=0 --speed=9600
terminal --dumb --timeout=5 serial console
title Vanilla Linux 4.7.4
root (hd0)
kernel /boot/vmlinuz-4.7.4 root=LABEL=/ console=tty1 console=ttyS0
initrd /boot/initrd.img-4.7.4
title Amazon Linux 2016.03 (4.4.11-23.53.amzn1.x86_64)
root (hd0,0)
kernel /boot/vmlinuz-4.4.11-23.53.amzn1.x86_64 root=LABEL=/ console=tty1
console=ttyS0
initrd /boot/initramfs-4.4.11-23.53.amzn1.x86_64.img

You don't need to specify a fallback kernel in your menu.lst file, but we recommend that you have a
fallback when you test a new kernel. GRUB can fall back to another kernel in the event that the new
kernel fails. Having a fallback kernel allows the instance to boot even if the new kernel isn't found.
If your new Vanilla Linux kernel fails, the output will be similar to the example below.
^M Entry 0 will be booted automatically in 3 seconds. ^M Entry 0 will be
booted automatically in 2 seconds. ^M Entry 0 will be booted automatically
in 1 seconds.
Error 13: Invalid or unsupported executable format
[ 0.000000] Initializing cgroup subsys cpuset

Paravirtual AMIs (PV-GRUB)
Amazon Machine Images that use paravirtual (PV) virtualization use a system called PV-GRUB during
the boot process. PV-GRUB is a paravirtual bootloader that runs a patched version of GNU GRUB
0.97. When you start an instance, PV-GRUB starts the boot process and then chain loads the kernel
specified by your image's menu.lst file.

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PV-GRUB understands standard grub.conf or menu.lst commands, which allows it to work
with all currently supported Linux distributions. Older distributions such as Ubuntu 10.04 LTS,
Oracle Enterprise Linux or CentOS 5.x require a special "ec2" or "xen" kernel package, while newer
distributions include the required drivers in the default kernel package.
Most modern paravirtual AMIs use a PV-GRUB AKI by default (including all of the paravirtual Linux
AMIs available in the Amazon EC2 Launch Wizard Quick Start menu), so there are no additional steps
that you need to take to use a different kernel on your instance, provided that the kernel you want to
use is compatible with your distribution. The best way to run a custom kernel on your instance is to
start with an AMI that is close to what you want and then to compile the custom kernel on your instance
and modify the menu.lst file as shown in Configuring GRUB for Paravirtual AMIs (p. 151) to boot
with that kernel.
You can verify that the kernel image for an AMI is a PV-GRUB AKI by executing the following describeimages command with the Amazon EC2 command line tools (substituting the kernel image ID you want
to check:
$ aws ec2 describe-images --filters Name=image-id,Values=aki-880531cd

Check whether the Name field starts with pv-grub.
Topics
• Limitations of PV-GRUB (p. 151)
• Configuring GRUB for Paravirtual AMIs (p. 151)
• Amazon PV-GRUB Kernel Image IDs (p. 152)
• Updating PV-GRUB (p. 154)

Limitations of PV-GRUB
PV-GRUB has the following limitations:
• You can't use the 64-bit version of PV-GRUB to start a 32-bit kernel or vice versa.
• You can't specify an Amazon ramdisk image (ARI) when using a PV-GRUB AKI.
• AWS has tested and verified that PV-GRUB works with these file system formats: EXT2, EXT3,
EXT4, JFS, XFS, and ReiserFS. Other file system formats might not work.
• PV-GRUB can boot kernels compressed using the gzip, bzip2, lzo, and xz compression formats.
• Cluster AMIs don't support or need PV-GRUB, because they use full hardware virtualization (HVM).
While paravirtual instances use PV-GRUB to boot, HVM instance volumes are treated like actual
disks, and the boot process is similar to the boot process of a bare metal operating system with a
partitioned disk and bootloader.
• PV-GRUB versions 1.03 and earlier don't support GPT partitioning; they support MBR partitioning
only.
• If you plan to use a logical volume manager (LVM) with Amazon EBS volumes, you need a separate
boot partition outside of the LVM. Then you can create logical volumes with the LVM.

Configuring GRUB for Paravirtual AMIs
To boot PV-GRUB, a GRUB menu.lst file must exist in the image; the most common location for this
file is /boot/grub/menu.lst.
The following is an example of a menu.lst configuration file for booting an AMI with a PV-GRUB AKI.
In this example, there are two kernel entries to choose from: Amazon Linux 2016.03 (the original
kernel for this AMI), and Vanilla Linux 4.7.4 (a newer version of the Vanilla Linux kernel from

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https://www.kernel.org/). The Vanilla entry was copied from the original entry for this AMI, and the
kernel and initrd paths were updated to the new locations. The default 0 parameter points the
bootloader to the first entry it sees (in this case, the Vanilla entry), and the fallback 1 parameter
points the bootloader to the next entry if there is a problem booting the first.
default 0
fallback 1
timeout 0
hiddenmenu
title Vanilla Linux 4.7.4
root (hd0)
kernel /boot/vmlinuz-4.7.4 root=LABEL=/ console=hvc0
initrd /boot/initrd.img-4.7.4
title Amazon Linux 2016.03 (4.4.11-23.53.amzn1.x86_64)
root (hd0)
kernel /boot/vmlinuz-4.4.11-23.53.amzn1.x86_64 root=LABEL=/ console=hvc0
initrd /boot/initramfs-4.4.11-23.53.amzn1.x86_64.img

You don't need to specify a fallback kernel in your menu.lst file, but we recommend that you have
a fallback when you test a new kernel. PV-GRUB can fall back to another kernel in the event that the
new kernel fails. Having a fallback kernel allows the instance to boot even if the new kernel isn't found.
PV-GRUB checks the following locations for menu.lst, using the first one it finds:
• (hd0)/boot/grub
• (hd0,0)/boot/grub
• (hd0,0)/grub
• (hd0,1)/boot/grub
• (hd0,1)/grub
• (hd0,2)/boot/grub
• (hd0,2)/grub
• (hd0,3)/boot/grub
• (hd0,3)/grub
Note that PV-GRUB 1.03 and earlier only check one of the first two locations in this list.

Amazon PV-GRUB Kernel Image IDs
PV-GRUB AKIs are available in all Amazon EC2 regions. There are AKIs for both 32-bit and 64-bit
architecture types. Most modern AMIs use a PV-GRUB AKI by default.
We recommend that you always use the latest version of the PV-GRUB AKI, as not all versions of the
PV-GRUB AKI are compatible with all instance types. Use the following describe-images command to
get a list of the PV-GRUB AKIs for the current region:
$ aws ec2 describe-images --owners amazon --filters Name=name,Values=pv-grub*.gz

Note that PV-GRUB is the only AKI available in the ap-southeast-2 region. You should verify that
any AMI you want to copy to this region is using a version of PV-GRUB that is available in this region.
The following are the current AKI IDs for each region. Register new AMIs using an hd0 AKI.

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Note
We continue to provide hd00 AKIs for backward compatibility in regions where they were
previously available.

ap-northeast-1, Asia Pacific (Tokyo)
Image ID

Image Name

aki-136bf512

pv-grub-hd0_1.04-i386.gz

aki-176bf516

pv-grub-hd0_1.04-x86_64.gz

ap-northeast-2, Asia Pacific (Seoul)
Image ID

Image Name

aki-01a66b6f

pv-grub-hd0_1.04-x86_64.gz

ap-southeast-1, Asia Pacific (Singapore) Region
Image ID

Image Name

aki-ae3973fc

pv-grub-hd0_1.04-i386.gz

aki-503e7402

pv-grub-hd0_1.04-x86_64.gz

ap-southeast-2, Asia Pacific (Sydney)
Image ID

Image Name

aki-cd62fff7

pv-grub-hd0_1.04-i386.gz

aki-c362fff9

pv-grub-hd0_1.04-x86_64.gz

ap-south-1, Asia Pacific (Mumbai)
Image ID

Image Name

aki-a7305ac8

pv-grub-hd0_1.04-x86_64.gz

eu-central-1, EU (Frankfurt)
Image ID

Image Name

aki-3e4c7a23

pv-grub-hd0_1.04-i386.gz

aki-184c7a05

pv-grub-hd0_1.04-x86_64.gz

eu-west-1, EU (Ireland)
Image ID

Image Name

aki-68a3451f

pv-grub-hd0_1.04-i386.gz

aki-52a34525

pv-grub-hd0_1.04-x86_64.gz

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sa-east-1, South America (São Paulo)
Image ID

Image Name

aki-5b53f446

pv-grub-hd0_1.04-i386.gz

aki-5553f448

pv-grub-hd0_1.04-x86_64.gz

us-east-1, US East (N. Virginia)
Image ID

Image Name

aki-8f9dcae6

pv-grub-hd0_1.04-i386.gz

aki-919dcaf8

pv-grub-hd0_1.04-x86_64.gz

us-gov-west-1, AWS GovCloud (US)
Image ID

Image Name

aki-1fe98d3c

pv-grub-hd0_1.04-i386.gz

aki-1de98d3e

pv-grub-hd0_1.04-x86_64.gz

us-west-1, US West (N. California)
Image ID

Image Name

aki-8e0531cb

pv-grub-hd0_1.04-i386.gz

aki-880531cd

pv-grub-hd0_1.04-x86_64.gz

us-west-2, US West (Oregon)
Image ID

Image Name

aki-f08f11c0

pv-grub-hd0_1.04-i386.gz

aki-fc8f11cc

pv-grub-hd0_1.04-x86_64.gz

Updating PV-GRUB
We recommend that you always use the latest version of the PV-GRUB AKI, as not all versions of
the PV-GRUB AKI are compatible with all instance types. Also, older versions of PV-GRUB are not
available in all regions, so if you copy an AMI that uses an older version to a region that does not
support that version, you will be unable to boot instances launched from that AMI until you update the
kernel image. Use the following procedures to check your instance's version of PV-GRUB and update it
if necessary.

To check your PV-GRUB version
1.

Find the kernel ID for your instance.
$ ec2-describe-instance-attribute instance_id --kernel --region region

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kernel instance_id aki-fc8f11cc

The kernel ID for this instance is aki-fc8f11cc.
2.

View the version information of that kernel ID.
$ ec2-describe-images aki-fc8f11cc --region region
IMAGE aki-fc8f11cc amazon/pv-grub-hd0_1.04-x86_64.gz ...

This kernel image is PV-GRUB 1.04. If your PV-GRUB version is not the newest version (as
shown in Amazon PV-GRUB Kernel Image IDs (p. 152)), you should update it using the following
procedure.

To update your PV-GRUB version
If your instance is using an older version of PV-GRUB, you should update it to the latest version.
1.

Identify the latest PV-GRUB AKI for your region and processor architecture from Amazon PVGRUB Kernel Image IDs (p. 152).

Stop your instance. Your instance must be stopped to modify the kernel image used.
$ ec2-stop-instances instance_id --region region
INSTANCE instance_id stopped stopped

Modify the kernel image used for your instance.
$ ec2-modify-instance-attribute --kernel kernel_id -region region instance_id

Restart your instance.
$ ec2-start-instances --region region instance_id

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Amazon EC2 Instances
If you're new to Amazon EC2, see the following topics to get started:
• What Is Amazon EC2? (p. 1)
• Setting Up with Amazon EC2 (p. 19)
• Getting Started with Amazon EC2 Linux Instances (p. 26)
• Instance Lifecycle (p. 275)
Before you launch a production environment, you need to answer the following questions.
Q. What instance type best meets my needs?
Amazon EC2 provides different instance types to enable you to choose the CPU, memory,
storage, and networking capacity that you need to run your applications. For more information, see
Instance Types (p. 156).
Q. What purchasing option best meets my needs?
Amazon EC2 supports On-Demand instances (the default), Spot instances, and Reserved
Instances. For more information, see Instance Purchasing Options (p. 193).
Q. Which type of root volume meets my needs?
Each instance is backed by Amazon EBS or backed by instance store. Select an AMI based
on which type of root volume you need. For more information, see Storage for the Root
Device (p. 71).
Q. Would I benefit from using a virtual private cloud?
If you can launch instances in either EC2-Classic or EC2-VPC, you'll need to decide which
platform meets your needs. For more information, see Supported Platforms (p. 549) and Amazon
EC2 and Amazon Virtual Private Cloud (p. 543).

Instance Types
When you launch an instance, the instance type that you specify determines the hardware of the host
computer used for your instance. Each instance type offers different compute, memory, and storage
capabilities and are grouped in instance families based on these capabilities. Select an instance type
based on the requirements of the application or software that you plan to run on your instance.
Amazon EC2 provides each instance with a consistent and predictable amount of CPU capacity,
regardless of its underlying hardware.

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Amazon EC2 dedicates some resources of the host computer, such as CPU, memory, and instance
storage, to a particular instance. Amazon EC2 shares other resources of the host computer, such as
the network and the disk subsystem, among instances. If each instance on a host computer tries to use
as much of one of these shared resources as possible, each receives an equal share of that resource.
However, when a resource is under-utilized, an instance can consume a higher share of that resource
while it's available.
Each instance type provides higher or lower minimum performance from a shared resource. For
example, instance types with high I/O performance have a larger allocation of shared resources.
Allocating a larger share of shared resources also reduces the variance of I/O performance. For most
applications, moderate I/O performance is more than enough. However, for applications that require
greater or more consistent I/O performance, consider an instance type with higher I/O performance.

Contents
• Available Instance Types (p. 157)
• Hardware Specifications (p. 158)
• Virtualization Types (p. 158)
• Networking and Storage Features (p. 158)
• Instance Limits (p. 159)

Available Instance Types
Amazon EC2 provides the instance types listed in the following tables.

Current Generation Instances
For the best performance, we recommend that you use the current generation instance types when you
launch new instances. For more information about the current generation instance types, see Amazon
EC2 Instances.
Instance Family

Current Generation Instance Types

General purpose

Compute optimized

Memory optimized

Storage optimized

GPU instances

g2.2xlarge | g2.8xlarge

Previous Generation Instances
Amazon Web Services offers previous generation instances for users who have optimized their
applications around these instances and have yet to upgrade. We encourage you to use the latest
generation of instances to get the best performance, but we will continue to support these previous

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generation instances. If you are currently using a previous generation instance, you can see which
current generation instance would be a suitable upgrade. For more information, see Previous
Generation Instances.
Instance Family

Previous Generation Instance Types

General purpose

m1.small | m1.medium | m1.large | m1.xlarge

Compute optimized

c1.medium | c1.xlarge | cc2.8xlarge

Memory optimized

m2.xlarge | m2.2xlarge | m2.4xlarge | cr1.8xlarge

Storage optimized

hi1.4xlarge | hs1.8xlarge

GPU instances

cg1.4xlarge

Micro instances

t1.micro

Hardware Specifications
For more information about the hardware specifications for each Amazon EC2 instance type, see
Amazon EC2 Instances.
To determine which instance type best meets your needs, we recommend that you launch an instance
and use your own benchmark application. Because you pay by the instance hour, it's convenient and
inexpensive to test multiple instance types before making a decision.
Even after you make a decision, if your needs change, you can resize your instance later on. For more
information, see Resizing Your Instance (p. 189).

Virtualization Types
Each instance type supports one or both of the following types of virtualization: paravirtual (PV) or
hardware virtual machine (HVM). The virtualization type of your instance is determined by the AMI that
you use to launch it.
For best performance, we recommend that you use an HVM AMI. In addition, HVM AMIs are required
to take advantage of enhanced networking. HVM virtualization uses hardware-assist technology
provided by the AWS platform. With HVM virtualization, the guest VM runs as if it were on a native
hardware platform, except that it still uses PV network and storage drivers for improved performance.
For more information, see Linux AMI Virtualization Types (p. 74).

Networking and Storage Features
When you select an instance type, this determines which of the following networking and storage
features are available:
• Some instance types are not available in EC2-Classic, so you must launch them in a VPC. By
launching an instance in a VPC, you can leverage features that are not available in EC2-Classic,
such as enhanced networking, assigning multiple private IP addresses to the instance, and changing
the security groups assigned to your instance. For more information, see Instance Types Available
Only in a VPC (p. 548).
• Some instance types support EBS volumes and instance store volumes, while other instance
types support only EBS volumes. Some instances that support instance store volumes use
solid state drives (SSD) to deliver very high random I/O performance. For more information, see
Storage (p. 633).

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• To obtain additional, dedicated capacity for Amazon EBS I/O, you can launch some instance
types as EBS–optimized instances. Some instance types are EBS–optimized by default. For more
information, see Amazon EBS–Optimized Instances (p. 692).
• To maximize the networking and bandwidth performance of your instance type, you can do the
following:
• Launch supported instance types into a placement group to optimize your instances for high
performance computing (HPC) applications. Instances in a common placement group can benefit
from high-bandwidth (10 Gbps), low-latency networking. For more information, see Placement
Groups (p. 602). Instance types that support 10 Gbps network speeds can only take advantage
of those network speeds when launched in a placement group.
• Enable enhanced networking for supported current generation instance types to get significantly
higher packet per second (PPS) performance, lower network jitter, and lower latencies. For more
information, see Enhanced Networking on Linux (p. 608).
• The maximum supported MTU varies across instance types. All Amazon EC2 instance types support
standard Ethernet V2 1500 MTU frames. All current generation instances support 9001 MTU, or
jumbo frames, and some previous generation instances support them as well. For more information,
see Network Maximum Transmission Unit (MTU) for Your EC2 Instance (p. 605).
The following table summarizes the networking and storage features supported by the current
generation instance types.
VPC only

EBS only

C3
C4

Yes

SSD
volumes

Placement
group

Yes

HVM only

Enhanced
networking
Intel 82599
VF

Yes

Intel 82599
VF

Yes

Intel 82599
VF

Yes

Intel 82599
VF

Yes
Yes

Yes

Intel 82599
VF

Yes

Intel 82599
VF

Yes

Yes
Yes

Yes

ENA

Instance Limits
There is a limit on the total number of instances that you can launch in a region, and there are
additional limits on some instance types.
For more information about the default limits, see How many instances can I run in Amazon EC2?

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For more information about viewing your current limits or requesting an increase in your current limits,
see Amazon EC2 Service Limits (p. 760).

T2 Instances
T2 instances are designed to provide moderate baseline performance and the capability to burst to
significantly higher performance as required by your workload. They are intended for workloads that
don't use the full CPU often or consistently, but occasionally need to burst. T2 instances are well suited
for general purpose workloads, such as web servers, developer environments, and small databases.
For more information about T2 instance pricing and additional hardware details, see Amazon EC2
Instances.
If your account is less than 12 months old, you can use a t2.micro instance for free within certain
usage limits. For more information, see AWS Free Tier.
Contents
• Hardware Specifications (p. 160)
• T2 Instance Requirements (p. 160)
• CPU Credits (p. 161)
• Monitoring Your CPU Credits (p. 162)

Hardware Specifications
For more information about the hardware specifications for each Amazon EC2 instance type, see
Amazon EC2 Instances.

T2 Instance Requirements
The following are the requirements for T2 instances:
• You must launch your T2 instances into a virtual private cloud (VPC); they are not supported on the
EC2-Classic platform. Amazon VPC enables you to launch AWS resources into a virtual network
that you've defined. You cannot change the instance type of an existing instance in EC2-Classic
to a T2 instance type. For more information about EC2-Classic and EC2-VPC, see Supported
Platforms (p. 549) For more information about launching a VPC-only instance, see Instance Types
Available Only in a VPC (p. 548).
• You must launch a T2 instance using an HVM AMI. For more information, see Linux AMI
Virtualization Types (p. 74).
• You must launch your T2 instances using an EBS volume as the root device. For more information,
see Amazon EC2 Root Device Volume (p. 14).
• T2 instances are available as On-Demand instances and Reserved Instances, but they are not
available as Spot instances, Scheduled Instances, or Dedicated instances. They are also not
supported on a Dedicated Host. For more information about these options, see Instance Purchasing
Options (p. 193).
• There is a limit on the total number of instances that you can launch in a region, and there
are additional limits on some instance types. By default, you can run up to 20 T2 instances
simultaneously. If you need more T2 instances, you can request them using the Amazon EC2
Instance Request Form.
• Ensure that the T2 instance size you choose passes the minimum memory requirements of your
operating system and applications. Operating systems with graphical user interfaces that consume
significant memory and CPU resources (for example, Windows) may require a t2.micro, or larger,
instance size for many use cases. As the memory and CPU requirements of your workload grows
over time, you can scale to larger T2 instance sizes, or other EC2 instance types.

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CPU Credits
A CPU Credit provides the performance of a full CPU core for one minute. Traditional Amazon
EC2 instance types provide fixed performance, while T2 instances provide a baseline level of CPU
performance with the ability to burst above that baseline level. The baseline performance and ability to
burst are governed by CPU credits.
What is a CPU credit?
One CPU credit is equal to one vCPU running at 100% utilization for one minute. Other combinations
of vCPUs, utilization, and time are also equal to one CPU credit; for example, one vCPU running at
50% utilization for two minutes or two vCPUs running at 25% utilization for two minutes.
How are CPU credits earned?
Each T2 instance starts with a healthy initial CPU credit balance and then continuously (at a
millisecond-level resolution) receives a set rate of CPU credits per hour, depending on instance size.
The accounting process for whether credits are accumulated or spent also happens at a millisecondlevel resolution, so you don't have to worry about overspending CPU credits; a short burst of CPU
takes a small fraction of a CPU credit.
When a T2 instance uses fewer CPU resources than its base performance level allows (such as when
it is idle), the unused CPU credits (or the difference between what was earned and what was spent)
are stored in the credit balance for up to 24 hours, building CPU credits for bursting. When your T2
instance requires more CPU resources than its base performance level allows, it uses credits from the
CPU credit balance to burst up to 100% utilization. The more credits your T2 instance has for CPU
resources, the more time it can burst beyond its base performance level when more performance is
needed.
The following table lists the initial CPU credit allocation received at launch, the rate at which CPU
credits are received, the baseline performance level as a percentage of a full core performance, and
the maximum earned CPU credit balance that an instance can accrue.
Instance type

Initial
CPU credits earned per hour
CPU
credit*

Base
performance
(CPU utilization)

Maximum earned
CPU credit
balance***

t2.nano

30 3

t2.micro

30 6

10%

144

t2.small

30 12

20%

288

t2.medium

60 24

40%**

576

t2.large

60 36

60%**

864

* There are limits to how many T2 instances will launch or start with the initial CPU credit, which
by default is set to 100 launches or starts of any T2 instance per account, per 24-hour period, per
region. If you'd like to increase this limit, you can file a customer support limit increase request by
using the Amazon EC2 Credit Based Instances Launch Credits Form. If your account does not
launch or start more than 100 T2 instances in 24 hours, this limit will not affect you.
** t2.medium and t2.large instances have two vCPUs. The base performance is an aggregate
of the two vCPUs. For example, if you use 100% of a single vCPU and a small amount of the other,
your CloudWatch metrics will show over 50% utilization.
*** This maximum does not include the initial CPU credits, which are used first and do not expire. For
example, a t2.micro instance that was launched and then remained idle for over 24 hours could
reach a credit balance of up to 174 (30 initial CPU credits + 144 earned credits). However, once the

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instance uses the initial 30 CPU credits, the credit balance can never exceed 144 unless a new initial
CPU credit balance is issued by stopping and starting the instance again.

The initial credit balance is designed to provide a good startup experience. The maximum earned credit
balance for an instance is equal to the number of CPU credits received per hour times 24 hours. For
example, a t2.micro instance earns 6 CPU credits per hour and can accumulate a maximum earned
CPU credit balance of 144 CPU credits.
Do CPU credits expire?
Initial CPU credits do not expire, but they are used first when an instance uses CPU credits. Unused
earned credits from a given 5 minute interval expire 24 hours after they are earned, and any expired
credits are removed from the CPU credit balance at that time, before any newly earned credits are
added. Additionally, the CPU credit balance for an instance does not persist between instance stops
and starts; stopping an instance causes it to lose its credit balance entirely, but when it restarts it will
receive its initial credit balance again.
For example, if a t2.small instance had a CPU utilization of 5% for the hour, it would have used
3 CPU credits (5% of 60 minutes), but it would have earned 12 CPU credits during the hour, so the
difference of 9 CPU credits would be added to the CPU credit balance. Any CPU credits in the balance
that reached their 24 hour expiration date during that time (which could be as many as 12 credits if the
instance was completely idle 24 hours ago) would also be removed from the balance. If the amount of
credits expired is greater than those earned, the credit balance will go down; conversely, if the amount
of credits expired is fewer than those earned, the credit balance will go up.
What happens if I use all of my credits?
If your instance uses all of its CPU credit balance, performance remains at the baseline performance
level. If your instance is running low on credits, your instance’s CPU credit consumption (and therefore
CPU performance) is gradually lowered to the base performance level over a 15-minute interval, so
you will not experience a sharp performance drop-off when your CPU credits are depleted. If your
instance consistently uses all of its CPU credit balance, we recommend a larger T2 size or a fixed
performance instance type such as M3 or C3.

Monitoring Your CPU Credits
You can see the credit balance for each T2 instance presented in the Amazon EC2 per-instance
metrics of the CloudWatch console. T2 instances have two metrics, CPUCreditUsage and
CPUCreditBalance. The CPUCreditUsage metric indicates the number of CPU credits used during
the measurement period. The CPUCreditBalance metric indicates the number of unused CPU credits
a T2 instance has earned. This balance is depleted during burst time as CPU credits are spent more
quickly than they are earned.
The following table describes the new available CloudWatch metrics. For more information about using
these metrics in CloudWatch, see List the Available CloudWatch Metrics for Your Instances (p. 421).
Metric

Description

CPUCreditUsage

(Only valid for T2 instances) The number of CPU credits
consumed during the specified period.
This metric identifies the amount of time during which physical
CPUs were used for processing instructions by virtual CPUs
allocated to the instance.

Note
CPU Credit metrics are available at a 5 minute frequency.
Units: Count

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Metric

Description

CPUCreditBalance

(Only valid for T2 instances) The number of CPU credits that an
instance has accumulated.
This metric is used to determine how long an instance can burst
beyond its baseline performance level at a given rate.

Note
CPU Credit metrics are available at a 5 minute frequency.
Units: Count

C4 Instances
C4 instances are ideal for compute-bound applications that benefit from high performance processors.
C4 instances are well suited for the following applications:
• Batch processing workloads
• Media transcoding
• High-traffic web servers, massively multiplayer online (MMO) gaming servers, and ad serving
engines
• High performance computing (HPC) and other compute-intensive applications
Contents
• Hardware Specifications (p. 163)
• C4 Instance Features (p. 164)
• C4 Instance Requirements (p. 164)
• Support for 36 vCPUs (p. 165)

Hardware Specifications
C4 instances are based on custom 2.9 GHz Intel Xeon E5-2666 v3 (Haswell) processors, optimized
specifically for Amazon EC2. With Intel Turbo Boost Technology, the processor clock speed in C4
instances can reach as high as 3.5Ghz with 1 or 2 core Turbo Boost on c4.8xlarge instances.
The following table highlights the feature set of the Intel Xeon E5-2666 v3 processor. For more
information, see Intel and Amazon Web Services.
Feature

Specification

Processor Number

E5-2666 v3

Intel Smart Cache

25 MiB

Instruction Set

64-bit

Instruction Set Extensions

AVX 2.0

Lithography

22 nm

Processor Base Frequency

2.9 GHz

Max All Core Turbo Frequency

3.2 GHz

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Feature

Specification

Max Turbo Frequency

3.5 GHz (available on c4.8xlarge)

Intel Turbo Boost Technology

2.0

Intel vPro Technology

Yes

Intel Hyper-Threading Technology

Yes

Intel 64

Yes

Idle States

Yes

Enhanced Intel SpeedStep Technology

Yes

Thermal Monitoring Technologies

Yes

AES New Instructions

Yes

Secure Key

Yes

Execute Disable Bit

Yes

For more information about the hardware specifications for each Amazon EC2 instance type, see
Amazon EC2 Instances.

C4 Instance Features
The following is a summary of the features for C4 instances:
• C4 instances are EBS-optimized by default, and deliver dedicated block storage throughput to
Amazon EBS ranging from 500 Mbps to 4,000 Mbps at no additional cost. EBS-optimized instances
enable you to get consistently high performance for your EBS volumes by eliminating contention
between Amazon EBS I/O and other network traffic from your C4 instance. For more information,
see Amazon EBS–Optimized Instances (p. 692).
• You can enable enhanced networking capabilities. Enhanced networking provides significantly
higher packet per second (PPS) performance, lower network jitter, and lower latencies. For more
information, see Enhanced Networking on Linux (p. 608).
• You can cluster C4 instances in a placement group. Placement groups provide low latency and highbandwidth connectivity between the instances within a single Availability Zone. For more information,
see Placement Groups (p. 602).
• The c4.8xlarge instance type provides the ability to control processor C-states and P-states
on Linux. C-states control the sleep levels that a core can enter when it is inactive, while P-states
control the desired performance (in CPU frequency) from a core. For more information, see
Processor State Control for Your EC2 Instance (p. 322).

C4 Instance Requirements
The following are the requirements for C4 instances:
• C4 instances require 64-bit HVM AMIs. They have high-memory (up to 60 GiB of RAM), and
require a 64-bit operating system to take advantage of that capacity. HVM AMIs provide superior
performance in comparison to paravirtual (PV) AMIs on high-memory instance types. In addition, you
must use an HVM AMI to take advantage of enhanced networking.
• You must launch your C4 instances into a virtual private cloud (VPC); they are not supported
on the EC2-Classic platform. Amazon VPC enables you to launch AWS resources into a virtual

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network that you've defined. For more information about EC2-Classic and EC2-VPC, see Supported
Platforms (p. 549) For more information about launching a VPC-only instance, see Instance Types
Available Only in a VPC (p. 548).
• There is a limit on the total number of instances that you can launch in a region, and there are
additional limits on some C4 instance types. For more information, see How many instances can I
run in Amazon EC2?
If you need more C4 instances, you can request them using the Amazon EC2 Instance Request
Form.

Support for 36 vCPUs
The c4.8xlarge instance type provides 36 vCPUs, which might cause launch issues in some Linux
operating systems that have a vCPU limit of 32. We strongly recommend that you use the latest AMIs
when you launch c4.8xlarge instances.
The following Linux AMIs support launching c4.8xlarge instances with 36 vCPUs:
• Amazon Linux AMI 2016.03 (HVM)
• Ubuntu Server 14.04 LTS (HVM)
• Red Hat Enterprise Linux 7.1 (HVM)
• SUSE Linux Enterprise Server 12 (HVM)
If you must use a different AMI for your application, and your c4.8xlarge instance launch does not
complete successfully (for example, if your instance status changes to stopped during launch with a
Client.InstanceInitiatedShutdown state transition reason), modify your instance as described
in the following procedure to support more than 32 vCPUs so that you can use the c4.8xlarge
instance type.

To update an instance to support more than 32 vCPUs
1.

Launch a C4 instance using your AMI, choosing any C4 instance type other than c4.8xlarge.

Update the kernel to the latest version by following your operating system-specific instructions. For
example, for RHEL 6, use the sudo yum update -y kernel command.

3.
4.

Stop the instance.
(Optional) Create an AMI from the instance that you can use to launch any additional c4.8xlarge
instances that you need in the future.
Change the instance type of your stopped instance to c4.8xlarge (choose Actions, select
Instance Settings, choose Change Instance Type, and then follow the directions).
Start the instance. If the instance launches properly, you are done. If the instance still does not
boot properly, proceed to the next step.
(Optional) If the instance still does not boot properly, the kernel on your instance may not support
more than 32 vCPUs. However, you may be able to boot the instance if you limit the vCPUs.

5.
6.
7.

Change the instance type of your stopped instance to any C4 instance type other than
c4.8xlarge (choose Actions, select Instance Settings, choose Change Instance Type,
and then follow the directions).

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hiddenmenu
title Red Hat Enterprise Linux Server (2.6.32-504.3.3.el6.x86_64)
root (hd0,0)
kernel /boot/vmlinuz-2.6.32-504.3.3.el6.x86_64 maxcpus=32
console=ttyS0 ro root=UUID=9996863e-b964-47d3-a33b-3920974fdbd9
rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8
xen_blkfront.sda_is_xvda=1 console=ttyS0,115200n8 console=tty0
rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_NO_LVM
rd_NO_DM
initrd /boot/initramfs-2.6.32-504.3.3.el6.x86_64.img

Stop the instance.

(Optional) Create an AMI from the instance that you can use to launch any additional
c4.8xlarge instances that you need in the future.

Change the instance type of your stopped instance to c4.8xlarge (choose Actions, select
Instance Settings, choose Change Instance Type, and then follow the directions).

Start the instance.

Linux GPU Instances
If you require high parallel processing capability, you'll benefit from using GPU instances, which
provide access to NVIDIA GPUs with up to 1,536 CUDA cores and 4 GB of video memory. You
can use GPU instances to accelerate many scientific, engineering, and rendering applications
by leveraging the Compute Unified Device Architecture (CUDA) or OpenCL parallel computing
frameworks. You can also use them for graphics applications, including game streaming, 3-D
application streaming, and other graphics workloads.
GPU instances run as HVM-based instances. Hardware virtual machine (HVM) virtualization uses
hardware-assist technology provided by the AWS platform. With HVM virtualization, the guest VM runs
as if it were on a native hardware platform, except that it still uses paravirtual (PV) network and storage
drivers for improved performance. This enables Amazon EC2 to provide dedicated access to one or
more discrete GPUs in each GPU instance.
You can cluster GPU instances into a placement group. Placement groups provide low latency
and high-bandwidth connectivity between the instances within a single Availability Zone. For more
information, see Placement Groups (p. 602).
Contents
• Hardware Specifications (p. 166)
• GPU Instance Limitations (p. 166)
• AMIs for GPU Instances (p. 167)
• Installing the NVIDIA Driver on Linux (p. 167)
For information about Windows GPU Instances, see Windows GPU Instances in the Amazon EC2 User
Guide for Windows Instances.

Hardware Specifications
For more information about the hardware specifications for each Amazon EC2 instance type, see
Amazon EC2 Instances.

GPU Instance Limitations
GPU instances have the following limitations:

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• You must launch the instance using an HVM AMI.
• They can't access the GPU unless the NVIDIA drivers are installed.
• There is a limit on the number of instances that you can run. For more information, see How many
instances can I run in Amazon EC2? in the Amazon EC2 FAQ. To request an increase in these
limits, use the following form: Request to Increase Amazon EC2 Instance Limit.

AMIs for GPU Instances
To help you get started, NVIDIA provides AMIs for GPU instances. These reference AMIs include the
NVIDIA driver, which enables full functionality and performance of the NVIDIA GPUs. For a list of AMIs
with the NVIDIA driver, see AWS Marketplace (NVIDIA GRID).
You can launch CG1 and G2 instances using any HVM AMI.

Installing the NVIDIA Driver on Linux
A GPU instance must have the appropriate NVIDIA driver. The NVIDIA driver you install must be
compiled against the kernel that you intend to run on your instance.
Amazon provides AMIs with updated and compatible builds of the NVIDIA kernel drivers for each
official kernel upgrade in the AWS Marketplace. If you decide to use a different NVIDIA driver version
than the one that Amazon provides, or decide to use a kernel that's not an official Amazon build, you
must uninstall the Amazon-provided NVIDIA packages from your system to avoid conflicts with the
versions of the drivers that you are trying to install.
Use this command to uninstall Amazon-provided NVIDIA packages:
[ec2-user ~]$ sudo yum erase nvidia cuda

The Amazon-provided CUDA toolkit package has dependencies on the NVIDIA drivers. Uninstalling
the NVIDIA packages erases the CUDA toolkit. You must reinstall the CUDA toolkit after installing the
NVIDIA driver.
You can download NVIDIA drivers from http://www.nvidia.com/Download/Find.aspx. Select the
appropriate driver for your instance:

G2 Instances
Product Type

GRID

Product Series

GRID Series

Product

GRID K520

Operating System

Linux 64-bit

Recommended/Beta

Recommended/Certified

CG1 Instances
Product Type

Tesla

Product Series

M-Class

Product

M2050

Operating System

Linux 64-bit

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Recommended/Beta

Recommended/Certified

For more information about installing and configuring the driver, open the ADDITIONAL
INFORMATION tab on the download page for the driver on the NVIDIA website and click the README
link.

Install the NVIDIA Driver Manually
To install the driver for an Amazon Linux AMI
1.

Run the yum update command to get the latest versions of packages for your instance.
[ec2-user ~]$ sudo yum update -y

Reboot your instance to load the latest kernel version.
[ec2-user ~]$ sudo reboot

Reconnect to your instance after it has rebooted.

Install the "Development tools" package group.
[ec2-user ~]$ sudo yum groupinstall -y "Development tools"

Make sure the kernel-devel package is installed and matches the version of the kernel you are
currently running.
[ec2-user ~]$ sudo yum install kernel-devel-`uname -r`

Download the driver package that you identified earlier. For example, the following command
downloads the 361.45.11 version of the G2 instance driver.
[ec2-user ~]$ wget http://us.download.nvidia.com/XFree86/Linuxx86_64/361.45.11/NVIDIA-Linux-x86_64-361.45.11.run

Run the self-install script to install the NVIDIA driver. For example:
[ec2-user ~]$ sudo /bin/bash ./NVIDIA-Linux-x86_64-361.45.11.run

Reboot the instance. For more information, see Reboot Your Instance (p. 302).

Confirm that the driver is functional. The response for the following command lists the installed
NVIDIA driver version and details about the GPUs.
[ec2-user ~]$ nvidia-smi -q | head
==============NVSMI LOG==============
Timestamp
Driver Version

: Thu Oct 2 17:28:29 2014
: 361.45.11

Attached GPUs
GPU 0000:00:03.0
Product Name
Product Brand

: 1
: GRID K520
: Grid

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I2 Instances
I2 instances are optimized to deliver tens of thousands of low-latency, random I/O operations per
second (IOPS) to applications. They are well suited for the following scenarios:
• NoSQL databases (for example, Cassandra and MongoDB)
• Clustered databases
• Online transaction processing (OLTP) systems
Contents
• Hardware Specifications (p. 169)
• I2 Instance Features (p. 169)
• I2 Instance Requirements (p. 169)
• SSD I/O Performance (p. 170)

Hardware Specifications
For more information about the hardware specifications for each Amazon EC2 instance type, see
Amazon EC2 Instances.

I2 Instance Features
The following is a summary of the features for I2 instances:
• The primary data storage is SSD-based instance storage. Like all instance storage, these volumes
persist only for the life of the instance. When you stop or terminate an instance, the applications
and data in its instance store are erased. We recommend that you regularly back up or replicate
the data that you've stored in instance storage. For more information, see SSD Instance Store
Volumes (p. 722).
• You can enable enhanced networking capabilities. Enhanced networking provides significantly
higher packet per second (PPS) performance, lower network jitter, and lower latencies. For more
information, see Enhanced Networking on Linux (p. 608).
• You can cluster I2 instances in a placement group. Placement groups provide low latency and highbandwidth connectivity between the instances within a single Availability Zone. For more information,
see Placement Groups (p. 602).
• You can enable EBS–optimization to obtain additional, dedicated capacity for Amazon EBS I/O. For
more information, see Amazon EBS–Optimized Instances (p. 692).

I2 Instance Requirements
The following are the requirements for I2 instances:
• You must launch an I2 instance using an HVM AMI.
• To ensure the best IOPS performance from your instance on Linux, we recommend that you use the
most recent version of the Amazon Linux AMI, or another Linux AMI with a kernel version of 3.8 or
later. If you do not use a Linux AMI with a kernel version of 3.8 or later, your instance will not achieve
the maximum IOPS performance available for this instance type. For more information, see SSD I/O
Performance (p. 170).
• There is a limit on the total number of instances that you can launch in a region, and there are
additional limits on some I2 instance types. For more information, see How many instances can I run
in Amazon EC2?

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If you need more I2 instances, you can request them using the Amazon EC2 Instance Request
Form.

SSD I/O Performance
If you use a Linux AMI with kernel version 3.8 or later and utilize all the SSD-based instance store
volumes available to the instance, you can get at least the minimum random IOPS (4,096 byte block
size) listed in the following table. Otherwise, you'll get lower IOPS performance than what is shown in
the table.
Instance Size

Read IOPS

First Write IOPS

i2.xlarge

35,000

i2.2xlarge

75,000

i2.4xlarge

175,000

155,000

i2.8xlarge

365,000

315,000

As you fill the SSD-based instance storage for your instance, the number of write IOPS that you
can achieve decreases. This is due to the extra work the SSD controller must do to find available
space, rewrite existing data, and erase unused space so that it can be rewritten. This process of
garbage collection results in internal write amplification to the SSD, expressed as the ratio of SSD write
operations to user write operations. This decrease in performance is even larger if the write operations
are not in multiples of 4,096 bytes or not aligned to a 4,096-byte boundary. If you write a smaller
amount of bytes or bytes that are not aligned, the SSD controller must read the surrounding data and
store the result in a new location. This pattern results in significantly increased write amplification,
increased latency, and dramatically reduced I/O performance.
SSD controllers can use several strategies to reduce the impact of write amplification. One such
strategy is to reserve space in the SSD instance storage so that the controller can more efficiently
manage the space available for write operations. This is called over-provisioning. The SSD-based
instance store volumes provided to an I2 instance don't have any space reserved for over-provisioning.
To reduce write amplification, you should leave 10% of the volume unpartitioned so that the SSD
controller can use it for over-provisioning. This decreases the storage that you can use, but increases
performance.
I2 instance store–backed volumes support TRIM. You can use the TRIM command to notify the SSD
controller whenever you no longer need data that you've written. This provides the controller with more
free space, which can reduce write amplification and increase performance. For more information, see
Instance Store Volume TRIM Support (p. 722).

D2 Instances
D2 instances are designed for workloads that require high sequential read and write access to very
large data sets on local storage. D2 instances are well suited for the following applications:
• Massive parallel processing (MPP) data warehouse
• MapReduce and Hadoop distributed computing
• Log or data processing applications
Contents
• Hardware Specifications (p. 171)

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D2 Instances

• D2 Instance Features (p. 171)
• D2 Instance Requirements (p. 171)
• Support for 36 vCPUs (p. 172)

Hardware Specifications
For more information about the hardware specifications for each Amazon EC2 instance type, see
Amazon EC2 Instances.

D2 Instance Features
The following is a summary of the features for D2 instances:
• The primary data storage for D2 instances is HDD-based instance storage. Like all instance storage,
these volumes persist only for the life of the instance. For more information about instance store
volumes, see Amazon EC2 Instance Store (p. 715).
• D2 instances are EBS-optimized by default, and deliver dedicated block storage throughput to
Amazon EBS ranging from 750 Mbps to 4,000 Mbps at no additional cost. EBS-optimized instances
enable you to get consistently high performance for your EBS volumes by eliminating contention
between Amazon EBS I/O and other network traffic from your D2 instance. For more information,
see Amazon EBS–Optimized Instances (p. 692).
• You can enable enhanced networking capabilities. Enhanced networking provides significantly
higher packet per second (PPS) performance, lower network jitter, and lower latencies. For more
information, see Enhanced Networking on Linux (p. 608).
• You can cluster D2 instances in a placement group. Placement groups provide low latency and highbandwidth connectivity between the instances within a single Availability Zone. For more information,
see Placement Groups (p. 602).
• The d2.8xlarge instance type provides the ability to control processor C-states and P-states
on Linux. C-states control the sleep levels that a core can enter when it is inactive, while P-states
control the desired performance (in CPU frequency) from a core. For more information, see
Processor State Control for Your EC2 Instance (p. 322).

D2 Instance Requirements
The following are the requirements for D2 instances:
• D2 instances require 64-bit HVM AMIs. They have high-memory (up to 244 GiB of RAM), and
require a 64-bit operating system to take advantage of that capacity. HVM AMIs provide superior
performance in comparison to paravirtual (PV) AMIs on high-memory instance types. In addition, you
must use an HVM AMI to take advantage of enhanced networking.
• There is a limit on the total number of instances that you can launch in a region, and there are
additional limits on some D2 instance types. For more information, see How many instances can I
run in Amazon EC2?
If you need more D2 instances, you can request them using the Amazon EC2 Instance Request
Form.
• Your d2.8xlarge instances are capable of providing up to 3.5 GB/s read performance and 3.1 GB/
s write performance with a 2 MiB block size. To ensure the best disk throughput performance from
your D2 instances on Linux, we recommend that you use the most recent version of the Amazon
Linux AMI, or another Linux AMI with a kernel version of 3.8 or later. D2 instances provide the best
disk performance when you use a Linux kernel that supports persistent grants, an extension to
the Xen block ring protocol that significantly improves disk throughput and scalability. For more
information about persistent grants, see this article in the Xen Project Blog.

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• The d2.8xlarge instance type has 36 vCPUs, which might cause launch issues in some
Linux operating systems that have a vCPU limit of 32. For more information, see Support for 36
vCPUs (p. 172).

Support for 36 vCPUs
The d2.8xlarge instance type provides 36 vCPUs, which might cause launch issues in some Linux
operating systems that have a vCPU limit of 32. We strongly recommend that you use the latest AMIs
when you launch d2.8xlarge instances.
The following Linux AMIs support launching d2.8xlarge instances with 36 vCPUs:
• Amazon Linux AMI 2016.03 (HVM)
• Ubuntu Server 14.04 LTS (HVM)
• Red Hat Enterprise Linux 7.1 (HVM)
• SUSE Linux Enterprise Server 12 (HVM)
If you must use a different AMI for your application, and your d2.8xlarge instance launch does not
complete successfully (for example, if your instance status changes to stopped during launch with a
Client.InstanceInitiatedShutdown state transition reason), modify your instance as described
in the following procedure to support more than 32 vCPUs so that you can use the d2.8xlarge
instance type.

To update an instance to support more than 32 vCPUs
1.

Launch a D2 instance using your AMI, choosing any D2 instance type other than d2.8xlarge.

Update the kernel to the latest version by following your operating system-specific instructions. For
example, for RHEL 6, use the sudo yum update -y kernel command.

Stop the instance.

(Optional) Create an AMI from the instance that you can use to launch any additional d2.8xlarge
instances that you need in the future.

Change the instance type of your stopped instance to d2.8xlarge (choose Actions, select
Instance Settings, choose Change Instance Type, and then follow the directions).

Start the instance. If the instance launches properly, you are done. If the instance still does not
boot properly, proceed to the next step.

(Optional) If the instance still does not boot properly, the kernel on your instance may not support
more than 32 vCPUs. However, you may be able to boot the instance if you limit the vCPUs.
a.

Change the instance type of your stopped instance to any D2 instance type other than
d2.8xlarge (choose Actions, select Instance Settings, choose Change Instance Type,
and then follow the directions).

Add the maxcpus=32 option to your boot kernel parameters by following your operating
system-specific instructions. For example, for RHEL 6, edit the /boot/grub/menu.lst file
and add the following option to the most recent and active kernel entry:
default=0
timeout=1
splashimage=(hd0,0)/boot/grub/splash.xpm.gz
hiddenmenu
title Red Hat Enterprise Linux Server (2.6.32-504.3.3.el6.x86_64)
root (hd0,0)
kernel /boot/vmlinuz-2.6.32-504.3.3.el6.x86_64 maxcpus=32
console=ttyS0 ro root=UUID=9996863e-b964-47d3-a33b-3920974fdbd9

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rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8
xen_blkfront.sda_is_xvda=1 console=ttyS0,115200n8 console=tty0
rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_NO_LVM
rd_NO_DM
initrd /boot/initramfs-2.6.32-504.3.3.el6.x86_64.img

Stop the instance.

(Optional) Create an AMI from the instance that you can use to launch any additional
d2.8xlarge instances that you need in the future.

Change the instance type of your stopped instance to d2.8xlarge (choose Actions, select
Instance Settings, choose Change Instance Type, and then follow the directions).

Start the instance.

HI1 Instances
HI1 instances (hi1.4xlarge) can deliver tens of thousands of low-latency, random I/O operations per
second (IOPS) to applications. They are well suited for the following scenarios:
• NoSQL databases (for example, Cassandra and MongoDB)
• Clustered databases
• Online transaction processing (OLTP) systems
You can cluster HI1 instances in a placement group. For more information, see Placement
Groups (p. 602).
By default, you can run up to two hi1.4xlarge instances. If you need more than two hi1.4xlarge
instances, contact http://aws.amazon.com/premiumsupport/.
Contents
• Hardware Specifications (p. 173)
• Disk I/O Performance (p. 173)
• SSD Storage (p. 174)

Hardware Specifications
The hi1.4xlarge instance type is based on solid-state drive (SSD) technology.
For more information about the hardware specifications for each Amazon EC2 instance type, see
Amazon EC2 Instances.

Disk I/O Performance
Using Linux paravirtual (PV) AMIs, HI1 instances can deliver more than 120,000 4 KB random read
IOPS and between 10,000 and 85,000 4 KB random write IOPS (depending on active logical block
addressing span) to applications across two SSD data volumes. Using hardware virtual machine
(HVM) AMIs, performance is approximately 90,000 4 KB random read IOPS and between 9,000 and
75,000 4 KB random write IOPS.
HI1 Windows instances deliver approximately 90,000 4 KB random read IOPS and between 9,000 and
75,000 4 KB random write IOPS.
The maximum sequential throughput is approximately 2 GB read per second and 1.1 GB write per
second.

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HS1 Instances

SSD Storage
With SSD storage on HI1 instances:
• The primary data source is an instance store with SSD storage.
• Read performance is consistent and write performance can vary.
• Write amplification can occur.
• The TRIM command is not currently supported.

Instance Store with SSD Storage
The hi1.4xlarge instances use an Amazon EBS-backed root device. However, their primary data
storage is provided by the SSD volumes in the instance store. Like other instance store volumes,
these instance store volumes persist only for the life of the instance. Because the root device of
the hi1.4xlarge instance is Amazon EBS-backed, you can still start and stop your instance.
When you stop an instance, your application persists, but your production data in the instance store
does not persist. For more information about instance store volumes, see Amazon EC2 Instance
Store (p. 715).

Variable Write Performance
Write performance depends on how your applications utilize logical block addressing (LBA) space.
If your applications use the total LBA space, write performance can degrade by about 90 percent.
Benchmark your applications and monitor the queue length (the number of pending I/O requests for a
volume) and I/O size.

Write Amplification
Write amplification refers to an undesirable condition associated with flash memory and SSDs, where
the actual amount of physical information written is a multiple of the logical amount intended to be
written. Because flash memory must be erased before it can be rewritten, the process to perform these
operations results in moving (or rewriting) user data and metadata more than once. This multiplying
effect increases the number of writes required over the life of the SSD, which shortens the time that it
can reliably operate. The hi1.4xlarge instances are designed with a provisioning model intended to
minimize write amplification.
Random writes have a much more severe impact on write amplification than serial writes. If you are
concerned about write amplification, allocate less than the full tebibyte of storage for your application
(also known as over provisioning).

The TRIM Command
The TRIM command enables the operating system to notify an SSD that blocks of previously saved
data are considered no longer in use. TRIM limits the impact of write amplification.
TRIM support is not available for HI1 instances. For information about instances that support TRIM,
see Instance Store Volume TRIM Support (p. 722).

HS1 Instances
HS1 instances (hs1.8xlarge) provide very high storage density and high sequential read and write
performance per instance. They are well suited for the following scenarios:
• Data warehousing
• Hadoop/MapReduce
• Parallel file systems

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You can cluster HS1 instances in a placement group. For more information, see Placement
Groups (p. 602).
By default, you can run up to two HS1 instances. If you need more than two HS1 instances, you can
request more using the Amazon EC2 Instance Request Form.
Contents
• Hardware Specifications (p. 175)
• Instance Store (p. 175)
• Disk Initialization (p. 175)
• Setting the Memory Limit (p. 175)
• Setting the User Limit (ulimit) (p. 175)

Hardware Specifications
HS1 instances support both Amazon Elastic Block Store (Amazon EBS)-backed and instance storebacked Amazon Machine Images (AMIs). HS1 instances support both paravirtual (PV) and hardware
virtual machine (HVM) AMIs.
HS1 instances provide high bandwidth networking and can also be used with Provisioned IOPS SSD
(io1) volumes for improved consistency and performance.
For more information about the hardware specifications for each Amazon EC2 instance type, see
Amazon EC2 Instances.

Instance Store
HS1 instances support both instance store and Amazon EBS root device volumes. However, even
when using an Amazon EBS-backed instance, primary data storage is provided by the hard disk drives
in the instance store. Like other instance store volumes, these instance store volumes persist only for
the life of the instance. For more information about instance store volumes, see Amazon EC2 Instance
Store (p. 715).

Disk Initialization
If you plan to run an HS1 instance in a steady state for long periods of time, we recommend that you
zero the hard disks first for improved performance. This process can take as long as six hours to
complete.

Setting the Memory Limit
Many Linux-based AMIs come with CONFIG_XEN_MAX_DOMAIN_MEMORY set to 70. We recommend
that you set this as appropriate for 117 GiB of memory.

Setting the User Limit (ulimit)
Many Linux-based AMIs come with a default ulimit of 1024. We recommend that you increase the ulimit
to 2048.

T1 Micro Instances
T1 Micro instances (t1.micro) provide a small amount of consistent CPU resources and allow you
to increase CPU capacity in short bursts when additional cycles are available. They are well suited for
lower throughput applications and websites that require additional compute cycles periodically.

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Note
The t1.micro is a previous generation instance and it has been replaced by the t2.micro,
which has a much better performance profile. We recommend using the t2.micro instance
type instead of the t1.micro. For more information, see T2 Instances (p. 160).
The t1.micro instance is available as an Amazon EBS-backed instance only.
This documentation describes how t1.micro instances work so that you can understand how to apply
them. It's not our intent to specify exact behavior, but to give you visibility into the instance's behavior
so you can understand its performance.
Topics
• Hardware Specifications (p. 176)
• Optimal Application of T1 Micro Instances (p. 176)
• Available CPU Resources During Spikes (p. 180)
• When the Instance Uses Its Allotted Resources (p. 180)
• Comparison with the m1.small Instance Type (p. 183)
• AMI Optimization for Micro Instances (p. 186)

Hardware Specifications
For more information about the hardware specifications for each Amazon EC2 instance type, see
Amazon EC2 Instances.

Optimal Application of T1 Micro Instances
A t1.micro instance provides spiky CPU resources for workloads that have a CPU usage profile
similar to what is shown in the following figure.

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The instance is designed to operate with its CPU usage at essentially only two levels: the normal low
background level, and then at brief spiked levels much higher than the background level. We allow
the instance to operate at up to 2 EC2 compute units (ECUs) (one ECU provides the equivalent CPU
capacity of a 1.0-1.2 GHz 2007 Opteron or 2007 Xeon processor). The ratio between the maximum
level and the background level is designed to be large. We designed t1.micro instances to support
tens of requests per minute on your application. However, actual performance can vary significantly
depending on the amount of CPU resources required for each request on your application.
Your application might have a different CPU usage profile than that described in the preceding section.
The next figure shows the profile for an application that isn't appropriate for a t1.micro instance. The
application requires continuous data-crunching CPU resources for each request, resulting in plateaus
of CPU usage that the t1.micro instance isn't designed to handle.

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The next figure shows another profile that isn't appropriate for a t1.micro instance. Here the spikes in
CPU use are brief, but they occur too frequently to be serviced by a micro instance.

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The next figure shows another profile that isn't appropriate for a t1.micro instance. Here the spikes
aren't too frequent, but the background level between spikes is too high to be serviced by a t1.micro
instance.

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In each of the preceding cases of workloads not appropriate for a t1.micro instance, we recommend
that you consider using a different instance type. For more information about instance types, see
Instance Types (p. 156).

Available CPU Resources During Spikes
When your instance bursts to accommodate a spike in demand for compute resources, it uses unused
resources on the host. The amount available depends on how much contention there is when the spike
occurs. The instance is never left with zero CPU resources, whether other instances on the host are
spiking or not.

When the Instance Uses Its Allotted Resources
We expect your application to consume only a certain amount of CPU resources in a period of time. If
the application consumes more than your instance's allotted CPU resources, we temporarily limit the
instance so it operates at a low CPU level. If your instance continues to use all of its allotted resources,
its performance will degrade. We will increase the time that we limit its CPU level, thus increasing the
time before the instance is allowed to burst again.
If you enable CloudWatch monitoring for your t1.micro instance, you can use the "Avg CPU
Utilization" graph in the AWS Management Console to determine whether your instance is regularly
using all its allotted CPU resources. We recommend that you look at the maximum value reached
during each given period. If the maximum value is 100%, we recommend that you use Auto Scaling to
scale out (with additional t1.micro instances and a load balancer), or move to a larger instance type.
For more information, see the Auto Scaling User Guide.

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The following figures show the three suboptimal profiles from the preceding section and what it might
look like when the instance consumes its allotted resources and we have to limit its CPU level. If the
instance consumes its allotted resources, we restrict it to the low background level.
The next figure shows the situation with the long plateaus of data-crunching CPU usage. The CPU hits
the maximum allowed level and stays there until the instance's allotted resources are consumed for
the period. At that point, we limit the instance to operate at the low background level, and it operates
there until we allow it to burst above that level again. The instance again stays there until the allotted
resources are consumed and we limit it again (not seen on the graph).

The next figure shows the situation where the requests are too frequent. The instance uses its allotted
resources after only a few requests and so we limit it. After we lift the restriction, the instance maxes
out its CPU usage trying to keep up with the requests, and we limit it again.

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The next figure shows the situation where the background level is too high. Notice that the instance
doesn't have to be operating at the maximum CPU level for us to limit it. We limit the instance when it's
operating above the normal background level and has consumed its allotted resources for the given
period. In this case (as in the preceding one), the instance can't keep up with the work, and we limit it
again.

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Comparison with the m1.small Instance Type
The t1.micro instance provides different levels of CPU resources at different times (up to 2 ECUs).
By comparison, the m1.small instance type provides 1 ECU at all times. The following figure
illustrates the difference.

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The following figures compare the CPU usage of a t1.micro instance with an m1.small instance for
the various scenarios we've discussed in the preceding sections.
The first figure that follows shows an optimal scenario for a t1.micro instance (the left graph) and
how it might look for an m1.small instance (the right graph). In this case, we don't need to limit the
t1.micro instance. The processing time on the m1.small instance would be longer for each spike in
CPU demand compared to the t1.micro instance.

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The next figure shows the scenario with the data-crunching requests that used up the allotted
resources on the t1.micro instance, and how they might look with the m1.small instance.

The next figure shows the frequent requests that used up the allotted resources on the t1.micro
instance, and how they might look on the m1.small instance.

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The next figure shows the situation where the background level used up the allotted resources on the
t1.micro instance, and how it might look on the m1.small instance.

AMI Optimization for Micro Instances
We recommend that you follow these best practices when optimizing an AMI for the t1.micro
instance type:
• Design the AMI to run on 600 MB of RAM
• Limit the number of recurring processes that use CPU time (for example, cron jobs, daemons)
You can optimize performance using swap space and virtual memory (for example, by setting up swap
space in a separate partition from the root file system).

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X1 Instances

X1 Instances
X1 instances are designed to deliver fast performance for workloads that process large data sets in
memory. X1 instances are well suited for the following applications:
• In-memory databases such SAP HANA, including SAP-certified support for Business Suite
S/4HANA, Business Suite on HANA (SoH), Business Warehouse on HANA (BW), and Data Mart
Solutions on HANA. For more information, see SAP HANA on the AWS Cloud.
• Big-data processing engines such as Apache Spark or Presto.
• High-performance computing (HPC) applications.

Hardware Specifications
For more information about the hardware specifications for each Amazon EC2 instance type, see
Amazon EC2 Instances.

Memory Performance
X1 instances include Intel Scalable Memory Buffers, providing 300 GiB/s of sustainable memory-read
bandwidth and 140 GiB/s of sustainable memory-write bandwidth.

Compute Performance
X1 instances feature up to 128 vCPUs and are powered by four Intel Xeon E7-8880 v3 processors
that feature high-memory bandwidth and larger L3 caches to boost the performance of in-memory
applications. X1 instances also enable increased cryptographic performance via the latest Intel AESNI feature, support Intel Transactional Synchronization Extensions (TSX) to boost the performance
of in-memory transactional data processing, and support Advanced Vector Extensions 2 (Intel AVX2)
processor instructions to expand most integer commands to 256 bits.
The following table highlights the feature set of the Intel Xeon E7-8880 v3 processor. For more
information, see Intel and Amazon Web Services.
Feature

Specification

Processor number

E7-8880 v3

Last level cache

45 MB

Intel QPI speed

9.6 GT/s

Number of QPI links

Instruction set

64-bit

Instruction set extensions

AVX 2.0

Lithography

22 nm

Processor base frequency

2.3 GHz

Max turbo frequency

3.1 GHz

Intel turbo boost technology

2.0

Intel hyperthreading technology

Yes

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Feature

Specification

Intel TSX-NI

Yes

Intel 64

Yes

Idle states

Yes

Enhanced Intel SpeedStep technology

Yes

Thermal monitoring technologies

Yes

Intel AES new instructions

Yes

X1 Instance Features
The following is a summary of the features for X1 instances:
• X1 instances are EBS-optimized by default, providing dedicated storage bandwidth of up to 10 Gbps
with Amazon EBS volumes. EBS-optimized instances enable consistently high performance by
eliminating contention between storage I/O and other network traffic from your X1 instance. For more
information, see Amazon EBS–Optimized Instances.
• X1 instances support SSD-based instance storage. Like all instance storage, these volumes persist
only for the life of the instance. For more information about instance store volumes, see Amazon
EC2 Instance Store.
• You can cluster X1 instances in a placement group. Placement groups provide low latency and highbandwidth connectivity between the instances within a single Availability Zone. For more information,
see Placement Groups.
• The x1.32xlarge instance type provides the ability to control processor C-states and P-states
on Linux. C-states control the sleep levels that a core can enter when it is inactive, while P-states
control the desired performance (measured by CPU frequency) from a core. For more information,
see Processor State Control for Your EC2 Instance.
• X1 instances are available as On-Demand Instances, Reserved Instances, Spot Instances, or
Scheduled Reserved Instances, but they are not available as Dedicated Instances. They are also
supported on Dedicated Hosts. For more information, see Instance Purchasing Options.
• There is a limit on the total number of instances that you can launch in a region, and there
are additional limits on some instance types. By default, you can run up to two X1 instances
simultaneously. If you need more X1 instances, you can request them using the Amazon EC2
Instance Request Form.

X1 Instance Requirements
The following are the requirements for X1 instances:
• The x1.32xlarge instance type offers 128 vCPUs, which might cause launch issues in some Linux
operating systems that have a vCPU limit lower than 128. For more information, see Support for 128
vCPUs (p. 189).
• The instance store for x1.32xlarge is capable of providing up to 126,000 random-read IOPS
with a 4 KiB block size. To ensure the best disk I/O performance from your X1 instances on Linux,
we recommend that you use the most recent version of the Amazon Linux AMI, or another Linux
AMI with a kernel version of 3.8 or later. X1 instances provide the best disk performance when you
use a Linux kernel that supports persistent grants, an extension to the Xen block ring protocol that
significantly improves disk throughput and scalability. For more information about persistent grants,
see the Improving block protocol scalability with persistent grants post on the Xen Project Blog.

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Resizing Instances

• X1 instances have high-memory (up to 1,952 GiB of RAM) and require 64-bit HVM AMIs to take
advantage of that capacity. HVM AMIs provide superior performance in comparison to paravirtual
(PV) AMIs on high-memory instance types. For more information, see Linux AMI Virtualization
Types.
• You must launch your X1 instances into a virtual private cloud (VPC); the EC2-Classic platform is
not supported. EC2-VPC enables you to launch AWS resources into a virtual network that you've
defined. You cannot change the instance type of an existing instance in EC2-Classic to an X1
instance type. For more information about EC2-Classicand EC2-VPC , see Supported Platforms .
For more information about launching a VPC-only instance, see Instance Types Available Only in a
VPC .

Support for 128 vCPUs
The x1.32xlarge instance type provides 128 vCPUs, which might cause launch issues in some Linux
operating systems that have a vCPU limit lower than 128. We strongly recommend that you use the
latest AMIs when you launch x1.32xlarge instances.
The following Linux AMIs support launching x1.32xlarge instances with 128 vCPUs:
• Amazon Linux AMI 2016.03 (HVM)
• Ubuntu Server 14.04 LTS (HVM)
• Red Hat Enterprise Linux 7.1 (HVM)
• SUSE Linux Enterprise Server 12 (HVM)

Resizing Your Instance
As your needs change, you might find that your instance is over-utilized (the instance type is too small)
or under-utilized (the instance type is too large). If this is the case, you can change the size of your
instance. For example, if your t2.micro instance is too small for its workload, you can change it to an
m3.medium instance.
If the root device for your instance is an EBS volume, you can change the size of the instance simply
by changing its instance type, which is known as resizing it. If the root device for your instance is an
instance store volume, you must migrate your application to a new instance with the instance type that
you want. For more information about root device volumes, see Storage for the Root Device (p. 71).
When you resize an instance, you must select an instance type that is compatible with the
configuration of the instance. If the instance type that you want is not compatible with the instance
configuration you have, then you must migrate your application to a new instance with the instance
type that you want.

Important
When you resize an instance, the resized instance usually has the same number of instance
store volumes that you specified when you launched the original instance. If you want to add
instance store volumes, you must migrate your application to a completely new instance with
the instance type and instance store volumes that you want. An exception to this rule is when
you resize to a storage-intensive instance type that by default contains a higher number of
volumes. For more information about instance store volumes, see Amazon EC2 Instance
Store (p. 715).
Contents
• Compatibility for Resizing Instances (p. 190)
• Resizing an Amazon EBS–backed Instance (p. 190)
• Migrating an Instance Store-backed Instance (p. 191)

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• Migrating to a New Instance Configuration (p. 192)

Compatibility for Resizing Instances
You can resize an instance only if its current instance type and the new instance type that you want are
compatible in the following ways:
• Virtualization type. Linux AMIs use one of two types of virtualization: paravirtual (PV) or hardware
virtual machine (HVM). You can't resize an instance that was launched from a PV AMI to an instance
type that is HVM only. For more information, see Linux AMI Virtualization Types (p. 74).
• Network. Some instance types are not supported in EC2-Classic and must be launched in a VPC.
Therefore, you can't resize an instance in EC2-Classic to a instance type that is available only in a
VPC unless you have a nondefault VPC. For more information, see Instance Types Available Only in
a VPC (p. 548).
• Platform. All Amazon EC2 instance types support 64-bit AMIs, but only the following instance
types support 32-bit AMIs: t2.nano, t2.micro, t2.small, t2.medium, c3.large, t1.micro,
m1.small, m1.medium, and c1.medium. If you are resizing a 32-bit instance, you are limited to
these instance types.
For example, T2 instances are not supported in EC2-Classic and they are HVM only. Therefore, you
can't resize a T1 instance to a T2 instance because T1 instances do not support HVM and must be
launched from PV AMIs. If you want to resize a T2 instance to a larger instance type, you can select
any current generation instance type, such as M3, because all current generation instance types
support HVM AMIs. For more information, see Available Instance Types (p. 157).

Resizing an Amazon EBS–backed Instance
You must stop your Amazon EBS–backed instance before you can change its instance type. When you
stop and start an instance, be aware of the following:
• We move the instance to new hardware; however, the instance ID does not change.
• If your instance is running in a VPC and has a public IP address, we release the address and give it
a new public IP address. The instance retains its private IP addresses and any Elastic IP addresses.
• If your instance is running in EC2-Classic, we give it new public and private IP addresses, and
disassociate any Elastic IP address that's associated with the instance. Therefore, to ensure that
your users can continue to use the applications that you're hosting on your instance uninterrupted,
you must re-associate any Elastic IP address after you restart your instance.
• If your instance is in an Auto Scaling group, the Auto Scaling service marks the stopped instance
as unhealthy, and may terminate it and launch a replacement instance. To prevent this, you can
suspend the Auto Scaling processes for the group while you're resizing your instance. For more
information, see Suspend and Resume Auto Scaling Processes in the Auto Scaling User Guide.
For more information, see Stop and Start Your Instance (p. 299).
Use the following procedure to resize an Amazon EBS–backed instance using the AWS Management
Console.

To resize an Amazon EBS–backed instance
1.

Open the Amazon EC2 console.

In the navigation pane, choose Instances, and select the instance.

[EC2-Classic] If the instance has an associated Elastic IP address, write down the Elastic IP
address and the instance ID shown in the details pane.

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Choose Actions, select Instance State, and then choose Stop.

In the confirmation dialog box, choose Yes, Stop. It can take a few minutes for the instance to
stop.
[EC2-Classic] When the instance state becomes stopped, the Elastic IP, Public DNS, Private
DNS, and Private IPs fields in the details pane are blank to indicate that the old values are no
longer associated with the instance.

With the instance still selected, choose Actions, select Instance Settings, and then choose
Change Instance Type. Note that this action is disabled if the instance state is not stopped.

In the Change Instance Type dialog box, do the following:
a.

From Instance Type, select the instance type that you want. If the instance type that you
want does not appear in the list, then it is not compatible with the configuration of your
instance (for example, because of virtualization type).

(Optional) If the instance type that you selected supports EBS–optimization, select EBSoptimized to enable EBS–optimization or deselect EBS-optimized to disable EBS–
optimization. Note that if the instance type that you selected is EBS–optimized by default,
EBS-optimized is selected and you can't deselect it.

Choose Apply to accept the new settings.

To restart the stopped instance, select the instance, choose Actions, select Instance State, and
then choose Start.

In the confirmation dialog box, choose Yes, Start. It can take a few minutes for the instance to
enter the running state.

10. [EC2-Classic] When the instance state is running, the Public DNS, Private DNS, and Private
IPs fields in the details pane contain the new values that we assigned to the instance. If your
instance had an associated Elastic IP address, you must reassociate it as follows:
a.

In the navigation pane, choose Elastic IPs.

Select the Elastic IP address that you wrote down before you stopped the instance.

Choose Actions and then choose Associate Address.

From Instance, select the instance ID that you wrote down before you stopped the instance,
and then choose Associate.

Migrating an Instance Store-backed Instance
When you want to move your application from one instance store-backed instance to an instance storebacked instance with a different instance type, you must migrate it by creating an image from your
instance, and then launching a new instance from this image with the instance type that you need.
To ensure that your users can continue to use the applications that you're hosting on your instance
uninterrupted, you must take any Elastic IP address that you've associated with your original instance
and associate it with the new instance. Then you can terminate the original instance.

To migrate an instance store-backed instance
1.

[EC2-Classic] If the instance you are migrating has an associated Elastic IP address, record the
Elastic IP address now so that you can associate it with the new instance later.

Back up any data on your instance store volumes that you need to keep to persistent storage.
To migrate data on your EBS volumes that you need to keep, take a snapshot of the volumes
(see Creating an Amazon EBS Snapshot (p. 686)) or detach the volume from the instance so
that you can attach it to the new instance later (see Detaching an Amazon EBS Volume from an
Instance (p. 669)).

Create an AMI from your instance store-backed instance by satisfying the prerequisites and
following the procedures in Creating an Instance Store-Backed Linux AMI (p. 92). When you are
finished creating an AMI from your instance, return to this procedure.

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Open the Amazon EC2 console and in the navigation pane, select AMIs. From the filter lists,
select Owned by me, and select the image that you created in the previous step. Notice that AMI
Name is the name that you specified when you registered the image and Source is your Amazon
S3 bucket.

Note
If you do not see the AMI that you created in the previous step, make sure that you have
selected the region in which you created your AMI.
5.

Choose Launch. When you specify options for the instance, be sure to select the new instance
type that you want. If the instance type that you want can't be selected, then it is not compatible
with configuration of the AMI that you created (for example, because of virtualization type). You
can also specify any EBS volumes that you detached from the original instance.
Note that it can take a few minutes for the instance to enter the running state.

[EC2-Classic] If the instance that you started with had an associated Elastic IP address, you must
associate it with the new instance as follows:
a.

In the navigation pane, choose Elastic IPs.

b.
c.

Select the Elastic IP address that you recorded at the beginning of this procedure.
Choose Actions and then choose Associate Address.

From Instance, select the new instance, and then choose Associate.

(Optional) You can terminate the instance that you started with, if it's no longer needed. Select
the instance and verify that you are about to terminate the original instance, not the new instance
(for example, check the name or launch time). Choose Actions, select Instance State, and then
choose Terminate.

Migrating to a New Instance Configuration
If the current configuration of your instance is incompatible with the new instance type that you want,
then you can't resize the instance to that instance type. Instead, you can migrate your application to a
new instance with a configuration that is compatible with the new instance type that you want.
If you want to move from an instance launched from a PV AMI to an instance type that is HVM only, the
general process is as follows:
1.

Back up any data on your instance store volumes that you need to keep to persistent storage.
To migrate data on your EBS volumes that you need to keep, create a snapshot of the volumes
(see Creating an Amazon EBS Snapshot (p. 686)) or detach the volume from the instance so
that you can attach it to the new instance later (see Detaching an Amazon EBS Volume from an
Instance (p. 669)).
Launch a new instance, selecting the following:
• An HVM AMI.
• The HVM only instance type.

• [EC2-VPC] If you are using an Elastic IP address, select the VPC that the original instance is
currently running in.
• Any EBS volumes that you detached from the original instance and want to attach to the new
instance, or new EBS volumes based on the snapshots that you created.
• If you want to allow the same traffic to reach the new instance, select the security group that is
associated with the original instance.
Install your application and any required software on the instance.

4.
5.

Restore any data that you backed up from the instance store volumes of the original instance.
If you are using an Elastic IP address, assign it to the newly launched instance as follows:
a.

In the navigation pane, choose Elastic IPs.

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Select the Elastic IP address that is associated with the original instance, choose Actions,
and then choose Disassociate Address. When prompted for confirmation, choose Yes,
Disassociate.

With the Elastic IP address still selected, choose Actions, and then choose Associate
Address.

From Instance, select the new instance, and then choose Associate.

(Optional) You can terminate the original instance if it's no longer needed. Select the instance and
verify that you are about to terminate the original instance, not the new instance (for example,
check the name or launch time). Choose Actions, select Instance State, and then choose
Terminate.

For information about migrating an application from an instance in EC2-Classic to an instance in a
VPC, see Migrating from a Linux Instance in EC2-Classic to a Linux Instance in a VPC (p. 560).

Instance Purchasing Options
Amazon EC2 provides the following purchasing options to enable you to optimize your costs based on
your needs:
• On-Demand instances — Pay, by the hour, for the instances that you launch.
• Reserved Instances — Purchase, at a significant discount, instances that are always available, for
a term from one to three years.
• Scheduled Instances — Purchase instances that are always available on the specified recurring
schedule, for a one-year term.
• Spot instances — Bid on unused instances, which can run as long as they are available and your
bid is above the Spot price, at a significant discount.
• Dedicated hosts — Pay for a physical host that is fully dedicated to running your instances, and
bring your existing per-socket, per-core, or per-VM software licenses to reduce costs.
• Dedicated instances — Pay, by the hour, for instances that run on single-tenant hardware. For
more information, see Dedicated Instances in the Amazon VPC User Guide.
If you require a capacity reservation, consider Reserved Instances or Scheduled Instances. Spot
instances are a cost-effective choice if you can be flexible about when your applications run and if
they can be interrupted. Dedicated hosts can help you address compliance requirements and reduce
costs by using your existing server-bound software licenses. For more information, see Amazon EC2
Instance Purchasing Options.
Contents
• Determining the Instance Lifecycle (p. 193)
• Reserved Instances (p. 194)
• Scheduled Reserved Instances (p. 215)
• Spot Instances (p. 219)
• Dedicated Hosts (p. 264)

Determining the Instance Lifecycle
The lifecycle of an instance starts when it is launched and ends when it is terminated. The purchasing
option that you choose effects the lifecycle of the instance. For example, an On-Demand instance
runs when you launch it and ends when you terminate it. A Spot instance runs as long as its capacity

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is available and your bid price is higher than the Spot price. You can launch a Scheduled Instance
during its scheduled time period; Amazon EC2 launches the instances and then terminates them three
minutes before the time period ends.
Use the following procedure to determine the lifecycle of an instance.

To determine the instance lifecycle using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances.

Select the instance.

On the Description tab, find Tenancy. If the value is host, the instance is running on a Dedicated
Host. If the value is dedicated, the instance is a Dedicated Instance.

On the Description tab, find Lifecycle. If the value is spot, the instance is a Spot instance. If the
value is scheduled, the instance is a Scheduled Instance. If the value is normal, the instance is
either an On-Demand instance or a Reserved Instance.

(Optional) If you have purchased a Reserved Instance and want to verify that it is being applied,
you can check the usage reports for Amazon EC2. For more information, see Reserved Instance
Utilization Reports (p. 767).

To determine the instance lifecycle using the AWS CLI
Use the following describe-instances command:
aws ec2 describe-instances --instance-ids i-1234567890abcdef0

If the instance is running on a Dedicated host, the output contains the following information:
"Tenancy": "host"

If the instance is a Dedicated instance, the output contains the following information:
"Tenancy": "dedicated"

If the instance is a Spot instance, the output contains the following information:
"InstanceLifecycle": "spot"

If the instance is a Scheduled Instance, the output contains the following information:
"InstanceLifecycle": "scheduled"

Otherwise, the output contains the following information:
"InstanceLifecycle": "normal"

Reserved Instances
Reserved Instances are a billing discount and capacity reservation that is applied to instances to lower
hourly running costs. A Reserved Instance is not a physical instance. The discounted usage price is

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fixed for as long as you own the Reserved Instance, allowing you to predict compute costs over the
term of the reservation. If you are expecting consistent, heavy, use, Reserved Instances can provide
substantial savings over owning your own hardware or running only On-Demand instances. For more
information, see Choosing a Reserved Instance Payment Option (p. 197).
When you purchase a Reserved Instance, the reservation is automatically applied to running instances
that match your specified parameters. Alternatively, you can launch an On-Demand EC2 instance with
the same configuration as the purchased reserved capacity. No Upfront and Partial Upfront Reserved
Instances are billed for usage on an hourly basis, regardless of whether or not they are being used. All
Upfront Reserved Instances have no additional hourly charges.
Reserved Instances do not renew automatically; you can continue using the EC2 instance without
interruption, but you will be charged On-Demand rates. New Reserved Instances can have the same
parameters as the expired ones, or you can purchase Reserved Instances with different parameters.
You can use Auto Scaling or other AWS services to launch the On-Demand instances that use your
Reserved Instance benefits. For information about launching On-Demand instances, see Launch Your
Instance. For information about launching instances using Auto Scaling, see the Auto Scaling User
Guide.
For product pricing information, see the following pages:
• AWS Service Pricing Overview
• Amazon EC2 On-Demand Instances Pricing
• Amazon EC2 Reserved Instance Pricing
• For information about the Reserved Instance pricing tiers, see Understanding Reserved Instance
Discount Pricing Tiers (p. 199).

Note
Light, Medium, and Heavy Utilization Reserved Instances are no longer available for
purchase. For more information about how these options are affected by changes to the
Reserved Instances pricing model, see Reserved Instances FAQ.
Topics
• How Reserved Instances Work (p. 195)
• Billing Benefits and Payment Options (p. 197)
• Buying Reserved Instances (p. 201)
• Selling in the Reserved Instance Marketplace (p. 204)
• Modifying Your Reserved Instances (p. 210)
• Troubleshooting Modification Requests (p. 215)

How Reserved Instances Work
Amazon EC2 Reserved Instances and the Reserved Instance Marketplace can be a powerful and
cost-saving strategy for running your business. However, before you use Reserved Instances or the
Reserved Instance Marketplace, ensure that you meet the requirements for purchase and sale. You
also must understand the details and restrictions on certain elements of Reserved Instances and the
Reserved Instance Marketplace—including seller registration, banking, using the AWS free tier, dealing
with cancelled instances, and so on. Use this topic as a checklist for buying and selling Reserved
Instances, and for buying and selling in the Reserved Instance Marketplace.

Note
To purchase and modify Reserved Instances, ensure that your IAM user account has the
appropriate permissions, such as the ability to describe Availability Zones. For information,

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see the Example Policies for Working With the AWS CLI or an AWS SDK and Example
Policies for Working in the Amazon EC2 Console.

Getting Started
• AWS account—You need to have an AWS account in order to purchase Reserved Instances. If
you don't have an AWS account, read and complete the instructions described in Setting Up with
Amazon EC2 (p. 19), which provides information on signing up for your Amazon EC2 account and
credentials.
• AWS free tier—The AWS free usage tier is available for new AWS accounts. If you are using the
AWS free usage tier to run Amazon EC2 instances, and then you purchase a Reserved Instance,
you will be charged under standard pricing guidelines. For information about the free tier and the
applicable services and usage amounts, see AWS Free Tier.

Buying Reserved Instances
• Usage fee—With Reserved Instances, you pay for the entire term regardless of whether or not you
use it.
• Tiered discounts on purchases—The Reserved Instance pricing tier discounts only apply to
purchases made from AWS. These discounts do not apply to purchases of third-party Reserved
Instances. For information, see Understanding Reserved Instance Discount Pricing Tiers (p. 199).
• Cancellation of purchase—Before you confirm your purchase, review the details of the Reserved
Instances that you plan to buy, and make sure that all the parameters are accurate. After you
purchase a Reserved Instance (either from a third-party seller in the Reserved Instance Marketplace
or from AWS), you cannot cancel your purchase. However, you may be able to sell the Reserved
Instance if your needs change. For information, see Listing Your Reserved Instances (p. 207).

Selling Reserved Instances and the Reserved Instance Marketplace
• Seller requirement—To become a seller in the Reserved Instance Marketplace, you must register
as a seller. For information, see Listing Your Reserved Instances (p. 207).
• Bank requirement—AWS must have your bank information in order to disburse funds collected
when you sell your Reserved Instance. The bank you specify must have a US address. For more
information, see Bank Accounts (p. 205).
• Tax requirement—Sellers who have 50 or more transactions or who plan to sell $20,000 or more in
Reserved Instances will have to provide additional information about their business for tax reasons.
For information, see Tax Information (p. 206).
• Minimum selling price—The minimum price allowed in the Reserved Instance Marketplace is
$0.00.
• When Reserved Instances can be sold—Reserved Instances can be sold only after AWS has
received the upfront payment and the Reserved Instance has been active (you've owned it) for at
least 30 days. In addition, there must be at least one month remaining in the term of the Reserved
Instance you are listing.
• Modifying your listing—It is not possible to modify your listing in the Reserved Instance
Marketplace directly. However, you can change your listing by first cancelling it and then
creating another listing with new parameters. For information, see Pricing Your Reserved
Instances (p. 209). You can also change your Reserved Instances before listing them. For
information, see Modifying Your Reserved Instances (p. 210).
• Selling discounted Reserved Instances—Amazon EC2 Reserved Instances purchased at a
reduced cost resulting from a tiering discount cannot be sold in the Reserved Instance Marketplace.
For more information, see Reserved Instance Marketplace (p. 197).
• Service fee—AWS charges a service fee of 12 percent of the total upfront price of each Reserved
Instance you sell in the Reserved Instance Marketplace. (The upfront price is the price the seller is
charging for the Reserved Instance.)

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• Other AWS Reserved Instances—Only Amazon EC2 Reserved Instances can be sold in the
Reserved Instance Marketplace. Other AWS Reserved Instances, such as Amazon Relational
Database Service (Amazon RDS) and Amazon ElastiCache Reserved Instances cannot be sold in
the Reserved Instance Marketplace.

Using Reserved Instances in an Amazon VPC
You can launch instances into an Amazon Virtual Private Cloud (Amazon VPC) and benefit from your
Reserved Instances. For more information see What is Amazon VPC? in the Amazon VPC User Guide.
If you have an EC2-Classic account, you can purchase Reserved Instances to apply to instances
launched into a nondefault VPC by selecting a platform that includes Amazon VPC in its name. For
more information, see Detecting Your Supported Platforms and Whether You Have a Default VPC.
If you have an EC2-VPC-only account, the listed platforms available do not include Amazon VPC
in its name because all platforms have default subnets. When you launch an instance with the
same configuration as the capacity you reserved, and that instance is launched into your default or
nondefault VPC, the capacity reservation and billing benefits are automatically applied to your instance.
For information about default VPCs, see Your Default VPC and Subnets in the Amazon VPC User
Guide.
You can also choose to purchase Reserved instances that are physically isolated at the host hardware
level by specifying dedicated as the instance tenancy. For more information about Dedicated
instances, see Dedicated Instances in the Amazon VPC User Guide.

Reserved Instance Marketplace
Note
Only Amazon EC2 Reserved Instances can be sold in the Reserved Instance Marketplace.
Other types, such as Amazon RDS and Amazon ElastiCache Reserved Instances, cannot be
sold on the Reserved Instance Marketplace.
The Reserved Instance Marketplace is a platform that supports the sale of third-party and AWS
customers' unused Reserved Instances, which will vary in term lengths and pricing options. For
example, an AWS customer may want to sell capacity after moving instances to a new AWS region,
changing to a new instance type, or ending projects before the term expiration. The Reserved Instance
Marketplace provides increased selection and flexibility by allowing you to address your specific
business and searching for Reserved Instances that most closely match your preferred combination
of instance type, region, and duration. Amazon EC2 instances purchased on the Reserved Instance
Marketplace offer the same capacity reservations as Reserved Instances purchased directly from
AWS.

Billing Benefits and Payment Options
The billing benefit of Reserved Instances is automatically applied to matching running instances.
You can also purchase Reserved Instances and then launch On-Demand instances with matching
specifications—the pricing benefit is automatically applied to those instances. The capacity reservation
ensures that you will always be able to launch instances with those specifications. You also can sell
your unused Reserved Instances in the Reserved Instance Marketplace, provided you meet certain
requirements.

Choosing a Reserved Instance Payment Option
There are three payment options for Reserved Instances:
• No Upfront—You are billed a discounted hourly rate for every hour within the term, regardless of
usage, and no upfront payment is required. This option is only available as a 1-year reservation.

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Note
No Upfront Reserved Instances are based on a contractual obligation to pay monthly for the
entire term of the reservation. For this reason, a successful billing history is required before
an account is eligible to purchase No Upfront Reserved Instances.
• Partial Upfront—A portion of the cost must be paid upfront and the remaining hours in the term are
billed at a discounted hourly rate, regardless of usage.
• All Upfront—Full payment is made at the start of the term, with no other costs incurred for the
remainder of the term regardless of the number of hours used.
Understanding hourly billing
Reserved Instances are billed for every clock-hour during the term that you select, regardless of
whether an instance is running or not. It's important to understand the difference between instance
states and how these impact billing hours. For more information, see Instance Lifecycle (p. 275).
Reserved Instance billing benefits only apply to one instance-hour per clock-hour. An instance-hour
begins when an instance is started and continues for 60 minutes or until the instance is stopped or
terminated—whichever happens first. A clock-hour is defined as the standard 24-hour clock that runs
from midnight to midnight, and is divided into 24 hours (for example, 1:00:00 to 1:59:59 is one clockhour).
A new instance-hour begins after an instance has run for 60 continuous minutes, or if an instance is
stopped and then started. Rebooting an instance does not reset the running instance-hour.
For example, if an instance is stopped and then started again during a clock-hour and continues
running for two more clock-hours, the first instance-hour (before the restart) is charged at the
discounted Reserved Instance rate. The next instance-hour (after restart) is charged at the OnDemand rate and the next two instance-hours are charged at the discounted Reserved Instance rate.
The Reserved Instance Utilization Reports (p. 767) section includes sample reports which illustrate
the savings against running On-Demand instances. The Reserved Instances FAQ includes a sample
list value calculation.
How to apply a Reserved Instance to a running instance
To cover a running instance with reservation, you can either modify an existing Reserved Instance or
purchase a Reserved Instance by selecting the Availability Zone (such as us-east-1b), instance type
(such as m3.large), platform (such as Amazon Linux VPC), and tenancy (such as default) to match
the configuration of the running instance.
Below is an example scenario where a customer has purchased the following On-Demand instances:
• 4 x m1.small instances in Availability Zone us-east-1a
• 4 x c1.medium instances in Availability Zone us-east-1b
• 2 x c1.xlarge instances in Availability Zone us-east-1b
The customer then purchases the following reservations:
• 2 x m1.small in Availability Zone us-east-1a
• 3 x c1.medium in Availability Zone us-east-1a
• 1 x c1.xlarge in Availability Zone us-east-1b
The pricing benefit is applied in the following way:
• The discount for the two m1.small reservations is applied to two of the four running m1.small
instances in Availability Zone us-east-1a.

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The other two instances in Availability Zone us-east-1a continue to be charged at the current OnDemand rate.
• The three c1.medium reservations don't match the Availability Zone of the running c1.medium
instances. The four running c1.medium instances continue to be charged at the current On-Demand
rate.
If the customer launches a c1.medium instance in Availability Zone us-east-1a, then the discounted
usage fee is applied to that instance.
• The discounted usage fee rate for one c1.xlarge reservation is applied to one of the two running
c1.xlarge instances in Availability Zone us-east-1b.
The other c1.xlarge instance in Availability Zone us-east-1b continues to be charged at the current
On-Demand rate.
In this example the hourly usage discount is immediately applied to the hourly fee for the two
m1.small and one c1.xlarge On-Demand instances that were already running; and the customer is
assured of the capacity to run the remaining four instances when they are needed.

Understanding Reserved Instance Discount Pricing Tiers
When your account qualifies for a discount pricing tier, it automatically receives discounts on upfront
and hourly usage fees for all Reserved Instance purchases that you make within that tier level from
that point on. To qualify for a discount, the list value of your Reserved Instances in the region must be
$500,000 USD or more.
Topics
• Calculating Reserved Instance Pricing Discounts (p. 199)
• Consolidated Billing for Pricing Tiers (p. 200)
• Buying with a Discount Tier (p. 200)
• Current Pricing Tier Limits (p. 200)
• Crossing Pricing Tiers (p. 201)

Calculating Reserved Instance Pricing Discounts
You can determine the pricing tier for your account by calculating the list value for all of your Reserved
Instances in a region. Multiply the hourly recurring price for each reservation by the hours left in each
term and add the undiscounted upfront price (known as the fixed price) listed on the AWS marketing
website at the time of purchase. Because the list value is based on undiscounted (public) pricing, it
is not affected if you qualify for a volume discount or if the price drops after you buy your Reserved
Instances.
List value = fixed price + (undiscounted recurring hourly price * hours in
term)

To view the fixed price values for Reserved Instances using the AWS Management Console
1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
2. Turn on the display of the Fixed Price column by choosing Show/Hide in the top right corner.
To view the fixed price values for Reserved Instances using the command line
• Using the AWS CLI, see describe-reserved-instances
• Using the AWS Tools for Windows PowerShell, see Get-EC2ReservedInstance

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• Using the Amazon EC2 API, see DescribeReservedInstances

Consolidated Billing for Pricing Tiers
A consolidated billing account aggregates the list value of member accounts within a region. When
the list value of all active Reserved Instances for the consolidated billing account reaches a discount
pricing tier, any Reserved Instances purchased after this point by any member of the consolidated
billing account are charged at the discounted rate (as long as the list value for that consolidated
account stays above the discount pricing tier threshold). For more information, see Reserved Instances
and Consolidated Billing (p. 201).

Buying with a Discount Tier
When you buy Reserved Instances, Amazon EC2 automatically applies any discounts to the part of
your purchase that falls within a discount pricing tier. You don't need to do anything differently, and
you can buy using any of the Amazon EC2 tools. For more information, see Buying in the Reserved
Instance Marketplace (p. 204).

Note
Reserved Instance purchases are the only purchases that determine your discount pricing
tiers, and the discounts apply only to Amazon EC2 Reserved Instance purchases.
After the list value of your active Reserved Instances in a region crosses into a discount pricing tier,
any future purchase of Reserved Instances in that region are charged at a discounted rate. If a single
purchase of Reserved Instances in a region takes you over the threshold of a discount tier, then
the portion of the purchase that is above the price threshold is charged at the discounted rate. For
more information about temporary Reserved Instance IDs created during the purchase process, see
Crossing Pricing Tiers (p. 201).
If your list value falls below the price point for that discount pricing tier—for example, if some of your
Reserved Instances expire—future purchases of Reserved Instances in the region are not discounted.
However, you continue to get the discount applied against any Reserved Instances that were originally
purchased within the discount pricing tier.
When you buy Reserved Instances, one of four possible scenarios occurs:
• No discount—Your purchase within a region is still below the discount threshold.
• Partial discount—Your purchase within a region crosses the threshold of the first discount tier. No
discount is applied to one or more reservations and the discounted rate is applied to the remaining
reservations.
• Full discount—Your entire purchase within a region falls within one discount tier and is discounted
appropriately.
• Two discount rates—Your purchase within a region crosses from a lower discount tier to a higher
discount tier. You are charged two different rates: one or more reservation at the lower discounted
rate, and the remaining reservations at the higher discounted rate.

Current Pricing Tier Limits
The following limitations currently apply to Reserved Instance pricing tiers:
• Reserved Instance pricing tiers and related discounts apply only to purchases of Amazon EC2
Reserved Instances.
• Reserved Instance pricing tiers do not apply to Reserved Instances for Windows with SQL Server
Standard or Windows with SQL Server Web.
• Reserved Instances purchased as part of a tiered discount cannot be sold in the Reserved Instance
Marketplace. For more information, see the Reserved Instance Marketplace (p. 197) page.

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Crossing Pricing Tiers
If your purchase crosses into a discounted pricing tier, you see multiple entries for that purchase: one
for that part of the purchase charged at the regular price, and another for that part of the purchase
charged at the applicable discounted rate.
The Reserved Instance service generates several Reserved Instance IDs because your purchase
crossed from an undiscounted tier, or from one discounted tier to another. There is an ID for each set
of reservations in a tier. Consequently, the ID returned by your purchase CLI command or API action
will be different from the actual ID of the new Reserved Instances.

Reserved Instances and Consolidated Billing
The pricing benefits of Reserved Instances are shared when the purchasing account is part of a set
of accounts billed under one consolidated billing payer account. The hourly usage across all subaccounts is aggregated in the payer account every month. This is typically useful for companies in
which there are different functional teams or groups; then, the normal Reserved Instance logic is
applied to calculate the bill. For more information, see Consolidated Billing in AWS Billing and Cost
Management User Guide.
For more information about how the discounts of the Reserved Instance pricing tiers apply to
consolidated billing accounts, see Amazon EC2 Reserved Instances.

Reading Your Statement (Invoice)
You can find out about the charges and fees to your account by viewing the Billing & Cost
Management page in the AWS Management Console. Choose the arrow beside your account name to
access it.
• The Dashboard page displays charges against your account—such as upfront and one-time fees,
and recurring charges. You can get both a summary or detailed list of your charges.
• The upfront charges from your purchase of third-party Reserved Instances in the Reserved Instance
Marketplace are listed in the AWS Marketplace Charges section, with the name of the seller
displayed beside it. All recurring or usage charges for these Reserved Instances are listed in the
AWS Service Charges section.
• The Detail section contains information about the Reserved Instance—such as the Availability Zone,
instance type, cost, and number of instances.
You can view the charges online, and you can also download a PDF rendering of the charge
information.

Buying Reserved Instances
You can search for specific types of Reserved Instances to buy, adjusting your parameters until you
find the exact match you're looking for.
It's important to note the following for any Reserved Instance purchase:
• Usage fee—With Reserved Instances, you pay for the entire term regardless of actual use.
• Tiered discounts on purchases—Pricing tier discounts apply only to AWS purchases. These
discounts do not apply to purchases of third-party Reserved Instances. For more information, see
Understanding Reserved Instance Discount Pricing Tiers (p. 199).
• Cancellation of purchase—After the purchase is confirmed, it cannot be cancelled. Before you
confirm, review the details of the Reserved Instances that you plan to buy, and make sure that all the
parameters are accurate. However, you may be able to sell the Reserved Instances if your needs
change and you meet the requirements. For more information, see Selling in the Reserved Instance
Marketplace (p. 204).

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After you select Reserved Instances to buy, you receive a quote on the total cost of your selections.
When you decide to proceed with the purchase, AWS automatically places a limit price on the
purchase price, so that the total cost of your Reserved Instances does not exceed the amount you
were quoted.
If the price rises or changes for any reason, you are returned to the previous screen and the purchase
is not completed. If, at the time of purchase, there are offerings similar to your choice but at a lower
price, AWS sells you the offerings at the lower price.

Buying Reserved Instances using the AWS Management Console
To buy Reserved Instances using the AWS Management Console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the Navigation pane, choose Reserved Instances.

On the Reserved Instances page, choose Purchase Reserved Instances.

Specify details for the Reserved Instances to purchase, and choose Search.

Note
The Seller column in the search results indicates whether the seller is a third-party. If so,
the Term column displays non-standard terms.
5.

Select the Reserved Instances that you want, enter the quantity, and choose Add to Cart.

To see a summary of the Reserved Instances that you have selected, choose View Cart.

To complete the order, choose Purchase.

Note
If, at the time of purchase, there are offerings similar to your choice but with a lower price,
AWS will sell you the offerings at the lower price.
To apply your reservation, launch an On-Demand instance, ensuring that you match the same criteria
that you specified for your Reserved Instance. AWS automatically charges you the lower hourly rate.
You do not have to restart your instance.

To view transaction status using the AWS Management Console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

Choose the Reserved Instances page. The status of your purchase is listed in the State column.
When your order is complete, the State value changes from payment-pending to active.

Buying Reserved Instances Using the Command Line Interface or API
To buy Reserved Instances using the command line or API
1. Using the AWS CLI, see purchase-reserved-instances-offering
2. Using the AWS Tools for Windows PowerShell, see New-EC2ReservedInstance
3. Using the Amazon EC2 API, see PurchaseReservedInstancesOffering
To view transaction status using the command line or API
1. Using the AWS CLI, see describe-reserved-instances
2. Using the AWS Tools for Windows PowerShell, see Get-EC2ReservedInstance
3. Using the Amazon EC2 API, see DescribeReservedInstances

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Applying Reserved Instances
Reserved Instances are automatically applied to running, or potential, On-Demand instances provided
that the specifications match. You can use the AWS Management Console, a command line tool, or the
Amazon EC2 API to perform any of these tasks.

Note
To purchase and modify Reserved Instances, ensure that your IAM user account has the
appropriate permissions, such as the ability to describe Availability Zones. For information,
see the Example Policies for Working With the AWS CLI or an AWS SDK and Example
Policies for Working in the Amazon EC2 Console.
Purchase—Determine how much capacity to reserve. Specify the following criteria:
• Platform (for example, Linux).

Note
To run your Reserved Instance on a specific Linux platform, you must identify the
platform when you purchase the reserved capacity. Then, when you launch your instance
with the intention of using the reserved capacity you purchased, you must choose the
Amazon Machine Image (AMI) that runs that specific Linux platform, along with any other
specifications you identified during the purchase.
• Instance type (for example, m1.small).
• Availability Zone in which to run the instance.
• Term (time period) over which you want to reserve capacity.
• Tenancy. You can reserve capacity for your instance to run in single-tenant hardware (dedicated
tenancy, as opposed to shared). The tenancy you select must match the tenancy of the OnDemand instance you're applying, or plan to apply, the Reserved Instance to. For more information,
see Dedicated Instances.
• Offering (No Upfront, Partial Upfront, All Upfront).
Use—To use your Reserved Instance, launch an On-Demand instance with the same specifications as
the reservation you purchased. The pricing benefits and capacity reservations automatically apply to
any matching instances you have that aren't already covered by a reservation.
For more information, see Launch Your Instance (p. 278).

Reserved Instance States
Reserved Instances can be in one of the following states:
• active—The Reserved Instance is available for use.
• payment-pending—AWS is processing your payment for the Reserved Instance. You can use the
Reserved Instance when the state becomes active.
• retired—The Reserved Instance has been terminated for any of the following reasons:
• AWS did not receive your payment. For example, the credit card transaction did not go through.
• The Reserved Instance term expired.
It's important to note that status information displayed in the State column in the Reserved Instance
page is different from the status information displayed in the Listing State in the My Listings tab.
If you are a seller in the Reserved Instance Marketplace the Listing State displays the status of
a reservation that's been listed in the Reserved Instance Marketplace. For more information, see
Reserved Instance Listing States (p. 208).

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Buying in the Reserved Instance Marketplace
You can purchase Amazon EC2 Reserved Instances from AWS or you can purchase from third-party
sellers who own Reserved Instances that they no longer need.
For a buyer, the Reserved Instance Marketplace provides increased selection and flexibility by allowing
you to search for Reserved Instances that most closely match your preferred combination of instance
type, region, and duration.
For more information about the Reserved Instance Marketplace, see Selling in the Reserved Instance
Marketplace (p. 204).
There are a few differences between Reserved Instances purchased in the Reserved Instance
Marketplace and Reserved Instances purchased directly from AWS:
• Term—Reserved Instances that you purchase from third-party sellers have less than a full standard
term remaining. Full standard terms from AWS run for one year or three years.
• Upfront price—Third-party Reserved Instances can be sold at different upfront prices. The usage
or recurring fees remain the same as the fees set when the Reserved Instances were originally
purchased from AWS.
Basic information about you is shared with the seller, for example, your ZIP code and country
information.
This information enables sellers to calculate any necessary transaction taxes that they have to remit to
the government (such as sales tax or value-added tax) and is provided in the form of a disbursement
report. In rare circumstances, AWS might have to provide the seller with your email address, so that
they can contact you regarding questions related to the sale (for example, tax questions).
For similar reasons, AWS shares the legal entity name of the seller on the buyer's purchase invoice.
If you need additional information about the seller for tax or related reasons, you can contact AWS
Support.

Selling in the Reserved Instance Marketplace
Selling unused reservations in the Reserved Instance Marketplace provides you with the flexibility to
move to new configurations when your business needs change or if you have capacity you no longer
need.
As soon as you list your Reserved Instances in the Reserved Instance Marketplace, they are available
for potential buyers to find. All Reserved Instances are grouped according to the duration of the term
remaining and the hourly price.
To fulfill a buyer's request, AWS first sells the Reserved Instance with the lowest upfront price in the
specified grouping; then it sells the Reserved Instance with the next lowest price, until the buyer's
entire order is fulfilled. AWS then processes the transactions and transfers ownership of the Reserved
Instances to the buyer.
You own your Reserved Instance until it's sold. After the sale, you've given up the capacity reservation
and the discounted recurring fees. If you continue to use your instance, AWS charges you the OnDemand price starting from the time that your Reserved Instance was sold. You can buy more
reserved capacity, or terminate your instances when your capacity reservation is sold.
Contents
• Getting Paid (p. 205)
• Registering as a Seller (p. 205)
• Listing Your Reserved Instances (p. 207)
• Pricing Your Reserved Instances (p. 209)

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Getting Paid
As soon as AWS receives funds from the buyer, a message is sent to the email address associated
with the account that is registered as owner of the Reserved Instance that was sold.
AWS sends an Automated Clearing House (ACH) wire transfer to your specified bank account.
Typically, this transfer occurs between one to three days after your Reserved Instance has been sold.
You can view the state of this disbursement by viewing your Reserved Instance disbursement report.
Disbursements take place once a day. Keep in mind that you will not be able to receive disbursements
until AWS has received verification from your bank. This period can take up to two weeks.
The Reserved Instance you sold will continue to appear in the results of
DescribeReservedInstances calls you make.
You receive a cash disbursement for your Reserved Instances through a wire transfer directly into your
bank account. AWS charges a service fee of 12 percent of the total upfront price of each Reserved
Instance you sell in the Reserved Instance Marketplace.

Note
Only Amazon EC2 Reserved Instances can be sold in the Reserved Instance Marketplace.
Other types, such as Amazon RDS and Amazon ElastiCache Reserved Instances, cannot be
sold on the Reserved Instance Marketplace.
The following are important limits to note:
• Reserved Instances can be sold after 30 days—Reserved Instances can only be sold when
you've owned them for at least 30 days. In addition, there must be at least a month remaining in the
term of the Reserved Instance you are listing.
• Listings cannot be modified—You cannot modify your listing in the Reserved Instance
Marketplace. However, you can change your listing by first cancelling it and then creating another
listing with new parameters. For information, see Listing Your Reserved Instances (p. 207). You
can also modify your Reserved Instances before listing them. For information, see Modifying Your
Reserved Instances (p. 210).
• Discounted Reserved instances cannot be sold—Reserved Instances purchased at a reduced
cost resulting from a tiering discount cannot be sold in the Reserved Instance Marketplace. For more
information, see Reserved Instance Marketplace (p. 197).

Registering as a Seller
To be able to sell in the Reserved Instance Marketplace, your first task is to register as a seller. During
registration, you need to provide the name of your business, information about your bank, and your
business's tax identification number.
After AWS receives your completed seller registration, you will receive an email confirming your
registration and informing you that you can get started selling in the Reserved Instance Marketplace.
Topics
• Bank Accounts (p. 205)
• Tax Information (p. 206)
• Sharing Information with the Buyer (p. 207)

Bank Accounts
AWS must have your bank information in order to disburse funds collected when you sell your
Reserved Instance. The bank you specify must have a US address.
To register a default bank account for disbursements

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1. On the Reserved Instance Marketplace Seller Registration page, sign in. If you do not yet have an
AWS account you can also create one via this page.
2. On the Manage Bank Account page, provide the following information about the bank through
which you will receive payment:
• Bank account holder name
• Routing number
• Account number
• Bank account type

Note
If you are using a corporate bank account, you are prompted to send the information about
the bank account via fax (1-206-765-3424).
After registration, the bank account provided is set as the default, pending verification with the bank.
It can take up to two weeks to verify a new bank account, during which time you will not be able to
receive disbursements. For an established account, it usually takes about two days for disbursements
to complete.
To change the default bank account for disbursement
1. On the Reserved Instance Marketplace Seller Registration page, sign in with the account you used
when you registered.
2. On the Manage Bank Account page, add a new bank account or modify the default bank account
as needed.

Tax Information
Your sale of Reserved Instances might be subject to a transactional tax, such as sales tax or valueadded tax. You should check with your business's tax, legal, finance, or accounting department to
determine if transaction-based taxes are applicable. You are responsible for collecting and sending the
transaction-based taxes to the appropriate tax authority.
As part of the seller registration process, you have the option of completing a tax interview. We
encourage you to complete this process if any of the following apply:
• You want AWS to generate a Form 1099-K.
• You anticipate having either 50 or more transactions or $20,000 or more in sales of Reserved
Instances in a calendar year. A transaction can involve one or more Reserved Instances. If you
choose to skip this step during registration, and later you reach transaction 49, you will get a
message saying, "You have reached the transaction limit for pre-tax. Please complete the tax
interview in the Seller Registration Portal".
• You are a non-US seller. In this case, you must electronically complete Form W-8BEN.
For more information about IRS requirements and the Form 1099-K, go to the IRS website.
The tax information you enter as part of the tax interview will differ depending on whether your
business is a US or non-US legal entity. As you fill out the tax interview, keep in mind the following:
• Information provided by AWS, including the information in this topic, does not constitute tax, legal, or
other professional advice. To find out how the IRS reporting requirements might affect your business,
or if you have other questions, please contact your tax, legal, or other professional advisor.
• To fulfill the IRS reporting requirements as efficiently as possible, answer all questions and enter all
information requested during the interview.

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• Check your answers. Avoid misspellings or entering incorrect tax identification numbers. They can
result in an invalidated tax form.
After you complete the tax registration process, AWS files Form 1099-K. You will receive a copy of
it through the US mail on or before January 31 in the year following the year that your tax account
reaches the threshold levels. For example, if your tax account reaches the threshold in 2016, you will
receive the form in 2017.

Sharing Information with the Buyer
When you sell in the Reserved Instance Marketplace, AWS shares your company’s legal name on the
buyer’s statement in accordance with US regulations. In addition, if the buyer calls AWS Customer
Support because the buyer needs to contact you for an invoice or for some other tax-related reason,
AWS may need to provide the buyer with your email address so that the buyer can contact you directly.
For similar reasons, the buyer's ZIP code and country information are provided to the seller in the
disbursement report. As a seller, you might need this information to accompany any necessary
transaction taxes that you remit to the government (such as sales tax and value-added tax).
AWS cannot offer tax advice, but if your tax specialist determines that you need specific additional
information, contact AWS Support.

Listing Your Reserved Instances
As a registered seller, you can choose to sell one or more of your Reserved Instances, and you can
choose to sell all of them in one listing or in portions. In addition, you can list any type of Reserved
Instance—including any configuration of instance type, platform, region, and Availability Zone.
If you decide to cancel your listing and a portion of that listing has already been sold, the cancellation is
not effective on the portion that has been sold. Only the portion of the listing not yet sold will no longer
be available in the Reserved Instance Marketplace.

Lifecycle of a Listing
Now that you have created a listing, let's walk through what happens when your listing sells.
When all the instances in your listing are matched and sold, the My Listings tab shows that your Total
instance count matches the count listed under Sold, there are no Available instances left for your
listing, and its Status is closed.
When only a portion of your listing is sold, AWS retires the Reserved Instances in the listing and
creates the number of Reserved Instances equal to the Reserved Instances remaining in the count. So,
the listing ID and the listing that it represents, which now has fewer reservations for sale, is still active.
Any future sales of Reserved Instances in this listing are processed this way. When all the Reserved
Instances in the listing are sold, AWS marks the listing as closed.
For example, let's say you created a listing Reserved Instances listing ID 5ec28771-05ff-4b9baa31-9e57dexample with a listing count of 5.
Your My Listings tab in the Reserved Instance page of the AWS Management Console will display
the listing this way:
Reserved Instance listing ID 5ec28771-05ff-4b9b-aa31-9e57dexample
• Total reservation count = 5
• Sold = 0
• Available = 5
• Status = active

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Let's say that a buyer purchases two of the reservations, which leaves a count of three reservations
still available for sale. As a result of this partial sale, AWS creates a new reservation with a count of
three to represent the remaining reservations that are still for sale.
This is how your listing will look in your My Listings tab:
Reserved Instance listing ID 5ec28771-05ff-4b9b-aa31-9e57dexample
• Total reservation count = 5
• Sold = 2
• Available = 3
• Status = active
If you decide to cancel your listing and a portion of that listing has already sold, the cancellation is not
effective on the portion that has been sold. Only the portion of the listing not yet sold will no longer be
available in the Reserved Instance Marketplace.

After Your Reserved Instance Is Sold
When your Reserved Instance is sold, AWS will send you an email notification. Each day that there
is any kind of activity (for example, you create a listing; you sell a listing; or AWS sends funds to your
account), you will receive one email notification capturing all the activities of the day.
You can track the status of your Reserved Instance listings by looking at the My Listings tab
of the selected Reserved Instance on the Reserved Instance page in the AWS Management
Console. The tab contains the Listing State as well as information about the term, listing price,
and a breakdown of how many instances in the listing are available, pending, sold, and cancelled.
You can also use the ec2-describe-reserved-instances-listings CLI command or the
DescribeReservedInstancesListings API call, with the appropriate filter to obtain information
about your listings.

Reserved Instance Listing States
Listing State displays the current status of your listings:
The information displayed by Listing State is about the status of your listing in the Reserved Instance
Marketplace. It is different from the status information that is displayed by the State column in the
Reserved Instances page. This State information is about your reservation. For more information, see
Reserved Instance States (p. 203).

Listing your Reserved Instances using the AWS CLI
To list a Reserved Instance in the Reserved Instance Marketplace using the AWS CLI
1. Get a list of your Reserved Instances by calling aws ec2 describe-reserved-instances.
2. Specify the ID of the Reserved Instance you want to list and call aws ec2 create-reservedinstances-listing. You have to specify the following required parameters:
• Reserved Instance ID
• Instance count
• MONTH:PRICE
To view your listing
• Run aws ec2 describe-reserved-instances-listings to get details about your listing.
To cancel and change your listing

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• Run aws ec2 cancel-reserved-instances-listings to cancel your listing.

Listing Your Reserved Instances using the Amazon EC2 API
To list a Reserved Instance in the Reserved Instance Marketplace using the Amazon EC2 API
1. Get a list of your Reserved Instances by calling DescribeReservedInstances. Note the ID of the
Reserved Instance to list in the Reserved Instance Marketplace.
2. Create a listing using CreateReservedInstancesListing.
To view your listing
1. Call DescribeReservedInstancesListings to get details about your listing.
To cancel your listing
1. Run CancelReservedInstancesListing.
2. Confirm that it's cancelled by calling DescribeReservedInstancesListings.

Listing Your Reserved Instance using the AWS Management Console
You can list the Reserved Instances you want to sell in the Reserved Instance Marketplace by using
the AWS Management Console.

To list a Reserved Instance in the Reserved Instance Marketplace using the AWS
Management Console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Reserved Instances.

Select the Reserved Instances to list, and choose Sell Reserved Instances.

On the Configure Your Reserved Instance Listing page, set the number of instances to sell
and the upfront price for the remaining term in the relevant columns. You can see how the value
of your reservation will change over the remainder of the term by clicking the arrow next to the
Months Remaining column.

If you are an advanced user and you want to customize the pricing, you can enter different values
for the subsequent months. To return to the default linear price drop, choose Reset.

Choose Continue when you are finished configuring your listing.

Confirm the details of your listing, on the Confirm Your Reserved Instance Listing page and if
you're satisfied, choose List Reserved Instance.

Listing State displays the current status of your listings:
• active—The listing is available for purchase.
• cancelled—The listing is cancelled and won't be available for purchase in the Reserved Instance
Marketplace.
• closed—The Reserved Instance is not listed. A Reserved Instance might be closed because the
sale of the listing was completed.

Pricing Your Reserved Instances
The upfront fee is the only fee that you can specify for the Reserved Instance that you're selling. The
upfront fee is the one-time fee that the buyer pays when they purchase a Reserved Instance. You

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cannot specify the usage fee or the recurring fee; The buyer will pay the same usage or recurring fees
that were set when the reservations were originally purchased.
The following are important limits to note:
• You can sell up to $50,000 in Reserved Instances per year. If you need to sell more, complete
the Request to Raise Sales Limit on Amazon EC2 Reserved Instances form.
• The minimum price is $0. The minimum allowed price allowed in the Reserved Instance
Marketplace is $0.00.
You cannot modify your listing directly. However, you can change your listing by first cancelling it and
then creating another listing with new parameters.
You can cancel your listing at any time, as long as it's in the activestate. You cannot cancel the
listing if it's already matched or being processed for a sale. If some of the instances in your listing are
matched and you cancel the listing, only the remaining unmatched instances are removed from the
listing.

Setting a Pricing Schedule
Because the value of Reserved Instances decreases over time, by default AWS can set prices to
decrease in equal increments month over month. However, you can set different upfront prices based
on when your reservation sells.
For example, if your Reserved Instance has nine months of its term remaining, you can specify the
amount you would accept if a customer were to purchase that Reserved Instance with nine months
remaining, and you could set another price with five months remaining, and yet another price with one
month remaining.

Modifying Your Reserved Instances
When your computing needs change, you can modify your Reserved Instances and continue to benefit
from your capacity reservation.
The following topics guide you through the modification process:
Topics
• Requirements for Modification (p. 211)
• Modifying the Instance Size of Your Reservations (p. 211)
• Submitting Modification Requests (p. 213)
Modification does not change the remaining term of your Reserved Instances; their end dates remain
the same. There is no fee, and you do not receive any new bills or invoices. Modification is separate
from purchasing and does not affect how you use, purchase, or sell Reserved Instances. You can
modify your whole reservation, or just a subset, in one or more of the following ways:
• Switch Availability Zones within the same region
• Change between EC2-VPC and EC2-Classic
• Change the instance size within the same instance type
Availability Zone and network platform modifications are supported for all product platform types
(Linux and Windows). Instance type modifications are supported only for the Linux platform types.
However, due to licensing differences, it is not possible to change the instance type of RedHat or
SUSE Linux Reserved Instances. For more information about RedHat and SUSE pricing, see Amazon
EC2 Reserved Instance Pricing.

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After modification, the pricing benefit of the Reserved Instances is applied only to instances that match
the new parameters. Instances that no longer match the new parameters are charged at the OnDemand rate unless your account has other applicable reservations.

Requirements for Modification
Amazon EC2 processes your modification request if there is sufficient capacity for your target
configuration, and if the following conditions are met.
Your modified Reserved Instances must be:
• Active
• Not pending another modification request
• Not listed in the Reserved Instance Marketplace
• Terminating in the same hour (but not minutes or seconds)
Your modification request must be:
• A unique combination of Availability Zone, instance type, and network platform attributes
• A match between the instance size footprint of the active reservation and the target configuration
If your Reserved Instances are not in the active state or cannot be modified, an API call returns an
error and the Modify Reserved Instances button in the AWS Management Console is not enabled. If
you select multiple Reserved Instances for modification and one or more are for a product platform that
does not allow instance type modification, the Modify Reserved Instances page does not show the
option of changing the instance type of any of the selected Reserved Instances. For more information,
see Modifying the Instance Size of Your Reservations (p. 211).
You may modify your reservations as frequently as you like; however, you cannot submit a modification
request for reservations that are pending a previous modification request. Also, you cannot change
or cancel a pending modification request after you submit it. After the modification has completed
successfully, you can submit another modification request to roll back any changes you made. For
more information, see Determining the Status of Your Modification (p. 214).
To modify Reserved Instances that are listed in the Reserved Instance Marketplace, cancel the
listing, request modification, and then list them again. In addition, you cannot modify an offering
before or at the same time that you purchase it. For more information, see Reserved Instance
Marketplace (p. 197).

Modifying the Instance Size of Your Reservations
You can adjust the instance size of your Reserved Instances if you have Amazon Linux reservations
in an instance type with multiple sizes. Keep in mind that instance size modifications are allowed only
if other attributes—such as region, utilization type, tenancy, product, end date and hour—match and if
capacity is available. It is not possible to modify the instance size of Windows Reserved Instances.

Note
Instances are grouped by family (based on storage, or CPU capacity); type (designed for
specific use cases); and size. For example, the c4 instance type is in the Compute optimized
instance family and is available in multiple sizes. While c3 instances are in the same family,
you can't modify c4 instances into c3 instances because they have different hardware
specifications. For more information, see Amazon EC2 Instance Types.
For information about the modification process and steps, see Submitting Modification
Requests (p. 213).
The following instances cannot be modified because there are no other sizes available.

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• t1.micro
• cc1.4xlarge
• cc2.8xlarge
• cg1.8xlarge
• cr1.8xlarge
• hi1.4xlarge
• hs1.8xlarge
• g2.2xlarge
Your request is successful if the capacity exists and the modification does not change the instance size
footprint of your Reserved Instances.

Understanding the Instance Size Footprint
Each Reserved Instance has an instance size footprint, which is determined by the normalization factor
of the instance type and the number of instances in the reservation. In the Amazon EC2 console, the
footprint is measured in units.
The normalization factor is based on size within the instance type (e.g., the m1 instance family), and
is only meaningful within the same instance type; instance types cannot be modified from one type to
another. The following table illustrates the normalization factor that applies within an instance type.
Instance size

Normalization factor

nano

0.25

micro

0.5

small

medium

large

xlarge

2xlarge

4xlarge

8xlarge

10xlarge

A modification request is not processed if the footprint of the target configuration does not match the
size of the original configuration.
To calculate the instance size footprint of a Reserved Instance, multiply the number of instances by the
normalization factor. For example, an m1.medium has a normalization factor of 2 so a reservation for
four m1.medium instances has a footprint of 8 units.
You can allocate your reservations into different instance sizes across the same instance type as
long as the instance size footprint of your reservation remains the same. For example, you can divide
a reservation for one m1.large (1 x 4) instance into four m1.small (4 x 1) instances, or you can
combine a reservation for four m1.small instances into one m1.large instance. However, you cannot
change your reservation for two m1.small (2 x 1) instances into one m1.large (1 x 4) instance
because the existing instance size footprint of your current reservation is smaller than the proposed
reservation.

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For more information, see Amazon EC2 Instance Types.

Submitting Modification Requests
AWS provides you with several ways to view and work with modification requests: You can use the
AWS Management Console, interact directly with the Amazon EC2 API, or use the command line
interface.
Topics
• AWS Management Console (p. 213)
• Command Line Interface (p. 214)
• Amazon EC2 API (p. 214)
• Determining the Status of Your Modification (p. 214)

AWS Management Console
Each target configuration row on the Modify Reserved Instances page keeps track of the number
of instances for the current instance type (Count) and the instance size footprint of your reservation
relative to its instance type (Units). For more information, see Understanding the Instance Size
Footprint (p. 212).
The allocated total is displayed in red if you have specified either more or fewer Reserved Instances
than are available for modification. The total changes to green and you can choose Continue after you
have specified changes for all the Reserved Instances that were available for modification.
When you modify a subset of your reservation, Amazon EC2 splits your original Reserved Instances
into two or more new Reserved Instances. For example, if you have reservations for 10 instances in
us-east-1a, and decide to move 5 instances to us-east-1b, the modification request results in two new
reservations—one for 5 instances in us-east-1a (the original Availability Zone), and the other for 5
instances in us-east-1b.

To modify your Reserved Instances using the AWS Management Console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

On the Reserved Instances page, select one or more Reserved Instances to modify, and choose
Modify Reserved Instances.

Note
The first entry in the modification table is the original, unmodified reservation. To modify
the attributes of all reservations, choose new specifications from the menus. To modify or
split only some of your reservations, add an additional line for each change.
3.

Choose Add for each additional attribute change and enter the number of reservations to modify in
the Count field.
•

To change the Availability Zone, select a value in the Availability Zone list.

•

To change the network platform, select a value in the Network list.

•

To change the instance type, select a value in the Instance Type list.

To delete a specified attribute, select X for that row.

Note
If the Modify Reserved Instances page contains only one row for attribute changes, you
cannot delete that row. To modify multiple Reserved Instance attributes, first add a row
for the new specifications and then delete the original row.
5.

Choose Continue.

To confirm your modification choices when you finish specifying your target configurations, choose
Submit Modifications. If you change your mind at any point, choose Cancel to exit the wizard.

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Command Line Interface
You can complete modification tasks programmatically by using the AWS CLI (modify-reservedinstances), the AWS Tools for Windows PowerShell (Edit-EC2ReservedInstance) the Amazon EC2 API
(ModifyReservedInstances), and the AWS SDK for Java.

Amazon EC2 API
You can use the ModifyReservedInstances action to modify your Reserved Instances. For more
information, see Amazon EC2 API Reference.

Determining the Status of Your Modification
You can determine the status of your modification request by looking at the state of the Reserved
Instances that you are modifying. The state returned shows your request as in-progress,
fulfilled, or failed. Use the following resources to get this information:
• The State field in the AWS Management Console
• The DescribeReservedInstancesModifications API action
• The describe-reserved-instances-modifications AWS CLI command
• The Get-EC2ReservedInstancesModifications AWS Tools for Windows PowerShell command
The following table illustrates the possible State values in the AWS Management Console
State

Description

active (pending modification)

Transition state for original Reserved Instances.

retired (pending modification)

Transition state for original Reserved Instances
while new Reserved Instances are being created.

retired

Reserved Instances successfully modified and
replaced.

active

New Reserved Instances created from a
successful modification request.
-OrOriginal Reserved Instances after a failed
modification request.

Note
If you use the DescribeReservedInstancesModifications API action, the status of your
modification request should show processing, fulfilled, or failed.
If your modification request succeeds:
• The modified reservation becomes effective immediately and the pricing benefit is applied
to the new instances beginning at the hour of the modification request. For example, if you
successfully modify your reservations at 9:15PM, the pricing benefit transfers to your new instance
at 9:00PM. (You can get the effective date of the modified Reserved Instances by using the
DescribeReservedInstances API action or the describe-reserved-instances command (AWS CLI).
• The original reservation is retired. Its end date is the start date of the new reservation, and the end
date of the new reservation is the same as the end date of the original Reserved Instance. If you
modify a three-year reservation that had 16 months left in its term, the resulting modified reservation
is a 16-month reservation with the same end date as the original one.

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• The modified reservation lists a $0 fixed price and not the fixed price of the original reservation.

Note
The fixed price of the modified reservation does not affect the discount pricing tier calculations
applied to your account, which are based on the fixed price of the original reservation.
If your modification request fails:
• Your Reserved Instances maintain their original configuration.
• Your Reserved Instances are immediately available for another modification request.
For more information about why some Reserved Instances cannot be modified, see Requirements for
Modification (p. 211).

Troubleshooting Modification Requests
If the target configuration settings that you requested were unique, you receive a message that your
request is being processed. At this point, Amazon EC2 has only determined that the parameters of
your modification request are valid. Your modification request can still fail during processing due to
unavailable capacity.
In some situations, you might get a message indicating incomplete or failed modification requests
instead of a confirmation. Use the information in such messages as a starting point for resubmitting
another modification request.
Not all selected Reserved Instances can be processed for modification
Amazon EC2 identifies and lists the Reserved Instances that cannot be modified. If you receive a
message like this, go to the Reserved Instances page in the AWS Management Console and check
the information details about these capacity reservations.
Error in processing your modification request
You submitted one or more Reserved Instances for modification and none of your requests can be
processed. Depending on the number of reservations you are modifying, you can get different versions
of the message.
Amazon EC2 displays the reasons why your request cannot be processed. For example, you might
have specified the same target configuration—a combination of Availability Zone and platform—for
one or more subsets of the Reserved Instances you are modifying. Try submitting these modification
requests again, but ensure that instance details of the reservations match, and that the target
configurations for all subsets being modified are unique.

Scheduled Reserved Instances
Scheduled Reserved Instances (Scheduled Instances) enable you to purchase capacity reservations
that recur on a daily, weekly, or monthly basis, with a specified start time and duration, for a one-year
term. You reserve the capacity in advance, so that you know it is available when you need it. You pay
for the time that the instances are scheduled, even if you do not use them.
Scheduled Instances are a good choice for workloads that do not run continuously, but do run on a
regular schedule. For example, you can use Scheduled Instances for an application that runs during
business hours or for batch processing that runs at the end of the week.
If you require a capacity reservation on a continuous basis, Reserved Instances might meet your
needs and decrease costs. For more information, see Reserved Instances (p. 194). If you are flexible
about when your instances run, Spot instances might meet your needs and decrease costs. For more
information, see Spot Instances (p. 219).

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Contents
• How Scheduled Instances Work (p. 216)
• Purchasing a Scheduled Instance (p. 216)
• Launching a Scheduled Instance (p. 217)
• Scheduled Instance Limits (p. 218)

How Scheduled Instances Work
Amazon EC2 sets aside pools of EC2 instances in each Availability Zone for use as Scheduled
Instances. Each pool supports a specific combination of instance type, operating system, and network
(EC2-Classic or EC2-VPC).
To get started, you must search for an available schedule. You can search across multiple pools or a
single pool. After you locate a suitable schedule, purchase it.
You must launch your Scheduled Instances during their scheduled time periods, using a launch
configuration that matches the following attributes of the schedule that you purchased: instance type,
Availability Zone, network, and platform. When you do so, Amazon EC2 launches EC2 instances
on your behalf, based on the specified launch specification. Amazon EC2 must ensure that the EC2
instances have terminated by the end of the current scheduled time period so that the capacity is
available for any other Scheduled Instances it is reserved for. Therefore, Amazon EC2 terminates the
EC2 instances three minutes before the end of the current scheduled time period.
You can't stop or reboot Scheduled Instances, but you can terminate them manually as needed. If you
terminate a Scheduled Instance before its current scheduled time period ends, you can launch it again
after a few minutes. Otherwise, you must wait until the next scheduled time period.
The following diagram illustrates the lifecycle of a Scheduled Instance.

Purchasing a Scheduled Instance
To purchase a Scheduled Instance, you can use the Scheduled Reserved Instances Reservation
Wizard.

Warning
After you purchase a Scheduled Instance, you can't cancel, modify, or resell your purchase.

To purchase a Scheduled Instance using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, under INSTANCES, choose Scheduled Instances.

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Choose Purchase Scheduled Instances.

On the Find available schedules page, do the following:

Under Create a schedule, select the starting date from Starting on, the schedule recurrence
(daily, weekly, or monthly) from Recurring, and the minimum duration from for duration.
Note that the console ensures that you specify a value for the minimum duration that meets
the minimum required utilization for your Scheduled Instance (1,200 hours per year).

Under Instance details, select the operating system and network from Platform. To narrow
the results, select one or more instance types from Instance type or one or more Availability
Zones from Availability Zone.

Choose Find schedules.

Under Available schedules, select one or more schedules. For each schedule that you
select, set the quantity of instances and choose Add to Cart.

Your cart is displayed at the bottom of the page. When you are finished adding and removing
schedules from your cart, choose Review and purchase.

On the Review and purchase page, verify your selections and edit them as needed. When you
are finished, choose Purchase.

To purchase a Scheduled Instance using the AWS CLI
Use the describe-scheduled-instance-availability command to list the available schedules that meet
your needs, and then use the purchase-scheduled-instances command to complete the purchase.

Launching a Scheduled Instance
After you purchase a Scheduled Instance, it is available for you to launch during its scheduled time
periods.

To launch a Scheduled Instance using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, under INSTANCES, choose Scheduled Instances.

Select the Scheduled Instance and choose Launch Scheduled Instances.

On the Configure page, complete the launch specification for your Scheduled Instances and
choose Review.

Important
The launch specification must match the instance type, Availability Zone, network, and
platform of the schedule that you purchased.
5.

On the Review page, verify the launch configuration and modify it as needed. When you are
finished, choose Launch.
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To launch a Scheduled Instance using the AWS CLI
Use the describe-scheduled-instances command to list your Scheduled Instances, and then use the
run-scheduled-instances command to launch each Scheduled Instance during its scheduled time
periods.

Scheduled Instance Limits
Scheduled Instances are subject to the following limits:
• The following are the only supported instance types: C3, C4, M4, and R3.
• The required term is 365 days (one year).
• The minimum required utilization is 1,200 hours per year.
• You can purchase a Scheduled Instance up to three months in advance.

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Spot Instances
Spot instances enable you to bid on unused EC2 instances, which can lower your Amazon EC2 costs
significantly. The hourly price for a Spot instance (of each instance type in each Availability Zone) is set
by Amazon EC2, and fluctuates depending on the supply of and demand for Spot instances. Your Spot
instance runs whenever your bid exceeds the current market price.
Spot instances are a cost-effective choice if you can be flexible about when your applications run and
if your applications can be interrupted. For example, Spot instances are well-suited for data analysis,
batch jobs, background processing, and optional tasks. For more information, see Amazon EC2 Spot
Instances.
The key differences between Spot instances and On-Demand instances are that Spot instances
might not start immediately, the hourly price for Spot instances varies based on demand, and Amazon
EC2 can terminate an individual Spot instance as the hourly price for or availability of Spot instances
changes. One strategy is to launch a core group of On-Demand instances to maintain a minimum level
of guaranteed compute resources for your applications, and supplement them with Spot instances
when the opportunity arises.

Another strategy is to launch Spot instances with a required duration (also known as Spot blocks),
which are not interrupted due to changes in the Spot price. For more information, see Specifying a
Duration for Your Spot Instances (p. 231).

Concepts
Before you get started with Spot instances, you should be familiar with the following concepts:
• Spot instance pool—A set of unused EC2 instances with the same instance type, operating system,
Availability Zone, and network platform (EC2-Classic or EC2-VPC).
• Spot price—The current market price of a Spot instance per hour, which is set by Amazon EC2
based on the last fulfilled bid. You can also retrieve the Spot price history.
• Spot instance request (or Spot bid)—Provides the maximum price (bid price) that you are willing
to pay per hour for a Spot instance. When your bid price exceeds the Spot price, Amazon EC2
fulfills your request. Note that a Spot instance request is either one-time or persistent. Amazon EC2
automatically resubmits a persistent Spot request after the Spot instance associated with the request
is terminated. Your Spot instance request can optionally specify a duration for the Spot instances.
• Spot fleet—A set of Spot instances that is launched based on criteria that you specify. The Spot
fleet selects the Spot instance pools that meet your needs and launches Spot instances to meet the
target capacity for the fleet. By default Spot fleets are set to maintain target capacity by launching
replacement instances after Spot instances in the fleet are terminated. They can also be submitted
as a one-time request which does not persist once instances have been terminated.
• Spot instance interruption—Amazon EC2 terminates your Spot instance when the Spot price
exceeds your bid price or there are no longer any unused EC2 instances. Amazon EC2 marks
the Spot instance for termination and provides a Spot instance termination notice, which gives the
instance a two-minute warning before it terminates.

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• Bid status—Provides detailed information about the current state of your Spot bid.

How to Get Started
The first thing you need to do is get set up to use Amazon EC2. It can also be helpful to have
experience launching On-Demand instances before launching Spot instances.

Get Up and Running
• Setting Up with Amazon EC2 (p. 19)
• Getting Started with Amazon EC2 Linux Instances (p. 26)

Spot Basics
• How Spot Instances Work (p. 221)
• How Spot Fleet Works (p. 224)

Working with Spot Instances
• Preparing for Interruptions (p. 260)
• Creating a Spot Instance Request (p. 232)
• Getting Bid Status Information (p. 258)

Working with Spot Fleets
• Spot Fleet Prerequisites (p. 238)
• Creating a Spot Fleet Request (p. 240)

Related Services
You can provision Spot instances directly using Amazon EC2. You can also provision Spot instances
using other services in AWS. For more information, see the following documentation.
Auto Scaling and Spot instances
You can create launch configurations with a bid price so that Auto Scaling can launch Spot
instances. For more information, see Launching Spot instances in Your Auto Scaling Group in the
Auto Scaling User Guide.
Amazon EMR and Spot instances
There are scenarios where it can be useful to run Spot instances in an Amazon EMR cluster. For
more information, see Lower Costs with Spot Instances in the Amazon EMR Developer Guide.
AWS CloudFormation Templates
AWS CloudFormation enables you to create and manage a collection of AWS resources using
a template in JSON format. AWS CloudFormation templates can include a Spot price. For more
information, see EC2 Spot Instance Updates - Auto Scaling and CloudFormation Integration.
AWS SDK for Java
You can use the Java programming language to manage your Spot instances. For more
information, see Tutorial: Amazon EC2 Spot Instances and Tutorial: Advanced Amazon EC2 Spot
Request Management.
AWS SDK for .NET
You can use the .NET programming environment to manage your Spot instances. For more
information, see Tutorial: Amazon EC2 Spot instances.

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Pricing
You pay the Spot price for Spot instances, which is set by Amazon EC2 and fluctuates periodically
depending on the supply of and demand for Spot instances. If your bid price exceeds the current Spot
price, Amazon EC2 fulfills your request and your Spot instances run until either you terminate them or
the Spot price increases above your bid price.
Everyone pays that same Spot price for that period, regardless of whether their bid price was higher.
You never pay more than your bid price per hour, and often pay less per hour. For example, if you bid
$0.25 per hour, and the Spot price is $0.20 per hour, you only pay $0.20 per hour. If the Spot price
drops, you pay the new, lower price. If the Spot price rises, you pay the new price if it is equal to or less
than your bid price. If the Spot price rises above your bid price, then your Spot instance is interrupted.
At the start of each instance hour, you are charged based on the Spot price. If your Spot instance is
interrupted in the middle of an instance hour because the Spot price exceeded your bid, you are not
charged for the hour of use that was interrupted. However, if you terminate your Spot instance in the
middle of an instance hour, you are charged for the hour.
Note that Spot instances with a predefined duration use a fixed hourly price that remains in effect for
the Spot instance while it runs.
View Prices
To view the current (updated every five minutes) lowest Spot price per region and instance type, see
the Spot Instances Pricing page.
To view the Spot price history for the past three months, use the Amazon EC2 console or the
describe-spot-price-history command (AWS CLI). For more information, see Spot Instance Pricing
History (p. 229).
Note that we independently map Availability Zones to codes for each AWS account. Therefore, you can
get different results for the same Availability Zone code (for example, us-west-2a) between different
accounts.
View Billing
To review your bill, go to your AWS Account Activity page. Your bill contains links to usage reports that
provide details about your bill. For more information, see AWS Account Billing.
If you have questions concerning AWS billing, accounts, and events, contact AWS Support.

How Spot Instances Work
To use Spot instances, create a Spot instance request or a Spot fleet request. The request includes the
maximum price that you are willing to pay per hour per instance (your bid price), and other constraints
such as the instance type and Availability Zone. If your bid price is greater than the current Spot price
for the specified instance, and the specified instance is available, your request is fulfilled immediately.
Otherwise, the request is fulfilled whenever the Spot price falls below your bid price or the specified
instance becomes available. Spot instances run until you terminate them or until Amazon EC2 must
terminate them (also known as a Spot instance interruption).
When you use Spot instances, you must be prepared for interruptions. Amazon EC2 can interrupt your
Spot instance when the Spot price rises above your bid price, when the demand for Spot instances
rises, or when the supply of Spot instances decreases. When Amazon EC2 marks a Spot instance
for termination, it provides a Spot instance termination notice, which gives the instance a two-minute
warning before it terminates. Note that you can't enable termination protection for Spot instances. For
more information, see Spot Instance Interruptions (p. 260).
Note that you can't stop and start an Amazon EBS-backed instance if it is a Spot instance, but you can
reboot or terminate it.

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Shutting down a Spot instance on OS-level results in the Spot instance being terminated. It is not
possible to change this behavior.
Contents
• Supply and Demand in the Spot Market (p. 222)
• Launching Spot Instances in a Launch Group (p. 223)
• Launching Spot Instances in an Availability Zone Group (p. 223)
• Launching Spot Instances in a VPC (p. 224)

Supply and Demand in the Spot Market
AWS continuously evaluates how many Spot instances are available in each Spot instance pool,
monitors the bids that have been made for each pool, and provisions the available Spot instances to
the highest bidders. The Spot price for a pool is set to the lowest fulfilled bid for that pool. Therefore,
the Spot price is the price above which you must bid to fulfill a Spot request for a single Spot instance
immediately.
For example, suppose that you create a Spot instance request, and that the corresponding Spot
instance pool has only five Spot instances for sale. Your bid price is $0.10, which is also the current
Spot price. The following table shows the current bids, ranked in descending order. Bids 1-5 are
fulfilled. Bid 5, being the last fulfilled bid, sets the Spot price at $0.10. Bid 6 is unfulfilled. Bids 3-5,
which share the same bid price of $0.10, are ranked in random order.
Bid

Bid price

Current Spot price

Notes

$1.00

$0.10

$1.00

$0.10

Your bid

$0.10

Last fulfilled bid, which
sets the Spot price.
Everyone pays the
same Spot price for the
period.

———

$0.05

Spot capacity cutoff

Now, let's say that the size of this pool drops to 3. Bids 1-3 are fulfilled. Bid 3, the last fulfilled bid, sets
the Spot price at $0.10. Bids 4-5, which also are $0.10, are unfulfilled. As you can see, even though
the Spot price didn't change, two of the bids, including your bid, are no longer fulfilled because the Spot
supply decreased.
Bid

Bid price

Current Spot price

$1.00

$0.10

$1.00

$0.10

222

Notes

Last fulfilled bid, which
sets the Spot price.
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Bid

Bid price

Current Spot price

Notes
same Spot price for the
period.

———

Spot capacity cutoff

$0.10

Your bid

$0.10

$0.05

To fulfill a Spot request for a single instance from this pool, you must bid above the current Spot
price of $0.10. If you bid $0.101, your request will be fulfilled, the Spot instance for bid 3 would be
interrupted, and the Spot price would become $0.101. If you bid $2.00, the Spot instance for bid 3
would be interrupted and the Spot price would become $1.00 (the price for bid 2).
Keep in mind that no matter how high you bid, you can never get more than the available number of
Spot instances in a Spot instance pool. If the size of the pool drops to zero, then all the Spot instances
from that pool would be interrupted.

Launching Spot Instances in a Launch Group
Specify a launch group in your Spot instance request to tell Amazon EC2 to launch a set of Spot
instances only if it can launch them all. In addition, if the Spot service must terminate one of the
instances in a launch group (for example, if the Spot price rises above your bid price), it must terminate
them all. However, if you terminate one or more of the instances in a launch group, Amazon EC2 does
not terminate the remaining instances in the launch group.
Note that although this option can be useful, adding this constraint can lower the chances that your
Spot instance request is fulfilled. It can also increase the chance that your Spot instances will be
terminated.
If you create another successful Spot instance request that specifies the same (existing) launch group
as an earlier successful request, then the new instances are added to the launch group. Subsequently,
if an instance in this launch group is terminated, all instances in the launch group are terminated, which
includes instances launched by the first and second requests.

Launching Spot Instances in an Availability Zone Group
Specify an Availability Zone group in your Spot instance request to tell the Spot service to launch a
set of Spot instances in the same Availability Zone. Note that Amazon EC2 need not terminate all
instances in an Availability Zone group at the same time. If Amazon EC2 must terminate one of the
instances in an Availability Zone group, the others remain running.
Note that although this option can be useful, adding this constraint can lower the chances that your
Spot instance request is fulfilled.
If you specify an Availability Zone group but don't specify an Availability Zone in the Spot instance
request, the result depends on whether you specified the EC2-Classic network, a default VPC,
or a nondefault VPC. For more information about EC2-Classic and EC2-VPC, see Supported
Platforms (p. 549).
EC2-Classic
Amazon EC2 finds the lowest-priced Availability Zone in the region and launches your Spot instances
in that Availability Zone if the lowest bid for the group is higher than the current Spot price in that
Availability Zone. Amazon EC2 waits until there is enough capacity to launch your Spot instances
together, as long as the Spot price remains lower than the lowest bid for the group.

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Default VPC
Amazon EC2 uses the Availability Zone for the specified subnet, or if you don't specify a subnet, it
selects an Availability Zone and its default subnet, but it might not be the lowest-priced Availability
Zone. If you deleted the default subnet for an Availability Zone, then you must specify a different
subnet.
Nondefault VPC
Amazon EC2 uses the Availability Zone for the specified subnet.

Launching Spot Instances in a VPC
To take advantage of the features of EC2-VPC when you use Spot instances, specify in your Spot
request that your Spot instances are to be launched in a VPC. You specify a subnet for your Spot
instances the same way that you specify a subnet for your On-Demand instances.
The process for making a Spot instance request that launches Spot instances in a VPC is the same as
the process for making a Spot instance request that launches Spot instances in EC2-Classic—except
for the following differences:
• You should base your bid on the Spot price history of Spot instances in a VPC.
• [Default VPC] If you want your Spot instance launched in a specific low-priced Availability Zone, you
must specify the corresponding subnet in your Spot instance request. If you do not specify a subnet,
Amazon EC2 selects one for you, and the Availability Zone for this subnet might not have the lowest
Spot price.
• [Nondefault VPC] You must specify the subnet for your Spot instance.

How Spot Fleet Works
A Spot fleet is a collection, or fleet, of Spot instances. The Spot fleet attempts to launch the number of
Spot instances that are required to meet the target capacity that you specified in the Spot fleet request.
The Spot fleet also attempts to maintain its target capacity fleet if your Spot instances are interrupted
due to a change in Spot prices or available capacity.
A Spot instance pool is a set of unused EC2 instances with the same instance type, operating system,
Availability Zone, and network platform (EC2-Classic or EC2-VPC). When you make a Spot fleet
request, you can include multiple launch specifications, that vary by instance type, AMI, Availability
Zone, or subnet. The Spot fleet selects the Spot instance pools that are used to fulfill the request,
based on the launch specifications included in your Spot fleet request, and the configuration of the
Spot fleet request. The Spot instances come from the selected pools.
Contents
• Spot Fleet Allocation Strategy (p. 224)
• Spot Price Overrides (p. 225)
• Spot Fleet Instance Weighting (p. 225)
• Walkthrough: Using Spot Fleet with Instance Weighting (p. 226)

Spot Fleet Allocation Strategy
The allocation strategy for your Spot fleet determines how it fulfills your Spot fleet request from the
possible Spot instance pools represented by its launch specifications. The following are the allocation
strategies that you can specify in your Spot fleet request:
lowestPrice
The Spot instances come from the pool with the lowest price. This is the default strategy.

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diversified
The Spot instances are distributed across all pools.

Choosing an Allocation Strategy
You can optimize your Spot fleets based on your use case.
If your fleet is small or runs for a short time, the probability that your Spot instances will be interrupted
is low, even with all the instances in a single Spot instance pool. Therefore, the lowestPrice strategy
is likely to meet your needs while providing the lowest cost.
If your fleet is large or runs for a long time, you can improve the availability of your fleet by distributing
the Spot instances across multiple pools. For example, if your Spot fleet request specifies 10 pools and
a target capacity of 100 instances, the Spot fleet launches 10 Spot instances in each pool. If the Spot
price for one pool increases above your bid price for this pool, only 10% of your fleet is affected. Using
this strategy also makes your fleet less sensitive to increases in the Spot price in any one pool over
time.
Note that with the diversified strategy, the Spot fleet does not launch Spot instances into any pools
with a Spot price that is higher than the On-Demand price.

Maintaining Target Capacity
After Spot instances are terminated due to a change in the Spot price or available capacity of a
Spot instance pool, the Spot fleet launches replacement Spot instances. If the allocation strategy
is lowestPrice, the Spot fleet launches replacement instances in the pool where the Spot price
is currently the lowest. If the allocation strategy is diversified, the Spot fleet distributes the
replacement Spot instances across the remaining pools.

Spot Price Overrides
Each Spot fleet request must include a global Spot price. By default, the Spot fleet uses this price as
the bid price for each of its launch specifications.
You can optionally specify a Spot price in one or more launch specifications. This bid price is specific to
the launch specification. If a launch specification includes a specific Spot price, the Spot fleet uses this
price as the bid price for that launch specification, overriding the global Spot price. Note that any other
launch specifications that do not include a specific Spot price still use the global Spot price.

Spot Fleet Instance Weighting
When you request a fleet of Spot instances, you can define the capacity units that each instance type
would contribute to your application's performance, and adjust your bid price for each Spot instance
pool accordingly using instance weighting.
By default, the Spot price that you specify represents your bid price per instance hour. When you use
the instance weighting feature, the Spot price that you specify represents your bid price per unit hour.
You can calculate your bid price per unit hour by dividing your bid price for an instance type by the
number of units that it represents. The Spot fleet calculates the number of Spot instances to launch by
dividing the target capacity by the instance weight. If the result isn't an integer, the Spot fleet rounds it
up to the next integer, so that the size of your fleet is not below its target capacity.
The following table includes examples of calculations to determine the bid price per unit for a Spot fleet
request with a target capacity of 10.
Instance
type

Instance
weight

Spot price
per instance
hour

Spot price per
unit hour

Number of instances launched

r3.xlarge

$0.05

.025

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Instance
type

r3.8xlarge

Instance
weight

Spot price
per instance
hour

$0.10

Spot price per
unit hour

Number of instances launched

(.05 divided by
2)

(10 divided by 2)

.0125

(.10 divided by
8)

(10 divided by 8, result rounded
up)

Use Spot fleet instance weighting as follows to provision the target capacity you want in the pools with
the lowest price per unit at the time of fulfillment:
1.

Set the target capacity for your Spot fleet either in instances (the default) or in the units of your
choice, such as virtual CPUs, memory, storage, or throughput.

Set the bid price per unit.

For each launch configuration, specify the weight, which is the number of units that the instance
type represents toward the target capacity.

Instance Weighting Example
Consider a Spot fleet request with the following configuration:
• A target capacity of 24
• A launch specification with an instance type r3.2xlarge and a weight of 6
• A launch specification with an instance type c3.xlarge and a weight of 5
The weights represent the number of units that instance type represents toward the target capacity. If
the first launch specification provides the lowest Spot price per unit (Spot price for r3.2xlarge per
instance hour divided by 6), the Spot fleet would launch four of these instances (24 divided by 6).
If the second launch specification provides the lowest Spot price per unit (Spot price for c3.xlarge
per instance hour divided by 5), the Spot fleet would launch five of these instances (24 divided by 5,
result rounded up).
Instance Weighting and Allocation Strategy
Consider a Spot fleet request with the following configuration:
• A target capacity of 30
• A launch specification with an instance type c3.2xlarge and a weight of 8
• A launch specification with an instance type m3.xlarge and a weight of 8
• A launch specification with an instance type r3.xlarge and a weight of 8
The Spot fleet would launch four instances (30 divided by 8, result rounded up). With the
lowestPrice strategy, all four instances come from the pool that provides the lowest Spot price per
unit. With the diversified strategy, the Spot fleet launches 1 instance in each of the three pools,
and the fourth instance in whichever of the three pools provides the lowest Spot price per unit.

Walkthrough: Using Spot Fleet with Instance Weighting
This walkthrough uses a fictitious company called Example Corp to illustrate the process of bidding for
a Spot fleet using instance weighting.
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Objective
Example Corp, a pharmaceutical company, wants to leverage the computational power of Amazon
EC2 for screening chemical compounds that might be used to fight cancer.

Planning
Example Corp first reviews Spot Best Practices. Next, Example Corp determines the following
requirements for their Spot fleet.
Instance Types
Example Corp has a compute- and memory-intensive application that performs best with at least
60 GB of memory and eight virtual CPUs (vCPUs). They want to maximize these resources for the
application at the lowest possible price. Example Corp decides that any of the following EC2 instance
types would meet their needs:
Instance type

Memory (GiB)

vCPUs

r3.2xlarge

r3.4xlarge

122

r3.8xlarge

244

Target Capacity in Units
With instance weighting, target capacity can equal a number of instances (the default) or a combination
of factors such as cores (vCPUs), memory (GiBs), and storage (GBs). By considering the base for
their application (60 GB of RAM and eight vCPUs) as 1 unit, Example Corp decides that 20 times this
amount would meet their needs. So the company sets the target capacity of their Spot fleet request to
20.
Instance Weights
After determining the target capacity, Example Corp calculates instance weights. To calculate the
instance weight for each instance type, they determine the units of each instance type that are required
to reach the target capacity as follows:
• r3.2xlarge (61.0 GB, 8 vCPUs) = 1 unit of 20
• r3.4xlarge (122.0 GB, 16 vCPUs) = 2 units of 20
• r3.8xlarge (244.0 GB, 32 vCPUs) = 4 units of 20
Therefore, Example Corp assigns instance weights of 1, 2, and 4 to the respective launch
configurations in their Spot fleet request.
Bid Price Per Unit Hour
Example Corp uses the On-Demand price per instance hour as a starting point for their bid price. They
could also use recent Spot prices, or a combination of the two. To calculate bid price per unit hour, they
divide their starting bid price per instance hour by the weight. For example:
Instance type

On-Demand price

Instance weight

Price per unit hour

r3.2xLarge

$0.7

r3.4xLarge

$1.4

$0.7

r3.8xLarge

$2.8

$0.7

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Example Corp could enter a global bid price per unit hour of $0.7 and be competitive for all three
instance types. They could also enter a global bid price per unit hour of $0.7 and a specific bid
price per unit hour of $0.9 in the r3.8xlarge launch specification. Depending on the strategy for
provisioning their Spot fleet, Example Corp could bid lower to further reduce costs, or bid higher to
reduce the probability of interruption.

Verifying Permissions
Before creating a Spot fleet request, Example Corp verifies that it has an IAM role with the required
permissions. For more information, see Spot Fleet Prerequisites (p. 238).

Creating the Request
Example Corp creates a file, config.json, with the following configuration for its Spot fleet request:
{
"SpotPrice": "0.70",
"TargetCapacity": 20,
"IamFleetRole": "arn:aws:iam::123456789012:role/my-spot-fleet-role",
"LaunchSpecifications": [
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "r3.2xlarge",
"SubnetId": "subnet-482e4972",
"WeightedCapacity": 1
},
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "r3.4xlarge",
"SubnetId": "subnet-482e4972",
"WeightedCapacity": 2
}
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "r3.8xlarge",
"SubnetId": "subnet-482e4972",
"SpotPrice": "0.90",
"WeightedCapacity": 4
}
]
}

Example Corp creates the Spot fleet request using the following request-spot-fleet command:
aws ec2 request-spot-fleet --spot-fleet-request-config file://config.json

For more information, see Spot Fleet Requests (p. 237).

Fulfillment
The allocation strategy determines which Spot instance pools your Spot instances come from.
With the lowestPrice strategy (which is the default strategy), the Spot instances come from the
pool with the lowest Spot price per unit at the time of fulfillment. To provide 20 units of capacity, the
Spot fleet launches either 20 r3.2xlarge instances (20 divided by 1), 10 r3.4xlarge instances (20
divided by 2), or 5 r3.8xlarge instances (20 divided by 4).
If Example Corp used the diversified strategy, the Spot instances would come from all three
pools. The Spot fleet would launch 6 r3.2xlarge instances (which provide 6 units), 3 r3.4xlarge

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instances (which provide 6 units), and 2 r3.8xlarge instances (which provide 8 units), for a total of
20 units.

Spot Instance Pricing History
The Spot price represents the price above which you have to bid to guarantee that a single Spot
request is fulfilled. When your bid price is above the Spot price, Amazon EC2 launches your Spot
instance, and when the Spot price rises above your bid price, Amazon EC2 terminates your Spot
instance. You can bid above the current Spot price so that your Spot request is fulfilled quickly.
However, before you specify a bid price for your Spot instance, we recommend that you review the
Spot price history. You can view the Spot price history for the last 90 days, filtering by instance type,
operating system, and Availability Zone.
Using the Spot price history as a guide, you can select a bid price that would have met your needs in
the past. For example, you can determine which bid price that would have provided 75 percent uptime
in the time range you viewed. However, keep in mind that the historical trends are not a guarantee
of future results. Spot prices vary based on real-time supply and demand, and the conditions that
generated certain patterns in the Spot price might not occur in the future.

To view the Spot price history using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

On the navigation pane, choose Spot Requests.

If you are new to Spot instances, you see a welcome page; choose Get started, scroll to the
bottom of the screen, and then choose Cancel.

Choose Pricing History. By default, the page displays a graph of the data for Linux t1.micro
instances in all Availability Zones over the past day. Move your mouse over the graph to display
the prices at specific times in the table below the graph.

(Optional) To review the Spot price history for a specific Availability Zone, select an Availability
Zone from the list. You can also select a different product, instance type, or date range.

To view the Spot price history using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• describe-spot-price-history (AWS CLI)
• Get-EC2SpotPriceHistory (AWS Tools for Windows PowerShell)
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Spot Instance Requests
To use Spot instances, you create a Spot instance request that includes the number of instances,
the instance type, the Availability Zone, and the maximum price that you are willing to pay per
instance hour (your bid). If your bid exceeds the current Spot price, Amazon EC2 fulfills your request
immediately. Otherwise, Amazon EC2 waits until your request can be fulfilled or until you cancel the
request.
The following illustration shows how Spot requests work. Notice that the action taken for a Spot
instance interruption depends on the request type (one-time or persistent). If the request is a persistent
request, the request is opened again after your Spot instance is terminated.

Contents
• Spot Instance Request States (p. 230)
• Specifying a Duration for Your Spot Instances (p. 231)
• Creating a Spot Instance Request (p. 232)
• Finding Running Spot Instances (p. 234)
• Tagging Spot Instance Requests (p. 234)
• Cancelling a Spot Instance Request (p. 235)
• Spot Request Example Launch Specifications (p. 235)

Spot Instance Request States
A Spot instance request can be in one of the following states:
• open—The request is waiting to be fulfilled.
• active—The request is fulfilled and has an associated Spot instance.
• failed—The request has one or more bad parameters.
• closed—The Spot instance was interrupted or terminated.
• cancelled—You cancelled the request, or the request expired.
The following illustration represents the transitions between the request states. Notice that the
transitions depend on the request type (one-time or persistent).

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A one-time Spot instance request remains active until Amazon EC2 launches the Spot instance, the
request expires, or you cancel the request. If the Spot price rises above your bid price, your Spot
instance is terminated and the Spot instance request is closed.
A persistent Spot instance request remains active until it expires or you cancel it, even if the request is
fulfilled. For example, if you create a persistent Spot instance request for one instance when the Spot
price is $0.25, Amazon EC2 launches your Spot instance if your bid price is above $0.25. If the Spot
price rises above your bid price, your Spot instance is terminated; however, the Spot instance request
is open again and Amazon EC2 launches a new Spot instance when the Spot price falls below your bid
price.
You can track the status of your Spot instance requests, as well as the status of the Spot instances
launched, through the bid status. For more information, see Spot Bid Status (p. 255).

Specifying a Duration for Your Spot Instances
Amazon EC2 does not terminate Spot instances with a specified duration (also known as Spot blocks)
when the Spot price changes. This makes them ideal for jobs that take a finite time to complete, such
as batch processing, encoding and rendering, modeling and analysis, and continuous integration.
You can specify a duration of 1, 2, 3, 4, 5, or 6 hours. The price that you pay depends on the specified
duration. To view the current prices for a 1 hour duration or a 6 hour duration, see Spot Instance
Prices. You can use these prices to estimate the cost of the 2, 3, 4, and 5 hour durations. When a
request with a duration is fulfilled, the price for your Spot instance is fixed, and this price remains in
effect until the instance terminates.
When you specify a duration in your Spot request, the duration period for each Spot instance starts
as soon as the instance receives its instance ID. The Spot instance runs until you terminate it or the
duration period ends. At the end of the duration period, Amazon EC2 marks the Spot instance for
termination and provides a Spot instance termination notice, which gives the instance a two-minute
warning before it terminates.
To launch Spot instances with a specified duration using the console
Select the appropriate request type. For more information, see Creating a Spot Instance
Request (p. 232).
To launch Spot instances with a specified duration using the AWS CLI
To specify a duration for your Spot instances, include the --block-duration-minutes option with
the request-spot-instances command. For example, the following command creates a Spot request that
launches Spot instances that run for two hours:
aws ec2 request-spot-instances --spot-price "0.050" --instance-count 5
--block-duration-minutes 120 --type "one-time" --launch-specification
file://specification.json

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To retrieve the cost for Spot instances with a specified duration using the AWS CLI
Use the describe-spot-instance-requests command to retrieve the fixed cost for your Spot instances
with a specified duration. The information is in the actualBlockHourlyPrice field.

Creating a Spot Instance Request
The process for requesting a Spot instance is similar to the process for launching an On-Demand
instance. Note that you can't change the parameters of your Spot request, including the bid price, after
you've submitted the request.
If you request multiple Spot instances at one time, Amazon EC2 creates separate Spot instance
requests so that you can track the status of each request separately. For more information about
tracking Spot requests, see Spot Bid Status (p. 255).
Prerequisites
Before you begin, decide on your bid price, how many Spot instances you'd like, and what instance
type to use. To review Spot price trends, see Spot Instance Pricing History (p. 229).

To create a Spot instance request using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

On the navigation pane, choose Spot Requests.

If you are new to Spot instances, you see a welcome page; choose Get started. Otherwise,
choose Request Spot Instances.

On the Find instance types page, do the following:
a.

For Request type, the default is a one-time Spot request created using a Spot fleet. For more
information, see Spot Fleet Requests (p. 237). To use Spot blocks instead, select Reserve
for duration.

For Target capacity, enter the number of units to request. You can choose instances or
performance characteristics that are important to your application workload, such as vCPUs,
memory, and storage.

[Spot block] For Reserved duration, select the number of hours for the job to complete.

For AMI, choose one of the basic Amazon Machine Images (AMI) provided by AWS, or
choose Use custom AMI to specify your own AMI.

For Instance type(s), choose Select. Select the instance types that have the minimum
hardware specifications that you need (vCPUs, memory, and storage).

[Spot fleet] For Allocation strategy, choose the strategy that meets your needs. For more
information, see Spot Fleet Allocation Strategy (p. 224).

For Network, your account supports either the EC2-Classic and EC2-VPC platforms, or the
EC2-VPC platform only. To find out which platforms your account supports, see Supported
Platforms (p. 549).

•

[Existing VPC] Select the VPC.

•

[New VPC] Select Create new VPC to go the Amazon VPC console. When you are done,
return to the wizard and refresh the list.

•

[EC2-Classic] Select EC2-Classic.

(Optional) For Availability Zones, the default is to let AWS choose the Availability Zones for
your Spot instances. If you prefer specific Availability Zones, do the following:
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•

[EC2-Classic] Select Select specific zone/subnet, and then select one or more
Availability Zones.

[Spot fleet] For Maximum price, you can use automated bidding or specify a bid price. Your
Spot instances are not launched if your bid price is lower than the Spot price for the instance
types that you selected.

Choose Next.

On the Configure page, do the following:
a.

(Optional) If you need to connect to your instances, specify your key pair using Key pair
name.

(Optional) If you need to launch your Spot instances with an IAM role, specify the role using
IAM instance profile.

(Optional) If you have any start-up scripts to run, specify them using User data.

For Security groups, choose one or more security groups.

[EC2-VPC] If you need to connect to your instances in a VPC, select auto-assign at launch
for Public IP.

By default, the request remains in effect until it is fulfilled or you cancel it. To create a request
that is valid only during a specific time period, edit Request valid from and Request valid to.

[Spot fleet] By default, we terminate your Spot instances when the request expires. To keep
them running after your request expires, clear Terminate instances at expiration.

Choose Review.

On the Review page, verify the launch configuration. To make changes, choose Previous. To
download a copy of the launch configuration for use with the AWS CLI, choose JSON config.
When you are ready, choose Launch.

On the confirmation page, choose OK.
[Spot fleet] The request type is fleet. When the request is fulfilled, requests of type instance
are added, where the state is active and the status is fulfilled.
[Spot block] The request type is block and the initial state is open. When the request is fulfilled,
the state is active and the status is fulfilled.

To create a Spot instance request using the AWS CLI
Use the following request-spot-instances command to create a one-time request:
aws ec2 request-spot-instances --spot-price "0.05" --instance-count 5 --type
"one-time" --launch-specification file://specification.json

Use the following request-spot-instances command to create a persistent request:
aws ec2 request-spot-instances --spot-price "0.05" --instance-count 5 --type
"persistent" --launch-specification file://specification.json

For example launch specification files, see Spot Request Example Launch Specifications (p. 235).
Amazon EC2 launches your Spot instance when the Spot price is below your bid. The Spot instance
runs until either it is interrupted, or you terminate it yourself. Use the following describe-spot-instancerequests command to monitor your Spot instance request:
aws ec2 describe-spot-instance-requests --spot-instance-requestids sir-08b93456

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Finding Running Spot Instances
Amazon EC2 launches a Spot instance when the Spot price is below your bid. A Spot instance runs
until either its bid price is no longer higher than the Spot price, or you terminate it yourself. (If your bid
price is exactly equal to the Spot price, there is a chance that your Spot instance will remain running,
depending on demand.)

To find running Spot instances using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Spot Requests.
You can see both Spot instance requests and Spot fleet requests. If a Spot instance request has
been fulfilled, Capacity is the ID of the Spot instance. For a Spot fleet, Capacity indicates how
much of the requested capacity has been fulfilled. To view the IDs of the instances in a Spot fleet,
choose the expand arrow, or select the fleet and then select the Instances tab.

Alternatively, in the navigation pane, choose Instances. In the top right corner, choose the Show/
Hide icon, and then select Lifecycle. For each instance, Lifecycle is either normal, spot, or
scheduled.

To find running Spot instances using the AWS CLI
To enumerate your Spot instances, use the describe-spot-instance-requests command with the -query option as follows:
aws ec2 describe-spot-instance-requests --query SpotInstanceRequests[*].
{ID:InstanceId}

The following is example output:
[
{
"ID": "i-1234567890abcdef0"
},
{
"ID": "i-0598c7d356eba48d7"
}
]

Alternatively, you can enumerate your Spot instances using the describe-instances command with the
--filters option as follows:
aws ec2 describe-instances --filters "Name=instance-lifecycle,Values=spot"

Tagging Spot Instance Requests
To help categorize and manage your Spot instance requests, you can tag them with metadata of your
choice. You tag your Spot instance requests in the same way that you tag other any other Amazon
EC2 resource. For more information, see Tagging Your Amazon EC2 Resources (p. 751).
You can assign a tag to the request after you create it.
The tags that you create for your Spot instance requests only apply to the requests. These tags are not
added automatically to the Spot instance that the Spot service launches to fulfill the request. You must
add tags to a Spot instance yourself after the Spot instance is launched.
To add a tag to your Spot instance request or Spot instance using the AWS CLI

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Use the following create-tags command to tag your resources:
aws ec2 create-tags --resources sir-08b93456 i-1234567890abcdef0 --tags
Key=purpose,Value=test

Cancelling a Spot Instance Request
If you no longer want your Spot request, you can cancel it. You can only cancel Spot instance requests
that are open or active. Your Spot request is open when your request has not yet been fulfilled and
no instances have been launched. Your Spot request is active when your request has been fulfilled,
and Spot instances have launched as a result. If your Spot request is active and has an associated
running Spot instance, cancelling the request does not terminate the instance; you must terminate the
running Spot instance manually.
If the Spot request is a persistent Spot request, it returns to the open state so that a new Spot instance
can be launched. To cancel a persistent Spot request and terminate its Spot instances, you must
cancel the Spot request first and then terminate the Spot instances. Otherwise, the Spot request can
launch a new instance.

To cancel a Spot instance request using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Spot Requests, and then select the Spot request.

3.
4.

Choose Actions, and then choose Cancel spot request.
(Optional) If you are finished with the associated Spot instances, you can terminate them. In the
navigation pane, choose Instances, select the instance, choose Actions, choose Instance State,
and then choose Terminate.

To cancel a Spot instance request using the AWS CLI
Use the following cancel-spot-instance-requests command to cancel the specified Spot request:
aws ec2 cancel-spot-instance-requests --spot-instance-requestids sir-08b93456

If you are finished with the associated Spot instances, you can terminate them manually using the
following terminate-instances command:
aws ec2 terminate-instances --instanceids i-1234567890abcdef0 i-0598c7d356eba48d7

Spot Request Example Launch Specifications
The following examples show launch configurations that you can use with the request-spot-instances
command to create a Spot instance request. For more information, see Creating a Spot Instance
Request (p. 232).
1. Launch Spot instances (p. 235)
2. Launch Spot instances in the specified Availability Zone (p. 236)
3. Launch Spot instances in the specified subnet (p. 236)

Example 1: Launch Spot Instances
The following example does not include an Availability Zone or subnet. Amazon EC2 selects an
Availability Zone for you. If your account supports EC2-VPC only, Amazon EC2 launches the instances

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in the default subnet of the selected Availability Zone. If your account supports EC2-Classic, Amazon
EC2 launches the instances in EC2-Classic in the selected Availability Zone.
{
"ImageId": "ami-1a2b3c4d",
"KeyName": "my-key-pair",
"SecurityGroupIds": [ "sg-1a2b3c4d" ],
"InstanceType": "m3.medium",
"IamInstanceProfile": {
"Arn": "arn:aws:iam::123456789012:instance-profile/my-iam-role"
}
}

Note that you can specify security groups for EC2-Classic either by ID or by name (using the
SecurityGroups field). You must specify security groups for EC2-VPC by ID.

Example 2: Launch Spot Instances in the Specified Availability Zone
The following example includes an Availability Zone. If your account supports EC2-VPC only, Amazon
EC2 launches the instances in the default subnet of the specified Availability Zone. If your account
supports EC2-Classic, Amazon EC2 launches the instances in EC2-Classic in the specified Availability
Zone.
{
"ImageId": "ami-1a2b3c4d",
"KeyName": "my-key-pair",
"SecurityGroupIds": [ "sg-1a2b3c4d" ],
"InstanceType": "m3.medium",
"Placement": {
"AvailabilityZone": "us-west-2a"
},
"IamInstanceProfile": {
"Arn": "arn:aws:iam::123456789012:instance-profile/my-iam-role"
}
}

Example 3: Launch Spot Instances in the Specified Subnet
The following example includes a subnet. Amazon EC2 launches the instances in the specified subnet.
If the VPC is a nondefault VPC, the instance does not receive a public IP address by default.
{
"ImageId": "ami-1a2b3c4d",
"SecurityGroupIds": [ "sg-1a2b3c4d" ],
"InstanceType": "m3.medium",
"SubnetId": "subnet-1a2b3c4d",
"IamInstanceProfile": {
"Arn": "arn:aws:iam::123456789012:instance-profile/my-iam-role"
}
}

To assign a public IP address to an instance in a nondefault VPC, specify the
AssociatePublicIpAddress field as shown in the following example. Note that when you specify
a network interface, you must include the subnet ID and security group ID using the network interface,
rather than using the SubnetId and SecurityGroupIds fields shown in example 3.
{

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"ImageId": "ami-1a2b3c4d",
"KeyName": "my-key-pair",
"InstanceType": "m3.medium",
"NetworkInterfaces": [
{
"DeviceIndex": 0,
"SubnetId": "subnet-1a2b3c4d",
"Groups": [ "sg-1a2b3c4d" ],
"AssociatePublicIpAddress": true
}
],
"IamInstanceProfile": {
"Arn": "arn:aws:iam::123456789012:instance-profile/my-iam-role"
}
}

Spot Fleet Requests
To use a Spot fleet, you create a Spot fleet request that includes the target capacity, one or more
launch specifications for the instances, and the bid price that you are willing to pay. Amazon EC2
attempts to maintain your Spot fleet's target capacity as Spot prices change. For more information, see
How Spot Fleet Works (p. 224).
You can create a Spot fleet to submit a one-time request for your desired capacity, or require it
to maintain a target capacity over time. Both types of requests benefit from Spot fleet's allocation
strategy.
When you request a target capacity, Spot fleet places the required bids but will not attempt to
replenish Spot instances if capacity is diminished. If capacity is not available, Spot fleet will not submit
bids in alternative Spot pools.
When you want to maintain a target capacity, Spot fleet will place the required bids to meet this
target capacity and automatically replenish any interrupted instances. By default, Spot fleets are set to
maintain the requested target capacity.
It is not possible to modify the target capacity of a one-time request once it's been submitted. To
change the target capacity, cancel the request and submit a new one.
A Spot fleet request remains active until it expires or you cancel it. When you cancel a Spot fleet
request, you may specify whether cancelling your Spot fleet request terminates the Spot instances in
your Spot fleet.
Each launch specification includes the information that Amazon EC2 needs to launch an instance—
such as an AMI, an instance type, a subnet or Availability Zone, and one or more security groups.
Contents
• Spot Fleet Request States (p. 238)
• Spot Fleet Prerequisites (p. 238)
• Spot Fleet and IAM Users (p. 239)
• Planning a Spot Fleet Request (p. 240)
• Creating a Spot Fleet Request (p. 240)
• Monitoring Your Spot Fleet (p. 241)
• Modifying a Spot Fleet Request (p. 242)
• Cancelling a Spot Fleet Request (p. 243)
• Spot Fleet Example Configurations (p. 244)

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Spot Fleet Request States
A Spot fleet request can be in one of the following states:
• submitted—The Spot fleet request is being evaluated and Amazon EC2 is preparing to launch the
target number of Spot instances.
• active—The Spot fleet has been validated and Amazon EC2 is attempting to maintain the target
number of running Spot instances. The request remains in this state until it is modified or cancelled.
• modifying—The Spot fleet request is being modified. The request remains in this state until
the modification is fully processed or the Spot fleet is cancelled. A one-time request cannot be
modified, and this state does not apply to such Spot requests.
• cancelled_running—The Spot fleet is cancelled and will not launch additional Spot instances,
but its existing Spot instances continue to run until they are interrupted or terminated. The request
remains in this state until all instances are interrupted or terminated.
• cancelled_terminating—The Spot fleet is cancelled and its Spot instances are terminating. The
request remains in this state until all instances are terminated.
• cancelled—The Spot fleet is cancelled and has no running Spot instances. The Spot fleet request
is deleted two days after its instances were terminated.
The following illustration represents the transitions between the request states. Note that if you exceed
your Spot fleet limits, the request is cancelled immediately.

Spot Fleet Prerequisites
If you use the AWS Management Console to create a Spot fleet, it creates a role named aws-ec2spot-fleet-role that grants the Spot fleet permission to bid on, launch, and terminate instances on
your behalf, and specifies it in your Spot fleet request. If you create a Spot fleet using the AWS CLI or
an API, you can use this role if it exists, or manually create your own role for this purpose as follows.

To manually create an IAM role with the AmazonEC2SpotFleetRole policy
1.

Open the Identity and Access Management (IAM) console at https://console.aws.amazon.com/
iam/.

In the navigation pane, choose Roles.

Choose Create New Role.

On the Set Role Name page, type a name for the role and then choose Next Step.

On the Select Role Type page, choose Select next to Amazon EC2 Spot Fleet Role.

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On the Attach Policy page, select the AmazonEC2SpotFleetRole policy, and then choose Next
Step.

On the Review page, choose Create Role.

Spot Fleet and IAM Users
If IAM users will be creating or managing Spot fleet, be sure to grant them the required permissions as
follows.

To grant an IAM user permissions for Spot fleet
1.

Open the Identity and Access Management (IAM) console at https://console.aws.amazon.com/
iam/.

In the navigation pane, choose Policies, and then choose Create Policy.

On the Create Policy page, choose Select next to Create Your Own Policy.

On the Review Policy page, enter a policy name and copy the following text into the Policy
Document section.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"ec2:*"
],
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"iam:PassRole",
"iam:ListRoles",
"iam:ListInstanceProfiles"
],
"Resource": "*"
}
]
}

The ec2:* enables an IAM user to call all Amazon EC2 API actions. To limit the user to specific
API actions, specify those actions instead.
The iam:PassRole action enables the user to specify the Spot fleet role in a Spot fleet
request. The iam:ListRoles action enables the user to enumerate existing roles. The
iam:ListInstanceProfiles action enables the user to enumerate existing instance
profiles. The Amazon EC2 console uses iam:ListRoles to populate the IAM role list and
iam:ListInstanceProfiles to populate the IAM instance profile list. To enable the user
to create roles or instance profiles using the console, you must add the following actions:
iam:CreateRole, iam:CreateInstanceProfile, and iam:AddRoleToInstanceProfile.
5.

Choose Create Policy.

In the navigation pane, choose Users, and then choose the user who will submit the Spot fleet
request.

On the Permissions tab, choose Attach Policy.

On the Attach Policy page, select the policy you created above, and choose Attach Policy.

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Planning a Spot Fleet Request
Before you create a Spot fleet request, review Spot Best Practices. Use these best practices when
you plan your Spot fleet request so that you can provision the type of instances you want at the lowest
possible price. We also recommend that you do the following:
• Determine whether you want to create a Spot fleet that submits a one-time request for the desired
target capacity, or one that will maintain a target capacity over time.
• Determine the instance types that meet your application requirements.
• Determine the target capacity for your Spot fleet request. You can set target capacity in instances or
in custom units. For more information, see Spot Fleet Instance Weighting (p. 225).
• Determine your bid price per instance hour. Bidding lower can further reduce costs, while bidding
higher can reduce the probability of interruption.
• Determine your bid price per unit, if you are using instance weighting. To calculate the bid price
per unit, divide the bid price per instance hour by the number of units (or weight) that this instance
represents. (If you are not using instance weighting, the default bid price per unit is the bid price per
instance hour.)
• Review the possible options for your Spot fleet request. For more information, see the request-spotfleet command in the AWS Command Line Interface Reference. For additional examples, see Spot
Fleet Example Configurations (p. 244).

Creating a Spot Fleet Request
When you create a Spot fleet request, you must specify information about the Spot instances to launch,
such as the instance type and the Spot price.

To create a Spot fleet request using the console
1.

Open the Spot console at https://console.aws.amazon.com/ec2spot.

If you are new to Spot, you see a welcome page; choose Get started. Otherwise, choose
Request Spot Instances.

On the Find instance types page, do the following:
a.

For Request type, select either Request or Request and Maintain.

For Target capacity, enter the number of units to request. You can choose instances or
performance characteristics that are important to your application workload, such as vCPUs,
memory, and storage.

For AMI, choose one of the basic Amazon Machine Images (AMI) provided by AWS, or
choose Use custom AMI to use an AMI from our user community, the AWS Marketplace, or
one of your own.

For Instance type(s), choose Select. Select the instance types that have the minimum
hardware specifications that you need (vCPUs, memory, and storage).

For Allocation strategy, choose the strategy that meets your needs. For more information,
see Spot Fleet Allocation Strategy (p. 224).

For Network, your account supports either the EC2-Classic and EC2-VPC platforms, or the
EC2-VPC platform only. To find out which platforms your account supports, see Supported
Platforms (p. 549).

•

[Existing VPC] Select the VPC.

•

[New VPC] Select Create new VPC to go the Amazon VPC console. When you are done,
return to the wizard and refresh the list.

•

[EC2-Classic] Select EC2-Classic.

(Optional) For Availability Zones, the default is to let AWS choose the Availability Zones for
your Spot instances. If you prefer specific Availability Zones, do the following:
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•

[EC2-VPC] Select one or more Availability Zones. If you have more than one subnet in
an Availability Zone, select the appropriate subnet from Subnet. To add subnets, select
Create new subnet to go to the Amazon VPC console. When you are done, return to the
wizard and refresh the list.
•
[EC2-Classic] Select Select specific zone/subnet, and then select one or more
Availability Zones.
For Maximum price, you can use automated bidding or specify a bid price. Your Spot
instances are not launched if your bid price is lower than the Spot price for the instance types
that you selected.

i.
Choose Next.
On the Configure page, do the following:
a.

(Optional) If you need to connect to your instances, specify your key pair using Key pair
name.

(Optional) If you need to launch your Spot instances with an IAM role, specify the role using
IAM instance profile.

(Optional) If you have any start-up scripts to run, specify them using User data.

For Security groups, choose one or more security groups.

[EC2-VPC] If you need to connect to your instances in a VPC, select auto-assign at launch
for Public IP.

By default, the request remains in effect until it is fulfilled or you cancel it. To create a request
that is valid only during a specific time period, edit Request valid from and Request valid to.

(Optional) By default, we terminate your Spot instances when the request expires. To keep
them running after your request expires, clear Terminate instances at expiration.

h. Choose Review.
On the Review page, verify the launch configuration. To make changes, choose Previous. To
download a copy of the launch configuration for use with the AWS CLI, choose JSON config.
When you are ready, choose Launch.
On the confirmation page, choose OK. The request type is fleet. When the request is fulfilled,
requests of type instance are added, where the state is active and the status is fulfilled.

To create a Spot fleet request using the AWS CLI
Use the following request-spot-fleet command to create a Spot fleet request:
aws ec2 request-spot-fleet --spot-fleet-request-config file://config.json

For example configuration files, see Spot Fleet Example Configurations (p. 244).
The following is example output:
{
"SpotFleetRequestId": "sfr-73fbd2ce-aa30-494c-8788-1cee4EXAMPLE"
}

Monitoring Your Spot Fleet
The Spot fleet launches Spot instances when the Spot price is below your bid. The Spot instances run
until either the bid price is no longer higher than the Spot price, or you terminate them yourself.

To monitor your Spot fleet using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

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In the navigation pane, choose Spot Requests.

Select your Spot fleet request. The configuration details are available in the Description tab.

To list the Spot instances for the Spot fleet, choose the Instances tab.

To view the history for the Spot fleet, choose the History tab.

To monitor your Spot fleet using the AWS CLI
Use the following describe-spot-fleet-requests command to describe your Spot fleet requests:
aws ec2 describe-spot-fleet-requests

Use the following describe-spot-fleet-instances command to describe the Spot instances for the
specified Spot fleet:
aws ec2 describe-spot-fleet-instances --spot-fleet-request-id sfr-73fbd2ceaa30-494c-8788-1cee4EXAMPLE

Use the following describe-spot-fleet-request-history command to describe the history for the specified
Spot fleet request:
aws ec2 describe-spot-fleet-request-history --spot-fleet-requestid sfr-73fbd2ce-aa30-494c-8788-1cee4EXAMPLE --start-time 2015-05-18T00:00:00Z

Modifying a Spot Fleet Request
You can modify an active Spot fleet request to complete the following tasks:
• Increase the target capacity
• Decrease the target capacity

Note
It is not possible to modify a one-time Spot fleet request.
When you increase the target capacity, the Spot fleet launches the additional Spot instances according
to the allocation strategy for its Spot fleet request. If the allocation strategy is lowestPrice, the Spot
fleet launches the instances from the lowest-priced Spot instance pool in the Spot fleet request. If the
allocation strategy is diversified, the Spot fleet distributes the instances across the pools in the
Spot fleet request.
When you decrease the target capacity, the Spot fleet cancels any open bids that exceed the new
target capacity. You can request that the Spot fleet terminate Spot instances until the size of the fleet
reaches the new target capacity. If the allocation strategy is lowestPrice, the Spot fleet terminates
the instances with the highest price per unit. If the allocation strategy is diversified, the Spot fleet
terminates instances across the pools. Alternatively, you can request that the Spot fleet keep the
fleet at its current size, but not replace any Spot instances that are interrupted or that you terminate
manually.

To modify a Spot fleet request using the console
1.

Open the Spot console at https://console.aws.amazon.com/ec2spot/home/fleet.

Select your Spot fleet request.

Choose Actions, and then choose Modify target capacity.

In Modify target capacity, do the following:

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Enter the new target capacity.

(Optional) If you are decreasing the target capacity but want to keep the fleet at its current
size, deselect Terminate instances.
Choose Submit.

To modify a Spot fleet request using the AWS CLI
Use the following modify-spot-fleet-request command to update the target capacity of the specified
Spot fleet request:
aws ec2 modify-spot-fleet-request --spot-fleet-request-id sfr-73fbd2ceaa30-494c-8788-1cee4EXAMPLE --target-capacity 20

You can modify the previous command as follows to decrease the target capacity of the specified Spot
fleet without terminating any Spot instances as a result:
aws ec2 modify-spot-fleet-request --spot-fleet-request-id sfr-73fbd2ceaa30-494c-8788-1cee4EXAMPLE --target-capacity 10 --excess-capacitytermination-policy NoTermination

Cancelling a Spot Fleet Request
When you are finished using your Spot fleet, you can cancel the Spot fleet request. This cancels all
Spot requests associated with the Spot fleet, so that no new Spot instances are launched for your Spot
fleet. You must specify whether the Spot fleet should terminate its Spot instances. If you terminate the
instances, the Spot fleet request enters the cancelled_terminating state. Otherwise, the Spot
fleet request enters the cancelled_running state and the instances continue to run until they are
interrupted or you terminate them manually.

To cancel a Spot fleet request using the console
1.
2.
3.

Open the Spot console at https://console.aws.amazon.com/ec2spot/home/fleet.
Select your Spot fleet request.
Choose Actions, and then choose Cancel spot request.

In Cancel spot request, verify that you want to cancel the Spot fleet. To keep the fleet at its
current size, deselect Terminate instances. When you are ready, choose Confirm.

To cancel a Spot fleet request using the AWS CLI
Use the following cancel-spot-fleet-requests command to cancel the specified Spot fleet request and
terminate the instances:
aws ec2 cancel-spot-fleet-requests --spot-fleet-request-ids sfr-73fbd2ceaa30-494c-8788-1cee4EXAMPLE --terminate-instances

The following is example output:
{
"SuccessfulFleetRequests": [
{
"SpotFleetRequestId": "sfr-73fbd2ce-aa30-494c-8788-1cee4EXAMPLE",
"CurrentSpotFleetRequestState": "cancelled_terminating",
"PreviousSpotFleetRequestState": "active"

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}
],
"UnsuccessfulFleetRequests": []
}

You can modify the previous command as follows to cancel the specified Spot fleet request without
terminating the instances:
aws ec2 cancel-spot-fleet-requests --spot-fleet-request-ids sfr-73fbd2ceaa30-494c-8788-1cee4EXAMPLE --no-terminate-instances

The following is example output:
{
"SuccessfulFleetRequests": [
{
"SpotFleetRequestId": "sfr-73fbd2ce-aa30-494c-8788-1cee4EXAMPLE",
"CurrentSpotFleetRequestState": "cancelled_running",
"PreviousSpotFleetRequestState": "active"
}
],
"UnsuccessfulFleetRequests": []
}

Spot Fleet Example Configurations
The following examples show launch configurations that you can use with the request-spotfleet command to create a Spot fleet request. For more information, see Creating a Spot Fleet
Request (p. 240).
1. Launch Spot instances using the lowest-priced Availability Zone or subnet in the region (p. 244)
2. Launch Spot instances using the lowest-priced Availability Zone or subnet in a specified
list (p. 245)
3. Launch Spot instances using the lowest-priced instance type in a specified list (p. 246)
4. Override the Spot price for the request (p. 248)
5. Launch a Spot fleet using the diversified allocation strategy (p. 249)
6. Launch a Spot fleet using instance weighting (p. 250)

Example 1: Launch Spot Instances Using the Lowest-priced Availability Zone or Subnet
in the Region
The following example specifies a single launch specification without an Availability Zone or subnet.
If your account supports EC2-VPC only, the Spot fleet launches the instances in the lowest-priced
Availability Zone that has a default subnet. If your account supports EC2-Classic, the Spot fleet
launches the instances in EC2-Classic in the lowest-priced Availability Zone. Note that the price you
pay will not exceed the specified Spot price for the request.
{
"SpotPrice": "0.07",
"TargetCapacity": 20,
"IamFleetRole": "arn:aws:iam::123456789012:role/my-spot-fleet-role",
"LaunchSpecifications": [
{
"ImageId": "ami-1a2b3c4d",
"KeyName": "my-key-pair",

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"SecurityGroups": [
{
"GroupId": "sg-1a2b3c4d"
}
],
"InstanceType": "m3.medium",
"IamInstanceProfile": {
"Arn": "arn:aws:iam::123456789012:instance-profile/my-iam-role"
}
}
]
}

Example 2: Launch Spot Instances Using the Lowest-priced Availability Zone or Subnet
in a Specified List
The following examples specify two launch specifications with different Availability Zones or subnets,
but the same instance type and AMI.
Availability Zones
If your account supports EC2-VPC only, the Spot fleet launches the instances in the default subnet of
the lowest-priced Availability Zone that you specified. If your account supports EC2-Classic, the Spot
fleet launches the instances in the lowest-priced Availability Zone that you specified.
{
"SpotPrice": "0.07",
"TargetCapacity": 20,
"IamFleetRole": "arn:aws:iam::123456789012:role/my-spot-fleet-role",
"LaunchSpecifications": [
{
"ImageId": "ami-1a2b3c4d",
"KeyName": "my-key-pair",
"SecurityGroups": [
{
"GroupId": "sg-1a2b3c4d"
}
],
"InstanceType": "m3.medium",
"Placement": {
"AvailabilityZone": "us-west-2a, us-west-2b"
},
"IamInstanceProfile": {
"Arn": "arn:aws:iam::123456789012:instance-profile/my-iam-role"
}
}
]
}

Subnets
You can specify default subnets or nondefault subnets, and the nondefault subnets can be from a
default VPC or a nondefault VPC. The Spot service launches the instances in whichever subnet is in
the lowest-priced Availability Zone.
Note that you can't specify different subnets from the same Availability Zone in a Spot fleet request.
{

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"SpotPrice": "0.07",
"TargetCapacity": 20,
"IamFleetRole": "arn:aws:iam::123456789012:role/my-spot-fleet-role",
"LaunchSpecifications": [
{
"ImageId": "ami-1a2b3c4d",
"KeyName": "my-key-pair",
"SecurityGroups": [
{
"GroupId": "sg-1a2b3c4d"
}
],
"InstanceType": "m3.medium",
"SubnetId": "subnet-a61dafcf, subnet-65ea5f08",
"IamInstanceProfile": {
"Arn": "arn:aws:iam::123456789012:instance-profile/my-iam-role"
}
}
]
}

If the instances are launched in a default VPC, they receive a public IP address by default. If the
instances are launched in a nondefault VPC, they do not receive a public IP address by default. Use a
network interface in the launch specification to assign a public IP address to instances launched in a
nondefault VPC. Note that when you specify a network interface, you must include the subnet ID and
security group ID using the network interface.
...
{
"ImageId": "ami-1a2b3c4d",
"KeyName": "my-key-pair",
"InstanceType": "m3.medium",
"NetworkInterfaces": [
{
"DeviceIndex": 0,
"SubnetId": "subnet-1a2b3c4d",
"Groups": [ "sg-1a2b3c4d" ],
"AssociatePublicIpAddress": true
}
],
"IamInstanceProfile": {
"Arn": "arn:aws:iam::880185128111:instance-profile/my-iam-role"
}
}
...

Example 3: Launch Spot Instances Using the Lowest-priced Instance Type in a
Specified List
The following examples specify two launch configurations with different instance types, but the same
AMI and Availability Zone or subnet. The Spot fleet launches the instances using the specified instance
type with the lowest price.
Availability Zone
{
"SpotPrice": "2.80",
"TargetCapacity": 20,

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"IamFleetRole": "arn:aws:iam::123456789012:role/my-spot-fleet-role",
"LaunchSpecifications": [
{
"ImageId": "ami-1a2b3c4d",
"SecurityGroups": [
{
"GroupId": "sg-1a2b3c4d"
}
],
"InstanceType": "cc2.8xlarge",
"Placement": {
"AvailabilityZone": "us-west-2b"
}
},
{
"ImageId": "ami-1a2b3c4d",
"SecurityGroups": [
{
"GroupId": "sg-1a2b3c4d"
}
],
"InstanceType": "r3.8xlarge",
"Placement": {
"AvailabilityZone": "us-west-2b"
}
}
]
}

Subnet
{
"SpotPrice": "2.80",
"TargetCapacity": 20,
"IamFleetRole": "arn:aws:iam::123456789012:role/my-spot-fleet-role",
"LaunchSpecifications": [
{
"ImageId": "ami-1a2b3c4d",
"SecurityGroups": [
{
"GroupId": "sg-1a2b3c4d"
}
],
"InstanceType": "cc2.8xlarge",
"SubnetId": "subnet-1a2b3c4d"
},
{
"ImageId": "ami-1a2b3c4d",
"SecurityGroups": [
{
"GroupId": "sg-1a2b3c4d"
}
],
"InstanceType": "r3.8xlarge",
"SubnetId": "subnet-1a2b3c4d"
}
]
}

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Example 4. Override the Spot Price for the Request
The ability to specify Spot prices for individual launch specifications provides you with additional control
over the bidding process. The following examples override the Spot price for the request (0.070)
with individual Spot prices for two of the three launch specifications. Note that the Spot price for the
request is used for any launch specification that does not specify an individual Spot price. The Spot
fleet launches the instances using the instance type with the lowest price.
Availability Zone
{
"SpotPrice": "1.68",
"TargetCapacity": 30,
"IamFleetRole": "arn:aws:iam::123456789012:role/my-spot-fleet-role",
"LaunchSpecifications": [
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "c3.2xlarge",
"Placement": {
"AvailabilityZone": "us-west-2b"
},
"SpotPrice": "0.04"
},
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "c3.4xlarge",
"Placement": {
"AvailabilityZone": "us-west-2b"
},
"SpotPrice": "0.06"
},
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "c3.8xlarge",
"Placement": {
"AvailabilityZone": "us-west-2b"
}
}
]
}

Subnet
{
"SpotPrice": "1.68",
"TargetCapacity": 30,
"IamFleetRole": "arn:aws:iam::123456789012:role/my-spot-fleet-role",
"LaunchSpecifications": [
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "c3.2xlarge",
"SubnetId": "subnet-1a2b3c4d",
"SpotPrice": "0.04"
},
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "c3.4xlarge",
"SubnetId": "subnet-1a2b3c4d",

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"SpotPrice": "0.06"
},
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "c3.8xlarge",
"SubnetId": "subnet-1a2b3c4d"
}
]
}

Example 5: Launch a Spot Fleet Using the Diversified Allocation Strategy
The following example uses the diversified allocation strategy. The launch specifications have
different instance types but the same AMI and Availability Zone or subnet. The Spot fleet distributes
the 30 instances across the 3 launch specifications, such that there are 10 instances of each type. For
more information, see Spot Fleet Allocation Strategy (p. 224).
Availability Zone
{
"SpotPrice": "0.70",
"TargetCapacity": 30,
"AllocationStrategy": "diversified",
"IamFleetRole": "arn:aws:iam::123456789012:role/my-spot-fleet-role",
"LaunchSpecifications": [
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "c4.2xlarge",
"Placement": {
"AvailabilityZone": "us-west-2b"
}
},
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "m3.2xlarge",
"Placement": {
"AvailabilityZone": "us-west-2b"
}
},
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "r3.2xlarge",
"Placement": {
"AvailabilityZone": "us-west-2b"
}
}
]
}

Subnet
{
"SpotPrice": "0.70",
"TargetCapacity": 30,
"AllocationStrategy": "diversified",
"IamFleetRole": "arn:aws:iam::123456789012:role/my-spot-fleet-role",
"LaunchSpecifications": [
{

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"ImageId": "ami-1a2b3c4d",
"InstanceType": "c4.2xlarge",
"SubnetId": "subnet-1a2b3c4d"
},
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "m3.2xlarge",
"SubnetId": "subnet-1a2b3c4d"
},
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "r3.2xlarge",
"SubnetId": "subnet-1a2b3c4d"
}
]
}

Example 6: Launch a Spot Fleet Using Instance Weighting
The following examples use instance weighting, which means that the bid price is per unit hour instead
of per instance hour. Each launch configuration lists a different instance type and a different weight.
The Spot fleet selects the instance type with the lowest price per unit hour. The Spot fleet calculates
the number of Spot instances to launch by dividing the target capacity by the instance weight. If the
result isn't an integer, the Spot fleet rounds it up to the next integer, so that the size of your fleet is not
below its target capacity.
If the r3.2xlarge bid is successful, Spot provisions 4 of these instances. (Divide 20 by 6 for a total of
3.33 instances, then round up to 4 instances.)
If the c3.xlarge bid is successful, Spot provisions 7 of these instances. (Divide 20 by 3 for a total of
6.66 instances, then round up to 7 instances.)
For more information, see Spot Fleet Instance Weighting (p. 225).
Availability Zone
{
"SpotPrice": "0.70",
"TargetCapacity": 20,
"IamFleetRole": "arn:aws:iam::123456789012:role/my-spot-fleet-role",
"LaunchSpecifications": [
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "r3.2xlarge",
"Placement": {
"AvailabilityZone": "us-west-2b"
},
"WeightedCapacity": 6
},
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "c3.xlarge",
"Placement": {
"AvailabilityZone": "us-west-2b"
},
"WeightedCapacity": 3
}
]
}

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Subnet
{
"SpotPrice": "0.70",
"TargetCapacity": 20,
"IamFleetRole": "arn:aws:iam::123456789012:role/my-spot-fleet-role",
"LaunchSpecifications": [
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "r3.2xlarge",
"SubnetId": "subnet-1a2b3c4d",
"WeightedCapacity": 6
},
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "c3.xlarge",
"SubnetId": "subnet-1a2b3c4d",
"WeightedCapacity": 3
}
]
}

Priority
You can also use instance weighting to give priority to an Availability Zone or subnet. For example,
the following launch specifications are nearly identical, except that they specify different subnets and
weights. The Spot fleet finds the specification with the highest value for WeightedCapacity, and
attempts to provision the request in the least expensive Spot instance pool in that subnet. (Note that
the second launch specification does not include a weight, so it defaults to 1.)
{
"SpotPrice": "0.42",
"TargetCapacity": 40,
"IamFleetRole": "arn:aws:iam::123456789012:role/my-spot-fleet-role",
"LaunchSpecifications": [
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "c3.2xlarge",
"SubnetId": "subnet-482e4972",
"WeightedCapacity": 2
},
{
"ImageId": "ami-1a2b3c4d",
"InstanceType": "c3.2xlarge",
"SubnetId": "subnet-bb3337d"
}
]
}

CloudWatch Metrics for Spot Fleet
Amazon EC2 provides Amazon CloudWatch metrics that you can use to monitor your Spot fleet.

Important
To ensure accuracy, we recommend that you enable detailed monitoring when using
these metrics. For more information, see Enable or Disable Detailed Monitoring for Your
Instances (p. 419).

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For more information about CloudWatch metrics provided by Amazon EC2, see Monitoring Your
Instances Using CloudWatch (p. 419).

Spot Fleet Metrics
The AWS/EC2Spot namespace includes the following metrics, plus the CloudWatch metrics for the
Spot instances in your fleet. For more information, see Instance Metrics (p. 421).
The AWS/EC2Spot namespace includes the following metrics.
Metric

Description

AvailableInstancePoolsCount
The Spot Instance pools specified in the Spot Fleet request.

Units: Count
BidsSubmittedForCapacity

The capacity for which Amazon EC2 has submitted bids.
Units: Count

EligibleInstancePoolCount The Spot Instance pools specified in the Spot Fleet request where
Amazon EC2 can fulfill bids. Amazon EC2 will not fulfill bids in
pools where your bid price is less than the Spot price or the Spot
price is greater than the price for On-Demand instances.

Units: Count
FulfilledCapacity

The capacity that Amazon EC2 has fulfilled.
Units: Count

MaxPercentCapacityAllocation
The maximum value of PercentCapacityAllocation across all
Spot Instance pools specified in the Spot Fleet request.

Units: Percent
PendingCapacity

The difference between TargetCapacity and
FulfilledCapacity.
Units: Count

PercentCapacityAllocation The capacity allocated for the Spot Instance pool for the specified
dimensions. To get the maximum value recorded across all Spot
Instance pools, use MaxPercentCapacityAllocation.

Units: Percent
TargetCapacity

The target capacity of the Spot Fleet request.
Units: Count

TerminatingCapacity

The capacity that is being terminated due to Spot Instance
interruptions.
Units: Count

If the unit of measure for a metric is Count, the most useful statistic is Average.

Spot Fleet Dimensions
To filter the data for your Spot fleet, you can use the following dimensions.

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Dimensions

Description

AvailabilityZone

Filter the data by Availability Zone.

FleetRequestId

Filter the data by Spot Fleet request.

InstanceType

Filter the data by instance type.

View the CloudWatch Metrics for Your Spot Fleet
You can view the CloudWatch metrics for your Spot fleet using the Amazon CloudWatch console.
These metrics are displayed as monitoring graphs. These graphs show data points if the Spot fleet is
active.
Metrics are grouped first by namespace, and then by the various combinations of dimensions within
each namespace. For example, you can view all Spot fleet metrics, or Spot fleet metrics groups by
Spot fleet request ID, instance type, or Availability Zone.

To view Spot fleet metrics
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

In the navigation pane, under Metrics, choose the EC2 Spot namespace.

(Optional) To filter the metrics by dimension, select one of the following:
• Fleet Request Metrics — Group by Spot fleet request
• By Availability Zone — Group by Spot fleet request and Availability Zone
• By Instance Type — Group by Spot fleet request and instance type
• By Availability Zone/Instance Type — Group by Spot fleet request, Availability Zone, and
instance type

To view the data for a metric, select the check box next to the metric.

Automatic Scaling for Spot Fleet
Automatic scaling is the ability to increase or decrease the target capacity of your Spot fleet
automatically based on demand. A Spot fleet can either launch instances (scale out) or terminate
instances (scale in), within the range that you choose, in response to one or more scaling policies. We
recommend that you create two policies, one for scaling out and one for scaling in.
A scaling policy uses CloudWatch alarms to trigger the scaling process. For example, if you want to
scale out when CPU utilization reaches a certain level, create an alarm using the CPUUtilization
metric provided by Amazon EC2.
When you create a scaling policy, you must specify one of the following scaling adjustment types:

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• Add — Increase the target capacity of the fleet by a specified number of capacity units or a specified
percentage of the current capacity.
• Remove — Decrease the target capacity of the fleet by a specified number of capacity units or a
specified percentage of the current capacity.
• Set to — Set the target capacity of the fleet to the specified number of capacity units.
You can also configure the cooldown period for a scaling policy. After Auto Scaling starts a scaling
activity, it waits for the cooldown period to complete before resuming scaling activities. This ensures
that Auto Scaling doesn't launch or terminate additional Spot instances before the previous launch or
terminate activity takes effect.

Limits
• The Spot fleet request must have a request type of maintain. Automatic scaling is not supported
for one-time requests or Spot blocks.

Prerequisites
• Consider which CloudWatch metrics are important to your application. You can create CloudWatch
alarms based on metrics provided by AWS or your own custom metrics.
• For the AWS metrics that you will use in your scaling policies, enable CloudWatch metrics collection
if the service that provides the metrics does not enable it by default.
• If you use the AWS Management Console to enable automatic scaling for your Spot fleet, it creates
a role named aws-ec2-spot-fleet-autoscale-role that grants Auto Scaling permission
to describe the alarms for your policies, monitor the current capacity of the fleet, and modify the
capacity of the fleet. If you configure automatic scaling using the AWS CLI or an API, you can use
this role if it exists, or manually create your own role for this purpose as follows.
1.

Open the Identity and Access Management (IAM) console at https://console.aws.amazon.com/
iam/.

In the navigation pane, choose Roles.

Choose Create New Role.

On the Set Role Name page, type a name for the role and then choose Next Step.

On the Select Role Type page, choose Select next to Amazon EC2.

On the Attach Policy page, select the AmazonEC2SpotFleetAutoscaleRole policy and then
choose Next Step.

On the Review page, choose Create Role.

Select the role that you just created.

On the Trust Relationships tab, choose Edit Trust Relationship.

10. Change ec2.amazonaws.com to application-autoscaling.amazonaws.com and then
choose Update Trust Policy.

To create a CloudWatch alarm
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

In the navigation pane, choose Alarms.

Choose Create Alarm.

For CloudWatch Metrics by Category, choose a category. For example, choose EC2 Spot
Metrics, Fleet Request Metrics.

Select a metric, and then choose Next.

For Alarm Threshold, type a name and description for the alarm, and set the threshold value and
number of time periods for the alarm.

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(Optional) To receive notification of a scaling event, for Actions, choose New list and type your
email address. Otherwise, you can delete the notification now and add one later if needed.

Choose Create Alarm.

To configure automatic scaling for your Spot fleet using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Spot Requests.

Select your Spot fleet request, and then choose the Auto Scaling tab.

If automatic scaling is not configured, choose Configure.

Use Scale capacity between to set the minimum and maximum capacity for your fleet. Automatic
scaling will not scale your fleet below the minimum capacity or above the maximum capacity.

Initially, Scaling policies contains policies named ScaleUp and ScaleDown. You can complete
these policies, or choose Remove policy to delete them. You can also choose Add policy to add
a policy.

To define a policy, do the following:

For Policy name, type a name for the policy.

For Policy trigger, select an existing alarm or choose Create new alarm to open the Amazon
CloudWatch console and create an alarm.

For Modify capacity, select a scaling adjustment type, select a number, and select a unit.

(Optional) To perform step scaling, choose Define steps. By default, an add policy has a
lower bound of -infinity and an upper bound of the alarm threshold. By default, a remove
policy has a lower bound of the alarm threshold and an upper bound of +infinity. To add
another step, choose Add step.

(Optional) To modify the default value for the cooldown period, select a number from
Cooldown period.

Choose Save.

To configure automatic scaling for your Spot fleet using the AWS CLI
1.

Create a scaling policy using the put-scaling-policy command.

Create an alarm that will trigger the scaling policy using the put-metric-alarm command.

Spot Bid Status
To help you track your Spot instance requests, plan your use of Spot instances, and bid strategically,
Amazon EC2 provides a bid status. For example, a bid status can tell you the reason why your Spot
request isn't fulfilled yet, or list the constraints that are preventing the fulfillment of your Spot request.
At each step of the process—also called the Spot request life cycle, specific events determine
successive request states.
Contents
• Life Cycle of a Spot Request (p. 256)
• Getting Bid Status Information (p. 258)
• Spot Bid Status Codes (p. 259)

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Life Cycle of a Spot Request
The following diagram shows you the paths that your Spot request can follow throughout its life cycle,
from submission to termination. Each step is depicted as a node, and the status code for each node
describes the status of the Spot request and Spot instance.

Pending evaluation
As soon as you make a Spot instance request, it goes into the pending-evaluation state unless
one or more request parameters is not valid (bad-parameters).
Status Code

Request State

Instance State

pending-evaluation

open

n/a

bad-parameters

closed

n/a

Holding
If one or more request constraints are valid but can't be met yet, or if there is not enough capacity, the
request goes into a holding state waiting for the constraints to be met. The request options affect the
likelihood of the request being fulfilled. For example, if you specify a bid price below the current Spot
price, your request stays in a holding state until the Spot price goes below your bid price. If you specify
an Availability Zone group, the request stays in a holding state until the Availability Zone constraint is
met.
Status Code

Request State

Instance State

capacity-not-available

open

n/a

capacity-oversubscribed

open

n/a

price-too-low

open

n/a

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Status Code

Request State

Instance State

not-scheduled-yet

open

n/a

launch-group-constraint

open

n/a

az-group-constraint

open

n/a

placement-groupconstraint

open

n/a

constraint-notfulfillable

open

n/a

Pending evaluation/fulfillment-terminal
Your Spot instance request can go to a terminal state if you create a request that is valid only during
a specific time period and this time period expires before your request reaches the pending fulfillment
phase, you cancel the request, or a system error occurs.
Status Code

Request State

Instance State

schedule-expired

closed

n/a

canceled-beforefulfillment*

cancelled

n/a

bad-parameters

failed

n/a

system-error

closed

n/a

* If you cancel the request.
Pending fulfillment
When the constraints you specified (if any) are met and your bid price is equal to or higher than the
current Spot price, your Spot request goes into the pending-fulfillment state.
At this point, Amazon EC2 is getting ready to provision the instances that you requested. If the process
stops at this point, it is likely to be because it was cancelled by the user before a Spot instance was
launched, or because an unexpected system error occurred.
Status Code

Request State

Instance State

pending-fulfillment

open

n/a

Fulfilled
When all the specifications for your Spot instances are met, your Spot request is fulfilled. Amazon EC2
launches the Spot instances, which can take a few minutes.
Status Code

Request State

Instance State

fulfilled

active

pending → running

Fulfilled-terminal

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Your Spot instances continue to run as long as your bid price is at or above the Spot price, there
is spare Spot capacity for your instance type, and you don't terminate the instance. If a change
in Spot price or available capacity requires Amazon EC2 to terminate your Spot instances, the
Spot request goes into a terminal state. For example, if your bid equals the Spot price but Spot
instances are oversubscribed at that price, the status code is instance-terminated-capacityoversubscribed. A request also goes into the terminal state if you cancel the Spot request or
terminate the Spot instances.
Status Code

Request State

Instance State

request-canceled-andinstance-running

cancelled

running

marked-for-termination

closed

running

instance-terminated-byprice

closed (one-time), open
(persistent)

terminated

instance-terminated-byuser

closed or cancelled *

terminated

instance-terminated-nocapacity

closed (one-time), open
(persistent)

terminated

instance-terminatedcapacity-oversubscribed

closed (one-time), open
(persistent)

terminated

instance-terminatedlaunch-group-constraint

closed (one-time), open
(persistent)

terminated

* The request state is closed if you terminate the instance but do not cancel the bid. The request state
is cancelled if you terminate the instance and cancel the bid. Note that even if you terminate a Spot
instance before you cancel its request, there might be a delay before Amazon EC2 detects that your
Spot instance was terminated. In this case, the request state can either be closed or cancelled.
Persistent requests
When your Spot instances are terminated (either by you or Amazon EC2), if the Spot request is a
persistent request, it returns to the pending-evaluation state and then Amazon EC2 can launch a
new Spot instance when the constraints are met.

Getting Bid Status Information
You can get bid status information using the AWS Management Console or a command line tool.

To get bid status information using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Spot Requests, and then select the Spot request.

Check the value of Status in the Description tab.

To get bid status information using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• describe-spot-instance-requests (AWS CLI)

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• Get-EC2SpotInstanceRequest (AWS Tools for Windows PowerShell)

Spot Bid Status Codes
Spot bid status information is composed of a bid status code, the update time, and a status message.
Together, they help you determine the disposition of your Spot request.
The following list describes the Spot bid status codes:
az-group-constraint
Amazon EC2 cannot launch all the instances you requested in the same Availability Zone.
bad-parameters
One or more parameters for your Spot request are not valid (for example, the AMI you specified
does not exist). The bid status message indicates which parameter is not valid.
cancelled-before-fulfillment
The user cancelled the Spot request before it was fulfilled.
capacity-not-available
There is not enough capacity available for the instances that you requested.
capacity-oversubscribed
The number of Spot requests with bid prices equal to or higher than your bid price exceeds the
available capacity in this Spot instance pool.
constraint-not-fulfillable
The Spot request can't be fulfilled because one or more constraints are not valid (for example, the
Availability Zone does not exist). The bid status message indicates which constraint is not valid.
fulfilled
The Spot request is active, and Amazon EC2 is launching your Spot instances.
instance-terminated-by-price
The Spot price rose above your bid price. If your request is a persistent bid, the process restarts,
so your bid is pending evaluation.
instance-terminated-by-user or spot-instance-terminated-by-user
You terminated a Spot instance that had been fulfilled, so the bid state is closed (unless it's a
persistent bid) and the instance state is terminated.
instance-terminated-capacity-oversubscribed
Your instance is terminated because the number of Spot requests with bid prices equal to or
higher than your bid price exceeded the available capacity in this Spot instance pool. (Note that
the Spot price might not have changed.) The Spot service randomly selects instances to be
terminated.
instance-terminated-launch-group-constraint
One or more of the instances in your launch group was terminated, so the launch group constraint
is no longer fulfilled.
instance-terminated-no-capacity
There is no longer enough Spot capacity available for the instance.
launch-group-constraint
Amazon EC2 cannot launch all the instances that you requested at the same time. All instances in
a launch group are started and terminated together.
marked-for-termination
The Spot instance is marked for termination.
not-scheduled-yet
The Spot request will not be evaluated until the scheduled date.
pending-evaluation
After you make a Spot instance request, it goes into the pending-evaluation state while the
system evaluates the parameters of your request.

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pending-fulfillment
Amazon EC2 is trying to provision your Spot instances.
placement-group-constraint
The Spot request can't be fulfilled yet because a Spot instance can't be added to the placement
group at this time.
price-too-low
The bid request can't be fulfilled yet because the bid price is below the Spot price. In this case, no
instance is launched and your bid remains open.
request-cancelled-and-instance-running
You canceled the Spot request while the Spot instances are still running. The request is
cancelled, but the instances remain running.
schedule-expired
The Spot request expired because it was not fulfilled before the specified date.
system-error
There was an unexpected system error. If this is a recurring issue, please contact customer
support for assistance.

Spot Instance Interruptions
Demand for Spot instances can vary significantly from moment to moment, and the availability of Spot
instances can also vary significantly depending on how many unused EC2 instances are available.
In addition, no matter how high you bid, it is still possible that your Spot instance will be interrupted.
Therefore, you must ensure that your application is prepared for a Spot instance interruption. We
strongly recommend that you do not use Spot instances for applications that can't be interrupted.
The following are the possible reasons that Amazon EC2 will terminate your Spot instances:
• Price—The Spot price is greater than your bid price.
• Capacity—If there are not enough unused EC2 instances to meet the demand for Spot instances,
Amazon EC2 terminates Spot instances, starting with those instances with the lowest bid prices.
If there are several Spot instances with the same bid price, the order in which the instances are
terminated is determined at random.
• Constraints—If your request includes a constraint such as a launch group or an Availability Zone
group, these Spot instances are terminated as a group when the constraint can no longer be met.

Preparing for Interruptions
Here are some best practices to follow when you use Spot instances:
• Choose a reasonable bid price. Your bid price should be high enough to make it likely that your
request will be fulfilled, but not higher than you are willing to pay. This is important because if the
supply is low for an extended period of time, the Spot price can remain high during that period
because it is based on the highest bid prices. We strongly recommend against bidding above the
price for On-Demand instances.
• Ensure that your instance is ready to go as soon as the request is fulfilled by using an Amazon
Machine Image (AMI) that contains the required software configuration. You can also use user data
to run commands at start-up.
• Store important data regularly in a place that won't be affected when the Spot instance terminates.
For example, you can use Amazon S3, Amazon EBS, or DynamoDB.
• Divide the work into small tasks (using a Grid, Hadoop, or queue-based architecture) or use
checkpoints so that you can save your work frequently.
• Use Spot instance termination notices to monitor the status of your Spot instances.

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• Test your application to ensure that it handles an unexpected instance termination gracefully. You
can do so by running the application using an On-Demand instance and then terminating the OnDemand instance yourself.

Spot Instance Termination Notices
The best way to protect against Spot instance interruption is to architect your application to be fault
tolerant. In addition, you can take advantage of Spot instance termination notices, which provide a twominute warning before Amazon EC2 must terminate your Spot instance.
This warning is made available to the applications on your Spot instance using an item in the instance
metadata. For example, you can check for this warning in the instance metadata periodically (we
recommend every 5 seconds) using the following query:
$ if curl -s http://169.254.169.254/latest/meta-data/spot/termination-time |
grep -q .*T.*Z; then echo terminated; fi

For information about other ways to retrieve instance metadata, see Retrieving Instance
Metadata (p. 338).
If your Spot instance is marked for termination by Amazon EC2, the termination-time item is
present and it specifies the approximate time in UTC when the instance will receive the shutdown
signal. For example:
2015-01-05T18:02:00Z

If Amazon EC2 is not preparing to terminate the instance, or if you terminated the Spot instance
yourself, the termination-time item is either not present (so you receive an HTTP 404 error) or
contains a value that is not a time value.
Note that while we make every effort to provide this warning the moment that your Spot instance
is marked for termination by Amazon EC2, it is possible that your Spot instance will be terminated
before Amazon EC2 can make the warning available. Therefore, you must ensure that your application
is prepared to handle an unexpected Spot instance interruption even if you are checking for Spot
instance termination notices.
If Amazon EC2 fails to terminate the instance, the Spot bid status is set to fulfilled. Note that
termination-time remains in the instance metadata with the original approximate time, which is
now in the past.

Spot Instance Data Feed
To help you understand the charges for your Spot instances, Amazon EC2 provides a data feed that
describes your Spot instance usage and pricing. This data feed is sent to an Amazon S3 bucket that
you specify when you subscribe to the data feed.
Data feed files arrive in your bucket typically once an hour, and each hour of usage is typically covered
in a single data file. These files are compressed (gzip) before they are delivered to your bucket.
Amazon EC2 can write multiple files for a given hour of usage where files are very large (for example,
when file contents for the hour exceed 50 MB before compression).

Note
If you don't have a Spot instance running during a certain hour, you won't receive a data feed
file for that hour.
Contents

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• Data Feed File Name and Format (p. 262)
• Amazon S3 Bucket Requirements (p. 262)
• Subscribing to Your Spot instance Data Feed (p. 263)
• Deleting Your Spot Instance Data Feed (p. 263)

Data Feed File Name and Format
The Spot instance data feed file name uses the following format (with the date and hour in UTC):
bucket-name.s3.amazonaws.com/{optional prefix}/aws-account-id.YYYY-MM-DDHH.n.unique-id.gz

For example, if your bucket name is myawsbucket and your prefix is myprefix, your file names are
similar to the following:
myawsbucket.s3.amazonaws.com/myprefix/
111122223333.2014-03-17-20.001.pwBdGTJG.gz

The Spot instance data feed files are tab-delimited. Each line in the data file corresponds to one
instance hour and contains the fields listed in the following table.
Field

Description

Timestamp

The timestamp used to determine the price charged for this instance hour.

UsageType

The type of usage and instance type being charged for. For m1.small Spot
instances, this field is set to SpotUsage. For all other instance types, this field is
set to SpotUsage:{instance-type}. For example, SpotUsage:c1.medium.

Operation

The product being charged for. For Linux Spot instances, this field is
set to RunInstances. For Windows Spot instances, this field is set to
RunInstances:0002. Spot usage is grouped according to Availability Zone.

InstanceID

The ID of the Spot instance that generated this instance hour.

MyBidID

The ID for the Spot instance request that generated this instance hour.

MyMaxPrice

The maximum price specified for this Spot instance request.

MarketPrice

The Spot price at the time specified in the Timestamp field.

Charge

The price charged for this instance hour.

Version

The version included in the data feed file name for this record.

Amazon S3 Bucket Requirements
When you subscribe to the data feed, you must specify an Amazon S3 bucket to store the data feed
files. Before you choose an Amazon S3 bucket for the data feed, consider the following:
• You must use a bucket from the US East (N. Virginia) (us-east-1) region.
• You must have FULL_CONTROL permission to the bucket.
If you're the bucket owner, you have this permission by default. Otherwise, the bucket owner must
grant your AWS account this permission.

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• When you create your data feed subscription, Amazon S3 updates the ACL of the specified bucket to
allow the AWS data feed account read and write permissions.
• Removing the permissions for the data feed account does not disable the data feed. If you remove
those permissions but don't disable the data feed, we restore those permissions the next time that
the data feed account needs to write to the bucket.
• Each data feed file has its own ACL (separate from the ACL for the bucket). The bucket owner has
FULL_CONTROL permission to the data files. The data feed account has read and write permissions.
• If you delete your data feed subscription, Amazon EC2 doesn't remove the read and write
permissions for the data feed account on either the bucket or the data files. You must remove these
permissions yourself.

Subscribing to Your Spot instance Data Feed
To subscribe to your data feed, use the following create-spot-datafeed-subscription command:
$ aws ec2 create-spot-datafeed-subscription --bucket myawsbucket [-prefix myprefix]

The following is example output:
{
"SpotDatafeedSubscription": {
"OwnerId": "111122223333",
"Prefix": "myprefix",
"Bucket": "myawsbucket",
"State": "Active"
}
}

Deleting Your Spot Instance Data Feed
To delete your data feed, use the following delete-spot-datafeed-subscription command:
$ aws ec2 delete-spot-datafeed-subscription

Spot Instance Limits
Spot instance requests are subject to the following limits:
Limits
• Unsupported Instance Types (p. 263)
• Spot Request Limits (p. 264)
• Spot Bid Price Limit (p. 264)
• Spot Fleet Limits (p. 264)
• Amazon EBS Encryption Unsupported (p. 264)

Unsupported Instance Types
The following instance types are not supported for Spot:
• T2

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• HS1
Some Spot instance types aren't available in every region. To view the supported instance types for a
region, go to Spot Instance Pricing and select the region.

Spot Request Limits
By default, there is an account limit of 20 Spot instances per region. If you terminate your Spot instance
but do not cancel the request, the request counts against this limit until Amazon EC2 detects the
termination and closes the request.
Spot instance limits are dynamic. When your account is new, your limit might be lower than 20 to
start, but increase over time. In addition, your account might have limits on specific Spot instance
types. If you submit a Spot instance request and you receive the error Max spot instance count
exceeded, you can go to AWS Support Center and submit a limit increase request form. For Use
Case Description, indicate that you need an increase in your limits for Spot instance requests.

Spot Bid Price Limit
The bid price limit for Spot instances is ten times on On-Demand price. This limit is designed to protect
you from incurring unexpected charges.

Spot Fleet Limits
The usual Amazon EC2 limits apply to instances launched by a Spot fleet, such as Spot bid price limits,
instance limits, and volume limits. In addition, the following limits apply:
• The number of active Spot fleets per region: 1,000
• The number of launch specifications per fleet: 50
• The size of the user data in a launch specification: 16 KB
• The target capacity per Spot fleet: 3,000
• The target capacity across all Spot fleets in a region: 5,000
• A Spot fleet request can't span regions.
• A Spot fleet request can't span different subnets from the same Availability Zone.

Amazon EBS Encryption Unsupported
You can specify encrypted EBS volumes in the launch specification for your Spot instances, but these
volumes are not encrypted.

Dedicated Hosts
An Amazon EC2 Dedicated Host is a physical server with EC2 instance capacity fully dedicated to your
use. Dedicated Hosts allow you to use your existing per-socket, per-core, or per-VM software licenses,
including Windows Server, Microsoft SQL Server, SUSE, Linux Enterprise Server, and so on.
Contents
• Differences between Dedicated Hosts and Dedicated Instances (p. 265)
• Pricing and Billing (p. 265)
• Dedicated Hosts Limitations and Restrictions (p. 266)
• Dedicated Host Configurations (p. 267)
• Using Dedicated Hosts (p. 267)
• Monitoring Dedicated Hosts (p. 274)

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Differences between Dedicated Hosts and Dedicated
Instances
Dedicated Hosts and Dedicated Instances can both be used to launch Amazon EC2 instances onto
physical servers that are dedicated for your use.
There are no performance, security, or physical differences between Dedicated Instances and
instances on Dedicated Hosts. However, Dedicated Hosts give you additional visibility and control over
how instances are placed on a physical server.
When you use Dedicated Hosts, you have control over instance placement on the host using the Host
Affinity and Instance Auto-placement settings. With Dedicated Instances, you don't have control over
which host your instance launches and runs on. If your organization wants to use AWS, but has an
existing software license with hardware compliance requirements, this allows visibility into the host's
hardware so you can meet those requirements.
For more information about the differences between Dedicated Hosts and Dedicated Instances, see
Amazon EC2 Dedicated Hosts.
For more information about working with Dedicated Hosts and Dedicated Instances, see Modifying
Instance Tenancies (p. 271).

Pricing and Billing
On-Demand Dedicated Hosts
On-Demand billing is automatically activated when you allocate a Dedicated Host to your account.
You are billed an hourly On-Demand rate. Rates vary based on the instance type that the Dedicated
Host supports and the region in which the Dedicated Host is running. The instance type size or the
number of instances that are running on the Dedicated Host do not have an impact on the cost of the
host.
To terminate On-Demand billing, you must first stop instances running on the Dedicated Host and then
release it. For more information, see Managing and Releasing Dedicated Hosts (p. 271).

Dedicated Host Reservations
Dedicated Host Reservations provide a billing discount compared to running On-Demand Dedicated
Hosts. Reservations are available in three payment options:
• No Upfront—No Upfront Reservations provide you with a discount on your Dedicated Host usage
over a term and do not require an upfront payment. Available for a one-year term only.
• Partial Upfront—A portion of the reservation must be paid upfront and the remaining hours in the
term are billed at a discounted rate. Available in one-year and three-year terms.
• All Upfront—Provides the lowest effective price. Available in one-year and three-year terms and
covers the entire cost of the term upfront, with no additional charges going forward.
You must have active Dedicated Hosts in your account before you can purchase reservations. Each
reservation covers a single, specific Dedicated Host in your account. Reservations are applied to the
instance family on the host, not the instance size. If you have three Dedicated Hosts with different
instances sizes (m4.xlarge, m4.medium, and m4.large) you can associate a single m4 reservation
with all those Dedicated Hosts. The instance family and region of the reservation must match that of
the Dedicated Hosts you want to associate it with.

Note
When a reservation is associated with a Dedicated Host, the Dedicated Host can't be released
until the reservation's term is over.

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Purchasing Dedicated Host Reservations
You can purchase Dedicated Host Reservations using the console or the API.

To purchase Dedicated Host Reservations using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

On the Dedicated Hosts page choose Dedicated Host Reservations.

Choose Purchase Dedicated Host Reservation.

On the Purchase Dedicated Host Reservation screen, you can search for offerings using the
default settings or you can specify a configuration for the offering.
• Host instance family—The options listed correspond with the Dedicated Hosts in your account
that are not assigned to a reservation.
• Availability Zone—The Availability Zone of the Dedicated Hosts in your account that aren't
assigned to a reservation.
• Payment Option—The payment option for the offering.
• Term—The term of the reservation. Can be one or three years.

Choose Find offering.

Select an offering.

Choose the Dedicated Hosts to associate with the Dedicated Host Reservation.

Choose Review.

Review your order and choose Purchase to complete the transaction.

Viewing Dedicated Host Reservations
You can view information about the Dedicated Hosts associated with your reservation, the term of the
reservation, the payment option selected, and the start and end dates of the reservation.

View details of Dedicated Host Reservations
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

On the Dedicated Hosts page, choose Dedicated Host Reservations.

Choose the reservation from the list provided.

Select Details for information about the reservation.

Select Hosts for information about the Dedicated Hosts the reservation is associated with.

Dedicated Hosts Limitations and Restrictions
Before you allocate Dedicated Hosts, take note of the following limitations and restrictions.
• Only BYOL RHEL, SUSE Linux, or Windows AMIs offered by AWS or on the AWS Marketplace can
be used with Dedicated Hosts.
• Up to two On-Demand Dedicated Hosts per instance family, per region can be allocated. It is
possible to request a limit increase: Request to Raise Allocation Limit on Amazon EC2 Dedicated
Hosts.
• The instances that run on a Dedicated Host can only be launched in a VPC.
• Host limits are independent from instance limits. Instances that you are running on Dedicated Hosts
do not count towards your instance limits.
• Auto Scaling groups are not supported.
• Amazon RDS instances are not supported.

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• The AWS Free Usage tier is not available for Dedicated Hosts.
• Instance placement control refers to managing instance launches onto Dedicated Hosts. Placement
groups are not supported for Dedicated Hosts.

Dedicated Host Configurations
Dedicated Hosts are configured to support a single instance type and size capacity. The number of
instances you can launch onto a Dedicated Host depends on the instance type that the Dedicated
Host is configured to support. For example, if you allocated a c3.xlarge Dedicated Host, you'd have
the right to launch up to 8 c3.xlarge instances on the Dedicated Host. To determine the number of
instance type sizes that you can run on a particular Dedicated Host, see Amazon EC2 Dedicated Hosts
Pricing.

Using Dedicated Hosts
To use a Dedicated Host, you first allocate hosts for use in your account. You then launch instances
onto the hosts by specifying host tenancy for the instance. The instance auto-placement setting allows
you to control whether an instance can launch onto a particular host. When an instance is stopped and
restarted, the Host affinity setting determines whether it's restarted on the same, or a different, host. If
you no longer need an On-Demand host, you can stop the instances running on the host, direct them
to launch on a different host, and then release the Dedicated Host.
Contents
• Bring Your Own License (p. 267)
• Allocating Dedicated Hosts (p. 268)
• Launching Instances onto Dedicated Hosts (p. 268)
• Understanding Instance Placement and Host Affinity (p. 270)
• Modifying Instance Tenancies (p. 271)
• Managing and Releasing Dedicated Hosts (p. 271)
• API and CLI Command Overview (p. 272)
• Tracking Configuration Changes with AWS Config (p. 273)

Bring Your Own License
You can use your own software licenses on Dedicated Hosts. These are the general steps you need to
follow in order to bring your own volume licensed machine image into Amazon EC2.
1. Verify that the license terms controlling the use of your machine images (AMIs) allow the usage of a
machine image in a virtualized cloud environment. For more information about Microsoft Licensing,
see Amazon Web Services and Microsoft Licensing.
2. After you have verified that your machine image can be used within Amazon EC2, import your
machine images using the ImportImage API operation made available by the VM Import/Export
tools. For information about restrictions and limitations, see VM Import/Export Prerequisites. For
information about how to import your VM using ImportImage, see Importing a VM into Amazon EC2
Using ImportImage.
3. If you need a mechanism to track how your images were used in AWS, enable host recording in
the AWS Config service. You can use AWS Config to record configuration changes to a Dedicated
Host and use the output as a data source for license reporting. For more information, see Tracking
Configuration Changes with AWS Config (p. 273).
4. After you've imported your machine image, you can launch instances from this image onto active
Dedicated Hosts in your account.
5. When you run these instances, depending on the operating system, you may be required to activate
these instances against your own KMS server (for example, Windows Server or Windows SQL

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Server). You cannot activate your imported Windows AMI against the Amazon Windows KMS
server.

Allocating Dedicated Hosts
To begin using Dedicated Hosts, they need to be allocated to your account. You can use the AWS
Management Console, interact directly with the API, or use the command line interface to perform
these tasks. Follow these steps every time you allocate a Dedicated Host.

To allocate Dedicated Hosts to your account
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
On the Dedicated Hosts page, choose Allocate Dedicated Host.

Configure your host using the options provided:

Instance type—Instance type that will be available on the Dedicated Host.

b.
c.

Availability Zone—The Availability Zone for the Dedicated Host.
Allow instance auto-placement—The default setting is Off. The Dedicated Host accepts
host tenancy instance launches only (provided capacity is available). When instance autoplacement is On, any instances with the tenancy of host, and matching the Dedicated Host's
configuration, can be launched onto the host.

d. Quantity—The number of hosts to allocate with these settings.
Choose Allocate host.

The Dedicated Host capacity is made available in your account immediately.
If you launch instances with tenancy host but do not have any active Dedicated Hosts in your account,
you receive an error and the instance launch fails.

Launching Instances onto Dedicated Hosts
After you have allocated a Dedicated Host, you can launch instances onto it. Instances with the
tenancy host can be launched onto a specific Dedicated Host or Amazon EC2 can select the
appropriate Dedicated Hosts for you (auto-placement). You cannot launch instances with the tenancy
host if you do not have active Dedicated Hosts in your account with available capacity matching the
instance type configuration of the instances you are launching.

Note
The instances launched onto Dedicated Hosts can only be launched in a VPC. For more
information, see Introduction to VPC.
Before you launch your instances, take note of the limitations. For more information, see Dedicated
Hosts Limitations and Restrictions (p. 266).

Launching instances onto a Dedicated Host from the Dedicated Hosts page
1.
2.
3.
4.
5.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
On the Dedicated Hosts page, select a host, choose Actions and then choose Launch
Instance(s) onto Host.
Select the AMI to use. If you have imported your own AMI, choose My AMIs on the left sidebar
and select the relevant AMI.
Choose the instance type for the Dedicated Host; this is the only instance type you can launch
onto the host.
On the Configure Instance Details page, the Tenancy and Host options are pre-selected. You
can toggle the Affinity setting to On or Off.
• On—If stopped, the instance always restarts on that specific host.

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• Off—The instance launches onto the specified Dedicated Host, but is not guaranteed to restart
on it if stopped.
6.

Complete the rest of the steps and choose Launch Instances.

The instance is automatically launched onto the Dedicated Host that you specified. To view the
instances on a Dedicated Host, go to the Dedicated Hosts page, and select the Dedicated Host that
you specified when you launched the instance.

Launching instances onto a specific Dedicated Host from the Instances page
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

On the Instances page, choose Launch Instance.

Select an AMI from the list. If you have imported your own AMI, choose My AMIs and select the
imported image. Not all AMIs can be used with Dedicated Hosts.

Select the type of instance to launch.

On the Configure Instance Details page, the Dedicated Host settings are:
• Tenancy—Dedicated host — Launch this instance on a Dedicated host. If you're not able to
choose this, check whether you have selected an incompatible AMI or instance type.
• Host—Select a host. If you are unable to select a Dedicated Host, check:
• Whether the selected subnet is in a different Availability Zone to the host.
• That the instance type you've selected matches the instance type that the Dedicated Host
supports. If you don't have matching, running hosts, the only option available is Use autoplacement but the instance launch fails unless there is available, matching Dedicated Host
capacity in your account.
• Affinity—The default setting for this is Off. The instance launches onto the specified Dedicated
Host, but is not guaranteed to restart on it if stopped.

Note
If you are unable to see these settings, check that you have selected a VPC in the
Network menu.
6.

Complete the rest of the configuration steps. Choose Review and Launch.

Choose Launch to launch your instance.

Select an existing key pair, or create a new one. Choose Launch Instances.

Launching instances onto any Dedicated Host from the Instances page
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

On the Instances page, choose Launch Instance.

Select an AMI from the list. If you have imported your own AMI, choose My AMIs and select the
imported image. Not all AMIs can be used with Dedicated Hosts.

Select the type of instance to launch.

On the Configure Instance Details page, the Dedicated Host settings are:
• Tenancy—Dedicated host — Launch this instance on a Dedicated host If you're not able to
choose this, check whether you have selected an incompatible AMI or instance type.
• Host—For this type of launch, keep the setting as Use auto-placement.
• Affinity—The default setting for this is Off. The instance launches onto any available Dedicated
Host in your account, but is not guaranteed to restart on that host if stopped.
If you are unable to see these settings, check that you have selected a VPC in the Network menu.

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Complete the rest of the configuration steps. Choose Review and Launch.

Choose Launch to launch your instance.

Select an existing key pair, or create a new one. Choose Launch Instances.

Understanding Instance Placement and Host Affinity
Placement control happens on both the instance level and host level.
Contents
• Instance Auto-Placement (p. 270)
• Host Affinity (p. 270)
• Modifying Instance Auto-Placement and Host Affinity (p. 270)
• Modifying Instance Host Affinity (p. 271)

Instance Auto-Placement
Auto-placement allows you to manage whether instances that you launch are launched onto a specific
host, or onto any host that has matching configurations. The default setting for this is Off. This means
that the Dedicated Host you are allocating only accepts host tenancy instances launches that specify
the unique host ID. Instances launched without a host ID specified are not able to launch onto a host
that have instance auto-placement set to Off.

Host Affinity
Host Affinity establishes a launch relationship between an instance and a Dedicated Host. When
affinity is set to host, an instance launched onto a specific host always restarts on the same host if
stopped. This applies to both targeted and untargeted launches.
If affinity is set to default, and you stop and restart the instance, it can be restarted on any available
host but tries to launch back onto the last Dedicated Host it ran on (on a best-effort basis).
You can modify the relationship between an instance and a Dedicated Host by changing the
affinity from host to default and vice-versa. For more information, see Modifying Instance
Tenancies (p. 271).

Modifying Instance Auto-Placement and Host Affinity
You can manage instance placement controls using the Amazon EC2 console, the API, or CLI.
To modify the instance placement settings of your instances, first stop the instances and then edit the
instance placement settings.

Note
If the instance is stopped and restarted, it is not guaranteed to restart on the same Dedicated
Host.

To edit an instance's placement settings (any available hosts)
1.
2.
3.
4.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
On the Instances page, select the instance to edit.
Choose Actions, Instance State, and Stop.
Choose Actions, Instance Settings, and Modify Instance Placement.

5.
6.
7.

Change the instance tenancy to Launch this instance on a Dedicated host.
Choose This instance can run on any one of my Hosts. The instance launches onto any
Dedicated Host that has auto-placement enabled.
Choose Save to continue.

Open the context (right-click) menu on the instance and choose Instance State, Start.

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To edit an instance's placement settings (specific Dedicated Host)
1.
2.
3.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
On the Instances page, select the instance to edit.
Choose Actions, Instance State, and Stop.

4.
5.

Choose Actions, Instance Settings, and Modify Instance Placement.
Change the instance tenancy to Launch this instance on a Dedicated host.

Choose This instance can only run on the selected Host. Then select a value for Target Host
and choose whether you want the instance to be placed on any available host, or a specific host.

Choose Save to continue.

Open the context (right-click) menu on the instance and choose Instance State, Start.

Modifying Instance Host Affinity
If you no longer want an instance to have affinity with a host, you can stop the instance and change its
affinity to default. This removes the persistence between the instance and the host. However, when
you restart the instance, it may launch back onto the same Dedicated Host (depending on Dedicated
Host availability in your account, and on a best-effort basis). However, if it is stopped again, it will not
restart on the same host.

Modifying Instance Tenancies
You can modify the tenancy of a Dedicated Instance from dedicated to host, and vice-versa if
it is not using a Windows, SUSE, or RHEL AMI provided by Amazon EC2. You need to stop your
Dedicated Instance in order to do this. Instances with shared tenancy cannot be modified to host
tenancy.

Modify instance tenancy from dedicated to host
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
Choose Instances, then select the Dedicated Instances to modify.

3.
4.

Choose Actions, Instance State, and Stop.
Open the context (right-click) menu on the instance and choose Instance Settings, Modify
Instance Placement.
On the Modify Instance Placement page, do the following:

• Tenancy—Choose Launch this instance on a Dedicated host.
• Affinity—Choose either This instance can run on any one of my Hosts or This instance can
only run on the selected Host.
If you choose This instance can run on any one of my Hosts, the instance launches onto any
available, compatible Dedicated Hosts in your account.
If you choose This instance can only run on the selected Host, select a value for Target
Host. If no target host is listed, you may not have available, compatible Dedicated Hosts in your
account.
6.
7.

Choose Save.
When you restart your instance Amazon EC2 places your instance on an available Dedicated Host
in your account, provided it supports the instance type that you're launching.

Managing and Releasing Dedicated Hosts
You can use the console, interact directly with the API, or use the command line interface to view
details about individual instances on a host and release an On-Demand Dedicated Host.

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To view details of instances on a Dedicated Host
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

On the Dedicated Hosts page, select the host to view more information about.

Choose the Description tab for information about the host. Choose the Instances tab for
information about instances running on your host.

To release a Dedicated Host
Any running instances on the Dedicated Host need to be stopped before you can release the host.
These instances can be migrated to other Dedicated Hosts in your account so that you can continue to
use them. For more information, see Modifying Instance Auto-Placement and Host Affinity (p. 270).
These steps apply only to On-Demand Dedicated Hosts.
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

On the Dedicated Hosts page, select the Dedicated Host to release.

Choose Actions, Release Hosts.

Confirm your choice by choosing Release.

After you release a Dedicated Host, you cannot reuse the same host or host ID again.
When the Dedicated Host is released you are no longer charged On-Demand billing rates for it. The
Dedicated Host status is changed to released and you are not able to launch any instances onto that
host.
If you've recently released Dedicated Hosts, it may take some time for them to stop counting towards
your limit. During this time, you may experience LimitExceeded errors when trying to allocate new
Dedicated Hosts. If this is the case, try allocating new hosts again after a few minutes.
The instances that were stopped are still available for use and are listed on the Instances page. They
retain their host tenancy setting.

API and CLI Command Overview
You can perform the tasks described in this section using an API or the command line.

To allocate Dedicated Hosts to your account
• allocate-hosts (AWS CLI)
• AllocateHosts (Amazon EC2 Query API)
• New-EC2Hosts (AWS Tools for Windows PowerShell)

To describe your Dedicated Hosts
• describe-hosts (AWS CLI)
• DescribeHosts (Amazon EC2 Query API)
• Get-EC2Hosts (AWS Tools for Windows PowerShell)

To modify your Dedicated Hosts
• modify-hosts (AWS CLI)
• ModifyHosts (Amazon EC2 Query API)
• Edit-EC2Hosts (AWS Tools for Windows PowerShell)

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To modify instance auto-placement
• modify-instance-placement (AWS CLI)
• ModifyInstancePlacement (Amazon EC2 Query API)
• Edit-EC2InstancePlacement (AWS Tools for Windows PowerShell)

To release your Dedicated Hosts
• release-hosts (AWS CLI)
• ReleaseHosts (Amazon EC2 Query API)
• Remove-EC2Hosts (AWS Tools for Windows PowerShell)

Tracking Configuration Changes with AWS Config
You can use AWS Config to record configuration changes for Dedicated Hosts, and instances that are
launched, stopped, or terminated on them. You can then use the information captured by AWS Config
as a data source for license reporting.
AWS Config records configuration information for Dedicated Hosts and instances individually and pairs
this information through relationships. There are three reporting conditions.
• AWS Config recording status—When On, AWS Config is recording one or more AWS resource
types, which can include Dedicated Hosts and Dedicated Instances. To capture the information
required for license reporting, verify that hosts and instances are being recorded with the following
fields.
• Host recording status—When Enabled, the configuration information for Dedicated Hosts is
recorded.
• Instance recording status—When Enabled, the configuration information for Dedicated Instances
is recorded.
If any of these three conditions are disabled, the icon in the Edit Config Recording button is red. To
derive the full benefit of this tool, ensure that all three recording methods are enabled. When all three
are enabled, the icon is green. To edit the settings, choose Edit Config Recording. You are directed
to the Set up AWS Config page in the AWS Config console, where you can set up AWS Config and
start recording for your hosts, instances, and other supported resource types. For more information,
see Setting up AWS Config using the Console in the AWS Config Developer Guide.

Note
AWS Config records your resources after it discovers them, which might take several minutes.
After AWS Config starts recording configuration changes to your hosts and instances, you can get the
configuration history of any host that you have allocated or released and any instance that you have
launched, stopped, or terminated. For example, at any point in the configuration history of a Dedicated
Host, you can look up how many instances are launched on that host alongside the number of sockets
and cores on the host. For any of those instances, you can also look up the ID of its Amazon Machine
Image (AMI). You can use this information to report on licensing for your own server-bound software
that is licensed per-socket or per-core.
You can view configuration histories in any of the following ways.
• By using the AWS Config console. For each recorded resource, you can view a timeline page, which
provides a history of configuration details. To view this page, choose the grey icon in the Config
Timeline column of the Dedicated Hosts page. For more information, see Viewing Configuration
Details in the AWS Config Console in the AWS Config Developer Guide.
• By running AWS CLI commands. First, you can use the list-discovered-resources command to get a
list of all hosts and instances. Then, you can use the get-resource-config-history command to get the

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configuration details of a host or instance for a specific time interval. For more information, see View
Configuration Details Using the CLI in the AWS Config Developer Guide.
• By using the AWS Config API in your applications. First, you can use the ListDiscoveredResources
action to get a list of all hosts and instances. Then, you can use the GetResourceConfigHistory
action to get the configuration details of a host or instance for a specific time interval.
For example, to get a list of all of your Dedicated Hosts from AWS Config, run a CLI command such as
the following:
aws configservice list-discovered-resources --resource-type
AWS::EC2::Host

To obtain the configuration history of a Dedicated Host from AWS Config, run a CLI command such as
the following:
aws configservice get-resource-config-history --resource type
AWS::EC2::Instance --resource-id i-36a47fdf

To manage AWS Config settings using the AWS Management Console
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
On the Dedicated Hosts page, choose Edit Config Recording.

In the AWS Config console, follow the steps provided to turn on recording. For more information,
see Setting up AWS Config using the Console.

For more information, see Viewing Configuration Details in the AWS Config Console.
To activate AWS Config using the command line or API
• Using the AWS CLI, see Viewing Configuration Details in the AWS Config Console in the AWS
Config Developer Guide.
• Using the Amazon EC2 API, see GetResourceConfigHistory.

Monitoring Dedicated Hosts
Amazon EC2 constantly monitors the state of your Dedicated Hosts; updates are communicated on the
Amazon EC2 console. You can also obtain information about your Dedicated Hosts using the API or
CLI.
The following table illustrates the possible State values in the console.
State

Description

available

AWS hasn't detected an issue with the Dedicated
Host; no maintenance or repairs are scheduled.
Instances can be launched onto this Dedicated
Host.

released

The Dedicated Host has been released. The host
ID is no longer in use. Released hosts cannot be
reused.

under-assessment

AWS is exploring a possible issue with the
Dedicated Host. If action needs to be taken,

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State

Description
you will be notified via the AWS Management
Console or email. Instances cannot be launched
onto a Dedicated Host in this state.

permanent-failure

An unrecoverable failure has been detected.
You will receive an eviction notice through your
instances and by email. Your instances may
continue to run. If you stop or terminate all
instances on a Dedicated Host with this state,
AWS retires the host. Instances cannot be
launched onto Dedicated Hosts in this state.

released-permanent-failure

AWS permanently releases Dedicated Hosts that
have failed and no longer have running instances
on them. The Dedicated Host ID is no longer
available for use.

Instance Lifecycle
By working with Amazon EC2 to manage your instances from the moment you launch them through
their termination, you ensure that your customers have the best possible experience with the
applications or sites that you host on your instances.
The following illustration represents the transitions between instance states. Notice that you can't
stop and start an instance store-backed instance. For more information about instance store-backed
instances, see Storage for the Root Device (p. 71).

Instance Launch
When you launch an instance, it enters the pending state. The instance type that you specified at
launch determines the hardware of the host computer for your instance. We use the Amazon Machine
Image (AMI) you specified at launch to boot the instance. After the instance is ready for you, it enters
the running state. You can connect to your running instance and use it the way that you'd use a
computer sitting in front of you.
As soon as your instance transitions to the running state, you're billed for each hour or partial hour
that you keep the instance running; even if the instance remains idle and you don't connect to it.
For more information, see Launch Your Instance (p. 278) and Connect to Your Linux
Instance (p. 289).

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Instance Stop and Start (Amazon
EBS-backed instances only)

Instance Stop and Start (Amazon EBS-backed
instances only)
If your instance fails a status check or is not running your applications as expected, and if the root
volume of your instance is an Amazon EBS volume, you can stop and start your instance to try to fix
the problem.
When you stop your instance, it enters the stopping state, and then the stopped state. We don't
charge hourly usage or data transfer fees for your instance after you stop it, but we do charge for the
storage for any Amazon EBS volumes. While your instance is in the stopped state, you can modify
certain attributes of the instance, including the instance type.
When you start your instance, it enters the pending state, and in most cases, we move the instance
to a new host computer. (Your instance may stay on the same host computer if there are no problems
with the host computer.) When you stop and start your instance, you'll lose any data on the instance
store volumes on the previous host computer.
If your instance is running in EC2-Classic, it receives a new private IP address, which means that
an Elastic IP address (EIP) associated with the private IP address is no longer associated with your
instance. If your instance is running in EC2-VPC, it retains its private IP address, which means that an
EIP associated with the private IP address or network interface is still associated with your instance.
Each time you transition an instance from stopped to running, we charge a full instance hour, even if
these transitions happen multiple times within a single hour.
For more information, see Stop and Start Your Instance (p. 299).

Instance Reboot
You can reboot your instance using the Amazon EC2 console, a command line tool, and the Amazon
EC2 API. We recommend that you use Amazon EC2 to reboot your instance instead of running the
operating system reboot command from your instance.
Rebooting an instance is equivalent to rebooting an operating system; the instance remains on the
same host computer and maintains its public DNS name, private IP address, and any data on its
instance store volumes. It typically takes a few minutes for the reboot to complete, but the time it takes
to reboot depends on the instance configuration.
Rebooting an instance doesn't start a new instance billing hour.
For more information, see Reboot Your Instance (p. 302).

Instance Termination
When you've decided that you no longer need an instance, you can terminate it. As soon as the status
of an instance changes to shutting-down or terminated, you stop incurring charges for that
instance.

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Differences Between Reboot, Stop, and Terminate

Note that if you enable termination protection, you can't terminate the instance using the console, CLI,
or API.
After you terminate an instance, it remains visible in the console for a short while, and then the entry is
deleted. You can also describe a terminated instance using the CLI and API. You can't connect to or
recover a terminated instance.
Each Amazon EBS-backed instance supports the InstanceInitiatedShutdownBehavior
attribute, which controls whether the instance stops or terminates when you initiate a shutdown from
within the instance itself (for example, by using the shutdown command on Linux). The default
behavior is to stop the instance. You can modify the setting of this attribute while the instance is
running or stopped.
Each Amazon EBS volume supports the DeleteOnTermination attribute, which controls whether
the volume is deleted or preserved when you terminate the instance it is attached to. The default is to
delete the root device volume and preserve any other EBS volumes.
For more information, see Terminate Your Instance (p. 305).

Differences Between Reboot, Stop, and
Terminate
The following table summarizes the key differences between rebooting, stopping, and terminating your
instance.
CharacteristicReboot

Stop/start (Amazon EBS- Terminate
backed instances only)

Host
computer

The instance stays on the
same host computer

The instance runs on a
new host computer

None

Private and
public IP
addresses

These addresses stay the
same

EC2-Classic: The instance
gets new private and
public IP addresses

None

EC2-VPC: The instance
keeps its private IP
address. The instance
gets a new public IP
address, unless it has an
Elastic IP address (EIP),
which doesn't change
during a stop/start.
Elastic IP
addresses
(EIP)

The EIP remains
associated with the
instance

EC2-Classic: The EIP is
disassociated from the
instance

The EIP is disassociated
from the instance

EC2-VPC: The EIP
remains associated with
the instance
Instance
store
volumes

The data is preserved

The data is erased

Root device
volume

The volume is preserved

The volume is deleted by
default

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CharacteristicReboot

Stop/start (Amazon EBS- Terminate
backed instances only)

Billing

You stop incurring
charges for an instance
as soon as its state
changes to stopping.
Each time an instance
transitions from stopped
to running, we start a
new instance billing hour.

The instance billing hour
doesn't change.

You stop incurring charges
for an instance as soon
as its state changes to
shutting-down.

Note that operating system shutdown commands always terminate an instance store-backed
instance. You can control whether operating system shutdown commands stop or terminate an
Amazon EBS-backed instance. For more information, see Changing the Instance Initiated Shutdown
Behavior (p. 307).

Launch Your Instance
An instance is a virtual server in the AWS cloud. You launch an instance from an Amazon Machine
Image (AMI). The AMI provides the operating system, application server, and applications for your
instance.
When you sign up for AWS, you can get started with Amazon EC2 for free using the AWS Free Tier.
You can either leverage the free tier to launch and use a micro instance for free for 12 months. If you
launch an instance that is not within the free tier, you incur the standard Amazon EC2 usage fees for
the instance. For more information, see the Amazon EC2 Pricing.
You can launch an instance using the following methods.
Method

Documentation

Use the Amazon EC2 console with an AMI that
you select

Launching an Instance (p. 279)

Use the Amazon EC2 console to launch an
instance using an existing instance as a template

Launching an Instance Using an Existing
Instance as a Template (p. 285)

Use the Amazon EC2 console with an Amazon
EBS snapshot that you created

Launching a Linux Instance from a
Backup (p. 286)

Use the Amazon EC2 console with an AMI that
you purchased from the AWS Marketplace

Launching an AWS Marketplace
Instance (p. 287)

Use the AWS CLI with an AMI that you select

Using Amazon EC2 through the AWS CLI

Use the AWS Tools for Windows PowerShell with Amazon EC2 from the AWS Tools for Windows
an AMI that you select
PowerShell

After you launch your instance, you can connect to it and use it. To begin, the instance state is
pending. When the instance state is running, the instance has started booting. There might be a
short time before you can connect to the instance. The instance receives a public DNS name that you
can use to contact the instance from the Internet. The instance also receives a private DNS name that
other instances within the same Amazon EC2 network (EC2-Classic or EC2-VPC) can use to contact
the instance. For more information about connecting to your instance, see Connect to Your Linux
Instance (p. 289).

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When you are finished with an instance, be sure to terminate it. For more information, see Terminate
Your Instance (p. 305).

Launching an Instance
Before you launch your instance, be sure that you are set up. For more information, see Setting Up
with Amazon EC2 (p. 19).
Your AWS account might support both the EC2-Classic and EC2-VPC platforms, depending on when
you created your account and which regions you've used. To find out which platform your account
supports, see Supported Platforms (p. 549). If your account supports EC2-Classic, you can launch an
instance into either platform. If your account supports EC2-VPC only, you can launch an instance into a
VPC only.

Important
When you launch an instance that's not within the AWS Free Tier, you are charged for the
time that the instance is running, even if it remains idle.

Launching Your Instance from an AMI
When you launch an instance, you must select a configuration, known as an Amazon Machine Image
(AMI). An AMI contains the information required to create a new instance. For example, an AMI might
contain the software required to act as a web server: for example, Linux, Apache, and your web site.

Tip
To ensure faster instance launches, break up large requests into smaller batches. For
example, create five separate launch requests for 100 instances each instead of one launch
request for 500 instances.

To launch an instance
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation bar at the top of the screen, the current region is displayed. Select the region
for the instance. This choice is important because some Amazon EC2 resources can be
shared between regions, while others can't. Select the region that meets your needs. For more
information, see Resource Locations (p. 743).

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From the Amazon EC2 console dashboard, choose Launch Instance.

On the Choose an Amazon Machine Image (AMI) page, choose an AMI as follows:
a.

Select the type of AMI to use in the left pane:
Quick Start
A selection of popular AMIs to help you get started quickly. To ensure that you select an
AMI that is eligible for the free tier, choose Free tier only in the left pane. (Notice that
these AMIs are marked Free tier eligible.)
My AMIs
The private AMIs that you own, or private AMIs that have been shared with you.
AWS Marketplace
An online store where you can buy software that runs on AWS, including AMIs. For more
information about launching an instance from the AWS Marketplace, see Launching an
AWS Marketplace Instance (p. 287).
Community AMIs
The AMIs that AWS community member have made available for others to use. To filter
the list of AMIs by operating system, choose the appropriate check box under Operating
system. You can also filter by architecture and root device type.

Check the Root device type listed for each AMI. Notice which AMIs are the type that you
need, either ebs (backed by Amazon EBS) or instance-store (backed by instance store).
For more information, see Storage for the Root Device (p. 71).

Check the Virtualization type listed for each AMI. Notice which AMIs are the type that you
need, either hvm or paravirtual. For example, some instance types require HVM. For more
information, see Linux AMI Virtualization Types (p. 74).

Choose an AMI that meets your needs, and then choose Select.

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On the Choose an Instance Type page, select the hardware configuration and size of the
instance to launch. Larger instance types have more CPU and memory. For more information, see
Instance Types (p. 156).
To remain eligible for the free tier, choose the t2.micro instance type. For more information, see
T2 Instances (p. 160).
By default, the wizard displays current generation instance types, and selects the first available
instance type based on the AMI that you selected. To view previous generation instance types,
choose All generations from the filter list.

Note
If you are new to AWS and would like to set up an instance quickly for testing purposes,
you can choose Review and Launch at this point to accept default configuration settings,
and launch your instance. Otherwise, to configure your instance further, choose Next:
Configure Instance Details.
6.

On the Configure Instance Details page, change the following settings as necessary (expand
Advanced Details to see all the settings), and then choose Next: Add Storage:
• Number of instances: Enter the number of instances to launch.

Note
To help ensure that you maintain the correct number of instances to handle your
application, you can choose Launch into Auto Scaling Group to create a launch
configuration and an Auto Scaling group. Auto Scaling scales the number of instances
in the group according to your specifications. For more information, see the Auto
Scaling User Guide.
• Purchasing option: Select Request Spot instances to launch a Spot instance. For more
information, see Spot Instances (p. 219).
• Your account may support the EC2-Classic and EC2-VPC platforms, or EC2-VPC only. To find
out which platform your account supports, see Supported Platforms (p. 549). If your account
supports EC2-VPC only, you can launch your instance into your default VPC or a nondefault
VPC. Otherwise, you can launch your instance into EC2-Classic or a nondefault VPC.

Note
Some instance types must be launched into a VPC. If you don't have a VPC, you can
let the wizard create one for you.
To launch into EC2-Classic:
• Network: Select Launch into EC2-Classic.
• Availability Zone: Select the Availability Zone to use. To let AWS choose an Availability Zone
for you, select No preference.
To launch into a VPC:
• Network: Select the VPC, or to create a new VPC, choose Create new VPC to go the
Amazon VPC console. When you have finished, return to the wizard and choose Refresh to
load your VPC in the list.
• Subnet: Select the subnet into which to launch your instance. If your account is EC2-VPC
only, select No preference to let AWS choose a default subnet in any Availability Zone. To
create a new subnet, choose Create new subnet to go to the Amazon VPC console. When
you are done, return to the wizard and choose Refresh to load your subnet in the list.
• Auto-assign Public IP: Specify whether your instance receives a public IP address.
By default, instances in a default subnet receive a public IP address and instances in
a nondefault subnet do not. You can select Enable or Disable to override the subnet's
default setting. For more information, see Public IP Addresses and External DNS
Hostnames (p. 572).
• IAM role: Select an AWS Identity and Access Management (IAM) role to associate with the
instance. For more information, see IAM Roles for Amazon EC2 (p. 536).
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• Shutdown behavior: Select whether the instance should stop or terminate when shut down.
For more information, see Changing the Instance Initiated Shutdown Behavior (p. 307).
• Enable termination protection: Select this check box to prevent accidental termination. For
more information, see Enabling Termination Protection for an Instance (p. 306).
• Monitoring: Select this check box to enable detailed monitoring of your instance using Amazon
CloudWatch. Additional charges apply. For more information, see Monitoring Your Instances
Using CloudWatch (p. 419).
• EBS-Optimized instance: An Amazon EBS-optimized instance uses an optimized configuration
stack and provides additional, dedicated capacity for Amazon EBS I/O. If the instance type
supports this feature, select this check box to enable it. Additional charges apply. For more
information, see Amazon EBS–Optimized Instances (p. 692).
• Tenancy: If you are launching your instance into a VPC, you can choose to run your instance on
isolated, dedicated hardware (Dedicated) or on a Dedicated host (Dedicated host). Additional
charges may apply. For more information, see Dedicated Instances in the Amazon VPC User
Guide and Dedicated Hosts (p. 264).
• Network interfaces: If you selected a specific subnet, you can specify up to two network
interfaces for your instance:
• For Network Interface, select New network interface to let AWS create a new interface, or
select an existing, available network interface.
• For Primary IP, enter a private IP address from the range of your subnet, or leave Autoassign to let AWS choose a private IP address for you.
• Choose Add IP to assign more than one private IP address to the selected network interface.
• Choose Add Device to add a secondary network interface. A secondary network interface
can reside in a different subnet of the VPC, provided it's in the same Availability Zone as your
instance.
For more information, see Elastic Network Interfaces (ENI) (p. 588). If you specify more
than one network interface, your instance cannot receive a public IP address. Additionally,
you cannot override the subnet's public IP setting using Auto-assign Public IP if you specify
an existing network interface for eth0. For more information, see Assigning a Public IP
Address (p. 575).
• Kernel ID: (Only valid for paravirtual (PV) AMIs) Select Use default unless you want to use a
specific kernel.
• RAM disk ID: (Only valid for paravirtual (PV) AMIs) Select Use default unless you want to use
a specific RAM disk. If you have selected a kernel, you may need to select a specific RAM disk
with the drivers to support it.
• Placement group: A placement group is a logical grouping for your cluster instances. Select
an existing placement group, or create a new one. This option is only available if you've
selected an instance type that supports placement groups. For more information, see Placement
Groups (p. 602).
• User data: You can specify user data to configure an instance during launch, or to run a
configuration script. To attach a file, select the As file option and browse for the file to attach.
7.

On the Add Storage page, you can specify volumes to attach to the instance besides the volumes
specified by the AMI (such as the root device volume). You can change the following options, then
choose Next: Tag Instance when you have finished:
• Type: Select instance store or Amazon EBS volumes to associate with your instance. The
type of volume available in the list depends on the instance type you've chosen. For more
information, see Amazon EC2 Instance Store (p. 715) and Amazon EBS Volumes (p. 636).
• Device: Select from the list of available device names for the volume.
• Snapshot: Enter the name or ID of the snapshot from which to restore a volume. You can also
search for public snapshots by typing text into the Snapshot field. Snapshot descriptions are
case-sensitive.
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• Size: For Amazon EBS-backed volumes, you can specify a storage size. Note that even if you
have selected an AMI and instance that are eligible for the free tier, you need to keep under 30
GiB of total storage to stay within the free tier.

Note
If you increase the size of your root volume at this point (or any other volume created
from a snapshot), you need to extend the file system on that volume in order to use
the extra space. For more information about extending your file system after your
instance has launched, see Expanding the Storage Space of an EBS Volume on
Linux (p. 671).
• Volume Type: For Amazon EBS volumes, select either a General Purpose SSD, Provisioned
IOPS SSD, or Magnetic volume. For more information, see Amazon EBS Volume
Types (p. 638).

Note
If you select a Magnetic boot volume, you'll be prompted when you complete the wizard
to make General Purpose SSD volumes the default boot volume for this instance and
future console launches. (This preference persists in the browser session, and does
not affect AMIs with Provisioned IOPS SSD boot volumes.) We recommended that you
make General Purpose SSD volumes the default because they provide a much faster
boot experience and they are the optimal volume type for most workloads. For more
information, see Amazon EBS Volume Types (p. 638).

Note
Some AWS accounts created before 2012 might have access to Availability Zones
in us-east-1, us-west-1, or ap-northeast-1 that do not support Provisioned IOPS SSD
(io1) volumes. If you are unable to create an io1 volume (or launch an instance with
an io1 volume in its block device mapping) in one of these regions, try a different
Availability Zone in the region. You can verify that an Availability Zone supports io1
volumes by creating a 4 GiB io1 volume in that zone.
• IOPS: If you have selected a Provisioned IOPS SSD volume type, then you can enter the
number of I/O operations per second (IOPS) that the volume can support.
• Delete on Termination: For Amazon EBS volumes, select this check box to delete the volume
when the instance is terminated. For more information, see Preserving Amazon EBS Volumes
on Instance Termination (p. 308).
• Encrypted: Select this check box to encrypt new Amazon EBS volumes. Amazon EBS volumes
that are restored from encrypted snapshots are automatically encrypted. Encrypted volumes
may only be attached to supported instance types (p. 697).
8.

On the Tag Instance page, specify tags (p. 751) for the instance by providing key and value
combinations. Choose Create Tag to add more than one tag to your resource. Choose Next:
Configure Security Group when you are done.

On the Configure Security Group page, use a security group to define firewall rules for your
instance. These rules specify which incoming network traffic is delivered to your instance. All other
traffic is ignored. (For more information about security groups, see Amazon EC2 Security Groups
for Linux Instances (p. 489).) Select or create a security group as follows, and then choose
Review and Launch.
To select an existing security group:

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Choose Select an existing security group. Your security groups are displayed. (If you are
launching into EC2-Classic, these are security groups for EC2-Classic. If you are launching
into a VPC, these are security group for that VPC.)

Select a security group from the list.

(Optional) You can't edit the rules of an existing security group, but you can copy them to
a new group by choosing Copy to new. Then you can add rules as described in the next
procedure.

To create a new security group:
1.

Choose Create a new security group. The wizard automatically defines the launch-wizard-x
security group.

(Optional) You can edit the name and description of the security group.

The wizard automatically defines an inbound rule to allow to you connect to your instance
over SSH (port 22) for Linux or RDP (port 3389) for Windows.

Caution
This rule enables all IP addresses (0.0.0.0/0) to access your instance over the
specified port. This is acceptable for this short exercise, but it's unsafe for production
environments. You should authorize only a specific IP address or range of addresses
to access your instance.
4.

You can add rules to suit your needs. For example, if your instance is a web server, open
ports 80 (HTTP) and 443 (HTTPS) to allow Internet traffic.
To add a rule, choose Add Rule, select the protocol to open to network traffic, and then
specify the source. Choose My IP from the Source list to let the wizard add your computer's
public IP address. However, if you are connecting through an ISP or from behind your firewall
without a static IP address, you need to find out the range of IP addresses used by client
computers.

10. On the Review Instance Launch page, check the details of your instance, and make any
necessary changes by choosing the appropriate Edit link.
When you are ready, choose Launch.
11. In the Select an existing key pair or create a new key pair dialog box, you can choose an
existing key pair, or create a new one. For example, choose Choose an existing key pair, then
select the key pair you created when getting set up.
To launch your instance, select the acknowledgment check box, then choose Launch Instances.

Important
If you choose the Proceed without key pair option, you won't be able to connect to the
instance unless you choose an AMI that is configured to allow users another way to log
in.
12. (Optional) You can create a status check alarm for the instance (additional fees may apply). (If
you're not sure, you can always add one later.) On the confirmation screen, choose Create status
check alarms and follow the directions. For more information, see Creating and Editing Status
Check Alarms (p. 414).
13. If the instance state immediately goes to terminated instead of running, you can get
information about why the instance didn't launch. For more information, see What To Do If An
Instance Immediately Terminates (p. 773).

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Launching an Instance Using an Existing Instance as a
Template
The Amazon EC2 console provides a Launch More Like This wizard option that enables you to use
a current instance as a template for launching other instances. This option automatically populates the
Amazon EC2 launch wizard with certain configuration details from the selected instance.

Note
The Launch More Like This wizard option does not clone your selected instance; it only
replicates some configuration details. To create a copy of your instance, first create an AMI
from it, then launch more instances from the AMI.
The following configuration details are copied from the selected instance into the launch wizard:
• AMI ID
• Instance type
• Availability Zone, or the VPC and subnet in which the selected instance is located
• Public IP address. If the selected instance currently has a public IP address, the new instance
receives a public IP address - regardless of the selected instance's default public IP address
setting. For more information about public IP addresses, see Public IP Addresses and External DNS
Hostnames (p. 572).
• Placement group, if applicable
• IAM role associated with the instance, if applicable
• Shutdown behavior setting (stop or terminate)
• Termination protection setting (true or false)
• CloudWatch monitoring (enabled or disabled)
• Amazon EBS-optimization setting (true or false)
• Tenancy setting, if launching into a VPC (shared or dedicated)
• Kernel ID and RAM disk ID, if applicable
• User data, if specified
• Tags associated with the instance, if applicable
• Security groups associated with the instance
The following configuration details are not copied from your selected instance; instead, the wizard
applies their default settings or behavior:
• (VPC only) Number of network interfaces: The default is one network interface, which is the primary
network interface (eth0).
• Storage: The default storage configuration is determined by the AMI and the instance type.

To use your current instance as a template
1.

On the Instances page, select the instance you want to use.

Choose Actions, and then Launch More Like This.

The launch wizard opens on the Review Instance Launch page. You can check the details of
your instance, and make any necessary changes by clicking the appropriate Edit link.
When you are ready, choose Launch to select a key pair and launch your instance.

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Launching a Linux Instance from a Backup
With an Amazon EBS-backed Linux instance, you can back up the root device volume of the instance
by creating a snapshot. When you have a snapshot of the root device volume of an instance, you can
terminate that instance and then later launch a new instance from the snapshot. This can be useful if
you don't have the original AMI that you launched an instance from, but you need to be able to launch
an instance using the same image.

Important
Some Linux distributions, such as Red Hat Enterprise Linux (RHEL) and SUSE Linux
Enterprise Server (SLES), use the EC2 billingProduct code associated with an AMI to
verify subscription status for package updates. Creating an AMI from an EBS snapshot does
not maintain this billing code, and subsequent instances launched from such an AMI will not
be able to connect to package update infrastructure.
Similarly, although you can create a Windows AMI from a snapshot, you can't successfully
launch an instance from the AMI.
To create Windows AMIs or AMIs for Linux operating systems that must retain AMI billing
codes to work properly, see Creating an Amazon EBS-Backed Linux AMI (p. 89) or Creating
an Instance Store-Backed Linux AMI (p. 92).
Use the following procedure to create an AMI from the root volume of your instance using the console.
If you prefer, you can use the register-image (AWS CLI) or Register-EC2Image (AWS Tools for
Windows PowerShell) command instead.

To create an AMI from your root volume using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, under Elastic Block Store, choose Snapshots.

Choose Create Snapshot.

In the Volumes field, start typing the name or ID of the root volume, and then select it from the list
of options.

Choose the snapshot that you just created, and then choose Create Image from the Actions list.

In the navigation pane, choose AMIs.

Choose the AMI that you just created, and then choose Launch. Follow the wizard to launch your
instance. For more information about how to configure each step in the wizard, see Launching an
Instance (p. 279).

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Launching an AWS Marketplace Instance
You can subscribe to an AWS Marketplace product and launch an instance from the product's AMI
using the Amazon EC2 launch wizard. For more information about paid AMIs, see Paid AMIs (p. 85).
To cancel your subscription after launch, you first have to terminate all instances running from it. For
more information, see Managing Your AWS Marketplace Subscriptions (p. 88).

To launch an instance from the AWS Marketplace using the launch wizard
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

From the Amazon EC2 dashboard, choose Launch Instance.

On the Choose an Amazon Machine Image (AMI) page, choose the AWS Marketplace category
on the left. Find a suitable AMI by browsing the categories, or using the search functionality.
Choose Select to choose your product.

A dialog displays an overview of the product you've selected. You can view the pricing information,
as well as any other information that the vendor has provided. When you're ready, choose
Continue.

Note
You are not charged for using the product until you have launched an instance with the
AMI. Take note of the pricing for each supported instance type, as you will be prompted to
select an instance type on the next page of the wizard.
5.

On the Choose an Instance Type page, select the hardware configuration and size of the
instance to launch. When you're done, choose Next: Configure Instance Details.

On the next pages of the wizard, you can configure your instance, add storage, and add
tags. For more information about the different options you can configure, see Launching an
Instance (p. 279). Choose Next until you reach the Configure Security Group page.
The wizard creates a new security group according to the vendor's specifications for the product.
The security group may include rules that allow all IP addresses (0.0.0.0/0) access on SSH
(port 22) on Linux or RDP (port 3389) on Windows. We recommend that you adjust these rules to
allow only a specific address or range of addresses to access your instance over those ports.
When you are ready, choose Review and Launch.

On the Review Instance Launch page, check the details of the AMI from which you're about
to launch the instance, as well as the other configuration details you set up in the wizard. When
you're ready, choose Launch to select or create a key pair, and launch your instance.

Depending on the product you've subscribed to, the instance may take a few minutes or more to
launch. You are first subscribed to the product before your instance can launch. If there are any
problems with your credit card details, you will be asked to update your account details. When the
launch confirmation page displays, choose View Instances to go to the Instances page.

Note
You are charged the subscription price as long as your instance is running, even if it is
idle. If your instance is stopped, you may still be charged for storage.
9.

When your instance is in the running state, you can connect to it. To do this, select your instance
in the list and choose Connect. Follow the instructions in the dialog. For more information about
connecting to your instance, see Connect to Your Linux Instance (p. 289).

Important
Check the vendor's usage instructions carefully, as you may need to use a specific user
name to log in to the instance. For more information about accessing your subscription
details, see Managing Your AWS Marketplace Subscriptions (p. 88).

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Launching an AWS Marketplace AMI Instance Using the API and CLI
To launch instances from AWS Marketplace products using the API or command line tools, first ensure
that you are subscribed to the product. You can then launch an instance with the product's AMI ID
using the following methods:
Method

Documentation

AWS CLI

Use the run-instances command, or see the following topic for more
information: Launching an Instance.

AWS Tools for Windows
PowerShell

Use the New-EC2Instance command, or see the following topic for
more information: Launch an Amazon EC2 Instance Using Windows
PowerShell

Query API

Use the RunInstances request.

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Connect to Your Linux Instance
Learn how to connect to the Linux instances that you launched and transfer files between your local
computer and your instance.
If you need to connect to a Windows instance, see Connecting to Your Windows Instance in the
Amazon EC2 User Guide for Windows Instances.
Your Computer

Topic

Linux

Connecting to Your Linux Instance Using SSH (p. 289)

Windows

Connecting to Your Linux Instance from Windows Using
PuTTY (p. 293)

All

Connecting to Your Linux Instance Using MindTerm (p. 298)

After you connect to your instance, you can try one of our tutorials, such as Tutorial: Installing a LAMP
Web Server on Amazon Linux (p. 33) or Tutorial: Hosting a WordPress Blog with Amazon Linux (p. 42).

Connecting to Your Linux Instance Using SSH
After you launch your instance, you can connect to it and use it the way that you'd use a computer
sitting in front of you.

Note
After you launch an instance, it can take a few minutes for the instance to be ready so that
you can connect to it. Check that your instance has passed its status checks - you can view
this information in the Status Checks column on the Instances page.
The following instructions explain how to connect to your instance using an SSH client. If you receive
an error while attempting to connect to your instance, see Troubleshooting Connecting to Your
Instance.

Prerequisites
Before you connect to your Linux instance, complete the following prerequisites:
• Install an SSH client
Your Linux computer most likely includes an SSH client by default. You can check for an SSH client
by typing ssh at the command line. If your computer doesn't recognize the command, the OpenSSH
project provides a free implementation of the full suite of SSH tools. For more information, see http://
www.openssh.com.
• Install the AWS CLI Tools
(Optional) If you're using a public AMI from a third party, you can use the command line tools to
verify the fingerprint. For more information about installing the AWS CLI, see Getting Set Up in the
AWS Command Line Interface User Guide.
• Get the ID of the instance
You can get the ID of your instance using the Amazon EC2 console (from the Instance ID column).
If you prefer, you can use the describe-instances (AWS CLI) or Get-EC2Instance (AWS Tools for
Windows PowerShell) command.
• Get the public DNS name of the instance
You can get the public DNS for your instance using the Amazon EC2 console (check the Public
DNS column; if this column is hidden, click the Show/Hide icon and select Public DNS). If you
prefer, you can use the describe-instances (AWS CLI) or Get-EC2Instance (AWS Tools for Windows
PowerShell) command.

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• Locate the private key
You'll need the fully-qualified path of the .pem file for the key pair that you specified when you
launched the instance.
• Enable inbound SSH traffic from your IP address to your instance
Ensure that the security group associated with your instance allows incoming SSH traffic from your
IP address. For more information, see Authorizing Network Access to Your Instances.

Important
Your default security group does not allow incoming SSH traffic by default.

Connecting to Your Linux Instance
Use the following procedure to connect to your Linux instance using an SSH client. If you receive an
error while attempting to connect to your instance, see Troubleshooting Connecting to Your Instance.

To connect to your instance using SSH
1.

(Optional) You can verify the RSA key fingerprint on your running instance by using
one of the following commands on your local system (not on the instance). This is
useful if you've launched your instance from a public AMI from a third party. Locate the
SSH HOST KEY FINGERPRINTS section, and note the RSA fingerprint (for example,
1f:51:ae:28:bf:89:e9:d8:1f:25:5d:37:2d:7d:b8:ca:9f:f5:f1:6f) and compare it to the fingerprint of the
instance.
• get-console-output (AWS CLI)
aws ec2 get-console-output --instance-id instance_id

Note
Ensure that the instance is in the running state, not the pending state. The SSH HOST
KEY FINGERPRINTS section is only available after the first boot of the instance.
2.

In a command line shell, change directories to the location of the private key file that you created
when you launched the instance.

Use the chmod command to make sure your private key file isn't publicly viewable. For example, if
the name of your private key file is my-key-pair.pem, use the following command:
chmod 400 /path/my-key-pair.pem

Use the ssh command to connect to the instance. You'll specify the private key (.pem) file and
user_name@public_dns_name. For Amazon Linux, the user name is ec2-user. For RHEL5, the
user name is either root or ec2-user. For Ubuntu, the user name is ubuntu. For Fedora, the
user name is either fedora or ec2-user. For SUSE Linux, the user name is either root or ec2user. Otherwise, if ec2-user and root don't work, check with your AMI provider.
ssh -i /path/my-key-pair.pem ec2user@ec2-198-51-100-1.compute-1.amazonaws.com

You'll see a response like the following.
The authenticity of host 'ec2-198-51-100-1.compute-1.amazonaws.com
(10.254.142.33)'
can't be established.
RSA key fingerprint is
1f:51:ae:28:bf:89:e9:d8:1f:25:5d:37:2d:7d:b8:ca:9f:f5:f1:6f.

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Are you sure you want to continue connecting (yes/no)?

(Optional) Verify that the fingerprint in the security alert matches the fingerprint that you obtained
in step 1. If these fingerprints don't match, someone might be attempting a "man-in-the-middle"
attack. If they match, continue to the next step.

Enter yes.
You'll see a response like the following.
Warning: Permanently added
'ec2-198-51-100-1.compute-1.amazonaws.com' (RSA)
to the list of known hosts.

Transferring Files to Linux Instances from Linux Using SCP
One way to transfer files between your local computer and a Linux instance is to use Secure Copy
(SCP). This section describes how to transfer files with SCP. The procedure is very similar to the
procedure for connecting to an instance with SSH.

Prerequisites
• Install an SCP client
Most Linux, Unix, and Apple computers include an SCP client by default. If yours doesn't, the
OpenSSH project provides a free implementation of the full suite of SSH tools, including an SCP
client. For more information, go to http://www.openssh.org.
• Get the ID of the instance
You can get the ID of your instance using the Amazon EC2 console (from the Instance ID column).
If you prefer, you can use the describe-instances (AWS CLI) or Get-EC2Instance (AWS Tools for
Windows PowerShell) command.
• Get the public DNS name of the instance
You can get the public DNS for your instance using the Amazon EC2 console (check the Public
DNS column; if this column is hidden, click the Show/Hide icon and select Public DNS). If you
prefer, you can use the describe-instances (AWS CLI) or Get-EC2Instance (AWS Tools for Windows
PowerShell) command.
• Locate the private key
You'll need the fully-qualified path of the .pem file for the key pair that you specified when you
launched the instance.
• Enable inbound SSH traffic from your IP address to your instance
Ensure that the security group associated with your instance allows incoming SSH traffic from your
IP address. For more information, see Authorizing Network Access to Your Instances.

Important
Your default security group does not allow incoming SSH traffic by default.
The following procedure steps you through using SCP to transfer a file. If you've already connected to
the instance with SSH and have verified its fingerprints, you can start with the step that contains the
SCP command (step 4).

To use SCP to transfer a file
1.

(Optional) You can verify the RSA key fingerprint on your instance by using one of
the following commands on your local system (not on the instance). This is useful
if you've launched your instance from a public AMI from a third party. Locate the
SSH HOST KEY FINGERPRINTS section, and note the RSA fingerprint (for example,
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1f:51:ae:28:bf:89:e9:d8:1f:25:5d:37:2d:7d:b8:ca:9f:f5:f1:6f) and compare it to the fingerprint of the
instance.
• get-console-output (AWS CLI)
aws ec2 get-console-output --instance-id instance_id

Note
The SSH HOST KEY FINGERPRINTS section is only available after the first boot of the
instance.
2.

In a command shell, change directories to the location of the private key file that you specified
when you launched the instance.

Transfer a file to your instance using the instance's public DNS name. For example, if the name of
the private key file is my-key-pair, the file to transfer is SampleFile.txt, and the public DNS
name of the instance is ec2-198-51-100-1.compute-1.amazonaws.com, use the following
command to copy the file to the ec2-user home directory.
scp -i /path/my-key-pair.pem /path/SampleFile.txt ec2user@ec2-198-51-100-1.compute-1.amazonaws.com:~

Tip
For Amazon Linux, the user name is ec2-user. For RHEL5, the user name is either
root or ec2-user. For Ubuntu, the user name is ubuntu. For Fedora, the user name
is either fedora or ec2-user. For SUSE Linux, the user name is either root or ec2user. Otherwise, if ec2-user and root don't work, check with your AMI provider.
You'll see a response like the following.
The authenticity of host 'ec2-198-51-100-1.compute-1.amazonaws.com
(10.254.142.33)'
can't be established.
RSA key fingerprint is
1f:51:ae:28:bf:89:e9:d8:1f:25:5d:37:2d:7d:b8:ca:9f:f5:f1:6f.
Are you sure you want to continue connecting (yes/no)?

Enter yes.
You'll see a response like the following.
Warning: Permanently added
'ec2-198-51-100-1.compute-1.amazonaws.com' (RSA)
to the list of known hosts.
Sending file modes: C0644 20 SampleFile.txt
Sink: C0644 20 SampleFile.txt
SampleFile.txt
100%
00:00

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Note
If you receive a "bash: scp: command not found" error, you must first install scp
on your Linux instance. For some operating systems, this is located in the opensshclients package. For Amazon Linux variants, such as the Amazon ECS-optimized AMI,
use the following command to install scp.
[ec2-user ~]$ sudo yum install -y openssh-clients

To transfer files in the other direction (from your Amazon EC2 instance to your local computer), simply
reverse the order of the host parameters. For example, to transfer the SampleFile.txt file from your
EC2 instance back to the home directory on your local computer as SampleFile2.txt, use the following
command on your local computer.
scp -i /path/my-key-pair.pem ec2user@ec2-198-51-100-1.compute-1.amazonaws.com:~/SampleFile.txt ~/
SampleFile2.txt

Connecting to Your Linux Instance from Windows Using
PuTTY
After you launch your instance, you can connect to it and use it the way that you'd use a computer
sitting in front of you.

Note
After you launch an instance, it can take a few minutes for the instance to be ready so that
you can connect to it. Check that your instance has passed its status checks - you can view
this information in the Status Checks column on the Instances page.
The following instructions explain how to connect to your instance using PuTTY, a free SSH client for
Windows. If you receive an error while attempting to connect to your instance, see Troubleshooting
Connecting to Your Instance.

Prerequisites
Before you connect to your Linux instance using PuTTY, complete the following prerequisites:
• Install PuTTY
Download and install PuTTY from the PuTTY download page. If you already have an older version
of PuTTY installed, we recommend that you download the latest version. Be sure to install the entire
suite.
• Get the ID of the instance
You can get the ID of your instance using the Amazon EC2 console (from the Instance ID column).
If you prefer, you can use the describe-instances (AWS CLI) or Get-EC2Instance (AWS Tools for
Windows PowerShell) command.
• Get the public DNS name of the instance
You can get the public DNS for your instance using the Amazon EC2 console (check the Public
DNS column; if this column is hidden, click the Show/Hide icon and select Public DNS). If you
prefer, you can use the describe-instances (AWS CLI) or Get-EC2Instance (AWS Tools for Windows
PowerShell) command.
• Locate the private key
You'll need the fully-qualified path of the .pem file for the key pair that you specified when you
launched the instance.
• Enable inbound SSH traffic from your IP address to your instance

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Ensure that the security group associated with your instance allows incoming SSH traffic from your
IP address. For more information, see Authorizing Network Access to Your Instances.

Important
Your default security group does not allow incoming SSH traffic by default.

Converting Your Private Key Using PuTTYgen
PuTTY does not natively support the private key format (.pem) generated by Amazon EC2. PuTTY
has a tool named PuTTYgen, which can convert keys to the required PuTTY format (.ppk). You must
convert your private key into this format (.ppk) before attempting to connect to your instance using
PuTTY.

To convert your private key
1.

Start PuTTYgen (for example, from the Start menu, click All Programs > PuTTY > PuTTYgen).

Under Type of key to generate, select SSH-2 RSA.

Click Load. By default, PuTTYgen displays only files with the extension .ppk. To locate your
.pem file, select the option to display files of all types.

Select your .pem file for the key pair that you specified when you launch your instance, and then
click Open. Click OK to dismiss the confirmation dialog box.

Click Save private key to save the key in the format that PuTTY can use. PuTTYgen displays a
warning about saving the key without a passphrase. Click Yes.

Note
A passphrase on a private key is an extra layer of protection, so even if your private key is
discovered, it can't be used without the passphrase. The downside to using a passphrase
is that it makes automation harder because human intervention is needed to log on to an
instance, or copy files to an instance.
6.

Specify the same name for the key that you used for the key pair (for example, my-key-pair).
PuTTY automatically adds the .ppk file extension.

Your private key is now in the correct format for use with PuTTY. You can now connect to your
instance using PuTTY's SSH client.

Starting a PuTTY Session
Use the following procedure to connect to your Linux instance using PuTTY. You'll need the .ppk
file that you created for your private key. If you receive an error while attempting to connect to your
instance, see Troubleshooting Connecting to Your Instance.

To start a PuTTY session
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1f:51:ae:28:bf:89:e9:d8:1f:25:5d:37:2d:7d:b8:ca:9f:f5:f1:6f) and compare it to the fingerprint of the
instance.
• get-console-output (AWS CLI)
aws ec2 get-console-output --instance-id instance_id

Note
The SSH HOST KEY FINGERPRINTS section is only available after the first boot of the
instance.
2.

Start PuTTY (from the Start menu, click All Programs > PuTTY > PuTTY).

In the Category pane, select Session and complete the following fields:
a.

In the Host Name box, enter user_name@public_dns_name. Be sure to specify the
appropriate user name for your AMI. For example:
• For an Amazon Linux AMI, the user name is ec2-user.
• For a RHEL5 AMI, the user name is either root or ec2-user.
• For an Ubuntu AMI, the user name is ubuntu.
• For a Fedora AMI, the user name is either fedora or ec2-user.
• For SUSE Linux, the user name is either root or ec2-user.
• Otherwise, if ec2-user and root don't work, check with the AMI provider.

Under Connection type, select SSH.

Ensure that Port is 22.

In the Category pane, expand Connection, expand SSH, and then select Auth. Complete the
following:
a.

Click Browse.

Select the .ppk file that you generated for your key pair, and then click Open.

(Optional) If you plan to start this session again later, you can save the session information
for future use. Select Session in the Category tree, enter a name for the session in Saved
Sessions, and then click Save.

Click Open to start the PuTTY session.
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If this is the first time you have connected to this instance, PuTTY displays a security alert dialog
box that asks whether you trust the host you are connecting to.

Note
If you specified a passphrase when you converted your private key to PuTTY's format,
you must provide that passphrase when you log in to the instance.
If you receive an error while attempting to connect to your instance, see Troubleshooting Connecting to
Your Instance.

Transferring Files to Your Linux Instance Using the PuTTY Secure Copy
Client
The PuTTY Secure Copy client (PSCP) is a command-line tool that you can use to transfer files
between your Windows computer and your Linux instance. If you prefer a graphical user interface
(GUI), you can use an open source GUI tool named WinSCP. For more information, see Transferring
Files to Your Linux Instance Using WinSCP (p. 296).
To use PSCP, you'll need the private key you generated in Converting Your Private Key Using
PuTTYgen (p. 294). You'll also need the public DNS address of your Linux instance.
The following example transfers the file Sample_file.txt from the C:\ drive on a Windows computer
to the /usr/local directory on a Linux instance:
C:\> pscp -i C:\Keys\my-key-pair.ppk C:
\Sample_file.txt user_name@public_dns:/usr/local/Sample_file.txt

Transferring Files to Your Linux Instance Using WinSCP
WinSCP is a GUI-based file manager for Windows that allows you to upload and transfer files to a
remote computer using the SFTP, SCP, FTP, and FTPS protocols. WinSCP allows you to drag and
drop files from your Windows machine to your Linux instance or synchronize entire directory structures
between the two systems.

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To use WinSCP, you'll need the private key you generated in Converting Your Private Key Using
PuTTYgen (p. 294). You'll also need the public DNS address of your Linux instance.
1.

Download and install WinSCP from http://winscp.net/eng/download.php. For most users, the
default installation options are OK.

Start WinSCP.

At the WinSCP login screen, for Host name, enter the public DNS address for your instance.

For User name, enter the default user name for your AMI. For Amazon Linux AMIs, the user name
is ec2-user. For Red Hat AMIs the user name is root, and for Ubuntu AMIs the user name is
ubuntu.

Specify the private key for your instance. For Private key, enter the path to your private key,
or click the "…" button to browse for the file. For newer versions of WinSCP, you need to click
Advanced to open the advanced site settings and then under SSH, click Authentication to find
the Private key file setting.

Note
WinSCP requires a PuTTY private key file (.ppk). You can convert a .pem security key
file to the .ppk format using PuTTYgen. For more information, see Converting Your
Private Key Using PuTTYgen (p. 294).
6.

(Optional) In the left panel, click Directories, and then, for Remote directory, enter the path for
the directory you want to add files to. For newer versions of WinSCP, you need to click Advanced
to open the advanced site settings and then under Environment, click Directories to find the
Remote directory setting.

Click Login to connect, and click Yes to add the host fingerprint to the host cache.

After the connection is established, in the connection window your Linux instance is on the right
and your local machine is on the left. You can drag and drop files directly into the remote file
system from your local machine. For more information on WinSCP, see the project documentation
at http://winscp.net/eng/docs/start.

Note
If you receive a "Cannot execute SCP to start transfer" error, you must first
install scp on your Linux instance. For some operating systems, this is located in the
openssh-clients package. For Amazon Linux variants, such as the Amazon ECSoptimized AMI, use the following command to install scp.

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[ec2-user ~]$ sudo yum install -y openssh-clients

Connecting to Your Linux Instance Using MindTerm
After you launch your instance, you can connect to it and use it the way that you'd use a computer
sitting in front of you.

Note
After you launch an instance, it can take a few minutes for the instance to be ready so that
you can connect to it. Check that your instance has passed its status checks - you can view
this information in the Status Checks column on the Instances page.
The following instructions explain how to connect to your instance using MindTerm through the
Amazon EC2 console. If you receive an error while attempting to connect to your instance, see
Troubleshooting Connecting to Your Instance.

Important
The Chrome browser does not support the NPAPI plugin, and therefore cannot run the
MindTerm client. For more information, go to the Chromium NPAPI deprecation article. You
can use Firefox, Safari, or Internet Explorer 9 or higher instead.

Prerequisites
• Install Java
Your Linux computer most likely includes Java. If not, see How do I enable Java in my web browser?
On a Windows or Mac client, you must run your browser using administrator credentials. For Linux,
additional steps may be required if you are not logged in as root.
• Enable Java in your browser
For instructions, see https://java.com/en/download/help/enable_browser.xml.
• Locate the private key
You'll need the fully-qualified path of the .pem file for the key pair that you specified when you
launched the instance.
• Enable inbound SSH traffic from your IP address to your instance
Ensure that the security group associated with your instance allows incoming SSH traffic from your
IP address. For more information, see Authorizing Network Access to Your Instances.

Important
Your default security group does not allow incoming SSH traffic by default.

Starting MindTerm
To connect to your instance using a web browser with MindTerm
1.

In the Amazon EC2 console, click Instances in the navigation pane.

2.
3.
4.

Select the instance, and then click Connect.
Click A Java SSH client directly from my browser (Java required).
Amazon EC2 automatically detects the public DNS name of your instance and the name of the
populates Public DNS for you. It also detects name of the key pair that you specified when you
launched the instance. Complete the following, and then click Launch SSH Client.
a.

In User name, enter the user name to log in to your instance.

Tip
For Amazon Linux, the user name is ec2-user. For RHEL5, the user name is either
root or ec2-user. For Ubuntu, the user name is ubuntu. For Fedora, the user

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name is either fedora or ec2-user. For SUSE Linux, the user name is either root
or ec2-user. Otherwise, if ec2-user and root don't work, check with your AMI
provider.
In Private key path, enter the fully-qualified path to your private key (.pem) file, including the
key pair name; for example:
C:\KeyPairs\my-key-pair.pem

(Optional) Click Store in browser cache to store the location of the private key in your
browser cache. This enables Amazon EC2 to detect the location of the private key in
subsequent browser sessions, until your clear your browser's cache.
If necessary, click Yes to trust the certificate, and click Run to run the MindTerm client.

If this is your first time running MindTerm, a series of dialog boxes asks you to accept the license
agreement, to confirm setup for your home directory, and to confirm setup of the known hosts
directory. Confirm these settings.

A dialog prompts you to add the host to your set of known hosts. If you do not want to store the
host key information on your local computer, click No.

A window opens and you are connected to your instance.

Note
If you clicked No in the previous step, you'll see the following message, which is
expected:
Verification of server key disabled in this session.

Stop and Start Your Instance
You can stop and restart your instance if it has an Amazon EBS volume as its root device. The
instance retains its instance ID, but can change as described in the Overview section.
When you stop an instance, we shut it down. We don't charge hourly usage for a stopped instance, or
data transfer fees, but we do charge for the storage for any Amazon EBS volumes. Each time you start
a stopped instance we charge a full instance hour, even if you make this transition multiple times within
a single hour.
While the instance is stopped, you can treat its root volume like any other volume, and modify it (for
example, repair file system problems or update software). You just detach the volume from the stopped
instance, attach it to a running instance, make your changes, detach it from the running instance, and
then reattach it to the stopped instance. Make sure that you reattach it using the storage device name
that's specified as the root device in the block device mapping for the instance.
If you decide that you no longer need an instance, you can terminate it. As soon as the state of an
instance changes to shutting-down or terminated, we stop charging for that instance. For more
information, see Terminate Your Instance (p. 305).
Contents
•
•
•
•

Overview (p. 299)
Stopping and Starting Your Instances (p. 300)
Modifying a Stopped Instance (p. 301)
Troubleshooting (p. 302)

Overview
You can only stop an Amazon EBS-backed instance. To verify the root device type of your instance,
describe the instance and check whether the device type of its root volume is ebs (Amazon EBS-

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backed instance) or instance store (instance store-backed instance). For more information, see
Determining the Root Device Type of Your AMI (p. 72).
When you stop a running instance, the following happens:
• The instance performs a normal shutdown and stops running; its status changes to stopping and
then stopped.
• Any Amazon EBS volumes remain attached to the instance, and their data persists.
• Any data stored in the RAM of the host computer or the instance store volumes of the host computer
is gone.
• The instance is migrated to a new underlying host computer when it's started.
• EC2-Classic: We release the public and private IP addresses for the instance when you stop the
instance, and assign new ones when you restart it.
EC2-VPC: The instance retains its private IP addresses when stopped and restarted. We release the
public IP address and assign a new one when you restart it.
• EC2-Classic: We disassociate any Elastic IP address that's associated with the instance. You're
charged for Elastic IP addresses that aren't associated with an instance. When you restart the
instance, you must associate the Elastic IP address with the instance; we don't do this automatically.
EC2-VPC: The instance retains its associated Elastic IP addresses. You're charged for any Elastic IP
addresses associated with a stopped instance.
• When you stop and start a Windows instance, the EC2Config service performs tasks on the instance
such as changing the drive letters for any attached Amazon EBS volumes. For more information
about these defaults and how you can change them, see Configuring a Windows Instance Using the
EC2Config Service in the Amazon EC2 User Guide for Windows Instances.
• If you've registered the instance with a load balancer, it's likely that the load balancer won't be able to
route traffic to your instance after you've stopped and restarted it. You must de-register the instance
from the load balancer after stopping the instance, and then re-register after starting the instance.
For more information, see Register or Deregister EC2 Instances for Your Classic Load Balancer in
the Classic Load Balancer Guide.
• If your instance is in an Auto Scaling group, the Auto Scaling service marks the stopped instance
as unhealthy, and may terminate it and launch a replacement instance. For more information, see
Health Checks for Auto Scaling Instances in the Auto Scaling User Guide.
• When you stop a ClassicLink instance, it's unlinked from the VPC to which it was linked. You must
link the instance to the VPC again after restarting it. For more information about ClassicLink, see
ClassicLink (p. 550).
For more information, see Differences Between Reboot, Stop, and Terminate (p. 277).
You can modify the following attributes of an instance only when it is stopped:
• Instance type
• User data
• Kernel
• RAM disk
If you try to modify these attributes while the instance is running, Amazon EC2 returns the
IncorrectInstanceState error.

Stopping and Starting Your Instances
You can start and stop your Amazon EBS-backed instance using the console or the command line.

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By default, when you initiate a shutdown from an Amazon EBS-backed instance (using the shutdown,
halt, or poweroff command), the instance stops. You can change this behavior so that it terminates
instead. For more information, see Changing the Instance Initiated Shutdown Behavior (p. 307).

To stop and start an Amazon EBS-backed instance using the console
1.

In the navigation pane, choose Instances, and select the instance.

[EC2-Classic] If the instance has an associated Elastic IP address, write down the Elastic IP
address and the instance ID shown in the details pane.

Choose Actions, select Instance State, and then choose Stop. If Stop is disabled, either the
instance is already stopped or its root device is an instance store volume.

Warning
When you stop an instance, the data on any instance store volumes is erased. Therefore,
if you have any data on instance store volumes that you want to keep, be sure to back it
up to persistent storage.
4.

While your instance is stopped, you can modify certain instance attributes. For more information,
see Modifying a Stopped Instance (p. 301).

To restart the stopped instance, select the instance, choose Actions, select Instance State, and
then choose Start.

In the confirmation dialog box, choose Yes, Start. It can take a few minutes for the instance to
enter the running state.
[EC2-Classic] When the instance state becomes running, the Public DNS, Private DNS, and
Private IPs fields in the details pane contain the new values that we assigned to the instance.

[EC2-Classic] If your instance had an associated Elastic IP address, you must reassociate it as
follows:
a.

In the navigation pane, choose Elastic IPs.

Select the Elastic IP address that you wrote down before you stopped the instance.

Choose Actions, and then select Associate Address.

Select the instance ID that you wrote down before you stopped the instance, and then choose
Associate.

To stop and start an Amazon EBS-backed instance using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• stop-instances and start-instances (AWS CLI)
• Stop-EC2Instance and Start-EC2Instance (AWS Tools for Windows PowerShell)

Modifying a Stopped Instance
You can change the instance type, user data, and EBS-optimization attributes of a stopped instance
using the AWS Management Console or the command line interface. You can't use the AWS
Management Console to modify the DeleteOnTermination, kernel, or RAM disk attributes.
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To modify an instance attribute
• To change the instance type, see Resizing Your Instance (p. 189).
• To change the user data for your instance, see Configuring Instances with User Data (p. 340).
• To enable or disable EBS–optimization for your instance, see Modifying EBS–
Optimization (p. 695).
• To change the DeleteOnTermination attribute of the root volume for your instance, see Updating
the Block Device Mapping of a Running Instance (p. 737).

To modify an instance attribute using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• modify-instance-attribute (AWS CLI)
• Edit-EC2InstanceAttribute (AWS Tools for Windows PowerShell)

Troubleshooting
If you have stopped your Amazon EBS-backed instance and it appears "stuck" in the stopping state,
you can forcibly stop it. For more information, see Troubleshooting Stopping Your Instance (p. 779).

Reboot Your Instance
An instance reboot is equivalent to an operating system reboot. In most cases, it takes only a few
minutes to reboot your instance. When you reboot an instance, it remains on the same physical host,
so your instance keeps its public DNS name, private IP address, and any data on its instance store
volumes.
Rebooting an instance doesn't start a new instance billing hour, unlike stopping and restarting your
instance.
We might schedule your instance for a reboot for necessary maintenance, such as to apply updates
that require a reboot. No action is required on your part; we recommend that you wait for the
reboot to occur within its scheduled window. For more information, see Scheduled Events for Your
Instances (p. 415).
We recommend that you use Amazon EC2 to reboot your instance instead of running the operating
system reboot command from your instance. If you use Amazon EC2 to reboot your instance, we
perform a hard reboot if the instance does not cleanly shut down within four minutes. If you use AWS
CloudTrail, then using Amazon EC2 to reboot your instance also creates an API record of when your
instance was rebooted.

To reboot an instance using the console
1.

Open the Amazon EC2 console.

In the navigation pane, choose Instances.

Select the instance, choose Actions, select Instance State, and then select Reboot.

Choose Yes, Reboot when prompted for confirmation.

To reboot an instance using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).

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• reboot-instances (AWS CLI)
• Restart-EC2Instance (AWS Tools for Windows PowerShell)

Instance Retirement
An instance is scheduled to be retired when AWS detects irreparable failure of the underlying hardware
hosting the instance. When an instance reaches its scheduled retirement date, it is stopped or
terminated by AWS. If your instance root device is an Amazon EBS volume, the instance is stopped,
and you can start it again at any time. Starting the stopped instance migrates it to new hardware. If
your instance root device is an instance store volume, the instance is terminated, and cannot be used
again.
Topics
• Identifying Instances Scheduled for Retirement (p. 303)
• Working with Instances Scheduled for Retirement (p. 304)
For more information about types of instance events, see Scheduled Events for Your
Instances (p. 415).

Identifying Instances Scheduled for Retirement
If your instance is scheduled for retirement, you'll receive an email prior to the event with the instance
ID and retirement date. This email is sent to the address that's associated with your account; the same
email address that you use to log in to the AWS Management Console. If you use an email account
that you do not check regularly, then you can use the Amazon EC2 console or the command line to
determine if any of your instances are scheduled for retirement. To update the contact information for
your account, go to the Account Settings page.

To identify instances scheduled for retirement using the console
1.
2.

Open the Amazon EC2 console.
In the navigation pane, choose EC2 Dashboard. Under Scheduled Events, you can see the
events associated with your Amazon EC2 instances and volumes, organized by region.

If you have an instance with a scheduled event listed, select its link below the region name to go to
the Events page.
The Events page lists all resources with events associated with them. To view instances that are
scheduled for retirement, select Instance resources from the first filter list, and then Instance
retirement from the second filter list.
If the filter results show that an instance is scheduled for retirement, select it, and note the date
and time in the Start time field in the details pane. This is your instance retirement date.

To identify instances scheduled for retirement using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).

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• describe-instance-status (AWS CLI)
• Get-EC2InstanceStatus (AWS Tools for Windows PowerShell)

Working with Instances Scheduled for Retirement
There are a number of actions available to you when your instance is scheduled for retirement. The
action you take depends on whether your instance root device is an Amazon EBS volume, or an
instance store volume. If you do not know what your instance root device type is, you can find out using
the Amazon EC2 console or the command line.

Determining Your Instance Root Device Type
To determine your instance root device type using the console
1.

In the navigation pane, select Events. Use the filter lists to identify retiring instances, as
demonstrated in the procedure above, Identifying instances scheduled for retirement (p. 303).

In the Resource ID column, select the instance ID to go to the Instances page.

Select the instance and locate the Root device type field in the Description tab. If the value is
ebs, then your instance is EBS-backed. If the value is instance-store, then your instance is
instance store-backed.

To determine your instance root device type using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• describe-instances (AWS CLI)
• Get-EC2Instance (AWS Tools for Windows PowerShell)

Managing Instances Scheduled for Retirement
You can perform one of the actions listed below in order to preserve the data on your retiring instance.
It's important that you take this action before the instance retirement date, to prevent unforeseen
downtime and data loss.

Warning
If your instance store-backed instance passes its retirement date, it's terminated and you
cannot recover the instance or any data that was stored on it. Regardless of the root device of
your instance, the data on instance store volumes is lost when the instance is retired, even if
they are attached to an EBS-backed instance.
Instance Root Device
Type

Action

EBS

Wait for the scheduled retirement date - when the instance is stopped or stop the instance yourself before the retirement date. You can start
the instance again at any time. For more information about stopping and
starting your instance, and what to expect when your instance is stopped,
such as the effect on public, private and Elastic IP addresses associated
with your instance, see Stop and Start Your Instance (p. 299).

EBS

Create an EBS-backed AMI from your instance, and launch a replacement
instance. For more information, see Creating an Amazon EBS-Backed
Linux AMI (p. 89).

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Instance Root Device
Type

Action

Instance store

Create an instance store-backed AMI from your instance using the AMI
tools, and launch a replacement instance. For more information, see
Creating an Instance Store-Backed Linux AMI (p. 92).

Instance store

Convert your instance to an EBS-backed instance by transferring your data
to an EBS volume, taking a snapshot of the volume, and then creating
an AMI from the snapshot. You can launch a replacement instance from
your new AMI. For more information, see Converting your Instance StoreBacked AMI to an Amazon EBS-Backed AMI (p. 129).

Terminate Your Instance
When you've decided that you no longer need an instance, you can terminate it. As soon as the state
of an instance changes to shutting-down or terminated, you stop incurring charges for that
instance.
You can't connect to or restart an instance after you've terminated it. However, you can launch
additional instances using the same AMI. If you'd rather stop and restart your instance, see Stop and
Start Your Instance (p. 299). For more information, see Differences Between Reboot, Stop, and
Terminate (p. 277).
Topics
• Instance Termination (p. 305)
• Terminating an Instance (p. 306)
• Enabling Termination Protection for an Instance (p. 306)
• Changing the Instance Initiated Shutdown Behavior (p. 307)
• Preserving Amazon EBS Volumes on Instance Termination (p. 308)
• Troubleshooting (p. 310)

Instance Termination
After you terminate an instance, it remains visible in the console for a short while, and then the entry is
automatically deleted. You cannot delete the terminated instance entry yourself.
When an instance terminates, the data on any instance store volumes associated with that instance is
deleted.
By default, Amazon EBS root device volumes are automatically deleted when the instance terminates.
However, by default, any additional EBS volumes that you attach at launch, or any EBS volumes that
you attach to an existing instance persist even after the instance terminates. This behavior is controlled
by the volume's DeleteOnTermination attribute, which you can modify. For more information, see
Preserving Amazon EBS Volumes on Instance Termination (p. 308).
You can prevent an instance from being terminated accidentally by someone using the AWS
Management Console, the CLI, and the API. This feature is available for both Amazon EC2 instance
store-backed and Amazon EBS-backed instances. Each instance has a DisableApiTermination
attribute with the default value of false (the instance can be terminated through Amazon EC2).
You can modify this instance attribute while the instance is running or stopped (in the case of
Amazon EBS-backed instances). For more information, see Enabling Termination Protection for an
Instance (p. 306).

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You can control whether an instance should stop or terminate when shutdown is initiated from the
instance using an operating system command for system shutdown. For more information, see
Changing the Instance Initiated Shutdown Behavior (p. 307).
If you run a script on instance termination, your instance might have an abnormal termination, because
we have no way to ensure that shutdown scripts run. Amazon EC2 attempts to shut an instance down
cleanly and run any system shutdown scripts; however, certain events (such as hardware failure) may
prevent these system shutdown scripts from running.

Terminating an Instance
You can terminate an instance using the AWS Management Console or the command line.

To terminate an instance using the console
1.

Before you terminate the instance, verify that you won't lose any data by checking that your
Amazon EBS volumes won't be deleted on termination and that you've copied any data that you
need from your instance store volumes to Amazon EBS or Amazon S3.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, select Instances.

Select the instance, choose Actions, select Instance State, and then select Terminate.

Select Yes, Terminate when prompted for confirmation.

To terminate an instance using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• terminate-instances (AWS CLI)
• Stop-EC2Instance (AWS Tools for Windows PowerShell)

Enabling Termination Protection for an Instance
By default, you can terminate your instance using the Amazon EC2 console, command line interface,
or API. If you want to prevent your instance from being accidentally terminated using Amazon EC2,
you can enable termination protection for the instance. The DisableApiTermination attribute
controls whether the instance can be terminated using the console, CLI, or API. By default, termination
protection is disabled for your instance. You can set the value of this attribute when you launch the
instance, while the instance is running, or while the instance is stopped (for Amazon EBS-backed
instances).
The DisableApiTermination attribute does not prevent you from terminating an instance by
initiating shutdown from the instance (using an operating system command for system shutdown) when
the InstanceInitiatedShutdownBehavior attribute is set. For more information, see Changing
the Instance Initiated Shutdown Behavior (p. 307).
You can't prevent instances that are part of an Auto Scaling group from terminating using termination
protection. However, you can specify which instances should terminate first. For more information, see
Choosing a Termination Policy in the Auto Scaling User Guide.
You can't enable termination protection for Spot instances — a Spot instance is terminated when the
Spot price exceeds your bid price. However, you can prepare your application to handle Spot instance
interruptions. For more information, see Spot Instance Interruptions (p. 260).
You can enable or disable termination protection using the AWS Management Console or the
command line.

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To enable termination protection for an instance at launch time
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

On the dashboard, choose Launch Instance and follow the directions in the wizard.

On the Configure Instance Details page, select the Enable termination protection check box.

To enable termination protection for a running or stopped instance
1.

Select the instance, choose Actions, Instance Settings, and then choose Change Termination
Protection.

Select Yes, Enable.

To disable termination protection for a running or stopped instance
1.

Select the instance, select Actions, select Instance Settings, and then choose Change
Termination Protection.

Select Yes, Disable.

To enable or disable termination protection using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• modify-instance-attribute (AWS CLI)
• Edit-EC2InstanceAttribute (AWS Tools for Windows PowerShell)

Changing the Instance Initiated Shutdown Behavior
By default, when you initiate a shutdown from an Amazon EBS-backed instance (using a command
such as shutdown, halt, or poweroff), the instance stops. You can change this behavior using the
InstanceInitiatedShutdownBehavior attribute for the instance so that it terminates instead. You
can update this attribute while the instance is running or stopped.
You can update the InstanceInitiatedShutdownBehavior attribute using the Amazon EC2
console or the command line. The InstanceInitiatedShutdownBehavior attribute only applies
when you perform a shutdown from the operating system of the instance itself; it does not apply when
you stop an instance using the StopInstances API or the Amazon EC2 console.

To change the shutdown behavior of an instance using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances.

Select the instance, select Actions, Instance Settings, and then choose Change Shutdown
Behavior. The current behavior is already selected.

To change the behavior, select an option from the Shutdown behavior list, and then select
Apply.

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To change the shutdown behavior of an instance using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• modify-instance-attribute (AWS CLI)
• Edit-EC2InstanceAttribute (AWS Tools for Windows PowerShell)

Preserving Amazon EBS Volumes on Instance Termination
When an instance terminates, Amazon EC2 uses the value of the DeleteOnTermination attribute
for each attached Amazon EBS volume to determine whether to preserve or delete the volume.
By default, the DeletionOnTermination attribute for the root volume of an instance is set to true.
Therefore, the default is to delete the root volume of an instance when the instance terminates.
By default, when you attach an EBS volume to an instance, its DeleteOnTermination attribute is set
to false. Therefore, the default is to preserve these volumes. After the instance terminates, you can
take a snapshot of the preserved volume or attach it to another instance.
To verify the value of the DeleteOnTermination attribute for an EBS volume that is in-use, look
at the instance's block device mapping. For more information, see Viewing the EBS Volumes in an
Instance Block Device Mapping (p. 738).
You can change value of the DeleteOnTermination attribute for a volume when you launch the
instance or while the instance is running.
Examples
• Changing the Root Volume to Persist at Launch Using the Console (p. 308)
• Changing the Root Volume to Persist at Launch Using the Command Line (p. 309)
• Changing the Root Volume of a Running Instance to Persist Using the Command Line (p. 309)

Changing the Root Volume to Persist at Launch Using the Console
Using the console, you can change the DeleteOnTermination attribute when you launch an
instance. To change this attribute for a running instance, you must use the command line.

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To change the root volume of an instance to persist at launch using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

From the console dashboard, select Launch Instance.

On the Choose an Amazon Machine Image (AMI) page, choose an AMI and choose Select.

Follow the wizard to complete the Choose an Instance Type and Configure Instance Details
pages.

On the Add Storage page, deselect the Delete On Termination check box for the root volume.

Complete the remaining wizard pages, and then choose Launch.

Changing the Root Volume to Persist at Launch Using the Command
Line
When you launch an instance, you can use one of the following commands to change the root device
volume to persist. The root device is typically /dev/sda1. For more information about these command
line interfaces, see Accessing Amazon EC2 (p. 3).
• run-instances (AWS CLI)
• New-EC2Instance (AWS Tools for Windows PowerShell)
For example, add the following option to your run-instances command:
--block-device-mappings file://mapping.json

Specify the following in mapping.json:
[
{
"DeviceName": "/dev/sda1",
"Ebs": {
"DeleteOnTermination": false,
"SnapshotId": "snap-1234567890abcdef0",
"VolumeType": "gp2"
}
}
]

Changing the Root Volume of a Running Instance to Persist Using the
Command Line
You can use one of the following commands to change the root device volume of a running instance
to persist. The root device is typically /dev/sda1. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• modify-instance-attribute (AWS CLI)
• Edit-EC2InstanceAttribute (AWS Tools for Windows PowerShell)
For example, use the following command:

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$ aws ec2 modify-instance-attribute --instance-id i-1234567890abcdef0 -block-device-mappings file://mapping.json

Specify the following in mapping.json:
[
{
"DeviceName": "/dev/sda1",
"Ebs": {
"DeleteOnTermination": false
}
}
]

Troubleshooting
If your instance is in the shutting-down state for longer than usual, it will eventually be cleaned
up (terminated) by automated processes within the Amazon EC2 service. For more information, see
Troubleshooting Terminating (Shutting Down) Your Instance (p. 781).

Recover Your Instance
You can create an Amazon CloudWatch alarm that monitors an Amazon EC2 instance and
automatically recovers the instance if it becomes impaired due to an underlying hardware failure
or a problem that requires AWS involvement to repair. Terminated instances cannot be recovered.
A recovered instance is identical to the original instance, including the instance ID, private IP
addresses, Elastic IP addresses, and all instance metadata. For more information about using
Amazon CloudWatch alarms to recover an instance, see Create Alarms That Stop, Terminate,
Reboot, or Recover an Instance (p. 450). To troubleshoot issues with instance recovery failures, see
Troubleshooting Instance Recovery Failures in the Amazon EC2 User Guide for Linux Instances.
When the StatusCheckFailed_System alarm is triggered, and the recover action is initiated, you
will be notified by the Amazon SNS topic that you selected when you created the alarm and associated
the recover action. During instance recovery, the instance is migrated during an instance reboot, and
any data that is in-memory is lost. When the process is complete, information is published to the SNS
topic you've configured for the alarm. Anyone who is subscribed to this SNS topic will receive an email
notification that includes the status of the recovery attempt and any further instructions. You will notice
an instance reboot on the recovered instance.
Examples of problems that cause system status checks to fail include:
• Loss of network connectivity
• Loss of system power
• Software issues on the physical host
• Hardware issues on the physical host

Important
The recover action is only supported on:
• C3, C4, M3, M4, R3, T2, and X1 instance types.
• Instances in a VPC

Note
If your instance has a public IP address, it retains the same public IP address after
recovery.

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• Instances with shared tenancy (where the tenancy attribute of the instance is set to
default)
• Instances that use Amazon EBS storage exclusively
Currently, the recover action is not supported on:
• EC2-Classic instances
• Dedicated tenancy instances
• Instances running on dedicated hosts
• Instances with encrypted EBS volumes
• Instances that use any instance store volumes, including instances launched with block
device mappings for instance store volumes

Configuring Your Amazon Linux Instance
After you have successfully launched and logged into your Amazon Linux instance, you can make
changes to it. There are many different ways you can configure an instance to meet the needs of a
specific application. The following are some common tasks to help get you started.
Contents
• Common Configuration Scenarios (p. 311)
• Managing Software on Your Linux Instance (p. 312)
• Managing User Accounts on Your Linux Instance (p. 320)
•
•
•
•

Processor State Control for Your EC2 Instance (p. 322)
Setting the Time for Your Linux Instance (p. 326)
Changing the Hostname of Your Linux Instance (p. 330)
Setting Up Dynamic DNS on Your Linux Instance (p. 332)

• Running Commands on Your Linux Instance at Launch (p. 334)
• Instance Metadata and User Data (p. 337)

Common Configuration Scenarios
The base distribution of Amazon Linux contains many software packages and utilities that are required
for basic server operations. However, many more software packages are available in various software
repositories, and even more packages are available for you to build from source code. For more

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information on installing and building software from these locations, see Managing Software on Your
Linux Instance (p. 312).
Amazon Linux instances come pre-configured with an ec2-user account, but you may want to add
other user accounts that do not have super-user privileges. For more information on adding and
removing user accounts, see Managing User Accounts on Your Linux Instance (p. 320).
The default time configuration for Amazon Linux instances uses Network Time Protocol to set
the system time on an instance. The default time zone is UTC. For more information on setting
the time zone for an instance or using your own time server, see Setting the Time for Your Linux
Instance (p. 326).
If you have your own network with a domain name registered to it, you can change the hostname
of an instance to identify itself as part of that domain. You can also change the system prompt to
show a more meaningful name without changing the hostname settings. For more information, see
Changing the Hostname of Your Linux Instance (p. 330). You can configure an instance to use a
dynamic DNS service provider. For more information, see Setting Up Dynamic DNS on Your Linux
Instance (p. 332).
When you launch an instance in Amazon EC2, you have the option of passing user data to the
instance that can be used to perform common configuration tasks and even run scripts after the
instance starts. You can pass two types of user data to Amazon EC2, cloud-init directives,
and shell scripts. For more information, see Running Commands on Your Linux Instance at
Launch (p. 334).

Managing Software on Your Linux Instance
The base distribution of Amazon Linux contains many software packages and utilities that are required
for basic server operations. However, many more software packages are available in various software
repositories, and even more packages are available for you to build from source code.
Contents
• Updating Instance Software (p. 313)
• Adding Repositories (p. 316)
• Finding Software Packages (p. 317)
• Installing Software Packages (p. 318)
• Preparing to Compile Software (p. 319)
It is important to keep software up-to-date. Many packages in a Linux distribution are updated
frequently to fix bugs, add features, and protect against security exploits. For more information, see
Updating Instance Software (p. 313).
By default, Amazon Linux instances launch with two repositories enabled: amzn-main and amznupdates. While there are many packages available in these repositories that are updated by Amazon
Web Services, there may be a package that you wish to install that is contained in another repository.
For more information, see Adding Repositories (p. 316). For help finding packages in enabled
repositories, see Finding Software Packages (p. 317). For information about installing software on an
Amazon Linux instance, see Installing Software Packages (p. 318).
Not all software is available in software packages stored in repositories; some software must be
compiled on an instance from its source code. For more information, see Preparing to Compile
Software (p. 319).
Amazon Linux instances manage their software using the yum package manager. The yum package
manager can install, remove, and update software, as well as manage all of the dependencies for each
package. Debian-based Linux distributions, like Ubuntu, use the apt-get command and dpkg package
manager, so the yum examples in the following sections do not work for those distributions.

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Updating Instance Software
It is important to keep software up-to-date. Many packages in a Linux distribution are updated
frequently to fix bugs, add features, and protect against security exploits. When you first launch
and connect to an Amazon Linux instance, you may see a message asking you to update software
packages for security purposes. This section shows how to update an entire system, or just a single
package.

Important
These procedures are intended for use with Amazon Linux. For more information about other
distributions, see their specific documentation.
__| __|_ )
_| (
/
___|\___|___|

Amazon Linux AMI

https://aws.amazon.com/amazon-linux-ami/2013.03-release-notes/
There are 12 security update(s) out of 25 total update(s) available
Run "sudo yum update" to apply all updates.
[ec2-user ~]$

To update all packages on an Amazon Linux instance
1.

(Optional) Start a screen session in your shell window. Sometimes you may experience a network
interruption that can disconnect the SSH connection to your instance. If this happens during a long
software update, it can leave the instance in a recoverable, although confused state. A screen
session allows you to continue running the update even if your connection is interrupted, and you
can reconnect to the session later without problems.
a.

Execute the screen command to begin the session.
[ec2-user ~]$ screen

If your session is disconnected, log back into your instance and list the available screens.
[ec2-user ~]$ screen -ls
There is a screen on:
17793.pts-0.ip-12-34-56-78 (Detached)
1 Socket in /var/run/screen/S-ec2-user.

Reconnect to the screen using the screen -r command and the process ID from the previous
command.
[ec2-user ~]$ screen -r 17793

When you are finished using screen, use the exit command to close the session.
[ec2-user ~]$ exit
[screen is terminating]

Run the yum update command. Optionally, you can add the --security flag to apply only
security updates.
[ec2-user ~]$ sudo yum update
Loaded plugins: priorities, security, update-motd, upgrade-helper
amzn-main
| 2.1 kB
00:00

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amzn-updates
| 2.3 kB
00:00
Setting up Update Process
Resolving Dependencies
--> Running transaction check
---> Package aws-apitools-ec2.noarch 0:1.6.8.1-1.0.amzn1 will be updated
---> Package aws-apitools-ec2.noarch 0:1.6.10.0-1.0.amzn1 will be an
update
---> Package gnupg2.x86_64 0:2.0.18-1.16.amzn1 will be updated
---> Package gnupg2.x86_64 0:2.0.19-8.21.amzn1 will be an update
---> Package libgcrypt.i686 0:1.4.5-9.10.amzn1 will be updated
---> Package libgcrypt.x86_64 0:1.4.5-9.10.amzn1 will be updated
---> Package libgcrypt.i686 0:1.4.5-9.12.amzn1 will be an update
---> Package libgcrypt.x86_64 0:1.4.5-9.12.amzn1 will be an update
---> Package openssl.x86_64 1:1.0.1e-4.53.amzn1 will be updated
---> Package openssl.x86_64 1:1.0.1e-4.54.amzn1 will be an update
---> Package python-boto.noarch 0:2.9.9-1.0.amzn1 will be updated
---> Package python-boto.noarch 0:2.13.3-1.0.amzn1 will be an update
--> Finished Dependency Resolution
Dependencies Resolved
================================================================================
Package
Arch
Version
Repository
Size
================================================================================
Updating:
aws-apitools-ec2
noarch
1.6.10.0-1.0.amzn1
amzn-updates
14 M
gnupg2
x86_64
2.0.19-8.21.amzn1
amzn-updates
2.4 M
libgcrypt
i686
1.4.5-9.12.amzn1
amzn-updates
248 k
libgcrypt
x86_64
1.4.5-9.12.amzn1
amzn-updates
262 k
openssl
x86_64
1:1.0.1e-4.54.amzn1
amzn-updates
1.7 M
python-boto
noarch
2.13.3-1.0.amzn1
amzn-updates
1.6 M
Transaction Summary
================================================================================
Upgrade
6 Package(s)
Total download size: 20 M
Is this ok [y/N]:

Review the packages listed, and type y and Enter to accept the updates. Updating all of the
packages on a system can take several minutes. The yum output shows the status of the update
while it is running.
Downloading Packages:
(1/6): aws-apitools-ec2-1.6.10.0-1.0.amzn1.noarch.rpm
00:00
(2/6): gnupg2-2.0.19-8.21.amzn1.x86_64.rpm
00:00
(3/6): libgcrypt-1.4.5-9.12.amzn1.i686.rpm
00:00

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| 2.4 MB
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(4/6): libgcrypt-1.4.5-9.12.amzn1.x86_64.rpm
| 262 kB
00:00
(5/6): openssl-1.0.1e-4.54.amzn1.x86_64.rpm
| 1.7 MB
00:00
(6/6): python-boto-2.13.3-1.0.amzn1.noarch.rpm
| 1.6 MB
00:00
-------------------------------------------------------------------------------Total
28 MB/s | 20 MB
00:00
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Updating
: libgcrypt-1.4.5-9.12.amzn1.x86_64
1/12
Updating
: gnupg2-2.0.19-8.21.amzn1.x86_64
2/12
Updating
: aws-apitools-ec2-1.6.10.0-1.0.amzn1.noarch
3/12
Updating
: 1:openssl-1.0.1e-4.54.amzn1.x86_64
4/12
...
Complete!

(Optional) Reboot your instance to ensure that you are using the latest packages and libraries
from your update; kernel updates are not loaded until a reboot occurs. Updates to any glibc
libraries should also be followed by a reboot. For updates to packages that control services, it may
be sufficient to restart the services to pick up the updates, but a system reboot ensures that all
previous package and library updates are complete.

To update a single package on an Amazon Linux instance
Use this procedure to update a single package (and its dependencies) and not the entire system.
1.

Run the yum update command with the name of the package you would like to update.
[ec2-user ~]$ sudo yum update openssl
Loaded plugins: priorities, security, update-motd, upgrade-helper
amzn-main
| 2.1 kB
00:00
amzn-updates
| 2.3 kB
00:00
Setting up Update Process
Resolving Dependencies
--> Running transaction check
---> Package openssl.x86_64 1:1.0.1e-4.53.amzn1 will be updated
---> Package openssl.x86_64 1:1.0.1e-4.54.amzn1 will be an update
--> Finished Dependency Resolution
Dependencies Resolved
================================================================================
Package
Arch
Version
Repository
Size
================================================================================
Updating:

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openssl
1.7 M

x86_64

1:1.0.1e-4.54.amzn1

amzn-updates

Transaction Summary
================================================================================
Upgrade
1 Package(s)
Total download size: 1.7 M
Is this ok [y/N]:

Review the package information listed, and type y and Enter to accept the update or updates.
Sometimes there will be more than one package listed if there are package dependencies that
must be resolved. The yum output shows the status of the update while it is running.
Downloading Packages:
openssl-1.0.1e-4.54.amzn1.x86_64.rpm
00:00
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Updating
: 1:openssl-1.0.1e-4.54.amzn1.x86_64
1/2
Cleanup
: 1:openssl-1.0.1e-4.53.amzn1.x86_64
2/2
Verifying : 1:openssl-1.0.1e-4.54.amzn1.x86_64
1/2
Verifying : 1:openssl-1.0.1e-4.53.amzn1.x86_64
2/2

| 1.7 MB

Updated:
openssl.x86_64 1:1.0.1e-4.54.amzn1
Complete!

Adding Repositories
By default, Amazon Linux instances launch with two repositories enabled: amzn-main and amznupdates. While there are many packages available in these repositories that are updated by Amazon
Web Services, there may be a package that you wish to install that is contained in another repository.

Important
These procedures are intended for use with Amazon Linux. For more information about other
distributions, see their specific documentation.
To install a package from a different repository with yum, you need to add the repository information
to the /etc/yum.conf file or to its own repository.repo file in the /etc/yum.repos.d directory.
You can do this manually, but most yum repositories provide their own repository.repo file at their
repository URL.

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To add a yum repository to /etc/yum.repos.d
1.
2.

Find the location of the .repo file. This will vary depending on the repository you are adding. In
this example, the .repo file is at https://www.example.com/repository.repo.
Add the repository with the yum-config-manager command.
[ec2-user ~]$ sudo yum-config-manager --add-repo https://
www.example.com/repository.repo
Loaded plugins: priorities, update-motd, upgrade-helper
adding repo from: https://www.example.com/repository.repo
grabbing file https://www.example.com/repository.repo to /etc/
yum.repos.d/repository.repo
repository.repo
| 4.0 kB
repo saved to /etc/yum.repos.d/repository.repo

00:00

To enable a yum repository in /etc/yum.repos.d
•

Use the yum-config-manager command with the --enable repository flag. The following
command enables the Extra Packages for Enterprise Linux (EPEL) repository from the Fedora
project. By default, this repository is present in /etc/yum.repos.d on Amazon Linux instances,
but it is not enabled.
[ec2-user ~]$ sudo yum-config-manager --enable epel

Note
For information on enabling the EPEL repository on other distributions, such as Red Hat and
CentOS, see the EPEL documentation at https://fedoraproject.org/wiki/EPEL.

Finding Software Packages
You can use the yum search command to search the descriptions of packages that are available in
your configured repositories. This is especially helpful if you don't know the exact name of the package
you want to install. Simply append the keyword search to the command; for multiple word searches,
wrap the search query with quotation marks.

Important
These procedures are intended for use with Amazon Linux. For more information about other
distributions, see their specific documentation.
Multiple word search queries in quotation marks only return results that match the exact query. If you
don't see the expected package, simplify your search to one keyword and then scan the results. You
can also try keyword synonyms to broaden your search.
[ec2-user ~]$ sudo yum search "find"
Loaded plugins: priorities, security, update-motd, upgrade-helper
============================== N/S Matched: find
===============================
findutils.x86_64 : The GNU versions of find utilities (find and xargs)
perl-File-Find-Rule.noarch : Perl module implementing an alternative
interface
: to File::Find
perl-Module-Find.noarch : Find and use installed modules in a (sub)category
libpuzzle.i686 : Library to quickly find visually similar images (gif, png,
jpg)
libpuzzle.x86_64 : Library to quickly find visually similar images (gif, png,

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: jpg)
mlocate.x86_64 : An utility for finding files by name

The yum package manager also combines several packages into groups that you can install with
one command to perform a particular task, such as installing a web server or build tools for software
compilation. To list the groups that are already installed on your system and the available groups that
you can install, use the yum grouplist command.
[ec2-user ~]$ sudo yum grouplist
Loaded plugins: priorities, security, update-motd, upgrade-helper
Setting up Group Process
Installed Groups:
Development Libraries
Development tools
Editors
Legacy UNIX compatibility
Mail Server
MySQL Database
Network Servers
Networking Tools
PHP Support
Perl Support
System Tools
Web Server
Available Groups:
Console internet tools
DNS Name Server
FTP Server
Java Development
MySQL Database client
NFS file server
Performance Tools
PostgreSQL Database client (version 8)
PostgreSQL Database server (version 8)
Scientific support
TeX support
Technical Writing
Web Servlet Engine
Done

You can see the different packages in a group by using the yum groupinfo "Group Name" command,
replacing Group Name with the name of the group to get information about. This command lists all of
the mandatory, default, and optional packages that can be installed with that group.
If you cannot find the software you need in the default amzn-main and amzn-updates repositories,
you can add more repositories, such as the Extra Packages for Enterprise Linux (EPEL) repository. For
more information, see Adding Repositories (p. 316).

Installing Software Packages
The yum package manager is a great tool for installing software, because it can search all of your
enabled repositories for different software packages and also handle any dependencies in the software
installation process.

Important
These procedures are intended for use with Amazon Linux. For more information about other
distributions, see their specific documentation.

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To install a package from a repository, use the yum install package command, replacing package
with the name of the software to install. For example, to install the links text-based web browser, enter
the following command.
[ec2-user ~]$ sudo yum install links

To install a group of packages, use the yum groupinstall Group Name command, replacing Group
Name with the name of the group you would like to install. For example, to install the "Performance
Tools" group, enter the following command.
[ec2-user@ip-10-161-113-54 ~]$ sudo yum groupinstall "Performance Tools"

By default, yum will only install the mandatory and default packages in the group listing. If you would
like to install the optional packages in the group also, you can set the group_package_types
configuration parameter in the command when you execute it that adds the optional packages.
[ec2-user ~]$ sudo yum -setopt=group_package_types=mandatory,default,optional groupinstall
"Performance Tools"

You can also use yum install to install RPM package files that you have downloaded from the Internet.
To do this, simply append the path name of an RPM file to the installation command instead of a
repository package name.
[ec2-user ~]$ sudo yum install my-package.rpm

Preparing to Compile Software
There is a wealth of open-source software available on the Internet that has not been pre-compiled
and made available for download from a package repository. You may eventually discover a software
package that you need to compile yourself, from its source code. For your system to be able to compile
software, you need to install several development tools, such as make, gcc, and autoconf.

Important
These procedures are intended for use with Amazon Linux. For more information about other
distributions, see their specific documentation.
Because software compilation is not a task that every Amazon EC2 instance requires, these tools are
not installed by default, but they are available in a package group called "Development Tools" that is
easily added to an instance with the yum groupinstall command.
[ec2-user ~]$ sudo yum groupinstall "Development Tools"

Software source code packages are often available for download (from web sites such as https://
github.com/ and http://sourceforge.net/) as a compressed archive file, called a tarball. These tarballs
will usually have the .tar.gz file extension. You can decompress these archives with the tar
command.
[ec2-user ~]$ tar -xzf software.tar.gz

After you have decompressed and unarchived the source code package, you should look for a README
or INSTALL file in the source code directory that can provide you with further instructions for compiling
and installing the source code.

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To retrieve source code for Amazon Linux packages
Amazon Web Services provides the source code for maintained packages. You can download the
source code for any installed packages with the get_reference_source command.
•

Run the get_reference_source -p package command to download the source code for package.
For example, to download the source code for the htop package, enter the following command.
[ec2-user ~]$ get_reference_source -p htop
Requested package: htop
Found package from local RPM database: htop-1.0.1-2.3.amzn1.x86_64
Corresponding source RPM to found package : htop-1.0.1-2.3.amzn1.src.rpm
Are these parameters correct? Please type 'yes' to continue: yes
Source RPM downloaded to: /usr/src/srpm/debug/htop-1.0.1-2.3.amzn1.src.rpm

The command output lists the location of the source RPM, in this case /usr/src/srpm/debug/
htop-1.0.1-2.3.amzn1.src.rpm.

Managing User Accounts on Your Linux
Instance
Each Linux instance type launches with a default Linux system user account. For Amazon Linux, the
user name is ec2-user. For RHEL5, the user name is either root or ec2-user. For Ubuntu, the user
name is ubuntu. For Fedora, the user name is either fedora or ec2-user. For SUSE Linux, the user
name is either root or ec2-user. Otherwise, if ec2-user and root don't work, check with your AMI
provider.

Note
Linux system users should not be confused with AWS Identity and Access Management (IAM)
users. For more information, see IAM Users and Groups in the IAM User Guide.
Using the default user account is adequate for many applications, but you may choose to add user
accounts so that individuals can have their own files and workspaces. Creating user accounts for new
users is much more secure than granting multiple (possibly inexperienced) users access to the ec2user account, since that account can cause a lot of damage to a system when used improperly.

To add a new user to the system
Effectively adding users to a Linux instance involves two basic operations: adding the user to the
system, and providing that user with a way to log in remotely.
1.

To add a new user to the system, use the adduser command followed by any relevant options and
the name of the user you wish to create.

Important
If you are adding a user to an Ubuntu system, you should add the --disabledpassword option to avoid adding a password to the account.
[ec2-user ~]$ sudo adduser newuser

This command adds the newuser account to the system (with an entry in the /etc/passwd file),
creates a newuser group, and creates a home directory for the account in /home/newuser.
To provide remote access to this account, you must create a .ssh directory in the newuser home
directory and create a file within it named "authorized_keys" that contains a public key.

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Switch to the new account so that newly created files have the proper ownership.
[ec2-user ~]$ sudo su - newuser
[newuser ~]$

Note that the prompt now says newuser instead of ec2-user; you have switched the shell
session to the new account.
b.

Create a .ssh directory for the authorized_keys file.
[newuser ~]$ mkdir .ssh

Change the file permissions of the .ssh directory to 700 (this means only the file owner can
read, write, or open the directory).

Important
This step is very important; without these exact file permissions, you will not be able
to log into this account using SSH.
[newuser ~]$ chmod 700 .ssh

Create a file named "authorized_keys" in the .ssh directory.
[newuser ~]$ touch .ssh/authorized_keys

Change the file permissions of the authorized_keys file to 600 (this means only the file
owner can read or write to the file).

Important
This step is very important; without these exact file permissions, you will not be able
to log into this account using SSH.
[newuser ~]$ chmod 600 .ssh/authorized_keys

Edit the authorized_keys file with your favorite text editor and paste the public key for your
key pair into the file, for example:
ssh-rsa
AAAAB3NzaC1yc2EAAAADAQABAAABAQClKsfkNkuSevGj3eYhCe53pcjqP3maAhDFcvBS7O6V
hz2ItxCih+PnDSUaw+WNQn/mZphTk/a/gU8jEzoOWbkM4yxyb/wB96xbiFveSFJuOp/
d6RJhJOI0iBXr
lsLnBItntckiJ7FbtxJMXLvvwJryDUilBMTjYtwB+QhYXUMOzce5Pjz5/
i8SeJtjnV3iAoG/cQk+0FzZ
qaeJAAHco
+CY/5WrUBkrHmFJr6HcXkvJdWPkYQS3xqC0+FmUZofz221CBt5IMucxXPkX4rWi
+z7wB3Rb
BQoQzd8v7yeb7OzlPnWOyN0qFU0XA246RA8QFYiCNYwI3f05p6KLxEXAMPLE

Note
For more information about creating a key pair, see Creating Your Key Pair Using
Amazon EC2 (p. 482). For more information about retrieving a public key from an
existing key pair, see Retrieving the Public Key for Your Key Pair on Linux (p. 484).
You should now be able to log into the newuser account on your instance via SSH using the private
key that matches the public key from Step 2.f (p. 321).
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To remove a user from the system
If a user account is no longer needed, you can remove that account so that it may no longer be used.
•

To delete a user account, the user's home directory, and the user's mail spool, execute the
userdel -r command followed by the user name you wish to delete.
[ec2-user ~]$ sudo userdel -r olduser

Note
To keep the user's home directory and mail spool, omit the -r option.

Processor State Control for Your EC2 Instance
C-states control the sleep levels that a core can enter when it is idle. C-states are numbered starting
with C0 (the shallowest state where the core is totally awake and executing instructions) and go to
C6 (the deepest idle state where a core is powered off). P-states control the desired performance (in
CPU frequency) from a core. P-states are numbered starting from P0 (the highest performance setting
where the core is allowed to use Intel Turbo Boost Technology to increase frequency if possible),
and they go from P1 (the P-state that requests the maximum baseline frequency) to P15 (the lowest
possible frequency).
The following instance types provide the ability for an operating system to control processor C-states
and P-states:
• c4.8xlarge
• d2.8xlarge
• m4.10xlarge
• x1.32xlarge
You might want to change the C-state or P-state settings to increase processor performance
consistency, reduce latency, or tune your instance for a specific workload. The default C-state and Pstate settings provide maximum performance, which is optimal for most workloads. However, if your
application would benefit from reduced latency at the cost of higher single- or dual-core frequencies,
or from consistent performance at lower frequencies as opposed to bursty Turbo Boost frequencies,
consider experimenting with the C-state or P-state settings that are available to these instances.
The following sections describe the different processor state configurations and how to monitor the
effects of your configuration. These procedures were written for, and apply to Amazon Linux; however,
they may also work for other Linux distributions with a Linux kernel version of 3.9 or newer. For more
information about other Linux distributions and processor state control, see your system-specific
documentation.

Note
The examples on this page use the turbostat utility (which is available on Amazon Linux by
default) to display processor frequency and C-state information, and the stress command
(which can be installed by running sudo yum install -y stress) to simulate a workload.
Contents
• Highest Performance with Maximum Turbo Boost Frequency (p. 323)
• High Performance and Low Latency by Limiting Deeper C-states (p. 324)
• Baseline Performance with the Lowest Variability (p. 325)

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Highest Performance with Maximum Turbo Boost
Frequency
This is the default processor state control configuration for the Amazon Linux AMI, and it is
recommended for most workloads. This configuration provides the highest performance with lower
variability. Allowing inactive cores to enter deeper sleep states provides the thermal headroom required
for single or dual core processes to reach their maximum Turbo Boost potential.
The following example shows a c4.8xlarge instance with two cores actively performing work
reaching their maximum processor Turbo Boost frequency.
[ec2-user ~]$ sudo turbostat stress -c 2 -t 10
stress: info: [30680] dispatching hogs: 2 cpu,
stress: info: [30680] successful run completed
pk cor CPU
%c0 GHz TSC SMI
%c1
%c3
%pc6
%pc7 Pkg_W RAM_W PKG_% RAM_%
5.54 3.44 2.90
0
9.18
0.00
0.00
0.00 94.04 32.70 54.18 0.00
0
0
0
0.12 3.26 2.90
0
3.61
0.00
0.00
0.00 48.12 18.88 26.02 0.00
0
0 18
0.12 3.26 2.90
0
3.61
0
1
1
0.12 3.26 2.90
0
4.11
0.00
0
1 19
0.13 3.27 2.90
0
4.11
0
2
2
0.13 3.28 2.90
0
4.45
0.00
0
2 20
0.11 3.27 2.90
0
4.47
0
3
3
0.05 3.42 2.90
0 99.91
0.00
0
3 21 97.84 3.45 2.90
0
2.11
...
1
1 10
0.06 3.33 2.90
0 99.88
0.01
1
1 28 97.61 3.44 2.90
0
2.32
...
10.002556 sec

0 io, 0 vm, 0 hdd
in 10s
%c6
%c7
%pc2

%pc3

85.28

0.00

96.27

0.00

95.77

0.00

95.42

0.00

0.05

0.00

0.06

0.00

In this example, vCPUs 21 and 28 are running at their maximum Turbo Boost frequency because
the other cores have entered the C6 sleep state to save power and provide both power and thermal
headroom for the working cores. vCPUs 3 and 10 (each sharing a processor core with vCPUs 21 and
28) are in the C1 state, waiting for instruction.
In the following example, all 18 cores are actively performing work, so there is no headroom for
maximum Turbo Boost, but they are all running at the "all core Turbo Boost" speed of 3.2 GHz.
[ec2-user ~]$ sudo turbostat stress -c 36 -t 10
stress: info: [30685] dispatching hogs: 36 cpu, 0 io, 0 vm, 0 hdd
stress: info: [30685] successful run completed in 10s
pk cor CPU
%c0 GHz TSC SMI
%c1
%c3
%c6
%c7
%pc2
%pc6
%pc7 Pkg_W RAM_W PKG_% RAM_%
99.27 3.20 2.90
0
0.26
0.00
0.47
0.00
0.00
0.00
0.00 228.59 31.33 199.26 0.00
0
0
0 99.08 3.20 2.90
0
0.27
0.01
0.64
0.00
0.00
0.00
0.00 114.69 18.55 99.32 0.00
0
0 18 98.74 3.20 2.90
0
0.62
0
1
1 99.14 3.20 2.90
0
0.09
0.00
0.76
0.00
0
1 19 98.75 3.20 2.90
0
0.49
0
2
2 99.07 3.20 2.90
0
0.10
0.02
0.81
0.00
0
2 20 98.73 3.20 2.90
0
0.44
0
3
3 99.02 3.20 2.90
0
0.24
0.00
0.74
0.00
0
3 21 99.13 3.20 2.90
0
0.13

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0
0
0
0
0
0
...

4
4
5
5
6
6

4
22
5
23
6
24

99.26
98.68
99.19
98.58
99.01
98.72

3.20
3.20
3.20
3.20
3.20
3.20

2.90
2.90
2.90
2.90
2.90
2.90

0
0
0
0
0
0

0.09
0.67
0.08
0.69
0.11
0.39

0.00

0.65

0.00

0.73

0.00

0.89

0.00

High Performance and Low Latency by Limiting Deeper Cstates
C-states control the sleep levels that a core may enter when it is inactive. You may want to control
C-states to tune your system for latency versus performance. Putting cores to sleep takes time, and
although a sleeping core allows more headroom for another core to boost to a higher frequency, it
takes time for that sleeping core to wake back up and perform work. For example, if a core that is
assigned to handle network packet interrupts is asleep, there may be a delay in servicing that interrupt.
You can configure the system to not use deeper C-states, which reduces the processor reaction
latency, but that in turn also reduces the headroom available to other cores for Turbo Boost.
A common scenario for disabling deeper sleep states is a Redis database application, which stores the
database in system memory for the fastest possible query response time.

To limit deeper sleep states on Amazon Linux
1.

Open the /boot/grub/grub.conf file with your editor of choice.
[ec2-user ~]$ sudo vim /boot/grub/grub.conf

Edit the kernel line of the first entry and add the intel_idle.max_cstate=1 option to set C1
as the deepest C-state for idle cores.
# created by imagebuilder
default=0
timeout=1
hiddenmenu
title Amazon Linux 2014.09 (3.14.26-24.46.amzn1.x86_64)
root (hd0,0)
kernel /boot/vmlinuz-3.14.26-24.46.amzn1.x86_64 root=LABEL=/ console=ttyS0
intel_idle.max_cstate=1
initrd /boot/initramfs-3.14.26-24.46.amzn1.x86_64.img

3.
4.

Save the file and exit your editor.
Reboot your instance to enable the new kernel option.
[ec2-user ~]$ sudo reboot

The following example shows a c4.8xlarge instance with two cores actively performing work at the
"all core Turbo Boost" core frequency.
[ec2-user ~]$
stress: info:
stress: info:
pk cor CPU
%pc6
%pc7

sudo turbostat stress -c 2 -t 10
[5322] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
[5322] successful run completed in 10s
%c0 GHz TSC SMI
%c1
%c3
%c6
%c7
%pc2
Pkg_W RAM_W PKG_% RAM_%

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0.00
0
0
0.00
0
0
0
1
0
1
...
1
1
1
1
1
2
1
2
...

5.56 3.20 2.90
0
0.00 131.90 31.11 199.47
0
0.03 2.08 2.90
0
0.00 67.23 17.11 99.76
18
0.01 1.93 2.90
0
1
0.02 1.96 2.90
0
19 99.70 3.20 2.90
0

94.44
0.00
99.97
0.00
99.99
99.98
0.30

0.00

10
28
11
29

99.98
0.33
99.96
99.98

0.00

0.02
99.67
0.04
0.02

1.97
3.20
2.63
2.11

2.90
2.90
2.90
2.90

0
0
0
0

In this example, the cores for vCPUs 19 and 28 are running at 3.2 GHz, and the other cores are in the
C1 C-state, awaiting instruction. Although the working cores are not reaching their maximum Turbo
Boost frequency, the inactive cores will be much faster to respond to new requests than they would be
in the deeper C6 C-state.

Baseline Performance with the Lowest Variability
You can reduce the variability of processor frequency with P-states. P-states control the desired
performance (in CPU frequency) from a core. Most workloads perform better in P0, which requests
Turbo Boost. But you may want to tune your system for consistent performance rather than bursty
performance that can happen when Turbo Boost frequencies are enabled.
Intel Advanced Vector Extensions (AVX or AVX2) workloads can perform well at lower frequencies,
and AVX instructions can use more power. Running the processor at a lower frequency, by disabling
Turbo Boost, can reduce the amount of power used and keep the speed more consistent. For
more information about optimizing your instance configuration and workload for AVX, see http://
www.intel.com/content/dam/www/public/us/en/documents/white-papers/performance-xeon-e5-v3advanced-vector-extensions-paper.pdf.
This section describes how to limit deeper sleep states and disable Turbo Boost (by requesting the P1
P-state) to provide low-latency and the lowest processor speed variability for these types of workloads.

To limit deeper sleep states and disable Turbo Boost on Amazon Linux
1.

Open the /boot/grub/grub.conf file with your editor of choice.
[ec2-user ~]$ sudo vim /boot/grub/grub.conf

3.
4.

Save the file and exit your editor.
Reboot your instance to enable the new kernel option.

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[ec2-user ~]$ sudo reboot

When you need the low processor speed variability that the P1 P-state provides, execute the
following command to disable Turbo Boost.
[ec2-user ~]$ sudo sh -c "echo 1 > /sys/devices/system/cpu/intel_pstate/
no_turbo"

When your workload is finished, you can re-enable Turbo Boost with the following command.
[ec2-user ~]$ sudo sh -c "echo 0 > /sys/devices/system/cpu/intel_pstate/
no_turbo"

The following example shows a c4.8xlarge instance with two vCPUs actively performing work at the
baseline core frequency, with no Turbo Boost.
[ec2-user ~]$ sudo turbostat stress -c 2 -t 10
stress: info: [5389] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
stress: info: [5389] successful run completed in 10s
pk cor CPU
%c0 GHz TSC SMI
%c1
%c3
%c6
%c7
%pc2
%pc6
%pc7 Pkg_W RAM_W PKG_% RAM_%
5.59 2.90 2.90
0 94.41
0.00
0.00
0.00
0.00
0.00
0.00 128.48 33.54 200.00 0.00
0
0
0
0.04 2.90 2.90
0 99.96
0.00
0.00
0.00
0.00
0.00
0.00 65.33 19.02 100.00 0.00
0
0 18
0.04 2.90 2.90
0 99.96
0
1
1
0.05 2.90 2.90
0 99.95
0.00
0.00
0.00
0
1 19
0.04 2.90 2.90
0 99.96
0
2
2
0.04 2.90 2.90
0 99.96
0.00
0.00
0.00
0
2 20
0.04 2.90 2.90
0 99.96
0
3
3
0.05 2.90 2.90
0 99.95
0.00
0.00
0.00
0
3 21 99.95 2.90 2.90
0
0.05
...
1
1 28 99.92 2.90 2.90
0
0.08
1
2 11
0.06 2.90 2.90
0 99.94
0.00
0.00
0.00
1
2 29
0.05 2.90 2.90
0 99.95

%pc3
0.00
0.00

The cores for vCPUs 21 and 28 are actively performing work at the baseline processor speed of 2.9
GHz, and all inactive cores are also running at the baseline speed in the C1 C-state, ready to accept
instructions.

Setting the Time for Your Linux Instance
A consistent and accurate time reference is crucial for many server tasks and processes. Most system
logs include a time stamp that you can use to determine when problems occur and in what order the
events take place. If you use the AWS CLI or an AWS SDK to make requests from your instance, these
tools sign requests on your behalf. If your instance's date and time are not set correctly, the date in the
signature may not match the date of the request, and AWS rejects the request. Network Time Protocol
(NTP) is configured by default on Amazon Linux instances, and the system time is synchronized
with a load-balanced pool of public servers on the Internet and set to the UTC time zone. For more
information about NTP, go to http://www.ntp.org/.
Tasks
• Changing the Time Zone (p. 327)

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• Configuring Network Time Protocol (NTP) (p. 328)

Important
These procedures are intended for use with Amazon Linux. For more information about other
distributions, see their specific documentation.

Changing the Time Zone
Amazon Linux instances are set to the UTC (Coordinated Universal Time) time zone by default, but
you may wish to change the time on an instance to the local time or to another time zone in your
network.

To change the time zone on an instance
1.

Identify the time zone to use on the instance. The /usr/share/zoneinfo directory contains a
hierarchy of time zone data files. Browse the directory structure at that location to find a file for
your time zone.
[ec2-user ~]$ ls /usr/share/zoneinfo
Africa
Chile
GB
Indian
America
CST6CDT GB-Eire
Iran
Antarctica Cuba
GMT
iso3166.tab
Arctic
EET
GMT0
Israel
...

Mideast
MST
MST7MDT
Navajo

posixrules
PRC
PST8PDT
right

US
UTC
WET
W-SU

Some of the entries at this location are directories (such as America), and these directories
contain time zone files for specific cities. Find your city (or a city in your time zone) to use for
the instance. In this example, you can use the time zone file for Los Angeles, /usr/share/
zoneinfo/America/Los_Angeles.
2.

Update the /etc/sysconfig/clock file with the new time zone.
a.

Open the /etc/sysconfig/clock file with your favorite text editor (such as vim or nano).
You need to use sudo with your editor command because /etc/sysconfig/clock is
owned by root.

Locate the ZONE entry, and change it to the time zone file (omitting the /usr/share/
zoneinfo section of the path). For example, to change to the Los Angeles time zone, change
the ZONE entry to the following.
ZONE="America/Los_Angeles"

Note

Do not change the UTC=true entry to another value. This entry is for the hardware
clock, and does not need to be adjusted when you're setting a different time zone on
your instance.
c. Save the file and exit the text editor.
Create a symbolic link between /etc/localtime and your time zone file so that the instance
finds the time zone file when it references local time information.
[ec2-user ~]$ sudo ln -sf /usr/share/zoneinfo/America/Los_Angeles /etc/
localtime

Reboot the system to pick up the new time zone information in all services and applications.
[ec2-user ~]$ sudo reboot

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Setting the Time

Configuring Network Time Protocol (NTP)
Network Time Protocol (NTP) is configured by default on Amazon Linux instances; however, an
instance needs access to the Internet for the standard NTP configuration to work. In addition, your
instance's security group rules must allow outbound UDP traffic on port 123 (NTP), and your network
ACL rules must allow both inbound and outbound UDP traffic on port 123. The procedures in this
section show how to verify that the default NTP configuration is working correctly. If your instance does
not have access to the Internet, you need to configure NTP to query a different server in your private
network to keep accurate time.

To verify that NTP is working properly
1.

Use the ntpstat command to view the status of the NTP service on the instance.
[ec2-user ~]$ ntpstat

If your output resembles the output below, then NTP is working properly on the instance.
synchronised to NTP server (12.34.56.78) at stratum 3
time correct to within 399 ms
polling server every 64 s

If your output states, "unsynchronised", wait a minute and try again. The first synchronization
may take a minute to complete.
If your output states, "Unable to talk to NTP daemon. Is it running?", you probably
need to start the NTP service and enable it to automatically start at boot time.
2.

(Optional) You can use the ntpq -p command to see a list of peers known to the NTP server and a
summary of their state.
[ec2-user ~]$ ntpq -p
remote
refid
st t when poll reach
delay
offset
jitter
==============================================================================
+lttleman.deekay 204.9.54.119
2 u
15 128 377
88.649
5.946
6.876
-bittorrent.tomh 91.189.94.4
3 u 133 128 377 182.673
8.001
1.278
*ntp3.junkemailf 216.218.254.202 2 u
68 128 377
29.377
4.726
11.887
+tesla.selinc.co 149.20.64.28
2 u
31 128 377
28.586
-1.215
1.435

If the output of this command shows no activity, check whether your security groups, network
ACLs, or firewalls block access to the NTP port.

To start and enable NTP
1.

Start the NTP service with the following command.
[ec2-user ~]$ sudo service ntpd start
Starting ntpd:

Enable NTP to start at boot time with the chkconfig command.
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[ec2-user ~]$ sudo chkconfig ntpd on

Verify that NTP is enabled with the following command.
[ec2-user ~]$ sudo chkconfig --list ntpd
ntpd
0:off 1:off 2:on 3:on 4:on 5:on 6:off

Here ntpd is on in runlevels 2, 3, 4, and 5, which is correct.

To change NTP servers
You may decide not to use the standard NTP servers or you may need to use your own NTP server
within your private network for instances that do not have Internet access.
1.

Open the /etc/ntp.conf file in your favorite text editor (such as vim or nano). You need to use
sudo with the editor command because /etc/ntp.conf is owned by root.

Find the server section, which defines the servers to poll for NTP configuration.
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
server 0.amazon.pool.ntp.org iburst
server 1.amazon.pool.ntp.org iburst
server 2.amazon.pool.ntp.org iburst
server 3.amazon.pool.ntp.org iburst

Note
The n.amazon.pool.ntp.org DNS records are intended to load balance NTP traffic
from AWS. However, these are public NTP servers in the pool.ntp.org project,
and they are not owned or managed by AWS. There is no guarantee that they are
geographically located near your instances, or even within the AWS network. For more
information, see http://www.pool.ntp.org/en/.
3.

Comment out the servers you don't want to use by adding a "#" character to the beginning of those
server definitions.
# Use public servers from the
# Please consider joining the
#server 0.amazon.pool.ntp.org
#server 1.amazon.pool.ntp.org
#server 2.amazon.pool.ntp.org
#server 3.amazon.pool.ntp.org

pool.ntp.org project.
pool (http://www.pool.ntp.org/join.html).
iburst
iburst
iburst
iburst

Add an entry for each server to poll for time synchronization. You can use a DNS name for this
entry or a dotted quad IP address (such as 10.0.0.254).
server my-ntp-server.my-domain.com iburst

Restart the NTP service to pick up the new servers.
[ec2-user ~]$ sudo service ntpd start
Starting ntpd:

Verify that your new settings work and that NTP is functioning.

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Changing the Hostname
[ec2-user ~]$ ntpstat
synchronised to NTP server (64.246.132.14) at stratum 2
time correct to within 99 ms

Changing the Hostname of Your Linux Instance
When you launch an instance, it is assigned a hostname that is a form of the private, internal IP
address. A typical Amazon EC2 private DNS name looks something like this: ip-12-34-56-78.uswest-2.compute.internal, where the name consists of the internal domain, the service (in this
case, compute), the region, and a form of the private IP address. Part of this hostname is displayed
at the shell prompt when you log into your instance (for example, ip-12-34-56-78). Each time you
stop and restart your Amazon EC2 instance (unless you are using an Elastic IP address), the public IP
address changes, and so does your public DNS name, system hostname, and shell prompt. Instances
launched into EC2-Classic also receive a new private IP address, private DNS hostname, and system
hostname when they're stopped and restarted; instances launched into a VPC don't.

Important
These procedures are intended for use with Amazon Linux. For more information about other
distributions, see their specific documentation.

Changing the System Hostname
If you have a public DNS name registered for the IP address of your instance (such as
webserver.mydomain.com), you can set the system hostname so your instance identifies itself as
a part of that domain. This also changes the shell prompt so that it displays the first portion of this
name instead of the hostname supplied by AWS (for example, ip-12-34-56-78). If you do not have a
public DNS name registered, you can still change the hostname, but the process is a little different.

To change the system hostname to a public DNS name
Follow this procedure if you already have a public DNS name registered.
1.

On your instance, open the /etc/sysconfig/network configuration file in your favorite
text editor and change the HOSTNAME entry to reflect the fully qualified domain name (such as
webserver.mydomain.com).
HOSTNAME=webserver.mydomain.com

Reboot the instance to pick up the new hostname.
[ec2-user ~]$ sudo reboot

Log into your instance and verify that the hostname has been updated. Your prompt should show
the new hostname (up to the first ".") and the hostname command should show the fully qualified
domain name.
[ec2-user@webserver ~]$ hostname
webserver.mydomain.com

To change the system hostname without a public DNS name
1.

Open the /etc/sysconfig/network configuration file in your favorite text editor and change the
HOSTNAME entry to reflect the desired system hostname (such as webserver).

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HOSTNAME=webserver.localdomain

Open the /etc/hosts file in your favorite text editor and change the entry beginning with
127.0.0.1 to match the example below, substituting your own hostname.
127.0.0.1 webserver.localdomain webserver localhost localhost.localdomain

Reboot the instance to pick up the new hostname.
[ec2-user ~]$ sudo reboot

Changing the Shell Prompt Without Affecting the
Hostname
If you do not want to modify the hostname for your instance, but you would like to have a more useful
system name (such as webserver) displayed than the private name supplied by AWS (for example,
ip-12-34-56-78), you can edit the shell prompt configuration files to display your system nickname
instead of the hostname.

To change the shell prompt to a host nickname
1.

Create a file in /etc/profile.d that sets the environment variable called NICKNAME to the value
you want in the shell prompt. For example, to set the system nickname to webserver, execute the
following command.
[ec2-user ~]$ sudo sh -c 'echo "export NICKNAME=webserver" > /etc/
profile.d/prompt.sh'

Open the /etc/bashrc file in your favorite text editor (such as vim or nano). You need to use
sudo with the editor command because /etc/bashrc is owned by root.

Edit the file and change the shell prompt variable (PS1) to display your nickname instead of the
hostname. Find the following line that sets the shell prompt in /etc/bashrc (several surrounding
lines are shown below for context; look for the line that starts with [ "$PS1"):
# Turn on checkwinsize
shopt -s checkwinsize
[ "$PS1" = "\\s-\\v\\\$ " ] && PS1="[\u@\h \W]\\$ "
# You might want to have e.g. tty in prompt (e.g. more virtual machines)
# and console windows

And change the \h (the symbol for hostname) in that line to the value of the NICKNAME variable.
# Turn on checkwinsize
shopt -s checkwinsize
[ "$PS1" = "\\s-\\v\\\$ " ] && PS1="[\u@$NICKNAME \W]\\$ "

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Setting Up Dynamic DNS
# You might want to have e.g. tty in prompt (e.g. more virtual machines)
# and console windows

(Optional) To set the title on shell windows to the new nickname, complete the following steps.
a.

Create a file called /etc/sysconfig/bash-prompt-xterm.
[ec2-user ~]$ sudo touch /etc/sysconfig/bash-prompt-xterm

Make the file executable with the following command.
[ec2-user ~]$ sudo chmod +x /etc/sysconfig/bash-prompt-xterm

Open the /etc/sysconfig/bash-prompt-xterm file in your favorite text editor (such as
vim or nano). You need to use sudo with the editor command because /etc/sysconfig/
bash-prompt-xterm is owned by root.

Add the following line to the file.
echo -ne "\033]0;${USER}@${NICKNAME}:${PWD/#$HOME/~}\007"

Log out and then log back in to pick up the new nickname value.

Changing the Hostname on Other Linux Distributions
The above procedures are intended for use with Amazon Linux only. For more information about other
Linux distributions, see their specific documentation and the following articles:
• How do I assign a static hostname to a private Amazon EC2 instance running RHEL 7 or Centos 7?
• How do I assign a static hostname to a private Amazon EC2 instance running SuSe Linux?
• How do I assign a static hostname to a private Amazon EC2 instance running Ubuntu Linux?

Setting Up Dynamic DNS on Your Linux Instance
When you launch an EC2 instance, it is assigned a public IP address and a public DNS (Domain Name
System) name that you can use to reach it from the Internet. Because there are so many hosts in
the Amazon Web Services domain, these public names must be quite long for each name to remain
unique. A typical Amazon EC2 public DNS name looks something like this: ec2-12-34-56-78.uswest-2.compute.amazonaws.com, where the name consists of the Amazon Web Services domain,
the service (in this case, compute), the region, and a form of the public IP address.
Dynamic DNS services provide custom DNS host names within their domain area that can be easy to
remember and that can also be more relevant to your host's use case; some of these services are also
free of charge. You can use a dynamic DNS provider with Amazon EC2 and configure the instance to
update the IP address associated with a public DNS name each time the instance starts. There are
many different providers to choose from, and the specific details of choosing a provider and registering
a name with them are outside the scope of this guide.

Important
These procedures are intended for use with Amazon Linux. For more information about other
distributions, see their specific documentation.

To use dynamic DNS with Amazon EC2
1.

Sign up with a dynamic DNS service provider and register a public DNS name with their service.
This procedure uses the free service from noip.com/free as an example.

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Configure the dynamic DNS update client. After you have a dynamic DNS service provider and
a public DNS name registered with their service, point the DNS name to the IP address for your
instance. Many providers (including noip.com) allow you to do this manually from your account
page on their website, but many also support software update clients. If an update client is running
on your EC2 instance, your dynamic DNS record is updated each time the IP address changes,
as after a shutdown and restart. In this example, you install the noip2 client, which works with the
service provided by noip.com.
a.

Enable the Extra Packages for Enterprise Linux (EPEL) repository to gain access to the
noip2 client.

Note
Amazon Linux instances have the GPG keys and repository information for the EPEL
repository installed by default; however, Red Hat and CentOS instances must first
install the epel-release package before you can enable the EPEL repository. For
more information and to download the latest version of this package, see https://
fedoraproject.org/wiki/EPEL.
[ec2-user ~]$ sudo yum-config-manager --enable epel

Install the noip package.
[ec2-user ~]$ sudo yum install -y noip

Create the noip2 configuration file. Enter the login and password information when prompted
and answer the subsequent questions to configure the client.
[ec2-user ~]$ sudo noip2 -C

Enable the noip service with the chkconfig command.
[ec2-user ~]$ sudo chkconfig noip on

You can verify that the service is enabled with the chkconfig --list command.
[ec2-user ~]$ chkconfig --list noip
noip
0:off 1:off 2:on 3:on 4:on 5:on 6:off

Here, noip is on in runlevels 2, 3, 4, and 5 (which is correct). Now the update client starts at every
boot and updates the public DNS record to point to the IP address of the instance.
4.

Start the noip service.
[ec2-user ~]$ sudo service noip start
Starting noip2:

[

]

This command starts the client, which reads the configuration file (/etc/no-ip2.conf) that you
created earlier and updates the IP address for the public DNS name that you chose.
5.

Verify that the update client has set the correct IP address for your dynamic DNS name. Allow a
few minutes for the DNS records to update, and then try to connect to your instance using SSH
with the public DNS name that you configured in this procedure.

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Running Commands at Launch

Running Commands on Your Linux Instance at
Launch
When you launch an instance in Amazon EC2, you have the option of passing user data to the
instance that can be used to perform common automated configuration tasks and even run scripts after
the instance starts. You can pass two types of user data to Amazon EC2: shell scripts and cloudinit directives. You can also pass this data into the launch wizard as plain text, as a file (this is useful
for launching instances via the command line tools), or as base64-encoded text (for API calls).
If you are interested in more complex automation scenarios, consider using AWS CloudFormation
and AWS OpsWorks. For more information, see the AWS CloudFormation User Guide and the AWS
OpsWorks User Guide.
For information about running commands on your Windows instance at launch, see Executing User
Data and Managing Windows Instance Configuration in the Amazon EC2 User Guide for Windows
Instances.
In the following examples, the commands from the Installing a LAMP Web Server tutorial (p. 33)
are converted to a shell script and a set of cloud-init directives that executes when the instance
launches. In each example, the following tasks are executed by the user data:
• The distribution software packages are updated.
• The necessary web server, php, and mysql packages are installed.
• The httpd service is started and turned on via chkconfig.
• The www group is added, and the ec2-user is added to that group.
• The appropriate ownership and file permissions are set for the web directory and the files contained
within it.
• A simple web page is created to test the web server and php engine.
Contents
• Prerequisites (p. 334)
• User Data and Shell Scripts (p. 334)
• User Data and cloud-init Directives (p. 336)
• API and CLI Overview (p. 337)

Prerequisites
The following examples assume that your instance has a public DNS name that is reachable from the
Internet. For more information, see Step 1: Launch an Instance (p. 27). You must also configure your
security group to allow SSH (port 22), HTTP (port 80), and HTTPS (port 443) connections. For more
information about these prerequisites, see Setting Up with Amazon EC2 (p. 19).
Also, these instructions are intended for use with Amazon Linux, and the commands and directives
may not work for other Linux distributions. For more information about other distributions, such as their
support for cloud-init, see their specific documentation.

User Data and Shell Scripts
If you are familiar with shell scripting, this is the easiest and most complete way to send instructions to
an instance at launch, and the cloud-init output log file (/var/log/cloud-init-output.log)
captures console output so it is easy to debug your scripts following a launch if the instance does not
behave the way you intended.

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Important
User data scripts and cloud-init directives only run during the first boot cycle when an
instance is launched.
User data shell scripts must start with the #! characters and the path to the interpreter you want
to read the script (commonly /bin/bash). For a great introduction on shell scripting, see the BASH
Programming HOW-TO at the Linux Documentation Project (tldp.org).
Scripts entered as user data are executed as the root user, so do not use the sudo command in the
script. Remember that any files you create will be owned by root; if you need non-root users to have
file access, you should modify the permissions accordingly in the script. Also, because the script is
not run interactively, you cannot include commands that require user feedback (such as yum update
without the -y flag).
Adding these tasks at boot time adds to the amount of time it takes to boot the instance. You should
allow a few minutes of extra time for the tasks to complete before you test that the user script has
finished successfully.

To pass a shell script to an instance with user data
1.

Follow the procedure for launching an instance at Launching Your Instance from an AMI (p. 279),
but when you get to Step 6 (p. 281), paste the user data script text into the User data field and
then complete the launch procedure. For the example below, the script creates and configures our
web server.
#!/bin/bash
yum update -y
yum install -y httpd24 php56 mysql55-server php56-mysqlnd
service httpd start
chkconfig httpd on
groupadd www
usermod -a -G www ec2-user
chown -R root:www /var/www
chmod 2775 /var/www
find /var/www -type d -exec chmod 2775 {} +
find /var/www -type f -exec chmod 0664 {} +
echo "" > /var/www/html/phpinfo.php

Allow enough time for the instance to launch and execute the commands in your script, and then
check to see that your script has completed the tasks that you intended. For our example, in a web
browser, enter the URL of the PHP test file the script created. This URL is the public DNS address
of your instance followed by a forward slash and the file name.
http://my.public.dns.amazonaws.com/phpinfo.php

You should see the PHP information page.

Tip
If you are unable to see the PHP information page, check that the security group you are
using contains a rule to allow HTTP (port 80) traffic. For information about adding an HTTP
rule to your security group, see Adding Rules to a Security Group (p. 495).
3.

(Optional) If your script did not accomplish the tasks you were expecting it to, or if you just want to
verify that your script completed without errors, examine the cloud-init output log file at /var/
log/cloud-init-output.log and look for error messages in the output.
For additional debugging information, you can create a Mime multipart archive that includes a
cloud-init data section with the following directive:
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output : { all : '| tee -a /var/log/cloud-init-output.log' }

This directive sends command output from your script to /var/log/cloud-init-output.log.
For more information on cloud-init data formats and creating Mime multi part archive, see
cloud-init Formats.

User Data and cloud-init Directives
The cloud-init package configures specific aspects of a new Amazon Linux instance when it is
launched; most notably, it configures the .ssh/authorized_keys file for the ec2-user so you can
log in with your own private key.
The cloud-init user directives can be passed to an instance at launch the same way that a script
is passed, although the syntax is different. For more information about cloud-init, go to http://
cloudinit.readthedocs.org/en/latest/index.html.

Important
User data scripts and cloud-init directives only run during the first boot cycle when an
instance is launched.
The Amazon Linux version of cloud-init does not support all of the directives that are available in
the base package, and some of the directives have been renamed (such as repo_update instead of
apt-upgrade).
Adding these tasks at boot time adds to the amount of time it takes to boot an instance. You should
allow a few minutes of extra time for the tasks to complete before you test that your user data
directives have completed.

To pass cloud-init directives to an instance with user data
1.

Follow the procedure for launching an instance at Launching Your Instance from an AMI (p. 279),
but when you get to Step 6 (p. 281), paste your cloud-init directive text into the User data
field and then complete the launch procedure. For the example below, the directives create and
configure a web server.
#cloud-config
repo_update: true
repo_upgrade: all
packages:
- httpd24
- php56
- mysql55
- server
- php56-mysqlnd
runcmd:
- service httpd start
- chkconfig httpd on
- groupadd www
- [ sh, -c, "usermod -a -G www ec2-user" ]
- [ sh, -c, "chown -R root:www /var/www" ]
- chmod 2775 /var/www
- [ find, /var/www, -type, d, -exec, chmod, 2775, {}, + ]
- [ find, /var/www, -type, f, -exec, chmod, 0664, {}, + ]
- [ sh, -c, 'echo "" > /var/www/html/phpinfo.php' ]

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Allow enough time for the instance to launch and execute the directives in your user data, and
then check to see that your directives have completed the tasks you intended. For our example,
in a web browser, enter the URL of the PHP test file the directives created. This URL is the public
DNS address of your instance followed by a forward slash and the file name.
http://my.public.dns.amazonaws.com/phpinfo.php

You should see the PHP information page.

(Optional) If your directives did not accomplish the tasks you were expecting them to, or if you
just want to verify that your directives completed without errors, examine the cloud-init output
log file at /var/log/cloud-init-output.log and look for error messages in the output. For
additional debugging information, you can add the following line to your directives:
output : { all : '| tee -a /var/log/cloud-init-output.log' }

This directive sends runcmd output to /var/log/cloud-init-output.log.

API and CLI Overview
You can pass user data to your instance during launch using one of the following commands. For more
information about these command line interfaces, see Accessing Amazon EC2 (p. 3).
• AWS CLI: Use the --user-data parameter with the run-instances command.
• AWS Tools for Windows PowerShell: Use the -UserData parameter with the New-EC2Instance
command.
• Amazon EC2 Query API: Use the UserData parameter with the RunInstances command.

Instance Metadata and User Data
Instance metadata is data about your instance that you can use to configure or manage the running
instance. Instance metadata is divided into categories. For more information, see Instance Metadata
Categories (p. 344).
EC2 instances can also include dynamic data, such as an instance identity document that is generated
when the instance is launched. For more information, see Dynamic Data Categories (p. 348).
You can also access the user data that you supplied when launching your instance. For example, you
can specify parameters for configuring your instance, or attach a simple script. You can also use this
data to build more generic AMIs that can be modified by configuration files supplied at launch time.
For example, if you run web servers for various small businesses, they can all use the same AMI and
retrieve their content from the Amazon S3 bucket you specify in the user data at launch. To add a new
customer at any time, simply create a bucket for the customer, add their content, and launch your AMI.
If you launch more than one instance at the same time, the user data is available to all instances in that
reservation.

Important
Although you can only access instance metadata and user data from within the instance itself,
the data is not protected by cryptographic methods. Anyone who can access the instance can
view its metadata. Therefore, you should take suitable precautions to protect sensitive data

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(such as long-lived encryption keys). You should not store sensitive data, such as passwords,
as user data.
Contents
• Retrieving Instance Metadata (p. 338)
• Configuring Instances with User Data (p. 340)
• Retrieving User Data (p. 341)
• Retrieving Dynamic Data (p. 341)
• Example: AMI Launch Index Value (p. 342)
• Instance Metadata Categories (p. 344)
• Instance Identity Documents (p. 349)

Retrieving Instance Metadata
Because your instance metadata is available from your running instance, you do not need to use the
Amazon EC2 console or the AWS CLI. This can be helpful when you're writing scripts to run from your
instance. For example, you can access the local IP address of your instance from instance metadata to
manage a connection to an external application.
To view all categories of instance metadata from within a running instance, use the following URI:
http://169.254.169.254/latest/meta-data/

Note that you are not billed for HTTP requests used to retrieve instance metadata and user data.
You can use a tool such as cURL, or if your instance supports it, the GET command; for example:
$ curl http://169.254.169.254/latest/meta-data/

$ GET http://169.254.169.254/latest/meta-data/

You can also download the Instance Metadata Query tool, which allows you to query the instance
metadata without having to type out the full URI or category names:
http://aws.amazon.com/code/1825
All metadata is returned as text (content type text/plain). A request for a specific metadata resource
returns the appropriate value, or a 404 - Not Found HTTP error code if the resource is not available.
A request for a general metadata resource (the URI ends with a /) returns a list of available resources,
or a 404 - Not Found HTTP error code if there is no such resource. The list items are on separate
lines, terminated by line feeds (ASCII 10).

Examples of Retrieving Instance Metadata
This example gets the available versions of the instance metadata. These versions do not necessarily
correlate with an Amazon EC2 API version. The earlier versions are available to you in case you have
scripts that rely on the structure and information present in a previous version.
$ curl http://169.254.169.254/
1.0
2007-01-19
2007-03-01
2007-08-29
2007-10-10

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2007-12-15
2008-02-01
2008-09-01
2009-04-04
2011-01-01
2011-05-01
2012-01-12
2014-02-25
latest

This example gets the top-level metadata items. Some items are only available for instances in a VPC.
For more information about each of these items, see Instance Metadata Categories (p. 344).
$ curl http://169.254.169.254/latest/meta-data/
ami-id
ami-launch-index
ami-manifest-path
block-device-mapping/
hostname
instance-action
instance-id
instance-type
kernel-id
local-hostname
local-ipv4
mac
network/
placement/
public-hostname
public-ipv4
public-keys/
reservation-id
security-groups
services/

These examples get the value of some of the metadata items from the preceding example.
$ curl http://169.254.169.254/latest/meta-data/ami-id
ami-12345678

$ curl http://169.254.169.254/latest/meta-data/reservation-id
r-fea54097

$ curl http://169.254.169.254/latest/meta-data/local-hostname
ip-10-251-50-12.ec2.internal

$ curl http://169.254.169.254/latest/meta-data/public-hostname
ec2-203-0-113-25.compute-1.amazonaws.com

This example gets the list of available public keys.
$ curl http://169.254.169.254/latest/meta-data/public-keys/
0=my-public-key

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This example shows the formats in which public key 0 is available.
$ curl http://169.254.169.254/latest/meta-data/public-keys/0/
openssh-key

This example gets public key 0 (in the OpenSSH key format).
$ curl http://169.254.169.254/latest/meta-data/public-keys/0/openssh-key
ssh-rsa MIICiTCCAfICCQD6m7oRw0uXOjANBgkqhkiG9w0BAQUFADCBiDELMAkGA1UEBhMC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 my-public-key

This example shows the information available for a specific network interface (indicated by the MAC
address) on an NAT instance in the EC2-Classic platform.
$ curl http://169.254.169.254/latest/meta-data/network/interfaces/
macs/02:29:96:8f:6a:2d/
device-number
local-hostname
local-ipv4s
mac
owner-id
public-hostname
public-ipv4s

This example gets the subnet ID for an instance launched into a VPC.
$ curl http://169.254.169.254/latest/meta-data/network/interfaces/
macs/02:29:96:8f:6a:2d/subnet-id
subnet-be9b61d7

Configuring Instances with User Data
When you specify user data, note the following:
• User data is treated as opaque data: what you give is what you get back. It is up to the instance to
be able to interpret it.
• User data is limited to 16 KB. This limit applies to the data in raw form, not base64-encoded form.
• User data must be base64-encoded before being submitted to the API. The EC2 command line tools
perform the base64 encoding for you. The data is decoded before being presented to the instance.
For more information about base64 encoding, see http://tools.ietf.org/html/rfc4648.
• User data is executed only at launch. If you stop an instance, modify the user data, and start the
instance, the new user data is not executed automatically.

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To specify user data when you launch an instance
You can specify user data when you launch an instance. For more information, see Launching
an Instance (p. 279), cloud-init (p. 145), and Running Commands on Your Linux Instance at
Launch (p. 334).

Modify User Data for a Running Instance
You can modify user data for an instance that previously had user data assigned and is currently
running. The new user data is available on your instance after you reboot it.

To modify the user data for an Amazon EBS-backed instance
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.

In the navigation pane, choose Instances, and select the instance.
Click Actions, select Instance State, and then choose Stop.

In the confirmation dialog box, click Yes, Stop. It can take a few minutes for the instance to stop.
With the instance still selected, choose Actions, select Instance Settings, and then choose View/
Change User Data. Note that you can't change the user data if the instance is running, but you
can view it.
In the View/Change User Data dialog box, update the user data, and then choose Save.

Retrieving User Data
To retrieve user data, use the following URI:
http://169.254.169.254/latest/user-data

Requests for user data returns the data as it is (content type application/x-octetstream).
This shows an example of returning comma-separated user data.
$ curl http://169.254.169.254/latest/user-data
1234,john,reboot,true | 4512,richard, | 173,,,

This shows an example of returning line-separated user data.
$ curl http://169.254.169.254/latest/user-data
[general]
instances: 4
[instance-0]
s3-bucket:
[instance-1]
reboot-on-error: yes

Retrieving Dynamic Data
To retrieve dynamic data from within a running instance, use the following URI:

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http://169.254.169.254/latest/dynamic/

This example shows how to retrieve the high-level instance identity categories:
$ curl http://169.254.169.254/latest/dynamic/instance-identity/
pkcs7
signature
document

For more information about dynamic data and examples of how to retrieve it, see Instance Identity
Documents (p. 349).

Example: AMI Launch Index Value
This example demonstrates how you can use both user data and instance metadata to configure your
instances.
Alice wants to launch four instances of her favorite database AMI, with the first acting as master and
the remaining three acting as replicas. When she launches them, she wants to add user data about the
replication strategy for each replicant. She is aware that this data will be available to all four instances,
so she needs to structure the user data in a way that allows each instance to recognize which parts are
applicable to it. She can do this using the ami-launch-index instance metadata value, which will be
unique for each instance.
Here is the user data that Alice has constructed:
replicate-every=1min | replicate-every=5min | replicate-every=10min

The replicate-every=1min data defines the first replicant's configuration, replicateevery=5min defines the second replicant's configuration, and so on. Alice decides to provide this data
as an ASCII string with a pipe symbol (|) delimiting the data for the separate instances.
Alice launches four instances using the run-instances command, specifying the user data:
aws ec2 run-instances --image-id ami-12345678 --count 4 --instance-type
t2.micro --user-data "replicate-every=1min | replicate-every=5min |
replicate-every=10min"

After they're launched, all instances have a copy of the user data and the common metadata shown
here:
• AMI id: ami-12345678
• Reservation ID: r-1234567890abcabc0
• Public keys: none
• Security group name: default
• Instance type: t2.micro
However, each instance has certain unique metadata.
Instance 1
Metadata

Value

instance-id

i-1234567890abcdef0

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Metadata

Value

ami-launch-index

public-hostname

ec2-203-0-113-25.compute-1.amazonaws.com

public-ipv4

67.202.51.223

local-hostname

ip-10-251-50-12.ec2.internal

local-ipv4

10.251.50.35

Instance 2
Metadata

Value

instance-id

i-0598c7d356eba48d7

ami-launch-index

public-hostname

ec2-67-202-51-224.compute-1.amazonaws.com

public-ipv4

67.202.51.224

local-hostname

ip-10-251-50-36.ec2.internal

local-ipv4

10.251.50.36

Instance 3
Metadata

Value

instance-id

i-0ee992212549ce0e7

ami-launch-index

public-hostname

ec2-67-202-51-225.compute-1.amazonaws.com

public-ipv4

67.202.51.225

local-hostname

ip-10-251-50-37.ec2.internal

local-ipv4

10.251.50.37

Instance 4
Metadata

Value

instance-id

i-1234567890abcdef0

ami-launch-index

public-hostname

ec2-67-202-51-226.compute-1.amazonaws.com

public-ipv4

67.202.51.226

local-hostname

ip-10-251-50-38.ec2.internal

local-ipv4

10.251.50.38

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Alice can use the ami-launch-index value to determine which portion of the user data is applicable to a
particular instance.
1. She connects to one of the instances, and retrieves the ami-launch-index for that instance to ensure
it is one of the replicants:
$ curl http://169.254.169.254/latest/meta-data/ami-launch-index
2

2. She saves the ami-launch-index as a variable:
$ ami_launch_index=`curl http://169.254.169.254/latest/meta-data/amilaunch-index`

3. She saves the user data as a variable:
$ user_data=`curl http://169.254.169.254/latest/user-data/`

4. Finally, Alice uses the cut command to extract the portion of the user data that is applicable to that
instance:
$ echo $user_data | cut -d"|" -f"$ami_launch_index"
replicate-every=5min

Instance Metadata Categories
The following table lists the categories of instance metadata.
Data

Description

Version Introduced

ami-id

The AMI ID used to launch the
instance.

1.0

ami-launch-index

If you started more than one
instance at the same time, this value
indicates the order in which the
instance was launched. The value of
the first instance launched is 0.

1.0

ami-manifest-path

The path to the AMI manifest file in
Amazon S3. If you used an Amazon
EBS-backed AMI to launch the
instance, the returned result is
unknown.

1.0

ancestor-ami-ids

The AMI IDs of any instances
that were rebundled to create this
AMI. This value will only exist if
the AMI manifest file contained an
ancestor-amis key.

2007-10-10

block-device-mapping/ami

The virtual device that contains the
root/boot file system.

2007-12-15

block-device-mapping/ebs
N

The virtual devices associated with
Amazon EBS volumes, if any are
present. Amazon EBS volumes

2007-12-15

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Data

Description

Version Introduced

are only available in metadata if
they were present at launch time or
when the instance was last started.
The N indicates the index of the
Amazon EBS volume (such as ebs1
or ebs2).
block-device-mapping/eph
emeral
N

The virtual devices associated
with ephemeral devices, if any are
present. The N indicates the index of
the ephemeral volume.

2007-12-15

block-device-mapping/root

The virtual devices or partitions
associated with the root devices,
or partitions on the virtual device,
where the root (/ or C:) file system is
associated with the given instance.

2007-12-15

block-device-mapping/swap

The virtual devices associated with
swap. Not always present.

2007-12-15

hostname

The private hostname of the
instance. In cases where multiple
network interfaces are present, this
refers to the eth0 device (the device
for which the device number is 0).

1.0

iam/info

If there is an IAM role associated
with the instance at launch, contains
information about the last time
the instance profile was updated,
including the instance's LastUpdated
date, InstanceProfileArn, and
InstanceProfileId. Otherwise, not
present.

2012-01-12

iam/security-credentials/
role-name

If there is an IAM role associated
with the instance at launch, rolename is the name of the role, and
role-name contains the temporary
security credentials associated with
the role (for more information, see
Retrieving Security Credentials
from Instance Metadata (p. 537)).
Otherwise, not present.

2012-01-12

instance-action

Notifies the instance that it should
reboot in preparation for bundling.
Valid values: none | shutdown |
bundle-pending.

2008-09-01

instance-id

The ID of this instance.

1.0

instance-type

The type of instance. For more
information, see Instance
Types (p. 156).

2007-08-29

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Data

Description

Version Introduced

kernel-id

The ID of the kernel launched with
this instance, if applicable.

2008-02-01

local-hostname

The private DNS hostname of the
instance. In cases where multiple
network interfaces are present, this
refers to the eth0 device (the device
for which the device number is 0).

2007-01-19

local-ipv4

The private IP address of the
instance. In cases where multiple
network interfaces are present, this
refers to the eth0 device (the device
for which the device number is 0).

1.0

mac

The instance's media access control
(MAC) address. In cases where
multiple network interfaces are
present, this refers to the eth0
device (the device for which the
device number is 0).

2011-01-01

network/interfaces/macs/
mac/device-number

The unique device number
associated with that interface. The
device number corresponds to
the device name; for example, a
device-number of 2 is for the eth2
device. This category corresponds
to the DeviceIndex and deviceindex fields that are used by the
Amazon EC2 API and the EC2
commands for the AWS CLI.

2011-01-01

network/interfaces/macs/
mac/ipv4-associations/pu
blic-ip

The private IPv4 addresses that
are associated with each publicip address and assigned to that
interface.

2011-01-01

network/interfaces/macs/
mac/local-hostname

The interface's local hostname.

2011-01-01

network/interfaces/macs/
mac/local-ipv4s

The private IP addresses associated
with the interface.

2011-01-01

network/interfaces/macs/
mac/mac

The instance's MAC address.

2011-01-01

network/interfaces/macs/
mac/owner-id

The ID of the owner of the network
interface. In multiple-interface
environments, an interface can be
attached by a third party, such as
Elastic Load Balancing. Traffic on
an interface is always billed to the
interface owner.

2011-01-01

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Data

Description

Version Introduced

network/interfaces/macs/
mac/public-hostname

The interface's public DNS. If
the instance is in a VPC, this
category is only returned if the
enableDnsHostnames attribute is
set to true. For more information,
see Using DNS with Your VPC.

2011-01-01

network/interfaces/macs/
mac/public-ipv4s

The Elastic IP addresses associated
with the interface. There may
be multiple IP addresses on an
instance.

2011-01-01

network/interfaces/macs/
mac/security-groups

Security groups to which the network
interface belongs. Returned only for
instances launched into a VPC.

2011-01-01

network/interfaces/macs/
mac/security-group-ids

IDs of the security groups to which
the network interface belongs.
Returned only for instances
launched into a VPC. For more
information on security groups in
the EC2-VPC platform, see Security
Groups for Your VPC.

2011-01-01

network/interfaces/macs/
mac/subnet-id

The ID of the subnet in which the
interface resides. Returned only for
instances launched into a VPC.

2011-01-01

network/interfaces/macs/
mac/subnet-ipv4-cidr-block

The CIDR block of the subnet
in which the interface resides.
Returned only for instances
launched into a VPC.

2011-01-01

network/interfaces/macs/
mac/vpc-id

The ID of the VPC in which the
interface resides. Returned only for
instances launched into a VPC.

2011-01-01

network/interfaces/macs/
mac/vpc-ipv4-cidr-block

The CIDR block of the VPC in which
the interface resides. Returned only
for instances launched into a VPC.

2011-01-01

placement/availability-z
one

The Availability Zone in which the
instance launched.

2008-02-01

product-codes

Product codes associated with the
instance, if any.

2007-03-01

public-hostname

The instance's public DNS. If
the instance is in a VPC, this
category is only returned if the
enableDnsHostnames attribute is
set to true. For more information,
see Using DNS with Your VPC.

2007-01-19

public-ipv4

The public IP address. If an Elastic
IP address is associated with the
instance, the value returned is the
Elastic IP address.

2007-01-19

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Data

Description

Version Introduced

public-keys/0/openssh-key

Public key. Only available if supplied
at instance launch time.

1.0

ramdisk-id

The ID of the RAM disk specified at
launch time, if applicable.

2007-10-10

reservation-id

The ID of the reservation.

1.0

security-groups

The names of the security groups
applied to the instance.
After launch, you can only change
the security groups of instances
running in a VPC. Such changes
are reflected here and in network/
interfaces/macs/mac/securitygroups.

1.0

services/domain

The domain for AWS resources
for the region; for example,
amazonaws.com for us-east-1.

2014-02-25

services/partition

The partition that the resource is
in. For standard AWS regions,
the partition is aws. If you have
resources in other partitions, the
partition is aws-partitionname.
For example, the partition for
resources in the China (Beijing)
region is aws-cn.

2015-10-20

spot/termination-time

The approximate time, in UTC, that
the operating system for your Spot
instance will receive the shutdown
signal. This item is present and
contains a time value (for example,
2015-01-05T18:02:00Z) only if the
Spot instance has been marked for
termination by Amazon EC2. The
termination-time item is not set to
a time if you terminated the Spot
instance yourself.

2014-11-05

Dynamic Data Categories
The following table lists the categories of dynamic data.
Data

Description

Version
introduced

fws/instancemonitoring

Value showing whether the customer has enabled
detailed one-minute monitoring in CloudWatch. Valid
values: enabled | disabled

2009-04-04

instance-identity/
document

JSON containing instance attributes, such as instanceid, private IP address, etc. See Instance Identity
Documents (p. 349).

2009-04-04

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Description

Version
introduced

instance-identity/
pkcs7

Used to verify the document's authenticity and
content against the signature. See Instance Identity
Documents (p. 349).

2009-04-04

instance-identity/
signature

Data that can be used by other parties to verify
its origin and authenticity. See Instance Identity
Documents (p. 349).

2009-04-04

Instance Identity Documents
An instance identity document is a JSON file that describes an instance. The instance identity
document is accompanied by a signature and a PKCS7 signature which can be used to verify the
accuracy, origin, and authenticity of the information provided in the document. For example, you may
have downloaded free software with paid updates.
The instance identity document is generated when the instance is launched, and exposed to the
instance through instance metadata (p. 337). It validates the attributes of the instances, such as the
subscribed software, instance size, instance type, operating system, and AMI.

Important
Due to the dynamic nature of instance identity documents and signatures, we recommend
retrieving the instance identity document and signature regularly.

Obtaining the Instance Identity Document and Signatures
To retrieve the instance identity document, use the following URL from your running instance:
http://169.254.169.254/latest/dynamic/instance-identity/document
{
"devpayProductCodes" : null,
"availabilityZone" : "us-east-1d",
"privateIp" : "10.158.112.84",
"version" : "2010-08-31",
"region" : "us-east-1",
"instanceId" : "i-1234567890abcdef0",
"billingProducts" : null,
"instanceType" : "t1.micro",
"accountId" : "123456789012",
"pendingTime" : "2015-11-19T16:32:11Z",
"imageId" : "ami-5fb8c835",
"kernelId" : "aki-919dcaf8",
"ramdiskId" : null,
"architecture" : "x86_64"
}

To retrieve the instance identity signature, use the following URL from your running instance:
http://169.254.169.254/latest/dynamic/instance-identity/signature
dExamplesjNQhhJan7pORLpLSr7lJEF4V2DhKGlyoYVBoUYrY9njyBCmhEayaGrhtS/AWY+LPx
lVSQURF5n0gwPNCuO6ICT0fNrm5IH7w9ydyaexamplejJw8XvWPxbuRkcN0TAA1p4RtCAqm4ms

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x2oALjWSCBExample=

To retrieve the PKCS7 signature, use the following URL from your running instance:
http://169.254.169.254/latest/dynamic/instance-identity/pkcs7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Example: Verifying the PKCS7 Signature
You can use the PKCS7 signature to verify your instance by validating it against the AWS public
certificate for the region.
The AWS public certificate for the US East (N. Virginia), US West (Oregon), US West (N. California),
EU (Ireland), EU (Frankfurt), Asia Pacific (Tokyo), Asia Pacific (Seoul), Asia Pacific (Singapore), Asia
Pacific (Sydney), Asia Pacific (Mumbai), and South America (São Paulo) regions is as follows:
-----BEGIN CERTIFICATE----MIIC7TCCAq0CCQCWukjZ5V4aZzAJBgcqhkjOOAQDMFwxCzAJBgNVBAYTAlVTMRkw
FwYDVQQIExBXYXNoaW5ndG9uIFN0YXRlMRAwDgYDVQQHEwdTZWF0dGxlMSAwHgYD
VQQKExdBbWF6b24gV2ViIFNlcnZpY2VzIExMQzAeFw0xMjAxMDUxMjU2MTJaFw0z
ODAxMDUxMjU2MTJaMFwxCzAJBgNVBAYTAlVTMRkwFwYDVQQIExBXYXNoaW5ndG9u
IFN0YXRlMRAwDgYDVQQHEwdTZWF0dGxlMSAwHgYDVQQKExdBbWF6b24gV2ViIFNl
cnZpY2VzIExMQzCCAbcwggEsBgcqhkjOOAQBMIIBHwKBgQCjkvcS2bb1VQ4yt/5e
ih5OO6kK/n1Lzllr7D8ZwtQP8fOEpp5E2ng+D6Ud1Z1gYipr58Kj3nssSNpI6bX3
VyIQzK7wLclnd/YozqNNmgIyZecN7EglK9ITHJLP+x8FtUpt3QbyYXJdmVMegN6P
hviYt5JH/nYl4hh3Pa1HJdskgQIVALVJ3ER11+Ko4tP6nwvHwh6+ERYRAoGBAI1j
k+tkqMVHuAFcvAGKocTgsjJem6/5qomzJuKDmbJNu9Qxw3rAotXau8Qe+MBcJl/U
hhy1KHVpCGl9fueQ2s6IL0CaO/buycU1CiYQk40KNHCcHfNiZbdlx1E9rpUp7bnF
lRa2v1ntMX3caRVDdbtPEWmdxSCYsYFDk4mZrOLBA4GEAAKBgEbmeve5f8LIE/Gf
MNmP9CM5eovQOGx5ho8WqD+aTebs+k2tn92BBPqeZqpWRa5P/+jrdKml1qx4llHW
MXrs3IgIb6+hUIB+S8dz8/mmO0bpr76RoZVCXYab2CZedFut7qc3WUH9+EUAH5mw
vSeDCOUMYQR7R9LINYwouHIziqQYMAkGByqGSM44BAMDLwAwLAIUWXBlk40xTwSw
7HX32MxXYruse9ACFBNGmdX2ZBrVNGrN9N2f6ROk0k9K
-----END CERTIFICATE-----

The AWS public certificate for the AWS GovCloud (US) region is as follows:
-----BEGIN CERTIFICATE----MIIC7TCCAq0CCQCWukjZ5V4aZzAJBgcqhkjOOAQDMFwxCzAJBgNVBAYTAlVTMRkw
FwYDVQQIExBXYXNoaW5ndG9uIFN0YXRlMRAwDgYDVQQHEwdTZWF0dGxlMSAwHgYD
VQQKExdBbWF6b24gV2ViIFNlcnZpY2VzIExMQzAeFw0xMjAxMDUxMjU2MTJaFw0z
ODAxMDUxMjU2MTJaMFwxCzAJBgNVBAYTAlVTMRkwFwYDVQQIExBXYXNoaW5ndG9u

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IFN0YXRlMRAwDgYDVQQHEwdTZWF0dGxlMSAwHgYDVQQKExdBbWF6b24gV2ViIFNl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-----END CERTIFICATE-----

For more information about AWS GovCloud (US), see the AWS GovCloud (US) User Guide.
For other regions, contact AWS Support to get the AWS public certificate.

To verify the PKCS7 signature
1.

From your Amazon Linux instance, create a temporary file for the PKCS7 signature:
PKCS7=$(mktemp)

Populate the file with the -----BEGIN PKCS7----- header, then append the contents of the
PKCS7 signature from the instance metadata, a new line, and the -----END PKCS7----- footer:
echo "-----BEGIN PKCS7-----" > $PKCS7

curl -s http://169.254.169.254/latest/dynamic/instance-identity/pkcs7 >>
$PKCS7

echo "" >> $PKCS7

echo "-----END PKCS7-----" >> $PKCS7

Create a temporary file for the instance identity document, and populate it with the contents of the
document from your instance metadata:
DOCUMENT=$(mktemp)

curl -s http://169.254.169.254/latest/dynamic/instance-identity/document >
$DOCUMENT

Open a text editor and create a file called AWSpubkey. Copy and paste the contents of the AWS
public certificate above to the file and save it.

Use the OpenSSL tools to verify the signature as follows:
openssl smime -verify -in $PKCS7 -inform PEM -content $DOCUMENT -certfile
AWSpubkey -noverify > /dev/null
Verification successful

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Remotely Manage Your Instances

Remotely Manage Your Instances
You can use Amazon Elastic Compute Cloud (Amazon EC2) Run Command to remotely manage the
configuration of your Amazon EC2 instances, virtual machines (VMs), or servers in your on-premises
environment or in an environment provided by other cloud providers. Using scripts, commands, or
the Amazon EC2 console, Run Command enables you to perform common administrative tasks and
manage configuration changes across a fleet without having to log on locally to each instance, server,
or VM.

Note
For information about Run Command for Windows, see Amazon EC2 Run Command in the
Amazon EC2 User Guide for Windows Instances.
How To Get Started
The following table includes information to help you get started with Run Command.

Topic

Details

Tutorial: Execute a Command Using Run
Command (p. 64)

The tutorial shows you how to quickly send
a command using Run Command with AWS
Command Line Interface (AWS CLI).

Run Command Components and
Concepts (p. 352)

Learn about Run Command features and
concepts.

Run Command Prerequisites (p. 355)

Verify that your instances meet the minimum
requirements for Run Command.

Setting Up Managed Instances (p. 371)

Register on-premises servers, VMs, or servers
hosted by other cloud providers with AWS. After
a server or VM has been registered, it is called a
managed instance.

Run Command Walkthroughs (p. 387)

Learn from these detailed walkthroughs how to
execute commands using Run Command from
either the Amazon EC2 console or the AWS CLI.

Related Content
• Amazon EC2 Simple Systems Manager API Reference
• SSM AWS Tools for Windows PowerShell Reference
• SSM AWS CLI Reference
• AWS SDKs

Amazon EC2 Run Command Components and
Concepts
As you get started with Amazon EC2 Run Command, you'll benefit from understanding the
components and concepts of this feature.

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Components and Concepts

Component/Concept

Details

Amazon EC2 Simple Systems Manager (SSM)

Run Command is a component of SSM.
Run Command uses the SSM API. For more
information, see Amazon EC2 Simple Systems
Manager API Reference.

Managed Instances

A managed instance is an on-premises server
or virtual machine (VM) hosted in your data
center, or a VM hosted by other cloud providers,
that is configured for Run Command. For
more information about managed instances,
see Setting Up Run Command On Managed
Instances (p. 371).

Commands

You can configure Amazon EC2 instances and
managed instances by sending commands
from your local machine. You don't need to
log on locally to configure your machines.
You can send commands using one of the
following: the Command History page of the
Amazon EC2 console, AWS Tools for Windows
PowerShell, the AWS Command Line Interface
(AWS CLI), the SSM API, or Amazon SDKs.
For more information, see SSM AWS Tools for
Windows PowerShell Reference, SSM AWS CLI
Reference, and the AWS SDKs.

SSM Documents

An SSM document defines the plugins to run
and the parameters to use when a command
executes on a machine. When you execute a
command, you specify the SSM document that
Run Command uses. Run Command includes
pre-defined documents that enable you to quickly
perform common tasks on a machine. You can
also create your own SSM documents. The first
time you execute a command from a new SSM
document, the system stores the document with
your AWS account. For more information, see
Creating SSM Documents (p. 378).

SSM Agent

The SSM agent is AWS software that you install
on your EC2 instances and managed instances.
The agent processes Run Command requests
and configures your machine as specified in the
request. For more information, see Installing the
SSM Agent (p. 357).

IAM Roles and Polices

AWS user accounts and instances must be
configured with AWS Identity and Access
Management (IAM) roles and trust policies that
enable them to communicate with the SSM API.
For more information, see Delegating Access to
Amazon EC2 Run Command (p. 365).

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How It Works
After you verify prerequisites for your EC2 instances and managed instances, you send a command
from your local machine. The SSM service verifies the integrity of the command and any parameters
and then forwards the request to the Amazon EC2 messaging service. The SSM agent running each
instance (or EC2Config service on EC2 Windows instances) communicates with the EC2 messaging
service to retrieve commands. The agent processes the command, configures the instance as
specified, and logs the output and results.

Note
The agent attempts to execute each command once. You can send multiple commands at the
same time.
The system manages the queuing, execution, cancellation, and reporting of each command. However,
the order of command execution is not guaranteed. By default, Run Command uses throttle limits
to ensure that no more than 60 commands are issued per minute per instance. If an instance is not
running or is unresponsive when you execute a command, the system queues the command and
attempts to run it when the instance is responsive. By default, the system will queue a command and
attempt to run it for up to 31 days after request. For more information about command status, see
Monitoring Commands (p. 394).
Run Command reports the status and results of each command for each instance, server, or VM. Run
Command stores the command history for 30 days. The information is also stored in AWS CloudTrail
and remains available until you delete the data. For more information, see Auditing API Calls in the
Amazon EC2 Simple Systems Manager API Reference.

More about SSM Documents
After you configure Run Command prerequisites, you determine what type of configuration change
you want to make on your instance and which SSM document will enable you to make that change.
Run Command includes pre-defined SSM documents that enable you to quickly execute commands
on instances. The commands available to you depend on the permissions your administrator specified
for you. Any command that begins with AWS-* uses a pre-defined SSM document provided by AWS. A
developer or administrator can create additional documents and provision these for you based on your
permissions. For more information, see Creating SSM Documents (p. 378).

Important
Only trusted administrators should be allowed to use AWS pre-configured documents. The
commands or scripts specified in SSM documents run with administrative privilege on your
instances because the Amazon SSM agent runs as root. If a user has permission to execute
any of the pre-defined SSM documents (any document that begins with AWS-*), then that user
also has administrator access to the instance. For all other users, you should create restrictive
documents and share them with specific users. For more information about restricting access
to Run Command, see Delegating Access to Amazon EC2 Run Command (p. 365).
Run Command includes the following pre-configured SSM documents.

Amazon Pre-configured SSM documents for Linux
Name

Description

AWS-RunShellScript

Run shell scripts

AWS-UpdateSSMAgent

Update the Amazon SSM agent

You can select a document from a list in the Amazon EC2 console or use a list documents
command to view a list a commands available to you in either the AWS CLI or AWS Tools for Windows
PowerShell.

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Prerequisites

Amazon EC2 Run Command Prerequisites
Amazon EC2 Run Command has the following limitations and prerequisites. For information about
Windows prerequisites, see Amazon EC2 Run Command Prerequisites in the Amazon EC2 User
Guide for Windows Instances.
Limitations
Run Command is only available in these regions.

Note
For managed instances, we recommend that you choose the region closest to your data
center or computing environment.

Prerequisites
Requirement

Details

For More Information

Supported Operating System

Instances must be running a
supported version of Linux.

Finding a Linux AMI (p. 75)

64-Bit and 32-Bit Systems
• Amazon Linux 2014.09,
2014.03 or later
• Ubuntu Server 14.04 LTS or
12.04 LTS
• Red Hat Enterprise Linux
(RHEL) 6.5 or later
• CentOS 6.3 or later

64-Bit Systems Only
• Amazon Linux 2015.09,
2015.03 or later
• Red Hat Enterprise Linux
(RHEL) 7.x or later
• CentOS 7.1 or later
SSM agent

The SSM agent processes
Run Command requests and
configures your machine as
specified in the request. You
must download and install
the SSM agent to your EC2
instance, on-premises servers
or VMs, or VMs hosted by other
cloud providers.

Important
Because of a known
issue, users in the
following regions
must download the
latest version of the
SSM agent: Asia
Pacific (Seoul), apnortheast-2 and China

355

Installing the SSM
Agent (p. 357)

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Prerequisites

Requirement

Details

For More Information

(Beijing), cn-north-1.
This is a one time
installation. After
installing the latest
version, you can
update the agent using
Run Command.
The source code for the SSM
agent is available on GitHub
so that you can adapt the
agent to meet your needs.
We encourage you to submit
pull requests for changes
that you would like to have
included. However, Amazon
Web Services does not
currently provide support for
running modified copies of this
software.
Access to Run Command

Before you can execute
commands using Run
Command, you must configure
an AWS Identity and Access
Management (IAM) EC2
instance role for instances that
will process commands. You
must also configure a separate
user role for users executing
commands. Both roles require
permission policies that enable
them to communicate with the
SSM API.

Delegating Access to Amazon
EC2 Run Command (p. 365)

Note
For managed
instances, you must
also create an IAM
service role that
enables your onpremises server or VM
to communicate with
the SSM service. For
more information, see
Create a Managed
Instance Service
Role (p. 371).
Internet Access

Verify that your EC2 instances
have outbound Internet access.
Inbound Internet access is not
required.

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Internet Gateways

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Installing the SSM Agent

Requirement

Details

For More Information

Amazon S3 Bucket (Optional)

You can store command output
in an Amazon Simple Storage
Service (S3) bucket. Command
output in the Amazon EC2
console is truncated after
2500 characters. Additionally,
you might want to create
an Amazon S3 key prefix (a
subfolder) to help you organize
Run Command output.

Create a Bucket

Note
SSM communicates with the SSM Agent on your instance by using the EC2 Messaging
service. If you monitor traffic, you will see your instances communicating with ec2messages.*
endpoints.
After you configure prerequisites, see Executing a Command Using Amazon EC2 Run
Command (p. 374) for step-by-step procedures using the Amazon EC2 console. To view AWS
Command Line Interface (AWS CLI) and AWS Tools for Windows PowerShell examples, see Amazon
EC2 Run Command Walkthroughs (p. 387).
Related Topics
• Amazon EC2 Simple Systems Manager API Reference
• Amazon EC2 Simple Systems Manager section of the AWS Command Line Interface Reference

Installing the SSM Agent
The Amazon EC2 Simple Systems Manager (SSM) agent processes Run Command requests and
configures your machine as specified in the request. Use the following procedures to install, configure,
or uninstall the SSM agent.

Note
The source code for the SSM agent is available on GitHub so that you can adapt the agent
to meet your needs. We encourage you to submit pull requests for changes that you would
like to have included. However, Amazon Web Services does not currently provide support for
running modified copies of this software.
The commands in this section require you to replace region with a region where SSM is available. To
avoid cross-region data transfer costs for the download, specify the region of your EC2 instance. For
managed instances, there is no cross-region data transfer cost, but we recommend that you specify the
region closest to your data center or computing environment.
Contents
• Install the SSM Agent on EC2 Instances at Start-Up (p. 358)
• Manually Install the SSM Agent on EC2 Instances (p. 359)
• Configure the SSM Agent to Use a Proxy (p. 363)
• Uninstall the SSM Agent (p. 364)

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Installing the SSM Agent

Install the SSM Agent on EC2 Instances at Start-Up
You can install the SSM agent when you launch an instance for the first time by using EC2 User Data.
On the Configure Instance Details page of the launch wizard, expand Advanced Details and then
copy and paste one of the following scripts into the User data field. For example:

Amazon Linux, RHEL, and CentOS 64-bit
#!/bin/bash
cd /tmp
curl https://amazon-ssm-region.s3.amazonaws.com/latest/linux_amd64/amazonssm-agent.rpm -o amazon-ssm-agent.rpm
yum install -y amazon-ssm-agent.rpm

Amazon Linux, RHEL, and CentOS 32-bit
#!/bin/bash
cd /tmp
curl https://amazon-ssm-region.s3.amazonaws.com/latest/linux_386/amazon-ssmagent.rpm -o amazon-ssm-agent.rpm
yum install -y amazon-ssm-agent.rpm

Ubuntu Server 64-bit
#!/bin/bash
cd /tmp
curl https://amazon-ssm-region.s3.amazonaws.com/latest/debian_amd64/amazonssm-agent.deb -o amazon-ssm-agent.deb
dpkg -i amazon-ssm-agent.deb

Ubuntu Server 32-bit
#!/bin/bash
cd /tmp
curl https://amazon-ssm-region.s3.amazonaws.com/latest/debian_386/amazon-ssmagent.deb -o amazon-ssm-agent.deb
dpkg -i amazon-ssm-agent.deb

Save your changes, and complete the wizard. When the instance launches, the system copies
the SSM agent to the instance and starts it. When the instance is online, you can configure it
using Run Command. For more information, see Executing a Command Using Amazon EC2 Run
Command (p. 374).

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Manually Install the SSM Agent on EC2 Instances
Use one of the following scripts to install the SSM agent on Amazon Linux, Ubuntu, CentOS, or Red
Hat Enterprise Linux. In these scripts, replace region with a region where SSM is available.
• Install the SSM Agent on Amazon Linux (p. 359)
• Install the SSM Agent on Ubuntu (p. 360)
• Install the SSM Agent on Red Hat Enterprise Linux (p. 360)
• Install the SSM Agent on CentOS (p. 362)

Install the SSM Agent on Amazon Linux
Connect to your Amazon Linux instance and perform the following steps to install the SSM agent.
Perform these steps on each instance that will execute commands using Run Command.

To install the SSM agent on Amazon Linux
1.

Create a temporary directory on the instance.
mkdir /tmp/ssm

32-Bit
curl https://amazon-ssm-region.s3.amazonaws.com/latest/linux_386/amazonssm-agent.rpm -o /tmp/ssm/amazon-ssm-agent.rpm

Run the SSM installer.
sudo yum install -y /tmp/ssm/amazon-ssm-agent.rpm

Run the following command to determine if the SSM agent is running. The command should return
"amazon-ssm-agent is running."
sudo status amazon-ssm-agent

Execute the following commands if the previous command returns, "amazon-ssm-agent is
stopped."
a.

Start the service.
sudo start amazon-ssm-agent

Check the status of the agent.
sudo status amazon-ssm-agent

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Install the SSM Agent on Ubuntu
Connect to your Ubuntu instance and perform the following steps to install the SSM agent. Perform
these steps on each instance that will execute commands using Run Command.

To install the SSM agent on Ubuntu
1.

Create a temporary directory on the instance.
mkdir /tmp/ssm

Use one of the following commands to download the SSM installer to the temporary directory.
Replace region with one of the AWS Regions where SSM is available. To avoid cross-region
data transfer costs for the download, specify the region of your EC2 instance.
64-Bit
curl https://amazon-ssm-region.s3.amazonaws.com/latest/debian_amd64/
amazon-ssm-agent.deb -o /tmp/ssm/amazon-ssm-agent.deb

32-Bit
curl https://amazon-ssm-region.s3.amazonaws.com/latest/debian_386/amazonssm-agent.deb -o /tmp/ssm/amazon-ssm-agent.deb

Run the SSM installer.
sudo dpkg -i /tmp/ssm/amazon-ssm-agent.deb

Run the following command to determine if the SSM agent is running. The command should return
"amazon-ssm-agent is running."
sudo status amazon-ssm-agent

Execute the following commands if the previous command returned, "amazon-ssm-agent is
stopped."
a.

Start the service.
sudo start amazon-ssm-agent

Check the status of the agent.
sudo status amazon-ssm-agent

Install the SSM Agent on Red Hat Enterprise Linux
Connect to your Red Hat Enterprise Linux (RHEL) instance and perform the following steps to
install the SSM agent. Perform these steps on each instance that will execute commands using Run
Command.

To install the SSM agent on Red Hat Enterprise Linux
1.

Create a temporary directory on the instance.
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mkdir /tmp/ssm

32-Bit
curl https://amazon-ssm-region.s3.amazonaws.com/latest/linux_386/amazonssm-agent.rpm -o /tmp/ssm/amazon-ssm-agent.rpm

Run the SSM installer.
sudo yum install -y /tmp/ssm/amazon-ssm-agent.rpm

Run one of the following commands to determine if the SSM agent is running. The command
should return "amazon-ssm-agent is running."
RHEL 7.x
sudo systemctl status amazon-ssm-agent

RHEL 6.x
sudo status amazon-ssm-agent

Execute the following commands if the previous command returned "amazon-ssm-agent is
stopped."
a.

Start the service.
RHEL 7.x
sudo systemctl start amazon-ssm-agent

RHEL 6.x
sudo start amazon-ssm-agent

Check the status of the agent.
RHEL 7.x
sudo systemctl status amazon-ssm-agent

RHEL 6.x

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sudo status amazon-ssm-agent

Install the SSM Agent on CentOS
Connect to your CentOS instance and perform the following steps to install the SSM agent. Perform
these steps on each instance that will execute commands using Run Command.

To install the SSM agent on CentOS
1.

Create a temporary directory on the instance.
mkdir /tmp/ssm

32-Bit
curl https://amazon-ssm-region.s3.amazonaws.com/latest/linux_386/amazonssm-agent.rpm -o /tmp/ssm/amazon-ssm-agent.rpm

Run the SSM installer.
sudo yum install -y /tmp/ssm/amazon-ssm-agent.rpm

Run one of the following commands to determine if the SSM agent is running. The command
should return "amazon-ssm-agent is running."
CentOS 7.x
sudo systemctl status amazon-ssm-agent

CentOS 6.x
status amazon-ssm-agent

Execute the following commands if the previous command returned "amazon-ssm-agent is
stopped."
a.

Start the service.
CentOS 7.x
sudo systemctl start amazon-ssm-agent

CentOS 6.x
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sudo start amazon-ssm-agent

Check the status of the agent.
CentOS 7.x
sudo systemctl status amazon-ssm-agent

CentOS 6.x
sudo status amazon-ssm-agent

Configure the SSM Agent to Use a Proxy
You can configure the SSM agent to communicate through an HTTP proxy by adding the http_proxy
and no_proxy settings to the SSM agent configuration file. This section includes procedures for
upstart and systemd environments.

To configure the SSM agent to use a proxy (Upstart)
1.

Connect to the instance where you installed the SSM agent.

Open the amazon-ssm-agent.conf file in an editor such as VIM. By default, the file is located here:
/etc/init/amazon-ssm-agent.conf

Add the http_proxy setting to the file in the following format:
env http_proxy=http://hostname:port

Add the no_proxy setting to the file in the following format. You must specify the IP address listed
here. It is the instance metadata endpoint for SSM and without this IP address calls to SSM fail:
env no_proxy=169.254.169.254

Save your changes and close the editor.

Restart the SSM agent using the following command:
/sbin/restart amazon-ssm-agent

The following Upstart example includes the http_proxy and no_proxy settings in the amazon-ssmagent.conf file:
description "Amazon SSM Agent"
author "Amazon.com"
start on (runlevel [345] and started network)
stop on (runlevel [!345] or stopping network)
respawn
env http_proxy=http://i-1234567890abcdef0:443
env no_proxy=169.254.169.254

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chdir /usr/bin/
exec ./amazon-ssm-agent

To configure the SSM agent to use a proxy (systemd)
1.

Connect to the instance where you installed the SSM agent.

Open the amazon-ssm-agent.service file in an editor such as VIM. By default, the file is located
here:
/etc/systemd/system/amazon-ssm-agent.service

Add the http_proxy setting to the file in the following format:
Environment="HTTP_PROXY=http://hostname:port"

Save your changes and close the editor.

Restart the SSM agent using the following commands:
systemctl stop amazon-ssm-agent
systemctl daemon-reload

The following systemd example includes the http_proxy and no_proxy settings in the amazon-ssmagent.service file:
Type=simple
Environment="HTTP_PROXY=http://i-1234567890abcdef0:443"
Environment="no_proxy=169.254.169.254"
WorkingDirectory=/opt/amazon/ssm/
ExecStart=/usr/bin/amazon-ssm-agent
KillMode=process
Restart=on-failure
RestartSec=15min

Uninstall the SSM Agent
Use the following commands to uninstall the SSM agent.
To uninstall the SSM agent on Amazon Linux, RHEL, or Cent OS
sudo yum erase amazon-ssm-agent –y

To uninstall the SSM agent on Ubuntu
sudo dpkg -r amazon-ssm-agent

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Delegating Access to Amazon EC2 Run
Command
Amazon EC2 Run Command requires an IAM role for EC2 instances that will process commands and
a separate role for users executing commands. Both roles require permission policies that enable them
to communicate with the SSM API. You can choose to use SSM managed policies or you can create
your own roles and specify permissions as described in this section.
If you are configuring managed instances (on-premises servers or VMs that you want to configure
using Run Command) you must also configure an IAM service role. For more information, see Create a
Managed Instance Service Role (p. 371).
This section includes the following information.
• Use SSM Managed Policies (p. 365)
• Configure Your Own Roles and Polices (p. 365)
• Create EC2 Instances that Use the EC2 Instance Role (p. 370)
After you configure roles and policies, we recommend that you further delegate access by creating
commands that perform specific operations and assign access to specific users. For low-level actions
that anyone in your group can perform, you can create low-level commands and make them public. For
more information, see Creating SSM Documents (p. 378).

Use SSM Managed Policies
IAM managed policies for SSM can help you quickly configure access and permissions for Run
Command users and instances. You can find these policies in the Policies page of the IAM console by
searching for SSM, as shown in the following screen shot.

The managed policies perform the following functions:
• AmazonEC2RoleforSSM (instance trust policy): Enables an instance to communicate with the
Run Command API.
• AmazonSSMFullAccess (user trust policy): Grants the user access to the Run Command API and
SSM JSON documents. Assign this policy to administrators and trusted power users.
• AmazonSSMReadOnlyAccess (user trust policy): Grants the user access to read-only API
actions, such as Get and List.
For information about how to configure these policies, see Managed Policies and Inline Policies.

Configure Your Own Roles and Polices
If you choose not to use SSM managed policies, then use the following procedures to create and
configure an SSM EC2 instance role and an SSM user account.

Important
If you want to use an existing EC2 instance role and user account, you must attach the
policies shown in this section to the role and the user account. You must also verify
that ec2.amazonaws.com is listed in the trust policy for the EC2 instance role. For more
information, see Verify the Trust Policy (p. 369).
Topics

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• Create the IAM Policy for EC2 Instances (p. 366)
• Create the IAM User Policy (p. 367)
• Create a Restrictive IAM User Policy (p. 368)
• Create the EC2 Instance Role (p. 369)
• Verify the Trust Policy (p. 369)
• Create the User Account (p. 370)

Create the IAM Policy for EC2 Instances
The following IAM policy enables EC2 instances to communicate with the Run Command API. You will
create the role and attach this policy to that role later in this topic.

To create an IAM policy for EC2 instances
1.

Open the Identity and Access Management (IAM) console at https://console.aws.amazon.com/
iam/.

In the navigation pane, choose Policies. (If this is your first time using IAM, choose Get Started,
and then choose Create Policy.)

Beside Create Your Own Policy, choose Select.

Type a policy name (for example, RunCommandInstance) and description, and then copy and
paste the following policy into the Policy Document field:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"ssm:DescribeAssociation",
"ssm:GetDocument",
"ssm:ListAssociations",
"ssm:UpdateAssociationStatus",
"ssm:UpdateInstanceInformation"
],
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"ec2messages:AcknowledgeMessage",
"ec2messages:DeleteMessage",
"ec2messages:FailMessage",
"ec2messages:GetEndpoint",
"ec2messages:GetMessages",
"ec2messages:SendReply"
],
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"cloudwatch:PutMetricData"
],
"Resource": "*"
},
{

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"Effect": "Allow",
"Action": [
"ec2:DescribeInstanceStatus"
],
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"ds:CreateComputer",
"ds:DescribeDirectories"
],
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"logs:CreateLogGroup",
"logs:CreateLogStream",
"logs:DescribeLogGroups",
"logs:DescribeLogStreams",
"logs:PutLogEvents"
],
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"s3:PutObject",
"s3:GetObject",
"s3:AbortMultipartUpload",
"s3:ListMultipartUploadParts",
"s3:ListBucketMultipartUploads"
],
"Resource": "*"
}
]
}

Important
In the last section of this IAM policy, you can restrict access to the Amazon S3 bucket
by specifying an Amazon Resource Name (ARN). For example, you can change the last
"Resource": "*" item to "Resource": "arn:aws:s3:::AnS3Bucket/*
5.

Choose Validate Policy. Verify that the policy is valid. If you receive an error, verify that you
included the opening and closing brackets { }. After the policy is validated, choose Create Policy.

Create the IAM User Policy
The IAM user policy determines which SSM documents a user can see in the Command document
list. Users can see this list in either the Amazon EC2 console or by calling ListDocuments using the
AWS CLI. The policy also limits the actions the user can perform with an SSM JSON document.

Note
You will create a user account and attach this policy to that account later on.
The IAM policy in the following procedure enables the user to perform any SSM action on the instance.
Assign this policy only to trusted administrators. For all other users, create a restrictive IAM policy, as
described in this section.

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To create the IAM user policy
1.
2.

Repeat the previous procedure to create a policy for a user.
Copy and paste the following policy into the Policy Document field and create the policy:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"ssm:*",
"ec2:DescribeInstanceStatus"
],
"Resource": "*"
}
]
}

Create a Restrictive IAM User Policy
Create restrictive IAM user policies to further delegate access to Run Command. The following
example IAM policy allows a user to list SSM JSON documents and view details about those
documents, send a command using the document, and cancel or view details about the command after
it has been sent. The user has permission to execute the document on three instances, as determined
by the "arn:aws:ec2:us-east-1:*:instance/i-xxxxxxxxxxxxxxxxx" items in the second Resource section. If
you want to give the user access to run the command on any instance for which the user currently has
access (as determined by the AWS user account), you could specify "arn:aws:ec2:us-east-1:*:instance/
*" in the Resource section and remove the other instance resources.
Note that the Resource section includes an S3 ARN entry:
arn:aws:s3:::bucket_name

You can also format this entry as follows:
arn:aws:s3:::bucket_name/*
arn:aws:s3:::bucket_name/key_prefix_name

{
"Version": "2012-10-17",
"Statement": [
{
"Action": [
"ssm:ListDocuments",
"ssm:DescribeDocument",
"ssm:GetDocument",
"ssm:DescribeInstanceInformation"
],
"Effect": "Allow",
"Resource": "*"
},
{
"Action": "ssm:SendCommand",
"Effect": "Allow",

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"Resource": [
"arn:aws:ec2:us-east-1:*:instance/i-1234567890abcdef0",
"arn:aws:ec2:us-east-1:*:instance/i-0598c7d356eba48d7",
"arn:aws:ec2:us-east-1:*:instance/i-345678abcdef12345",
"arn:aws:s3:::bucket_name",
"arn:aws:ssm:us-east-1:*:document/RestartLinuxService"
]
},
{
"Action": [
"ssm:CancelCommand",
"ssm:ListCommands",
"ssm:ListCommandInvocations"
],
"Effect": "Allow",
"Resource": "*"
},
{
"Action": "ec2:DescribeInstanceStatus",
"Effect": "Allow",
"Resource": "*"
}
]
}

For more information about creating IAM user policies, see Managed Policies and Inline Policies.

Create the EC2 Instance Role
The EC2 Instance role enables the instance to communicate with the Run Command API. The role
uses the EC2 instance policy you created earlier.

To create the EC2 instance role
1.

In the navigation pane of the IAM console, choose Roles, and then choose Create New Role.

On the Set Role Name page, enter a name for the role that designates it as the instance role, for
example, RunCommandInstance. Choose Next Step.

3.
4.

On the Select Role Type page, choose Select next to Amazon EC2.
On the Attach Policy page, select the RunCommandInstance policy you created earlier. Choose
Next Step.
Review the role information and then choose Create Role.

Verify the Trust Policy
If you want to use an existing EC2 instance role, you must verify that ec2.amazonaws.com is listed in
the trust policy for the role. If you created a new EC2 instance role, you must add ec2.amazonaws.com
as a trusted entity.

To verify the trust policy
1.

In the navigation pane of the IAM console, choose Roles, and then choose the server role you just
created.

2.
3.

Choose Trust Relationships.
Under Trusted Entities verify that ec2.amazonaws.com is listed. If it's not listed, choose Edit
Trust Relationship.
Copy and paste the following policy into the Policy Document field and create the policy:

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{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "",
"Effect": "Allow",
"Principal": {
"Service": "ec2.amazonaws.com"
},
"Action": "sts:AssumeRole"
}
]
}

Create the User Account
The user account enables a user to call the Run Command API on an instance. This account uses the
IAM user policy you created earlier.

To create the user account
1.

From the Users page on the IAM console, choose Create New Users.

Specify a user name (for example, RunCommandUser) and verify that the Generate an access
key for each user option is selected.

Choose Create.

Choose Download Credentials. By default, the system prompts you to save the credentials as
a .csv file.

Important
Make a note of the RunCommandUser access key and secret key from the .csv file you
downloaded.
5.

Choose Close.

In the IAM Dashboard, choose Users, and then locate the user you just created.

Choose the user name (do not select the option beside the name), and then choose Attach
Policy.

Choose the user policy you created earlier, and then choose Attach Policy.

Create EC2 Instances that Use the EC2 Instance Role
This procedure describes how to create an EC2 instance that uses the role you created. You must
assign a role to an EC2 instance when you launch it. You can't assign a role to an instance that is
already running. Instead, you would create an image of the instance, and then launch an instance from
that image, with the role assigned.

To create an instance that use the EC2 instance role
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

Select a supported region.

Choose Launch Instance and select a Linux instance.

Choose your instance type and then choose Next: Configure Instance Details.

In the IAM role drop-down list choose the EC2 instance role you created earlier.

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Complete the wizard.

If you create other instances that you want to configure using Run Command, you must specify the
EC2 instance role for each instance.

Setting Up Run Command On Managed
Instances
You can remotely manage on-premises servers and virtual machines (VMs), and VMs from other cloud
providers, using Amazon EC2 Run Command. An on-premises server or VM that is configured for Run
Command is called a managed instance. By setting up managed instances, you create a consistent
and secure way to remotely manage your on-premises and cloud workloads using the same tools or
scripts.

Note
For information about setting up managed instances for Windows, see Setting Up Run
Command On Managed Instances (On-Premises Servers and VMs) in the Amazon EC2 User
Guide for Windows Instances.
Managed instances support the following features and services.
• Send commands using the AWS CLI, AWS Tools for Windows PowerShell, the Commands page in
the Amazon EC2 console, or AWS SDKs.
• Send commands using the public SSM documents or documents that you create. Public SSM
documents currently include AWS-RunShellScript and AWS-UpdateSSMAgent.
• Control the Run Command actions that users can perform using AWS Identity and Access
Management (IAM) roles and policies.
• Record and audit the Run Command actions that users perform using AWS CloudTrail.
• Create base images as templates for launching new servers using Sysprep.
• Organize managed instances using standard Amazon Elastic Compute Cloud (EC2) tags.

To get started using Run Command on managed instances
1.

Create IAM service and user roles: The IAM service role enables your on-premises servers and
VMs to communicate with the SSM service. The IAM user role enables users to communicate with
the SSM API to execute commands from either the Amazon EC2 console or by directly calling the
API. This topic describes how to create the service role and provides a link to a new topic with
information about how to create a user role.
Create a managed-instance activation: A managed-instance activation registers your servers,
VMs, or VMs hosted by other cloud providers with Amazon EC2 Simple Systems Manager. This
topic describes how to create a managed-instance activation.
Verify prerequisites: Verify that your on-premises servers and VMs meet the minimum
requirements for Run Command. For more information, see Amazon EC2 Run Command
Prerequisites (p. 355).
Deploy the SSM agent: The SSM agent processes Run Command requests and configures your
machine as specified in the request. You must download and install the SSM agent on your onpremises servers or VMs, or VMs hosted by other cloud providers. This topic describes how to
install the SSM agent on your managed instances.

Create a Managed Instance Service Role
Managed instances require an IAM role to communicate with the SSM service. The role grants
AssumeRole trust to the SSM service.

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The following example shows how to create the IAM service role for SSM using AWS Tools for
Windows PowerShell. For examples of how to create a service role using the AWS Management
Console or the AWS CLI, see Creating a Role to Delegate Permissions to an AWS Service.

Note
You only need to create the service role once for each AWS account.

To create an IAM service role for managed instances using AWS Tools for Windows
PowerShell
1.

Create a text file (in this example it is named SSMService-Trust.json) with the following trust
policy. Save the file with the .json file extension.
{
"Version": "2012-10-17",
"Statement": {
"Effect": "Allow",
"Principal": {"Service": "ssm.amazonaws.com"},
"Action": "sts:AssumeRole"
}
}

Use New-IAMRole as follows to create a service role. This example creates a role named
SSMServiceRole.
New-IAMRole -RoleName SSMServiceRole -AssumeRolePolicyDocument (GetContent -raw SSMService-Trust.json)

Use Register-IAMRolePolicy as follows to enable the SSMServiceRole to create a session token.
The session token gives your managed instance permission to execute commands using Run
Command.
Register-IAMRolePolicy -RoleName SSMServiceRole -PolicyArn
arn:aws:iam::ssm:policy/service-role/AmazonEC2RoleforSSM

You must now create IAM roles that enable users to communicate with the SSM API. For more
information, see Delegating Access to Amazon EC2 Run Command (p. 365).

Create a Managed Instance Activation
To set up managed instances, you need to create a managed-instance activation. After you complete
the activation, you receive an activation code and ID. This code/ID combination functions like an
Amazon EC2 access ID and secret key to provide secure access to the Run Command service from
your managed instances.

Important
Store the managed-instance activation code and ID in a safe place. You specify this code and
ID when you install the SSM agent on an on-premises server or VM. If you lose them, you
must create a new activation.
The procedures in this section require that you specify a region where SSM is available. We
recommend that you specify the region closest to your data center or computing environment.

Note
When you create a managed-instance activation, you specify a date when the activation
expires. If you want to register additional managed instances after the expiry date, you must
create a new activation. The expiry date has no impact on registered and running instances.

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To create a managed-instance activation using the console
1.

Open the Amazon EC2 console, expand Run Command in the navigation pane, and choose
Activations.

Choose Create an Activation.

Fill out the form and choose Create Activation.

To create a managed-instance activation using the AWS Tools for Windows PowerShell
1.

Execute the following command.
New-SSMActivation -DefaultInstanceName name -IamRole IAM service role RegistrationLimit number of managed instances –Region region

For example:
New-SSMActivation -DefaultInstanceName MyWebServers -IamRole
RunCommandServiceRole -RegistrationLimit 10 –Region us-east-1

Press Enter. If the activation is successful, the system returns an activation code and an ID. Store
the activation code and ID in a safe place.

To create a managed-instance activation using the AWS CLI
1.

Execute the following command in the CLI.
aws ssm create-activation --default-instance-name name --iam-role IAM
service role –-registration-limit number of managed instances -region region

For example:
aws ssm create-activation --default-instance-name MyWebServers --iam-role
RunCommandServiceRole –-registration-limit 10 --region us-east-1

Press Enter. If the activation is successful, the system returns an activation code and an ID. Store
the activation code and ID in a safe place.

Install the SSM Agent on Managed Instances
Before you begin, locate the activation code and ID that was sent to you after you completed the
managed-instance activation. You will specify the code and ID in the following procedure.

To install the SSM agent on a managed instance
1.

Log on to the on-premises server or VM.

Copy and paste the following command block into the AWS CLI. Specify your activation code,
activation ID, and the region where you want to download the SSM agent from. Note that sudo is
not necessary if you are a root user.
On Amazon Linux, RHEL 6.x, and CentOS 6.x
mkdir /tmp/ssm

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sudo curl https://amazon-ssm-region.s3.amazonaws.com/latest/linux_amd64/
amazon-ssm-agent.rpm -o /tmp/ssm/amazon-ssm-agent.rpm
sudo yum install -y /tmp/ssm/amazon-ssm-agent.rpm
sudo stop amazon-ssm-agent
sudo amazon-ssm-agent -register -code "code" -id "id" -region "region"
sudo start amazon-ssm-agent

On RHEL 7.x and CentOS 7.x
mkdir /tmp/ssm
sudo curl https://amazon-ssm-region.s3.amazonaws.com/latest/linux_amd64/
amazon-ssm-agent.rpm -o /tmp/ssm/amazon-ssm-agent.rpm
sudo yum install -y /tmp/ssm/amazon-ssm-agent.rpm
sudo systemctl stop amazon-ssm-agent
sudo amazon-ssm-agent -register -code "code" -id "id" -region "region"
sudo systemctl start amazon-ssm-agent

On Ubuntu
mkdir /tmp/ssm
sudo curl https://amazon-ssm-region.s3.amazonaws.com/latest/debian_amd64/
amazon-ssm-agent.deb -o /tmp/ssm/amazon-ssm-agent.deb
sudo dpkg -i /tmp/ssm/amazon-ssm-agent.deb
sudo stop amazon-ssm-agent
sudo amazon-ssm-agent -register -code "code" -id "id" -region "region"
sudo start amazon-ssm-agent

Press Enter.

The command downloads and installs the SSM agent onto the local server or VM. The command also
registers the server or VM with the SSM service. The server or VM is now a managed instance.
For information about how to execute commands on managed instances using Run Command, see
Executing a Command Using Amazon EC2 Run Command (p. 374).

Executing a Command Using Amazon EC2 Run
Command
You can run commands on EC2 instances using the Command History page in the Amazon EC2
console. You can also execute commands using the CLI, the Amazon EC2 Simple Systems Manager
API Reference, or the AWS SDKs. For more information, see the .
Topics
• Running Shell Scripts Using Amazon EC2 Run Command (p. 374)
• Updating the Amazon SSM Agent Using Amazon EC2 Run Command (p. 375)

Running Shell Scripts Using Amazon EC2 Run Command
You can use the AWS-RunShellScript document to run shell scripts on your instances.

Note
This procedure does not include information about how to configure Run Command for
Amazon SNS notifications. To learn more about the Amazon SNS notification fields on the
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Command History page and how to execute commands that return notifications, see Getting
Amazon SNS Notifications When a Command Changes Status (p. 396).

To run shell scripts using Run Command
1.

Open the Amazon EC2 console and choose Command History in the navigation pane.

Choose Run a Command.

In the Command document list, choose AWS-RunShellScript.

Choose Select target instances to select the instances where you want the command
to run. If you do not see a complete list of instances, the missing instances might not be
configured properly for Run Command. For more information, see Amazon EC2 Run Command
Prerequisites (p. 355).

Enter a script or the path to a script in the Commands field.

(Optional) In the Working Directory field, enter the path to the folder on your EC2 instances
where you want to run the command.

(Optional) In the Execution Timeout field, enter the number of seconds the Amazon SSM agent
will attempt to run the command before it times out and fails.

(Optional) In the Comment field, enter information you want to provide about this command.
Comments are stored in the log file and appear in the Command Invocation List in the console.

Tip
We recommend that you enter specific comments about each command you run. The
list of commands that you send can grow quickly, and the Comment field can help you
identify commands that you want to monitor.
9.

In the Timeout (seconds) field, enter the number of seconds Run Command should attempt to
reach instances before an instance is considered unreachable and the command execution fails.
The minimum is 30 seconds. The maximum is 30 days. The default value is 10 minutes.

10. In the Amazon S3 bucket field enter the name of an Amazon S3 bucket where you want to store
the output of the command.

Important
The Run Command Output page in the Amazon EC2 console truncates output after 2500
characters. Configure an Amazon S3 bucket before executing commands using Run
Command. If your command output was longer than 2500 characters, you can view the
full output in your Amazon S3 bucket. For more information, see Create a Bucket.
11. In the S3 key prefix, field enter the name of a subfolder in the Amazon S3 bucket. This subfolder
can help you organize Run Command output.

Note
The section called AWS Command Line Interface command displays a usable CLI script
that is generated based on the parameters you entered.
For information about how to view the results of your command, see Viewing Command Output in the
Amazon EC2 Console (p. 377).
For information about how to run commands using the AWS CLI, see the SSM CLI Reference.

Updating the Amazon SSM Agent Using Amazon EC2 Run
Command
You can use the AWS-UpdateSSMAgent document to update the Amazon SSM agent running on your
instances. You can update to either the latest version or downgrade to an older version. When you
execute the command, the system downloads the version from AWS, installs it, and then uninstalls the

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version that existed before the command was run. If an error occurs during this process, the system
rolls back to the version on the server before the command was run and the command status shows
that the command failed.

Note
This procedure does not include information about how to configure Run Command for
Amazon SNS notifications. To learn more about the Amazon SNS notification fields on the
Command History page and how to execute commands that return notifications, see Getting
Amazon SNS Notifications When a Command Changes Status (p. 396).

To update the Amazon SSM Agent using Run Command
1.

Open the Amazon EC2 console and choose Command History in the navigation pane.

Choose Run a Command.

In the Command document list, choose AWS-UpdateSSMAgent.

(Optional) In the Version field, type a specific version of the Amazon SSM agent to install. You
can install older versions of the agent. If you do not specify a version, the service will be updated
to the latest version.

(Optional) In the Allow downgrade list, choose True if you want to install an earlier version of
the Amazon SSM agent. If you choose this option, you must specify the earlier version number.
Choose False if you want the system to install only the newest version of the service.

(Optional) In the Comment field, type information you want to provide about this command.
Comments are stored in the log file and appear in the Command Invocation List in the Amazon
EC2 console.

In the Timeout (seconds) field, type the number of seconds Run Command should attempt to
reach instances before an instance is considered unreachable and the command execution fails.
The minimum is 30 seconds. The maximum is 30 days. The default value is 10 minutes.

In the S3 bucket field type the name of an Amazon S3 bucket where you want to store the output
of the command.

Important
The Run Command Output page in the Amazon EC2 console truncates output after 2500
characters. Configure an Amazon S3 bucket before executing commands using Run
Command. If your command output was longer than 2500 characters, you can view the
full output in your Amazon S3 bucket. For more information, see Create a Bucket.
10. In the S3 key prefix, field enter the name of a subfolder in the Amazon S3 bucket. This subfolder
can help you organize Run Command output.

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Viewing Command Output in the Amazon EC2
Console
After you execute a command using Run Command, the system returns you to the commands list.

Important
The Amazon EC2 console truncates all command output beyond 2500 characters. If your
command output was longer than 2500 characters, you can view the full output in your S3
bucket.

To view command output
1.

In the Amazon EC2 console, select a command in the list.

Choose the Output tab.

Choose View Output.

The command output page shows the results of your command execution.

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Creating SSM Documents
When you execute a command using Amazon EC2 Run Command, the system reads the actions to
be performed from a document that defines the plugins to run and parameters to use. This document
is called an SSM document. The first time you execute a command from a new SSM document, the
system stores the document with your AWS account.
Limitations
As you begin working with SSM documents, be aware of the following limitations.
• You can create a maximum of 200 SSM documents per AWS account.
• SSM documents that you create are only available in the region where you created them. To add a
document in another region, copy the content and recreate it in the new region.

Note
If you need to create more than the maximum number of SSM documents, contact AWS
Support.

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When giving a user access to Run Command the best practice is to start with a policy of least privilege.
Create different SSM documents that allow the user to do a minimum number of tasks. For example,
you could specify the name of a specific service on an instance so that a Run Command user could
only restart that service.

Create an SSM Document Using the Amazon EC2 Console
1.
2.

Open the Amazon EC2 console and choose Command History in the navigation pane.
Choose Documents and then choose Create Document.

Enter a descriptive name for the document and then specify plugins and parameters in the
Content field in JSON format. For more information, see SSM Plugins in the Amazon EC2 Simple
Systems Manager API Reference.

Choose Create Document to save it with your AWS user account.

Create an SSM Document Using Windows PowerShell
1.

Specify plugins and parameters in a file. Save the document with a descriptive name and a .json
file extension. For more information, see SSM Plugins in the Amazon EC2 Simple Systems
Manager API Reference.
Create the document and save it with your AWS user account using AWS Tools for Windows
PowerShell.
$json = Get-Content C:\your file | Out-String
New-SSMDocument -Name document name -Content $json

Create an SSM Document Using the AWS CLI
1.

Create the document and save it with your AWS user account using the AWS CLI.
aws ssm create-document --content file://c:\temp\your file --name
"document name"

Sample SSM Documents
SSM documents are currently supported in JavaScript Object Notation (JSON) and use the following:
• schemaVersion 1.2
• A runtimeConfig that uses one or more plugins to execute tasks. Plugins are platform specific,
meaning they run on either a supported version of Windows or Linux. For more information about
plugins, see SSM Plugins in the Amazon EC2 Simple Systems Manager API Reference.
Use the following examples as a foundation to create your own documents.

Restrictive SSM Document for Linux
The following example shows a highly-restrictive SSM document that uses the AWS-RunShellScript
document on Linux. The user can only run the ifconfig command to check the IP configuration of the
instance:

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{
"schemaVersion": "1.2",
"description": "Check ip configuration of a Linux instance.",
"parameters": {
},
"runtimeConfig": {
"aws:runShellScript": {
"properties": [
{
"id": "0.aws:runShellScript",
"runCommand": ["ifconfig"]
}
]
}
}
}

This section includes several JSON templates that you can use to create your own SSM documents.
These templates are based on the AWS public SSM documents. http://docs.aws.amazon.com/
AWSEC2/latest/WindowsGuide/;
AWS-RunShellScript
{
"schemaVersion":"1.2",
"description":"Run a shell script or specify the commands to run.",
"parameters":{
"commands":{
"type":"StringList",
"description":"(Required) Specify a shell script or a command to
run.",
"minItems":1,
"displayType":"textarea"
},
"workingDirectory":{
"type":"String",
"default":"",
"description":"(Optional) The path to the working directory on
your instance.",
"maxChars":4096
},
"executionTimeout":{
"type":"String",
"default":"3600",
"description":"(Optional) The time in seconds for a command to
complete before it is considered to have failed. Default is 3600 (1 hour).
Maximum is 28800 (8 hours).",
"allowedPattern":"([1-9][0-9]{0,3})|(1[0-9]{1,4})|(2[0-7][0-9]
{1,3})|(28[0-7][0-9]{1,2})|(28800)"
}
},
"runtimeConfig":{
"aws:runShellScript":{
"properties":[
{
"id":"0.aws:runShellScript",

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"runCommand":"{{ commands }}",
"workingDirectory":"{{ workingDirectory }}",
"timeoutSeconds":"{{ executionTimeout }}"
}
]
}
}
}

AWS-UpdateSSMAgent
{
"schemaVersion": "1.2",
"description": "Update the Amazon SSM Agent to the latest version or
specified version.",
"parameters": {
"version": {
"default": "",
"description": "(Optional) A specific version of the Amazon SSM
Agent to install. If not specified, the agent will be updated to the latest
version.",
"type": "String"
},
"allowDowngrade": {
"default": "false",
"description": "(Optional) Allow the Amazon SSM Agent service
to be downgraded to an earlier version. If set to false, the service can
be upgraded to newer versions only (default). If set to true, specify the
earlier version.",
"type": "String",
"allowedValues": [
"true",
"false"
]
}
},
"runtimeConfig": {
"aws:updateSsmAgent": {
"properties": [
{
"agentName": "amazon-ssm-agent",
"allowDowngrade": "{{ allowDowngrade }}",
"targetVersion": "{{ version }}"
}
]
}
}
}

Sharing SSM Documents
You can share Amazon EC2 Simple Systems Manager (SSM) documents privately or publicly. To
privately share an SSM document, you modify the document permissions and allow specific individuals
to access it according to their Amazon Web Services (AWS) ID. To publicly share a SSM document,
you modify the document permissions and specify All.

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Warning
Use shared SSM documents only from trusted sources. When using any shared document,
carefully review the contents of the document before using it so that you understand how it will
change the configuration of your instance. For more information about shared document best
practices, see Guidelines for Sharing and Using Shared SSM Documents (p. 382).
Limitations
As you begin working with SSM documents, be aware of the following limitations.
• Only the owner can share a document.
• You must stop sharing a document before you can delete it. For more information, see How to
Modify Permissions for a Shared Document (p. 385).
• You can share a document with a maximum of 20 AWS accounts.
• You can publicly share a maximum of five SSM documents.

Note
If you need to share more than the maximum number of AWS accounts or SSM documents,
contact AWS Support.
This topic includes the following sections.
• Guidelines for Sharing and Using Shared SSM Documents (p. 382)
• How to Share an SSM Document (p. 383)
• How to Modify Permissions for a Shared Document (p. 385)
• How to Use a Shared SSM Document (p. 385)

Guidelines for Sharing and Using Shared SSM Documents
Review the following guidelines before you share or use a shared document.
Remove Sensitive Information
Review your SSM document carefully and remove any sensitive information. For example, verify
that the document does not include your AWS credentials. If you share a document with specific
individuals, those users can view the information in the document. If you share a document
publicly, anyone can view the information in the document.
Limit Run Command Actions Using an IAM User Trust Policy
Create a restrictive AWS Identity and Access Management (IAM) user policy for users who will
have access to the document. The IAM policy determines which SSM documents a user can see
in either the Amazon EC2 console or by calling ListDocuments using the AWS CLI or AWS
Tools for Windows PowerShell. The policy also limits the actions the user can perform with an
SSM document. You can create a restrictive policy so that a user can only use specific documents.
For more information, see Delegating Access to Amazon EC2 Run Command (p. 365).
Review the Contents of a Shared Document Before Using It
Review the contents of every document that is shared with you, especially public documents, to
understand the commands that will be executed on your instances. A document could intentionally
or unintentionally have negative repercussions after it is run. If the document references an
external network, review the external source before you use the document.
Send Commands Using the Document Hash
When you share a document, the system creates a Sha-256 hash and assigns it to the document.
The system also saves a snapshot of the document content. When you send a command using
a shared document, you can specify the hash in your command to ensure that the following
conditions are true:

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• You are executing a command from the correct SSM document
• The content of the document has not changed since it was shared with you.
If the hash does not match the specified document or if the content of the shared document has
changed, the command returns an InvalidDocument exception. Note: The hash cannot verify
document content from external locations.

How to Share an SSM Document
You can share an SSM document by using the Amazon EC2 console or by programmatically calling
the ModifyDocumentPermission API operation using the AWS CLI, AWS Tools for Windows
PowerShell, or the AWS SDK. Before you share a document, get the AWS account IDs of the people
with whom you want to share. You will specify these account IDs when you share the document.

Share a Document Using the Amazon EC2 Console
1.

Open the Amazon EC2 console and choose Command History in the navigation pane.

Choose Documents.

In the documents list, choose the document you want to share. Choose the Permissions tab and
verify that you are the document owner. Only a document owner can share a document.

Choose Edit.

To share the command publicly, choose Public and then choose Save. To share the command
privately, choose Private, enter the AWS account ID, choose Add Permission, and then choose
Save.

Share a Document Using the AWS CLI
The following procedure requires that you specify a region for your CLI session. Run Command is
currently available in the following SSM regions.
1.

Open the AWS CLI on your local computer and execute the following command to specify your
credentials.
aws config
AWS Access Key ID: [your key]
AWS Secret Access Key: [your key]
Default region name: [us-east-1]
Default output format [None]:

Use the following command to list all of the SSM documents that are available for you. The list
includes documents that you created and documents that were shared with you.
aws ssm list-documents --document-filter-list key=Owner,value=all

Use the following command to get a specific document.
aws ssm get-document --name document name

Use the following command to get a description of the document.
aws ssm describe-document --name document name

Use the following command to view the permissions for the document.

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aws ssm describe-document-permission --name document name --permissiontype Share

Use the following command to modify the permissions for the document and share it. You must be
the owner of the document to edit the permissions. This command privately shares the document
with a specific individual, based on that person's AWS account ID.
aws ssm modify-document-permission --name document name --permission-type
Share --account-ids-to-add AWS account ID

Use the following command to share a document publicly.
aws ssm modify-document-permission --name document name --permission-type
Share --account-ids-to-add 'all'

Share a Document Using AWS Tools for Windows PowerShell
The following procedure requires that you specify a region for your PowerShell session. Run Command
is currently available in the following SSM regions.
1.

Open AWS Tools for Windows PowerShell on your local computer and execute the following
command to specify your credentials.
Set-AWSCredentials –AccessKey your key –SecretKey your key

Use the following command to set the region for your PowerShell session. The example uses the
us-west-2 region.
Set-DefaultAWSRegion -Region us-west-2

Use the following command to list all of the SSM documents available for you. The list includes
documents that you created and documents that were shared with you.
Get-SSMDocumentList -DocumentFilterList (@{"key"="Owner";"value"="All"})

Use the following command to get a specific document.
Get-SSMDocument –Name document name

Use the following command to get a description of the document.
Get-SSMDocumentDescription –Name document name

Use the following command to view the permissions of the document.
Get- SSMDocumentPermission –Name document name -PermissionType Share

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Edit-SSMDocumentPermission –Name document name -PermissionType Share AccountIdsToAdd AWS account ID

Use the following command to share a document publicly.
Edit-SSMDocumentPermission -Name document name -AccountIdsToAdd ('all') PermissionType Share

How to Modify Permissions for a Shared Document
If you share a command, users can view and use that command until you either remove access to the
SSM document or delete the SSM document. However, you cannot delete a document as long as it is
shared. You must stop sharing it first and then delete it.

Stop Sharing a Document Using the Amazon EC2 Console
1.

Open the Amazon EC2 console and choose Command History in the navigation pane.

Choose Documents.

In the documents list, choose the document you want to stop sharing. Choose the Permissions
tab and verify that you are the document owner. Only a document owner can stop sharing a
document.

Choose Edit.

Delete the AWS account ID that should no longer have access to the command, and then choose
Save.

Stop Sharing a Document Using the AWS CLI
Open the AWS CLI on your local computer and execute the following command to stop sharing a
command.
aws ssm modify-document-permission --name document name --permission-type
Share --account-ids-to-remove 'AWS account ID'

Stop Sharing a Document Using AWS Tools for Windows PowerShell
Open AWS Tools for Windows PowerShell on your local computer and execute the following
command to stop sharing a command.
Edit-SSMDocumentPermission -Name document name –AccountIdsToRemove AWS
account ID -PermissionType Share

How to Use a Shared SSM Document
When you share an SSM document, the system generates an Amazon Resource Name (ARN) and
assigns it to the command. If you select and execute a shared document from the Amazon EC2
console, you do not see the ARN. However, if you want to execute a shared SSM document from
a command line application, you must specify a full ARN. You are shown the full ARN for an SSM
document when you execute the command to list documents.

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Note
You are not required to specify ARNs for AWS public documents (documents that begin with
AWS-*) or commands that you own.
This section includes examples of how to view and execute shared SSM documents from the AWS CLI
and AWS Tools for Windows PowerShell.

Using a Shared SSM Document from the AWS CLI
To list all public SSM documents
aws ssm list-documents --document-filter-list key=Owner,value=Public

To list private SSM documents that have been shared with you
aws ssm list-documents --document-filter-list key=Owner,value=Private

To list all SSM documents available to you
aws ssm list-documents --document-filter-list key=Owner,value=All

Execute a command from a shared SSM document using a full ARN
aws ssm send-command --document-name FullARN/name

For example:
aws ssm send-command --document-name arn:aws:ssm:useast-1:12345678912:document/highAvailabilityServerSetup --instance-ids
i-12121212

Using a Shared SSM Document from the AWS Tools for Windows
PowerShell
To list all public SSM documents
Get-SSMDocumentList -DocumentFilterList @(New-Object
Amazon.SimpleSystemsManagement.Model.DocumentFilter("Owner", "Public"))

To list private SSM documents that have been shared with you
Get-SSMDocumentList -DocumentFilterList @(New-Object
Amazon.SimpleSystemsManagement.Model.DocumentFilter("Owner", "Shared"))

To get information about an SSM document that has been shared with you
Get-SSMDocument –Name FullARN/name

For example:
Get-SSMDocument –Name arn:aws:ssm:us-east-1:12345678912:document/
highAvailabilityServerSetup

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To get a description of an SSM document that has been shared with you
Get-SSMDocumentDescription –Name FullARN/name

For example:
Get-SSMDocumentDescription –Name arn:aws:ssm:us-east-1:12345678912:document/
highAvailabilityServerSetup

To execute a command from a shared SSM document using a full ARN
Send-SSMCommand –DocumentName FullARN/name –InstanceId IDs

For example:
Send-SSMCommand –DocumentName arn:aws:ssm:us-east-1:555450671542:document/
highAvailabilityServerSetup –InstanceId @{"i-273d4e9e"}

Amazon EC2 Run Command Walkthroughs
The following examples or walkthroughs to help you understand how to execute commands using Run
Command from either the Amazon EC2 console or the AWS CLI.

Caution
If this is your first time using Run Command, we recommend executing commands against a
test instance or an instance that is not being used in a production environment.
Contents
• Amazon EC2 Run Command Walkthrough Using the Console (p. 387)
• Amazon EC2 Run Command Walkthrough Using the AWS CLI (p. 391)

Amazon EC2 Run Command Walkthrough Using the
Console
The following sample walkthrough shows you how to execute commands using Run Command
from the Command History page in the Amazon EC2 console. You will learn how to execute a
command with the AWS-RunShellScript SSM document. To view CLI examples, see Amazon EC2 Run
Command Walkthrough Using the AWS CLI (p. 391).
1.

In the Amazon EC2 console choose Command History in the navigation pane, and then choose
Run a command.

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In the Command document list, choose AWS-RunShellScript.

Choose Select instances and then choose the instances where you want to execute the
command. If you do not see a complete list of instances, the missing instances might not be
configured properly for Run Command. For more information, see Amazon EC2 Run Command
Prerequisites (p. 355).

Type a valid shell script or command in the Commands field. You can specify a Working
Directory and Execution Timeout, if you want. The Execution Timeout is the number of
seconds the amazon-ssm-agent will attempt to run the command before it is considered to have
failed. We recommend entering a comment in the Comments field. A comment will help you
identify the command in the list of pending commands and make it easier to view the output.

In the Timeout (seconds) field, type the number of seconds Run Command should attempt to
reach instances before an instance is considered unreachable and the command execution fails.

In the S3 bucket field type the name of an Amazon S3 bucket where you want to store command
output. Enter an Amazon S3 subfolder in the S3 key prefix field. A subfolder can help you
organize output if you are executing multiple commands against multiple instances.

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Choose Run to execute the command simultaneously on the selected instances. Run Command
displays a status screen.

Choose View result.

The command list shows three invocations for the command because it was sent to three
instances. Each invocation has it's own Command ID and status. To view status, choose an
invocation, choose the Output tab for the invocation, and then choose View Output.

10. The system displays the output in your browser. If the output is longer than 2500 characters, only
the first 2500 characters are shown and the rest is truncated.
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11. You can view the full command output in Amazon S3. Open the S3 console and choose your
Amazon S3 bucket.

12. Choose the Command-ID.Instance-ID for which you want to view command output.

13. Choose the awsrunShellScript sub-folder.

14. Choose the stdout.text file. Amazon S3 displays the full command output.

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Amazon EC2 Run Command Walkthrough Using the AWS
CLI
The following sample walkthrough shows you how to use the AWS CLI to view information about
commands and command parameters, how to execute commands, and how to view the status of those
commands.

Tip
The Command History page in the console includes a section called AWS Command Line
Interface command. This section displays a usable CLI script that’s generated based on the
parameters you entered.

Step 1: Getting Started
You must either have administrator privileges on the instances you want to configure or you must have
been granted the appropriate permission in IAM. Also note, this example uses the us-east-1 region.
Run Command is currently available in the following SSM regions. For more information, see Amazon
EC2 Run Command Prerequisites (p. 355).

To execute commands using the AWS CLI
1.

Open the AWS CLI on your local computer and execute the following command to specify your
credentials and the region.
aws configure

The system prompts you to specify the following.

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AWS Access Key ID [None]: key_name
AWS Secret Access Key [None]: key_name
Default region name [None]: us-east-1
Default output format [None]: ENTER

List all available documents
This command lists all of the documents available for your account based on IAM permissions.
The command returns a list of Linux and Windows documents.
aws ssm list-documents

Verify that an instance is ready to receive commands
The output of the following command shows if instances are online.
aws ssm describe-instance-information --output text --query
"InstanceInformationList[*]"

Use the following command to view details about a particular instance.

Note
To execute the commands in this walkthrough, you must replace the instance and
command IDs. The command ID is returned as a response of the send-command. The
instance ID is available from the Amazon EC2 console.
aws ssm describe-instance-information --instance-information-filter-list
key=InstanceIds,valueSet=instance ID

Step 2: Running Shell Scripts
Using Run Command and the AWS-RunShellScript document, you can execute any command or script
on an EC2 instance as if you were logged on locally.

To view the description and available parameters
• Use the following command to view a description of the SSM JSON document.
aws ssm describe-document --name "AWS-RunShellScript" --query
"[Document.Name,Document.Description]"

• Use the following command to view the available parameters and details about those parameters.
aws ssm describe-document --name "AWS-RunShellScript" --query
"Document.Parameters[*]"

Step 3: Send a Command Using the AWS-RunShellScript document Example 1
Use the following command to get IP information for an instance.

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aws ssm send-command --instance-ids "instance ID" --document-name "AWSRunShellScript" --comment "IP config" --parameters commands=ifconfig --output
text

Get command information with response data
The following command uses the Command ID that was returned from the previous command to get
the details and response data of the command execution. The system returns the response data if
the command completed. If the command execution shows "Pending" you will need to execute this
command again to see the response data.
aws ssm list-command-invocations --command-id "command ID" --details

Step 4: Send a Command Using the AWS-RunShellScript document Example 2
The following command displays the default user account running the commands.
sh_command_id=$(aws ssm send-command --instance-ids "instance ID" --documentname "AWS-RunShellScript" --comment "Demo run shell script on Linux Instance"
--parameters commands=whoami --output text --query "Command.CommandId")

Get command status
The following command uses the Command ID to get the status of the command execution on the
instance. This example uses the Command ID that was returned in the previous command.
aws ssm list-commands

--command-id $sh_command_id

Get command details
The following command uses the Command ID from the previous command to get the status of the
command execution on a per instance basis.
aws ssm list-command-invocations --command-id $sh_command_id --details

Get command information with response data for a specific instance
The following command returns the output of the original aws ssm send-command for a specific
instance.
aws ssm list-command-invocations --instance-id instance ID --command-id
$sh_command_id –-details

Step 5: Additional Examples
The following command returns the version of Python running on an instance.
sh_command_id=$(aws ssm send-command --instance-ids "instance ID" -document-name "AWS-RunShellScript" --comment "Demo run shell script on Linux

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Instances" --parameters commands='python' --version --output text --query
"Command.CommandId")

The following command executes a Python script using Run Command.
py_command_id=$(aws ssm send-command --instance-ids "instance ID" -document-name "AWS-RunShellScript" --comment "Demo run shell script on Linux
Instances" --parameters commands='#!/usr/bin/python', 'print \"Hello world
from python\"' --output text --query "Command.CommandId")

Cancelling a Command
You can attempt to cancel a command as long as the service shows that it is in either a Pending or
Executing state. However, even if a command is still in one of these states, we cannot guarantee that
the command will be terminated and the underlying process stopped.

To cancel a command using the console
1.

Open the Amazon EC2 console and choose Command History in the navigation pane.

Select the command invocation that you want to cancel.

Choose Actions and then choose Cancel command.

To cancel a command using the AWS CLI
Use the following command.
aws ssm cancel-command --command-id "command
ID"

ID" --instance-ids "instance

For information about the status of a cancelled command, see Monitoring Commands (p. 394).

Monitoring Commands
There are several ways to monitor the status of the commands you send with Run Command:
• Configure CloudWatch Events to log status changes.
• Configure Amazon SNS to send notifications for all status changes or specific statuses like Failed or
TimedOut.
• Click the Refresh icon on the Command History page in the Amazon EC2 console.
• Call the ListCommand or ListCommandInvocation API using a command line tool.
This section includes information about how to automate monitoring by using CloudWatch Events and
SNS notifications.
When you send a command to multiple instances at the same time, each copy of the command
targeting each instance is a command invocation. For example, if you use the AWS-RunShellScript
JSON document and send an ifconfig command to 20 instances, that command has 20 invocations.
Run Command monitoring options enable you to examine the details of each invocation, which can
help you troubleshoot problems if a command fails.
Command Status

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Each command invocation individually reports status. Furthermore, each SSM document consists
of one or more code-execution blocks called plugins. The plugins for a given command invocation
individually report status as well. The following table describes Run Command execution statuses.
For more information about plugins, see SSM Plugins in the Amazon EC2 Simple Systems Manager
API Reference.
Status

Details

Pending

The command was not yet received by the SSM
agent. If the command is not received by the
agent before the value specified by the Timeout
(seconds) parameter is reached, then the status
changes to Timed Out.

In Progress

The command was received by the SSM
agent, or the command started executing on
the instance. Depending on the result of all
command plugins, the status will change to
Success, Failed, or Timed Out. If the SSM
agent is not available on the instance, the
command status will show In Progress until the
agent is available again. The status will then
change to a terminal state.

Success

The command, including all plugins, finished
executing on the instance.

Failed

One or more plugins failed to execute. To help
you identify and troubleshoot problems with a
command, if a plugin fails, the entire invocation
status is changed to Failed.

Timed Out

The command did not reach the SSM agent on
the instance before the value specified by the
Timeout (seconds) parameter was reached.
Or, the command execution ran longer than the
allowable execution time. The amount of time a
command execution can run varies by plugin.
Default values range from two hours to eight
hours.

Cancelling

You sent the command to cancel a command
invocation. The command has not reached a
terminal state (Success, Failed, or Timed Out).
If the SSM agent responds within the time-frame
specified by the Timeout (seconds) parameter,
then the status will change to reflect a terminal
state. Otherwise the status will change to Timed
Out.

Cancelled

The command was successfully cancelled.

Note
In the Amazon EC2 console, click the Refresh symbol in the upper-right corner to monitor
command status as command execution progresses.
Contents

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• Getting Amazon SNS Notifications When a Command Changes Status (p. 396)
• Log Command Execution Status Changes for Run Command (p. 401)

Getting Amazon SNS Notifications When a Command
Changes Status
You can configure Amazon Simple Notification Service (Amazon SNS) to send notifications about the
status of commands you send using Amazon EC2 Run Command. Amazon SNS coordinates and
manages the delivery or sending of notifications to subscribing clients or endpoints. You can receive a
notification whenever a command changes to a new state or changes to a specific state, such as failed
or timed out. In cases where you send a command to multiple instances, you can receive a notification
for each copy of the command sent to a specific instance. Each copy is called an invocation.
Amazon SNS can deliver notifications as HTTP or HTTPS POST, email (SMTP, either plain-text or in
JSON format), or as a message posted to an Amazon Simple Queue Service (Amazon SQS) queue.
For more information, see What Is Amazon SNS in the Amazon Simple Notification Service Developer
Guide.
For example, if you configure Amazon SNS to send a notification when a command status changes to
failed, SNS sends an email notification with the details of the command execution.

Note
If you prefer, you can use Amazon CloudWatch Events to configure a target to invoke an AWS
Lambda function when a command changes status. For more information, see Log Command
Execution Status Changes for Run Command (p. 401).
To set up Amazon SNS notifications when a command changes status, you must complete the
following tasks.
1. Configure Account Permissions (p. 398)
2. Create an IAM Role for Notifications (p. 398)
3. Configure Amazon SNS (p. 399)
4. Send a Command that Returns Status Notifications (p. 400)

Configure Amazon SNS Notifications for SSM
Run Command supports sending Amazon SNS notifications for commands that enter the following
statuses. For information about the conditions that cause a command to enter one of these statuses,
see Monitoring Commands (p. 394).
• In Progress
• Success
• Failed
• Timed Out
• Canceled

Note
Commands sent using Run Command also report Cancelling and Pending status. These
statuses are not captured by SNS notifications.
If you configure Run Command for SNS notifications, SNS sends summary messages that include the
following information:

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Field

Type

Description

EventTime

String

The time the event was
triggered. The time stamp
is important because SNS
does not guarantee message
delivery order. Example:
2016-04-26T13:15:30Z

DocumentName

String

The name of the SSM document
used to execute this command.

CommandId

String

The ID generated by Run
Command after the command
was sent.

ExpiresAfter

Date

If this time is reached and the
command has not already
started executing, it will not
execute.

OutputS3BucketName

String

The Amazon Simple Storage
Service (Amazon S3) bucket
where the responses to the
command execution should be
stored.

OutputS3KeyPrefix

String

The Amazon S3 directory path
inside the bucket where the
responses to the command
execution should be stored.

RequestedDateTime

String

The time and date the request
was sent to this specific
instance.

InstanceId

String

The instance targeted by the
command.

Status

String

Command status for the
command.

If you send a command to multiple instances, Amazon SNS can send messages about each copy or
invocation of the command that include the following information:
Field

Type

Description

EventTime

String

The time the event was
triggered. The time stamp
is important because SNS
does not guarantee message
delivery order. Example:
2016-04-26T13:15:30Z

DocumentName

String

The name of the SSM document
used to execute this command.

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Field

Type

Description

RequestedDateTime

String

The time and date the request
was sent to this specific
instance.

CommandId

String

The ID generated by Run
Command after the command
was sent.

InstanceId

String

The instance targeted by the
command.

Status

String

Command status for this
invocation.

Configure Account Permissions
When you send a command that is configured for notifications, you specify a service role Amazon
Resource Name (ARN). For example: --service-role-arn=arn:aws:iam::123456789012:myrole. This
service role is used by SSM to trigger SNS notifications.
To receive notifications from the Amazon SNS service, you must either attach the iam:PassRole
policy to your existing AWS Identity and Access Management (IAM) user account, or create a new
IAM account and attach this policy to it. If you create a new account, you must also attach the
AmazonSSMFullAccess policy so the account can communicate with the SSM API.
Use the following procedure to attach an IAM policy to your user account. If you need to create a new
user account, see Creating an IAM User in Your AWS Account in the IAM User Guide.

To attach the iam:PassRole policy to your user account
1.

Open the Identity and Access Management (IAM) console at https://console.aws.amazon.com/
iam/.

In the navigation pane at the left, choose Users and then double-click your user account.

At the top of the page, copy your User ARN to the clipboard.

In the Managed Policies section, verify that either the AmazonSSMFullAccess policy is listed or
there is a comparable policy that gives you permission to the SSM API.

Choose the down arrow beside Inline Policies, and then choose click here.

On the Set Permissions page, choose Policy Generator, and then choose Select.

Verify that Effect is set to Allow.

From AWS Services choose AWS Identity and Access Management.

From Actions choose PassRole.

10. In the Amazon Resource Name (ARN) field, paste your ARN.
11. Choose Add Statement, and then choose Next.
12. On the Review Policy page, choose Apply Policy.

Create an IAM Role for Notifications
In the previous procedure, you added an IAM policy to your user account so that you could send
commands that return notifications. In the following procedure, you will create a role so that the SSM
service can act on your behalf when sending notifications.

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Open the Identity and Access Management (IAM) console at https://console.aws.amazon.com/
iam/.

In the navigation pane, choose Roles, and then choose Create New Role.

In Step 1: Set Role Name enter a name that identifies this role as a Run Command role for
notifications.

In Step 2: Select Role Type choose Amazon EC2. The system skips Step 3: Establish Trust
because this is a managed policy.

In Step 4: Attach Policy choose AmazonSNSFullAccess.

Choose Next Step and then choose Create Role. The system returns you to the Roles page.

Locate the role you just created and double-click it.

Choose the Trust Relationships tab, and then choose Edit Trust Relationship.

Add "ssm.amazonaws.com" to the existing policy as the following code snippet illustrates:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "",
"Effect": "Allow",
"Principal": {
"Service": "ec2.amazonaws.com",
"Service": "ssm.amazonaws.com"
},
"Action": "sts:AssumeRole"
}
]
}

Note
You must add a comma after the existing entry. "Service": "sns.amazonaws.com", or the
JSON will not validate.
10. Choose Update Trust Policy.
11. Copy or make a note of the Role ARN. You will specify this ARN when you send a command that
is configured to return notifications.

Configure Amazon SNS
To use Amazon SNS to send email notifications, you must first create a topic and then subscribe your
email addresses to the topic.

Create an Amazon SNS Topic
An Amazon SNS topic is a logical access point, a communication channel that Run Command uses to
send the notifications. You create a topic by specifying a name for your topic.
For more information, see Create a Topic in the Amazon Simple Notification Service Developer Guide.

Note
After you create the topic, copy or make a note of the Topic ARN. You will specify this ARN
when you send a command that is configured to return status notifications.

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Subscribe to the Amazon SNS Topic
To receive the notifications that Run Command sends to the topic, you must subscribe an endpoint
to the topic. In this procedure, for Endpoint, specify the email address where you want to receive the
notifications from Run Command.
For more information, see Subscribe to a Topic in the Amazon Simple Notification Service Developer
Guide.

Confirm Your Amazon SNS Subscription
Amazon SNS sends a confirmation email to the email address that you specified in the previous step.
Make sure you open the email from AWS Notifications and choose the link to confirm the subscription
before you continue with the next step.
You will receive an acknowledgement message from AWS. Amazon SNS is now configured to receive
notifications and send the notification as an email to the email address that you specified.

Send a Command that Returns Status Notifications
This section shows you how to send a command that is configured to return status notifications using
either the Amazon EC2 console or the AWS Command Line Interface (AWS CLI).

To send a command from the Amazon EC2 console that returns notifications
1.

Open the Amazon EC2 console and choose Command History in the navigation pane.

Choose Run a Command.

In the Command document list, choose an SSM document.

Enter information in the fields required by the SSM document. In the SNS Notifications section,
choose Enable SNS notifications.

In the Role field, type or paste the IAM role ARN you created earlier.

In the SNS Topic field, type or paste the Amazon SNS ARN you created earlier.

In the Notify me on field, choose the events for which you want to receive notifications.

In the Notify me for field, choose to receive notifications for each copy of a command sent to
multiple instances (invocations) or the command summary.

10. Choose Run.
11. Check your email for a message from Amazon SNS and open the email. Amazon SNS can take a
few minutes to send the mail.

To send a command that is configured for notifications from the AWS CLI
1.

Open the AWS CLI.

Specify parameters in the following command.
aws ssm send-command --instance-ids "ID-1, ID-2" --document-name "name"
--parameters commands=date --service-role ServiceRole ARN --notificationconfig NotificationArn=SNS ARN

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For example
aws ssm send-command --instance-ids "i-12345678, i-34567890" -document-name "AWS-RunPowerShellScript" --parameters commands=date -service-role arn:aws-cn:iam:: 123456789012:myrole --notification-config
NotificationArn=arn:aws-cn:sns:cn-north-1:123456789012:test

Press Enter.

Check your email for a message from Amazon SNS and open the email. Amazon SNS can take a
few minutes to send the mail.

For more information about configuring Run Command from the command line, see Amazon EC2
Simple Systems Manager API Reference and the SSM AWS CLI Reference.

Log Command Execution Status Changes for Run
Command
You can use Amazon CloudWatch Events and a simple AWS Lambda function to log command
execution status changes. You can create a rule that runs whenever there is a state transition, or when
there is a transition to one or more states that are of interest.

Amazon EC2 Simple Systems Manager Event Types
SSM sends the following data to CloudWatch Events.
Example 1—EC2 Command Status-change Notification: This example includes information about
execution status changes for a command that was sent to multiple instances.
{
"version": "0",
"id": "6a7e8feb-b491-4cf7-a9f1-bf3703467718",
"detail-type": "EC2 Run Command – Command Status change",
"source": "aws.ssm",
"account": "123456789012",
"time": "2016-03-14T18:43:48Z",
"region": "us-east-1",
"resources": [
"arn:aws:ec2:us-east-1:123456789012:instance/i-12345678",
"arn:aws:ec2:us-east-1:123456789012:instance/i-12345670",
"arn:aws:ec2:us-east-1:123456789012:instance/i-12345679"
],
"detail": {
"command-id": "aws.ssm.12345678-1234-1234-1234-12345678",
"requested-date-time":"2016-03-14T18:43:48Z",
"expire-after":"2016-03-14T18:43:48Z",
"output-s3bucket-name":"mybucket",
"output-s3key-prefix":"test",
"parameters":"parameter",
"status": "Success"
}
}

Example 2—EC2 Command Invocation Status-change Notification: This example includes
information about a command that was sent to multiple instances, but the event shows details for only
one instance, or invocation of that command.

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{
"version": "0",
"id": "6a7e8feb-b491-4cf7-a9f1-bf3703467718",
"detail-type": "EC2 Run Command – Command Invocation Status change",
"source": "aws.ssm",
"account": "123456789012",
"time": "2016-03-14T18:43:48Z",
"region": "us-east-1",
"resources": [
"arn:aws:ec2:us-east-1:123456789012:instance/i-12345678"
],
"detail": {
"command-id": "aws.ssm.12345678-1234-1234-1234-12345678",
"instance-id":"i-12345678",
"requested-date-time":"2016-03-14T18:43:48Z",
"status": "Success"
}
}

Log SSM Command Execution Status Changes
In the following example scenario, you will create a simple AWS Lambda function, route events from
SSM to it, and then test your scenario to ensure that it's set up correctly.
To log command execution status changes for Run Command, you must do the following.
1. Step 1: Create an AWS Lambda Function (p. 402)
2. Step 2: Route Events to Your AWS Lambda Function (p. 403)
3. Step 3: Test Your Amazon CloudWatch Events Rule (p. 403)

Step 1: Create an AWS Lambda Function
To create an AWS Lambda function
1.

Open the AWS Lambda console at https://console.aws.amazon.com/lambda/.

Choose Create a Lambda function, and then on the Select blueprint screen, choose helloworld.

On the Configure function screen, in the Name field, type a name for the event. This example
uses SomethingHappened.

In the Lambda function code section, edit the sample code to match the following example:
console.log('Loading function');
exports.handler = function(event, context, callback) {
console.log('SomethingHappened()');
console.log('Here is the event:', JSON.stringify(event, null, 2));
callback(null, “Ready”);
};

Under Lambda function handler and role, in the Role field, if you have a
lambda_basic_execution_rule, select it. Otherwise, create a new basic execution role.

Choose Next, and then on the Review screen, choose Edit to make any changes. If you're
satisfied with the function, choose Create function.

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Step 2: Route Events to Your AWS Lambda Function
To create a CloudWatch Events rule
1.
2.
3.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.
In the navigation pane, choose Events.
Choose Create rule, and then under Event selector, choose EC2 instance state-change
notification.

4.
5.

Choose Specific state(s), and then Running from the list.
Do one of the following:
• To make the rule respond to any of your instances in the region, choose Any instance.

• To make the rule respond to a specific instance, choose Specific instance(s) and then in the
text box, enter the instance ID.
Under Targets, choose Add target. In the Select target type list, choose AWS Lambda
function.

In the Function list, select the function that you created in "Step 1: Create an AWS Lambda
Function."

Choose Configure input, and then choose one of the following options:
• Matched event
—Sends all of the data fields in the event to CloudWatch Logs.
• Part of the matched event
—Sends only the specified data field of the event to CloudWatch Logs. You specify the part of
the event using a string formatted $.first_parameter.second_parameter
For example, to send just the Amazon EC2 instance ID, type $.detail.state in the field.
• Constant

—Sends a JSON-formatted text string that you specify to CloudWatch Logs. For example, to
send a text string for the event, type {"Name":"MyInstance"}. The constant must be valid JSON.
Choose Configure details. On the Configure rule details screen, in the Name field, type a name
for the rule.

10. In the Description field, type a brief description for your rule, for example, Log command
execution status changes.
11. If you're satisfied with the rule, choose Create rule.

Step 3: Test Your Amazon CloudWatch Events Rule
You can test your rule by executing a command with Run Command. After waiting a few minutes
for the command to process, check your AWS Lambda metrics in the Amazon CloudWatch Events
console to verify that your function was invoked.

To test your CloudWatch Events rule using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane choose Command History, and then execute a command to one or more
instances. For more information about executing a command, see Executing a Command Using
Amazon EC2 Run Command (p. 374).
To view your AWS Lambda metrics, open the CloudWatch console https://
console.aws.amazon.com/cloudwatch/.
In the navigation pane, under Metrics, choose Lambda to view the metrics generated by your
Lambda function.

3.
4.

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5.
6.

To view the output from your function, in the navigation pane, choose Logs, and then in the Log
Groups list, select the /aws/lambda log group that contains the data.
Under Log Streams, select a log stream to view the data about command execution status
changes.

Troubleshooting Amazon EC2 Run Command
Use the following information to help troubleshoot problems with Run Command. For information about
troubleshooting Run Command for Windows, see Troubleshooting Run Command in the User Guide
for Windows.

Where Are My Instances?
If you do not see the expected list of instances when you choose Select Target instances then verify
that your instance is configured with an AWS Identity and Access Management (IAM) role that enables
the instance to communicate with the SSM API. Also verify that your user account has an IAM user
trust policy that enables your account to communicate with the SSM API. The following procedures
describe how to configure the instance role and the user trust policy.

Note
You must assign the IAM instance role when you create a new instance. You can't assign a
role to an instance that is already running. To configure an existing instance to use an SSMsupported role, you must create an image of the instance, launch an instance from that image,
and assign the IAM role as you launch the instance. For more information, see Creating an
Amazon EBS-Backed Linux AMI.

To create an instance that uses an SSM-supported role
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.
4.

Select a supported region.
Choose Launch Instance and select a Linux instance.
Choose your instance type and then choose Next: Configure Instance Details.

Beside IAM role choose Create new IAM role. The IAM console opens in a new tab.
a.
b.

Choose Create New Role.
In Step 1: Set Role Name, enter a name that identifies this role as a Run Command role.

In Step 2: Select Role Type, choose Amazon EC2 Role for Simple Systems Manager. The
system skips Step 3: Establish Trust because this is a managed policy.
In Step 4: Attach Policy, choose AmazonEC2RoleforSSM.
Choose Next Step, and then choose Create Role.

d.
e.
6.

f. Close the tab with the IAM console.
In the EC2 Management Console, choose the Refresh button beside Create New IAM role.

7.
8.

In the IAM role drop-down list, choose the role you just created.
Complete the wizard to create and launch the new instance.

Grant Your User Account Access to SSM
Use the following procedure to attach an the AmazonSSMFullAccess IAM policy to your user
account. This policy grants you full access to SSM API actions.

To create an IAM policy for EC2 instances
1.

Open the Identity and Access Management (IAM) console at https://console.aws.amazon.com/
iam/.

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In the navigation pane, choose Policies. (If this is your first time using IAM, choose Get Started,
and then choose Create Policy.)

In the Filter field, type AmazonSSMFullAccess and press Enter.

Select the checkbox next to AmazonSSMFullAccess and then choose Policy Actions, Attach.

On the Attach Policy page, choose your user account and then choose Attach Policy.

After you attach the policy, see if your instances are visible in the Select Target instances section of
the EC2 console. If they are not visible, then one or more of the prerequisites have not been met. For
more information, see Amazon EC2 Run Command Prerequisites (p. 355).

Check Instance Status Using the Health API
You can use the Amazon EC2 Health API to quickly determine the following information about Amazon
EC2 instances:
• The version of the SSM agent
• The status of one or more instances
• The operating system
• The status of the SSM agent
• The last time the instance sent a heartbeat value
Use the following command to get status details about one or more instances:
aws ssm describe-instance-information --instance-information-filter-list
key=InstanceIds,valueSet=instance-ID

Use the following command with no filters to see all instances registered to your account that are
currently reporting an online status. Substitute the ValueSet="Online" with "ConnectionLost" or
"Inactive" to view those statuses:
aws ssm describe-instance-information --instance-information-filter-list
key=PingStatus,valueSet=Online

Use the following command to see which instances are running the latest version of the SSM agent.
Substitute ValueSet="LATEST" with a specific version (for example, 1.0.145 or 1.0) to view those
details:
aws ssm describe-instance-information --instance-information-filter-list
key=AgentVersion,valueSet=LATEST

If the describe-instance-information API operation returns an AgentStatus of Online, then your instance
is ready to be managed using Run Command. If the status is Inactive, the instance has one or more of
the following problems.

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• The SSM agent is not installed. For more information, see Installing the SSM Agent (p. 357).
• The instance does not have outbound internet connectivity.
• The instance was not launched with an IAM role that enables it to communicate with the SSM API,
or the permissions for the IAM role are not correct for Run Command. For more information, see
Delegating Access to Amazon EC2 Run Command (p. 365).

Troubleshooting the Amazon SSM Agent
If you experience problems executing commands using Run Command, there might be a problem with
the SSM agent. Use the following information to help you troubleshoot the agent.
View Agent Logs
The SSM agent logs information in the following files using cihub/seelog. The information in these files
can help you troubleshoot problems.
• /var/log/amazon/ssm/amazon-ssm-agent.log
• /var/log/amazon/ssm/error.log
You can enable extended logging by updating the seelog.xml file. By default, the configuration file is
located here: /opt/amazon/ssm/seelog.xml.
For more information about cihub/seelog configuration, go to the cihub/seelog Wiki. For examples of
cihub/seelog configurations, go to cihub/seelog examples.

Importing and Exporting Virtual Machines
You can use the Amazon Web Services (AWS) VM Import/Export tools to import virtual machine
(VM) images from your local environment into AWS and convert them into ready-to-use Amazon EC2
Amazon machine images (AMIs) or instances. Later, you can export the VM images back to your
local environment as an instance. VM Import/Export allows you to leverage your existing investments
in the VMs that you have built to meet your IT security, configuration management, and compliance
requirements by bringing those VMs into Amazon Elastic Compute Cloud (Amazon EC2) as ready-touse AMIs or instances.
For more information, see VM Import/Export and the VM Import/Export User Guide.

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Monitoring Amazon EC2
Monitoring is an important part of maintaining the reliability, availability, and performance of your
Amazon Elastic Compute Cloud (Amazon EC2) instances and your AWS solutions. You should collect
monitoring data from all of the parts in your AWS solutions so that you can more easily debug a multipoint failure if one occurs. Before you start monitoring Amazon EC2, however, you should create a
monitoring plan that should include:
• What are your goals for monitoring?
• What resources you will monitor?
• How often you will monitor these resources?
• What monitoring tools will you use?
• Who will perform the monitoring tasks?
• Who should be notified when something goes wrong?
After you have defined your monitoring goals and have created your monitoring plan, the next step is
to establish a baseline for normal Amazon EC2 performance in your environment. You should measure
Amazon EC2 performance at various times and under different load conditions. As you monitor
Amazon EC2, you should store a history of monitoring data that you've collected. You can compare
current Amazon EC2 performance to this historical data to help you to identify normal performance
patterns and performance anomalies, and devise methods to address them. For example, you can
monitor CPU utilization, disk I/O, and network utilization for your Amazon EC2 instances. When
performance falls outside your established baseline, you might need to reconfigure or optimize the
instance to reduce CPU utilization, improve disk I/O, or reduce network traffic.
To establish a baseline you should, at a minimum, monitor the following items:
Item to Monitor

Amazon EC2 Metric

CPU utilization

CPUUtilization (p. 421)

Memory utilization

Monitoring Script/CloudWatch
Logs

(Linux instances) Monitoring
Memory and Disk Metrics for
Amazon EC2 Linux Instances
(Windows instances) Sending
Performance Counters to CW;
and Logs to CloudWatch Logs

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Item to Monitor

Amazon EC2 Metric

Memory used

Monitoring Script/CloudWatch
Logs
(Linux instances) Monitoring
Memory and Disk Metrics for
Amazon EC2 Linux Instances
(Windows instances) Sending
Performance Counters to CW;
and Logs to CloudWatch Logs

Memory available

(Linux instances) Monitoring
Memory and Disk Metrics for
Amazon EC2 Linux Instances
(Windows instances) Sending
Performance Counters to CW;
and Logs to CloudWatch Logs

Network utilization

NetworkIn (p. 421)
NetworkOut (p. 421)

Disk performance

DiskReadOps (p. 421)
DiskWriteOps (p. 421)

Disk Swap utilization (Linux
instances only)

Monitoring Memory and Disk
Metrics for Amazon EC2 Linux
Instances

Swap used (Linux instances
only)
Page File utilization (Windows
instances only)

Sending Performance Counters
to CW; and Logs to CloudWatch
Logs

Page File used (Windows
instances only)
Page File available (Windows
instances only)
Disk Reads/Writes

DiskReadBytes (p. 421)
DiskWriteBytes (p. 421)

Disk Space utilization (Linux
instances only)

Monitoring Memory and Disk
Metrics for Amazon EC2 Linux
Instances

Disk Space used (Linux
instances only)

Monitoring Memory and Disk
Metrics for Amazon EC2 Linux
Instances

Disk Space available (Linux
instances only)

Monitoring Memory and Disk
Metrics for Amazon EC2 Linux
Instances

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Automated and Manual Monitoring
AWS provides various tools that you can use to monitor Amazon EC2. You can configure some of
these tools to do the monitoring for you, while some of the tools require manual intervention.
Topics
• Automated Monitoring Tools (p. 409)
• Manual Monitoring Tools (p. 410)

Automated Monitoring Tools
You can use the following automated monitoring tools to watch Amazon EC2 and report back to you
when something is wrong:
• System Status Checks - monitor the AWS systems required to use your instance to ensure they are
working properly. These checks detect problems with your instance that require AWS involvement to
repair. When a system status check fails, you can choose to wait for AWS to fix the issue or you can
resolve it yourself (for example, by stopping and restarting or terminating and replacing an instance).
Examples of problems that cause system status checks to fail include:
• Loss of network connectivity
• Loss of system power
• Software issues on the physical host
• Hardware issues on the physical host
For more information, see Status Checks for Your Instances (p. 411).
• Instance Status Checks - monitor the software and network configuration of your individual
instance. These checks detect problems that require your involvement to repair. When an instance
status check fails, typically you will need to address the problem yourself (for example by rebooting
the instance or by making modifications in your operating system). Examples of problems that may
cause instance status checks to fail include:
• Failed system status checks
• Misconfigured networking or startup configuration
• Exhausted memory
• Corrupted file system
• Incompatible kernel
For more information, see Status Checks for Your Instances (p. 411).
• Amazon CloudWatch Alarms - watch a single metric over a time period you specify, and perform
one or more actions based on the value of the metric relative to a given threshold over a number of
time periods. The action is a notification sent to an Amazon Simple Notification Service (Amazon
SNS) topic or Auto Scaling policy. Alarms invoke actions for sustained state changes only.
CloudWatch alarms will not invoke actions simply because they are in a particular state, the state
must have changed and been maintained for a specified number of periods. For more information,
see Monitoring Your Instances Using CloudWatch (p. 419).
• Amazon CloudWatch Logs - monitor, store, and access your log files from Amazon EC2 instances,
AWS CloudTrail, or other sources. For more information, see Monitoring Log Files.
• Amazon EC2 Monitoring Scripts - Perl scripts that can monitor memory, disk, and swap file usage
in your instances. For more information, see Monitoring Memory and Disk Metrics for Amazon EC2
Linux Instances.
• AWS Management Pack for Microsoft System Center Operations Manager - links Amazon
EC2 instances and the Windows or Linux operating systems running inside them. The AWS
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Management Pack is an extension to Microsoft System Center Operations Manager. It uses a
designated computer in your datacenter (called a watcher node) and the Amazon Web Services
APIs to remotely discover and collect information about your AWS resources. For more information,
see AWS Management Pack for Microsoft System Center.

Manual Monitoring Tools
Another important part of monitoring Amazon EC2 involves manually monitoring those items that
the monitoring scripts, status checks, and CloudWatch alarms don't cover. The Amazon EC2 and
CloudWatch console dashboards provide an at-a-glance view of the state of your Amazon EC2
environment.
• Amazon EC2 Dashboard shows:
• Service Health and Scheduled Events by region
• Instance state
• Status checks
• Alarm status
• Instance metric details (In the navigation pane click Instances, select an instance, and then click
the Monitoring tab)
• Volume metric details (In the navigation pane click Volumes, select a volume, and then click the
Monitoring tab)
• Amazon CloudWatch Dashboard shows:
• Current alarms and status
• Graphs of alarms and resources
• Service health status
In addition, you can use CloudWatch to do the following:
• Graph Amazon EC2 monitoring data to troubleshoot issues and discover trends
• Search and browse all your AWS resource metrics
• Create and edit alarms to be notified of problems
• See at-a-glance overviews of your alarms and AWS resources

Best Practices for Monitoring
Use the following best practices for monitoring to help you with your Amazon EC2 monitoring tasks.
• Make monitoring a priority to head off small problems before they become big ones.
• Create and implement a monitoring plan that collects monitoring data from all of the parts in your
AWS solution so that you can more easily debug a multi-point failure if one occurs. Your monitoring
plan should address, at a minimum, the following questions:
• What are your goals for monitoring?
• What resources you will monitor?
• How often you will monitor these resources?
• What monitoring tools will you use?
• Who will perform the monitoring tasks?
• Who should be notified when something goes wrong?
• Automate monitoring tasks as much as possible.
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Monitoring the Status of Your Instances
You can monitor the status of your instances by viewing status checks and scheduled events for your
instances. A status check gives you the information that results from automated checks performed by
Amazon EC2. These automated checks detect whether specific issues are affecting your instances.
The status check information, together with the data provided by Amazon CloudWatch, gives you
detailed operational visibility into each of your instances.
You can also see status on specific events scheduled for your instances. Events provide information
about upcoming activities such as rebooting or retirement that are planned for your instances, along
with the scheduled start and end time of each event.
Contents
• Status Checks for Your Instances (p. 411)
• Scheduled Events for Your Instances (p. 415)

Status Checks for Your Instances
With instance status monitoring, you can quickly determine whether Amazon EC2 has detected
any problems that might prevent your instances from running applications. Amazon EC2 performs
automated checks on every running EC2 instance to identify hardware and software issues. You
can view the results of these status checks to identify specific and detectable problems. This data
augments the information that Amazon EC2 already provides about the intended state of each instance
(such as pending, running, stopping) as well as the utilization metrics that Amazon CloudWatch
monitors (CPU utilization, network traffic, and disk activity).
Status checks are performed every minute and each returns a pass or a fail status. If all checks pass,
the overall status of the instance is OK. If one or more checks fail, the overall status is impaired.
Status checks are built into Amazon EC2, so they cannot be disabled or deleted. You can, however
create or delete alarms that are triggered based on the result of the status checks. For example, you
can create an alarm to warn you if status checks fail on a specific instance. For more information, see
Creating and Editing Status Check Alarms (p. 414).
Contents
• Types of Status Checks (p. 411)
• Viewing Status Checks (p. 412)
• Reporting Instance Status (p. 413)
• Creating and Editing Status Check Alarms (p. 414)

Types of Status Checks
There are two types of status checks: system status checks and instance status checks.
System Status Checks
Monitor the AWS systems required to use your instance to ensure they are working properly. These
checks detect problems with your instance that require AWS involvement to repair. When a system
status check fails, you can choose to wait for AWS to fix the issue, or you can resolve it yourself (for
example, by stopping and starting an instance, or by terminating and replacing an instance).
The following are examples of problems that can cause system status checks to fail:
• Loss of network connectivity
• Loss of system power

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Instance Status Checks

• Software issues on the physical host
• Hardware issues on the physical host
Instance Status Checks
Monitor the software and network configuration of your individual instance. These checks detect
problems that require your involvement to repair. When an instance status check fails, typically you will
need to address the problem yourself (for example, by rebooting the instance or by making instance
configuration changes).
The following are examples of problems that can cause instance status checks to fail:
• Failed system status checks
• Incorrect networking or startup configuration
• Exhausted memory
• Corrupted file system
• Incompatible kernel

Viewing Status Checks
Amazon EC2 provides you with several ways to view and work with status checks.

Viewing Status Using the Console
You can view status checks using the AWS Management Console.

To view status checks using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.
4.

In the navigation pane, choose Instances.
On the Instances page, the Status Checks column lists the operational status of each instance.
To view the status of a specific instance, select the instance, and then choose the Status Checks
tab.

If you have an instance with a failed status check and the instance has been unreachable for over
20 minutes, choose AWS Support to submit a request for assistance. To troubleshoot system
or instance status check failures yourself, see Troubleshooting Instances with Failed Status
Checks (p. 782).

Viewing Status Using the Command Line or API
You can view status checks for running instances using the describe-instance-status (AWS CLI)
command.

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Instance Status Checks

To view the status of all instances, use the following command:
aws ec2 describe-instance-status

To get the status of all instances with a instance status of impaired:
aws ec2 describe-instance-status --filters Name=instancestatus.status,Values=impaired

To get the status of a single instance, use the following command:
aws ec2 describe-instance-status --instance-ids i-1234567890abcdef0

Alternatively, use the following commands:
• Get-EC2InstanceStatus (AWS Tools for Windows PowerShell)
• DescribeInstanceStatus (Amazon EC2 Query API)
If you have an instance with a failed status check, see Troubleshooting Instances with Failed Status
Checks (p. 782).

Reporting Instance Status
You can provide feedback if you are having problems with an instance whose status is not shown as
impaired, or want to send AWS additional details about the problems you are experiencing with an
impaired instance.
We use reported feedback to identify issues impacting multiple customers, but do not respond to
individual account issues. Providing feedback does not change the status check results that you
currently see for the instance.

Reporting Status Feedback Using the Console
To report instance status using the console
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Instances.

3.
4.

Select the instance.
Select the Status Checks tab, and then choose Submit feedback.

Complete the Report Instance Status form, and then choose Submit.

Reporting Status Feedback Using the Command Line or API
Use the following report-instance-status (AWS CLI) command to send feedback about the status of an
impaired instance:
aws ec2 report-instance-status --instances i-1234567890abcdef0 --status
impaired --reason-codes code

Alternatively, use the following commands:
• Send-EC2InstanceStatus (AWS Tools for Windows PowerShell)
• ReportInstanceStatus (Amazon EC2 Query API)

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Instance Status Checks

Creating and Editing Status Check Alarms
You can create instance status and system status alarms to notify you when an instance has a failed
status check.

Creating a Status Check Alarm Using the Console
You can create status check alarms for an existing instance to monitor instance status or system
status. You can configure the alarm to send you a notification by email or stop, terminate, or recover an
instance when it fails an instance status check or system status check.

To create a status check alarm
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances.

Select the instance.

Select the Status Checks tab, and then choose Create Status Check Alarm.

Select Send a notification to. Choose an existing SNS topic, or click create topic to create a
new one. If creating a new topic, in With these recipients, enter your email address and the
addresses of any additional recipients, separated by commas.

(Optional) Choose Take the action, and then select the action that you'd like to take.

In Whenever, select the status check that you want to be notified about.

Note
If you selected Recover this instance in the previous step, select Status Check Failed
(System).
8.

In For at least, set the number of periods you want to evaluate and in consecutive periods,
select the evaluation period duration before triggering the alarm and sending an email.

(Optional) In Name of alarm, replace the default name with another name for the alarm.

10. Choose Create Alarm.

Important
If you added an email address to the list of recipients or created a new topic, Amazon
SNS sends a subscription confirmation email message to each new address. Each
recipient must confirm the subscription by clicking the link contained in that message.
Alert notifications are sent only to confirmed addresses.
If you need to make changes to an instance status alarm, you can edit it.

To edit a status check alarm
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances.

Select the instance, choose Actions, select CloudWatch Monitoring, and then choose Add/Edit
Alarms.

In the Alarm Details dialog box, choose the name of the alarm.

In the Edit Alarm dialog box, make the desired changes, and then choose Save.

Creating a Status Check Alarm Using the AWS CLI
In the following example, the alarm publishes a notification to an SNS topic, arn:aws:sns:uswest-2:111122223333:my-sns-topic, when the instance fails either the instance check or system
status check for at least two consecutive periods. The metric is StatusCheckFailed.

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Scheduled Events

To create a status check alarm using the CLI
1.
2.

Select an existing SNS topic or create a new one. For more information, see Using the AWS CLI
with Amazon SNS in the AWS Command Line Interface User Guide.
Use the following list-metrics command to view the available Amazon CloudWatch metrics for
Amazon EC2:
aws cloudwatch list-metrics --namespace AWS/EC2

Use the following put-metric-alarm command to create the alarm:
aws cloudwatch put-metric-alarm --alarm-name StatusCheckFailed-Alarm-fori-1234567890abcdef0 --metric-name StatusCheckFailed --namespace AWS/EC2 -statistic Maximum --dimensions Name=InstanceId,Value=i-1234567890abcdef0
--unit Count --period 300 --evaluation-periods 2 --threshold
1 --comparison-operator GreaterThanOrEqualToThreshold --alarmactions arn:aws:sns:us-west-2:111122223333:my-sns-topic

Note
• --period is the time frame, in seconds, in which Amazon CloudWatch metrics are collected.
This example uses 300, which is 60 seconds multiplied by 5 minutes.
• --evaluation-periods is the number of consecutive periods for which the value of the
metric must be compared to the threshold. This example uses 2.
• --alarm-actions is the list of actions to perform when this alarm is triggered. Each action is
specified as an Amazon Resource Name (ARN). This example configures the alarm to send an
email using Amazon SNS.

Scheduled Events for Your Instances
AWS can schedule events for your instances, such as a reboot, stop/start, or retirement. These events
do not occur frequently. If one of your instances will be affected by a scheduled event, AWS sends an
email to the email address that's associated with your AWS account prior to the scheduled event, with
details about the event, including the start and end date. Depending on the event, you might be able to
take action to control the timing of the event.
To update the contact information for your account so that you can be sure to be notified about
scheduled events, go to the Account Settings page.
Contents
•
•
•
•

Types of Scheduled Events (p. 415)
Viewing Scheduled Events (p. 416)
Working with Instances Scheduled for Retirement (p. 417)
Working with Instances Scheduled for Reboot (p. 418)

• Working with Instances Scheduled for Maintenance (p. 418)

Types of Scheduled Events
Amazon EC2 supports the following types of scheduled events for your instances:
• Instance stop: The instance will be stopped. When you start it again, it's migrated to a new host
computer. Applies only to instances backed by Amazon EBS.
• Instance retirement: The instance will be stopped or terminated.

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• Reboot: Either the instance will be rebooted (instance reboot) or the host computer for the instance
will be rebooted (system reboot).
• System maintenance: The instance might be temporarily affected by network maintenance or
power maintenance.

Viewing Scheduled Events
In addition to receiving notification of scheduled events in email, you can check for scheduled events.

To view scheduled events for your instances using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, click Events. Any resources with an associated event are displayed. You
can filter by resource type, or by specific event types. You can select the resource to view details.

Alternatively, in the navigation pane, choose EC2 Dashboard. Any resources with an associated
event are displayed under Scheduled Events.

Note that events are also shown for affected resource. For example, in the navigation pane,
choose Instances, and then select an instance. If the instance has an associated event, it is
displayed in the lower pane.

To view scheduled events for your instances using the command line or API
Use the following AWS CLI command:
aws ec2 describe-instance-status --instance-id i-1234567890abcdef0

The following is example output showing an instance retirement event:
{
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"InstanceStatuses": [
{
"InstanceStatus": {
"Status": "ok",
"Details": [
{
"Status": "passed",
"Name": "reachability"
}
]
},
"AvailabilityZone": "us-west-2a",
"InstanceId": "i-1234567890abcdef0",
"InstanceState": {
"Code": 16,
"Name": "running"
},
"SystemStatus": {
"Status": "ok",
"Details": [
{
"Status": "passed",
"Name": "reachability"
}
]
},
"Events": [
{
"Code": "instance-stop",
"Description": "The instance is running on degraded
hardware",
"NotBefore": "2015-05-23T00:00:00.000Z"
}
]
}
]
}

Alternatively, use the following commands:
• Get-EC2InstanceStatus (AWS Tools for Windows PowerShell)
• DescribeInstanceStatus (Amazon EC2 Query API)

Working with Instances Scheduled for Retirement
When AWS detects irreparable failure of the underlying host computer for your instance, it
schedules the instance to stop or terminate, depending on the type of root device for the instance.
If the root device is an EBS volume, the instance is scheduled to stop. If the root device is an
instance store volume, the instance is scheduled to terminate. For more information, see Instance
Retirement (p. 303).

Important
Any data stored on instance store volumes is lost when an instance is stopped or terminated.
This includes instance store volumes that are attached to an instance that has an EBS volume
as the root device. Be sure to save data from your instance store volumes that you will need
later before the instance is stopped or terminated.
Actions for Instances Backed by Amazon EBS

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You can wait for the instance to stop as scheduled. Alternatively, you can stop and start the instance
yourself, which migrates it to a new host computer. For more information about stopping your instance,
as well as information about the changes to your instance configuration when it's stopped, see Stop
and Start Your Instance (p. 299).
Actions for Instances Backed by Instance Store
We recommend that you launch a replacement instance from your most recent AMI and migrate all
necessary data to the replacement instance before the instance is scheduled to terminate. Then, you
can terminate the original instance, or wait for it to terminate as scheduled.

Working with Instances Scheduled for Reboot
When AWS needs to perform tasks such as installing updates or maintaining the underlying host
computer, it can schedule an instance or the underlying host computer for the instance for a reboot.
Regardless of any existing instances that are scheduled for reboot, a new instance launch does not
require a reboot, as the updates are already applied on the underlying host.
You can determine whether the reboot event is an instance reboot or a system reboot.

To view the type of scheduled reboot event using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Events.

3.
4.

Select Instance resources from the filter list, and then select your instance.
In the bottom pane, locate Event type. The value is either system-reboot or instancereboot.

To view the type of scheduled reboot event using the AWS CLI
Use the following describe-instance-status command:
aws ec2 describe-instance-status --instance-ids i-1234567890abcdef0

Actions for Instance Reboot
You can wait for the reboot to occur within its scheduled maintenance window. Alternatively, you can
reboot your instance yourself at a time that is convenient for you. For more information, see Reboot
Your Instance (p. 302).
After you reboot your instance, the scheduled event for the instance reboot is canceled immediately
and the event's description is updated. The pending maintenance to the underlying host computer is
completed, and you can begin using your instance again after it has fully booted.
Actions for System Reboot
No action is required on your part; the system reboot occurs during its scheduled maintenance window.
A system reboot typically completes in a matter of minutes. To verify that the reboot has occurred,
check that there is no longer a scheduled event for the instance. We recommend that you check
whether the software on your instance is operating as you expect.

Working with Instances Scheduled for Maintenance
When AWS needs to maintain the underlying host computer for an instance, it schedules the instance
for maintenance. There are two types of maintenance events: network maintenance and power
maintenance.
During network maintenance, scheduled instances lose network connectivity for a brief period of time.
Normal network connectivity to your instance will be restored after maintenance is complete.

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During power maintenance, scheduled instances are taken offline for a brief period, and then rebooted.
When a reboot is performed, all of your instance's configuration settings are retained.
After your instance has rebooted (this normally takes a few minutes), verify that your application is
working as expected. At this point, your instance should no longer have a scheduled event associated
with it, or the description of the scheduled event begins with [Completed]. It sometimes takes up to 1
hour for this instance status to refresh. Completed maintenance events are displayed on the Amazon
EC2 console dashboard for up to a week.
Actions for Instances Backed by Amazon EBS
You can wait for the maintenance to occur as scheduled. Alternatively, you can stop and start the
instance, which migrates it to a new host computer. For more information about stopping your instance,
as well as information about the changes to your instance configuration when it's stopped, see Stop
and Start Your Instance (p. 299).
Actions for Instances Backed by Instance Store
You can wait for the maintenance to occur as scheduled. Alternatively, if you want to maintain normal
operation during a scheduled maintenance window, you can launch a replacement instance from
your most recent AMI, migrate all necessary data to the replacement instance before the scheduled
maintenance window, and then terminate the original instance.

Monitoring Your Instances Using CloudWatch
You can monitor your instances using Amazon CloudWatch, which collects and processes raw data
from Amazon EC2 into readable, near real-time metrics. These statistics are recorded for a period of
two weeks, so that you can access historical information and gain a better perspective on how your
web application or service is performing.
By default, Amazon EC2 sends metric data to CloudWatch in 5-minute periods. To send metric data for
your instance to CloudWatch in 1-minute periods, you can enable detailed monitoring on the instance.
For more information, see Enable or Disable Detailed Monitoring for Your Instances (p. 419).
The Amazon EC2 console displays a series of graphs based on the raw data from Amazon
CloudWatch. Depending on your needs, you might prefer to get data for your instances from Amazon
CloudWatch instead of the graphs in the console.
For more information about Amazon CloudWatch, see the Amazon CloudWatch Developer Guide.
Contents
• Enable or Disable Detailed Monitoring for Your Instances (p. 419)
• List the Available CloudWatch Metrics for Your Instances (p. 421)
• Get Statistics for Metrics for Your Instances (p. 426)
• Graph Metrics for Your Instances (p. 441)
• Create a CloudWatch Alarm (p. 444)
• Create Alarms That Stop, Terminate, Reboot, or Recover an Instance (p. 450)

Enable or Disable Detailed Monitoring for Your
Instances
By default, your instance is enabled for basic monitoring. You can optionally enable detailed
monitoring. After you enable detailed monitoring, the Amazon EC2 console displays monitoring graphs
with a 1-minute period for the instance. The following table describes basic and detailed monitoring for
instances.

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Enable Detailed Monitoring

Type

Description

Basic

Data is available automatically in 5-minute
periods at no charge.

Detailed

Data is available in 1-minute periods for an
additional cost. To get this level of data, you
must specifically enable it for the instance. For
the instances where you've enabled detailed
monitoring, you can also get aggregated data
across groups of similar instances.
For information about pricing, see the Amazon
CloudWatch product page.

Enabling Detailed Monitoring
You can enable detailed monitoring on an instance as you launch it or after the instance is running or
stopped.

To enable detailed monitoring for an existing instance using the console
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, click Instances.

Select the instance, click Actions, select CloudWatch Monitoring, and then click Enable
Detailed Monitoring.

4.
5.

In the Enable Detailed Monitoring dialog box, click Yes, Enable.
In the Enable Detailed Monitoring confirmation dialog box, click Close.

To enable detailed monitoring when launching an instance using the console
When launching an instance using the AWS Management Console, select the Monitoring check box
on the Configure Instance Details page.
To enable detailed monitoring for an existing instance using the AWS CLI
Use the following monitor-instances command to enable detailed monitoring for the specified
instances.
$ aws ec2 monitor-instances --instance-ids i-1234567890abcdef0

To enable detailed monitoring when launching an instance using the AWS CLI
Use the run-instances command with the --monitoring flag to enable detailed monitoring.
$ aws ec2 run-instances --image-id ami-09092360 --monitoring Enabled=true...

Disabling Detailed Monitoring
You can disable detailed monitoring on an instance as you launch it or after the instance is running or
stopped.

To disable detailed monitoring using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

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In the navigation pane, click Instances.

3.
4.

Select the instance, click Actions, select CloudWatch Monitoring, and then click Disable
Detailed Monitoring.
In the Disable Detailed Monitoring dialog box, click Yes, Disable.

In the Disable Detailed Monitoring confirmation dialog box, click Close.

To disable detailed monitoring using the AWS CLI
Use the following unmonitor-instances command to disable detailed monitoring for the specified
instances.
$ aws ec2 unmonitor-instances --instance-ids i-1234567890abcdef0

List the Available CloudWatch Metrics for Your
Instances
Amazon EC2 sends metrics to Amazon CloudWatch. You can use the AWS Management Console, the
AWS CLI, or an API to list the metrics that Amazon EC2 sends to CloudWatch. By default, each data
point covers the previous 5 minutes of activity for the instance. If you've enabled detailed monitoring,
each data point covers the previous 1 minute of activity.
For information about getting the statistics for these metrics, see Get Statistics for Metrics for Your
Instances (p. 426).

Instance Metrics
The following table describes the metrics for your instances. For information about the metrics provided
for your EBS volumes, see Amazon EBS Metrics (p. 658). For information about the metrics provided
for your Spot fleets, see CloudWatch Metrics for Spot Fleet (p. 251).
The AWS/EC2 namespace includes the following metrics.
Metric

Description

CPUCreditUsage

Note
CPU Credit metrics are available at a 5 minute frequency.
Units: Count
CPUCreditBalance

Note
CPU Credit metrics are available at a 5 minute frequency.
Units: Count

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Metric

Description

CPUUtilization

The percentage of allocated EC2 compute units that are currently
in use on the instance. This metric identifies the processing power
required to run an application upon a selected instance.

Note
Depending on the instance type, tools in your operating
system may show a lower percentage than CloudWatch
when the instance is not allocated a full processor core.
Units: Percent
DiskReadOps

Completed read operations from all instance store volumes
available to the instance in a specified period of time.

Note
To calculate the average I/O operations per second
(IOPS) for the period, divide the total operations in the
period by the number of seconds in that period.
Units: Count
DiskWriteOps

Completed write operations to all instance store volumes available
to the instance in a specified period of time.

Note
To calculate the average I/O operations per second
(IOPS) for the period, divide the total operations in the
period by the number of seconds in that period.
Units: Count
DiskReadBytes

Bytes read from all instance store volumes available to the
instance.
This metric is used to determine the volume of the data the
application reads from the hard disk of the instance. This can be
used to determine the speed of the application.
Units: Bytes

DiskWriteBytes

Bytes written to all instance store volumes available to the
instance.
This metric is used to determine the volume of the data the
application writes onto the hard disk of the instance. This can be
used to determine the speed of the application.
Units: Bytes

NetworkIn

The number of bytes received on all network interfaces by the
instance. This metric identifies the volume of incoming network
traffic to an application on a single instance.
Units: Bytes

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Metric

Description

NetworkOut

The number of bytes sent out on all network interfaces by the
instance. This metric identifies the volume of outgoing network
traffic to an application on a single instance.
Units: Bytes

NetworkPacketsIn

The number of packets received on all network interfaces by the
instance. This metric identifies the volume of incoming traffic in
terms of the number of packets on a single instance. This metric is
available for basic monitoring only.
Units: Count
Statistics: Minimum, Maximum, Average

NetworkPacketsOut

The number of packets sent out on all network interfaces by the
instance. This metric identifies the volume of outgoing traffic in
terms of the number of packets on a single instance. This metric is
available for basic monitoring only.
Units: Count
Statistics: Minimum, Maximum, Average

StatusCheckFailed

A combination of StatusCheckFailed_Instance and
StatusCheckFailed_System that reports if either of the status
checks has failed. Values for this metric are either 0 (zero) or
1 (one.) A zero indicates that the status check passed. A one
indicates a status check failure.

Note
Status check metrics are available at 1 minute frequency.
For a newly-launched instance, status check metric data
is only available after the instance has completed the
initialization state. Status check metrics become available
within a few minutes of the instance being in the running
state.
Units: Count
StatusCheckFailed_InstanceReports whether the instance has passed the Amazon EC2
instance status check in the last minute. Values for this metric are
either 0 (zero) or 1 (one.) A zero indicates that the status check
passed. A one indicates a status check failure.

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Metric

Description

StatusCheckFailed_System

Reports whether the instance has passed the EC2 system status
check in the last minute. Values for this metric are either 0 (zero)
or 1 (one.) A zero indicates that the status check passed. A one
indicates a status check failure.

Note
Status check metrics are available at a 1 minute
frequency. For a newly-launched instance, status check
metric data is only available after the instance has
completed the initialization state. Status check metrics
become available within a few minutes of the instance
being in the running state.
Units: Count

Amazon EC2 Dimensions
You can use the dimensions in the following table to refine the metrics returned for your instances.
Dimension

Description

AutoScalingGroupName

This dimension filters the data you request for all instances in a
specified capacity group. An Auto Scaling group is a collection of
instances you define if you're using Auto Scaling. This dimension
is available only for Amazon EC2 metrics when the instances
are in such an Auto Scaling group. Available for instances with
Detailed or Basic Monitoring enabled.

ImageId

This dimension filters the data you request for all instances running
this Amazon EC2 Amazon Machine Image (AMI). Available for
instances with Detailed Monitoring enabled.

InstanceId

This dimension filters the data you request for the identified
instance only. This helps you pinpoint an exact instance from
which to monitor data.

InstanceType

This dimension filters the data you request for all instances
running with this specified instance type. This helps you categorize
your data by the type of instance running. For example, you
might compare data from an m1.small instance and an m1.large
instance to determine which has the better business value for
your application. Available for instances with Detailed Monitoring
enabled.

Listing Metrics Using the Console
You can view metrics by category. Metrics are grouped first by namespace, and then by the various
dimension combinations within each namespace. For example, you can view all metrics provided by
Amazon EC2, or metrics grouped by instance ID, instance type, image (AMI) ID, or Auto Scaling group.

To view available metrics by category
1.
2.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.
If necessary, from the navigation bar, change the region to match the region where you have your
instances.

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In the navigation pane, click Metrics.

In the CloudWatch Metrics by Category pane, under EC2 Metrics, select Per-Instance Metrics.

In the upper pane, scroll down to view the full list of metrics.

Listing Metrics Using the AWS CLI
Use the list-metrics command to list the CloudWatch metrics for your instances.
To list the available metrics across all instances
Specify the AWS/EC2 namespace to limit the results to the metrics sent by Amazon EC2.
$ aws cloudwatch list-metrics --namespace AWS/EC2

The following is example output:

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...
{
"Namespace": "AWS/EC2",
"Dimensions": [
{
"Name": "InstanceId",
"Value": "i-1234567890abcdef0"
}
],
"MetricName": "NetworkOut"
},
{
"Namespace": "AWS/EC2",
"Dimensions": [
{
"Name": "InstanceId",
"Value": "i-1234567890abcdef0"
}
],
"MetricName": "CPUUtilization"
},
{
"Namespace": "AWS/EC2",
"Dimensions": [
{
"Name": "InstanceId",
"Value": "i-1234567890abcdef0"
}
],
"MetricName": "NetworkIn"
},
...

To list the available metrics for a specified instance
Specify the AWS/EC2 namespace and the InstanceId dimension to limit the results to metrics sent by
Amazon EC2 for the specified instance.
$ aws cloudwatch list-metrics --namespace AWS/EC2 --dimensions
Name=InstanceId,Value=i-1234567890abcdef0

To list a metric across all instances
Specify the AWS/EC2 namespace and the metric name to limit the results to the specified metric sent
by Amazon EC2.
$ aws cloudwatch list-metrics --namespace AWS/EC2 --metricname CPUUtilization

Get Statistics for Metrics for Your Instances
The following scenarios demonstrate how to get statics for the CloudWatch metrics for your instances.
Contents
• Get Statistics for a Specific Instance (p. 427)

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• Aggregate Statistics Across Instances (p. 430)
• Aggregate Statistics by Auto Scaling Group (p. 434)
• Aggregate Statistics by Image (AMI) ID (p. 437)

Get Statistics for a Specific Instance
The following scenario walks you through how to use the AWS Management Console or the getmetric-statistics command to determine the maximum CPU utilization of a specific EC2
instance.

Note
Start and end times must be within the last 14 days.
For this example, we assume that you have an EC2 instance ID. You can get an active EC2 instance
ID through the AWS Management Console or with the describe-instances command.

AWS Management Console
To display the CPU utilization for a specific instance using the console
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

If necessary, from the navigation bar, change the region to match the region where you have your
instances.

In the navigation pane, click Metrics.

In the CloudWatch Metrics by Category pane, select EC2: Metrics.

Select a row that contains CPUUtilization for a specific instance, which displays a graph for this
metric for the instance.

To change the statistic or the period for the metric, choose a different value from the list.

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AWS Command Line Interface
To get the CPU utilization for a specific instance using the AWS CLI
Use the following get-metric-statistics command.
$ aws cloudwatch get-metric-statistics --namespace AWS/EC2 --metricname CPUUtilization --period 3600 --statistics Maximum --dimensions
Name=InstanceId,Value=i-1234567890abcdef0 --start-time 2014-02-18T23:18:00
--end-time 2014-02-19T23:18:00

The returned statistics are six-minute values for the requested two-day time interval. Each value
represents the maximum CPU utilization percentage for a single EC2 instance. The following is
example output:
{
"Datapoints": [
{
"Timestamp": "2014-02-19T00:18:00Z",
"Maximum": 0.33000000000000002,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T03:18:00Z",
"Maximum": 99.670000000000002,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T07:18:00Z",
"Maximum": 0.34000000000000002,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T12:18:00Z",
"Maximum": 0.34000000000000002,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T02:18:00Z",

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"Maximum": 0.34000000000000002,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T01:18:00Z",
"Maximum": 0.34000000000000002,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T17:18:00Z",
"Maximum": 3.3900000000000001,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T13:18:00Z",
"Maximum": 0.33000000000000002,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-18T23:18:00Z",
"Maximum": 0.67000000000000004,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T06:18:00Z",
"Maximum": 0.34000000000000002,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T11:18:00Z",
"Maximum": 0.34000000000000002,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T10:18:00Z",
"Maximum": 0.34000000000000002,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T19:18:00Z",
"Maximum": 8.0,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T15:18:00Z",
"Maximum": 0.34000000000000002,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T14:18:00Z",
"Maximum": 0.34000000000000002,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T16:18:00Z",
"Maximum": 0.34000000000000002,
"Unit": "Percent"
},
{

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"Timestamp": "2014-02-19T09:18:00Z",
"Maximum": 0.34000000000000002,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T04:18:00Z",
"Maximum": 2.0,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T08:18:00Z",
"Maximum": 0.68000000000000005,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T05:18:00Z",
"Maximum": 0.33000000000000002,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-19T18:18:00Z",
"Maximum": 6.6699999999999999,
"Unit": "Percent"
}
],
"Label": "CPUUtilization"
}

Aggregate Statistics Across Instances
Aggregate statistics are available for the instances that have detailed monitoring enabled. Instances
that use basic monitoring are not included in the aggregates. In addition, Amazon CloudWatch does
not aggregate data across Regions. Therefore, metrics are completely separate between Regions.
Before you can get statistics aggregated across instances, you must enable detailed monitoring (at
an additional charge), which provides data in 1-minute periods. This scenario shows you how to use
detailed monitoring with either the AWS Management Console, the GetMetricStatistics API,
or the get-metric-statistics command to get the average CPU usage for your EC2 instances.
Because no dimension is specified, CloudWatch returns statistics for all dimensions in the AWS/EC2
namespace. To get statistics for other metrics, see Amazon CloudWatch Namespaces, Dimensions,
and Metrics Reference.

Important
This technique for retrieving all dimensions across an AWS namespace does not work for
custom namespaces that you publish to Amazon CloudWatch. With custom namespaces, you
must specify the complete set of dimensions that are associated with any given data point to
retrieve statistics that include the data point.

AWS Management Console
To display average CPU utilization across your instances
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

If necessary, from the navigation bar, change the region to match the region where you have your
instances.

In the navigation pane, click Metrics.

In the CloudWatch Metrics by Category pane, under EC2 Metrics, select Across All Instances.

In the upper pane, select the row that contains CPUUtilization.

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A graph showing CPUUtilization for your EC2 instances is displayed in the details pane.

To change the statistic or period for the metric, choose a different value from the list.

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AWS Command Line Interface
To get average CPU utilization across your instances
Use the get-metric-statistics command as follows.
$ aws cloudwatch get-metric-statistics --namespace AWS/EC2 --metric-name
CPUUtilization --period 3600 --statistics "Average" "SampleCount" --starttime 2014-02-11T23:18:00 --end-time 2014-02-12T23:18:00

The following is example output:
{
"Datapoints": [
{
"SampleCount": 238.0,
"Timestamp": "2014-02-12T07:18:00Z",
"Average": 0.038235294117647062,
"Unit": "Percent"
},
{
"SampleCount": 240.0,
"Timestamp": "2014-02-12T09:18:00Z",
"Average": 0.16670833333333332,
"Unit": "Percent"
},
{
"SampleCount": 238.0,
"Timestamp": "2014-02-11T23:18:00Z",
"Average": 0.041596638655462197,
"Unit": "Percent"
},
{
"SampleCount": 240.0,
"Timestamp": "2014-02-12T16:18:00Z",
"Average": 0.039458333333333345,
"Unit": "Percent"
},
{
"SampleCount": 239.0,
"Timestamp": "2014-02-12T21:18:00Z",
"Average": 0.041255230125523033,
"Unit": "Percent"
},
{
"SampleCount": 240.0,
"Timestamp": "2014-02-12T01:18:00Z",
"Average": 0.044583333333333336,
"Unit": "Percent"
},
{
"SampleCount": 239.0,
"Timestamp": "2014-02-12T18:18:00Z",
"Average": 0.043054393305439344,
"Unit": "Percent"
},
{
"SampleCount": 240.0,

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"Timestamp": "2014-02-12T13:18:00Z",
"Average": 0.039458333333333345,
"Unit": "Percent"
},
{
"SampleCount": 238.0,
"Timestamp": "2014-02-12T15:18:00Z",
"Average": 0.041260504201680689,
"Unit": "Percent"
},
{
"SampleCount": 240.0,
"Timestamp": "2014-02-12T19:18:00Z",
"Average": 0.037666666666666668,
"Unit": "Percent"
},
{
"SampleCount": 240.0,
"Timestamp": "2014-02-12T06:18:00Z",
"Average": 0.037541666666666675,
"Unit": "Percent"
},
{
"SampleCount": 240.0,
"Timestamp": "2014-02-12T20:18:00Z",
"Average": 0.039333333333333338,
"Unit": "Percent"
},
{
"SampleCount": 240.0,
"Timestamp": "2014-02-12T08:18:00Z",
"Average": 0.039250000000000014,
"Unit": "Percent"
},
{
"SampleCount": 239.0,
"Timestamp": "2014-02-12T03:18:00Z",
"Average": 0.037740585774058588,
"Unit": "Percent"
},
{
"SampleCount": 240.0,
"Timestamp": "2014-02-12T11:18:00Z",
"Average": 0.039500000000000007,
"Unit": "Percent"
},
{
"SampleCount": 238.0,
"Timestamp": "2014-02-12T02:18:00Z",
"Average": 0.039789915966386563,
"Unit": "Percent"
},
{
"SampleCount": 238.0,
"Timestamp": "2014-02-12T22:18:00Z",
"Average": 0.039705882352941181,
"Unit": "Percent"
},
{

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"SampleCount": 240.0,
"Timestamp": "2014-02-12T14:18:00Z",
"Average": 0.082458333333333328,
"Unit": "Percent"
},
{
"SampleCount": 240.0,
"Timestamp": "2014-02-12T05:18:00Z",
"Average": 0.04287500000000001,
"Unit": "Percent"
},
{
"SampleCount": 240.0,
"Timestamp": "2014-02-12T17:18:00Z",
"Average": 0.039458333333333345,
"Unit": "Percent"
},
{
"SampleCount": 240.0,
"Timestamp": "2014-02-12T10:18:00Z",
"Average": 0.083416666666666667,
"Unit": "Percent"
},
{
"SampleCount": 236.0,
"Timestamp": "2014-02-12T00:18:00Z",
"Average": 0.036567796610169498,
"Unit": "Percent"
},
{
"SampleCount": 240.0,
"Timestamp": "2014-02-12T12:18:00Z",
"Average": 0.039541666666666676,
"Unit": "Percent"
},
{
"SampleCount": 240.0,
"Timestamp": "2014-02-12T04:18:00Z",
"Average": 0.043000000000000003,
"Unit": "Percent"
}
],
"Label": "CPUUtilization"
}

Aggregate Statistics by Auto Scaling Group
Aggregate statistics are available for the instances that have detailed monitoring enabled. Instances
that use basic monitoring are not included in the aggregates. In addition, Amazon CloudWatch does
not aggregate data across Regions. Therefore, metrics are completely separate between Regions.
Before you can get statistics aggregated across instances, you must enable detailed monitoring (at an
additional charge), which provides data in 1-minute periods.
This scenario shows you how to use the AWS Management Console, the get-metric-statistics
command, or the GetMetricStatistics API with the DiskWriteBytes metric to retrieve the total
bytes written to disk for one Auto Scaling group. The total is computed for one-minute periods for a 24hour interval across all EC2 instances in the specified AutoScalingGroupName.

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Note
Start and end times must be within the last 14 days.
We assume for this example that an EC2 application is running and has an Auto Scaling group named
test-group-1.

AWS Management Console
To display total DiskWriteBytes for an auto-scaled application
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

If necessary, from the navigation bar, change the region to match the region where you have your
instances.

In the navigation pane, click Metrics.

In the CloudWatch Metrics by Category pane, under EC2 Metrics, select By Auto Scaling
Group.

Select the row that contains DiskWriteBytes.
A graph showing DiskWriteBytes for all EC2 instances appears in the details pane.

To change the statistic or period for the metric, choose a different value from the list.

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AWS Command Line Interface
To get total DiskWriteBytes for an auto-scaled application
Use the get-metric-statistics command as follows.
$ aws cloudwatch get-metric-statistics --namespace AWS/EC2 --metric-name
DiskWriteBytes --period 360 --statistics "Sum" "SampleCount" --dimensions
Name=AutoScalingGroupName,Value=my-group --start-time 2014-02-16T23:18:00 -end-time 2014-02-18T23:18:00

The following is example output:
{
"Datapoints": [
{
"SampleCount": 18.0,
"Timestamp": "2014-02-19T21:36:00Z",
"Sum": 0.0,
"Unit": "Bytes"
},
{
"SampleCount": 5.0,
"Timestamp": "2014-02-19T21:42:00Z",
"Sum": 0.0,
"Unit": "Bytes"
}
],
"Label": "DiskWriteBytes"
}

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Aggregate Statistics by Image (AMI) ID
Aggregate statistics are available for the instances that have detailed monitoring enabled. Instances
that use basic monitoring are not included in the aggregates. In addition, Amazon CloudWatch does
not aggregate data across Regions. Therefore, metrics are completely separate between Regions.
Before you can get statistics aggregated across instances, you must enable detailed monitoring (at an
additional charge), which provides data in 1-minute periods.
This scenario shows you how to use the AWS Management Console, the get-metric-statistics
command, or the GetMetricStatistics API to determine average CPU utilization for all instances
that match a given image ID. The average is over 60-second time intervals for a one-day period.

Note
Start and end times must be within the last 14 days.
In this scenario, the EC2 instances are running an image ID of ami-c5e40dac.

AWS Management Console
To display the average CPU utilization for an image ID
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

If necessary, from the navigation bar, change the region to match the region where you have your
instances.

In the navigation pane, click Metrics.

In the CloudWatch Metrics by Category pane, under EC2 Metrics, select By Image (AMI) Id.

Select a row that contains CPUUtilization and an image ID.
A graph showing average CPUUtilization for all EC2 instances based on the ami-c5e40dac
image ID appears in the details pane.

To change the statistic or period for the metric, choose a different value from the list.

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AWS Command Line Interface
To get the average CPU utilization for an image ID
Use the get-metric-statistics command as follows.
$ aws cloudwatch get-metric-statistics --namespace AWS/EC2 --metricname CPUUtilization --period 3600 --statistics Average --dimensions
Name=ImageId,Value=ami-3c47a355 --start-time 2014-02-10T00:00:00 --endtime 2014-02-11T00:00:00

The following is example output:
{
"Datapoints": [
{
"Timestamp": "2014-02-10T07:00:00Z",
"Average": 0.041000000000000009,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T14:00:00Z",
"Average": 0.079579831932773085,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T06:00:00Z",
"Average": 0.036000000000000011,
"Unit": "Percent"

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},
{
"Timestamp": "2014-02-10T13:00:00Z",
"Average": 0.037625000000000013,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T18:00:00Z",
"Average": 0.042750000000000003,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T21:00:00Z",
"Average": 0.039705882352941188,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T20:00:00Z",
"Average": 0.039375000000000007,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T02:00:00Z",
"Average": 0.041041666666666671,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T01:00:00Z",
"Average": 0.041083333333333354,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T23:00:00Z",
"Average": 0.038016877637130804,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T15:00:00Z",
"Average": 0.037666666666666668,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T12:00:00Z",
"Average": 0.039291666666666676,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T03:00:00Z",
"Average": 0.036000000000000004,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T04:00:00Z",
"Average": 0.042666666666666672,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T19:00:00Z",
"Average": 0.038305084745762719,

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"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T22:00:00Z",
"Average": 0.039291666666666676,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T09:00:00Z",
"Average": 0.17126050420168065,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T08:00:00Z",
"Average": 0.041166666666666678,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T11:00:00Z",
"Average": 0.082374999999999962,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T17:00:00Z",
"Average": 0.037625000000000013,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T10:00:00Z",
"Average": 0.039458333333333345,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T05:00:00Z",
"Average": 0.039250000000000007,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T00:00:00Z",
"Average": 0.037625000000000013,
"Unit": "Percent"
},
{
"Timestamp": "2014-02-10T16:00:00Z",
"Average": 0.041512605042016815,
"Unit": "Percent"
}
],
"Label": "CPUUtilization"
}

The operation returns statistics that are one-minute values for the one-day interval. Each value
represents an average CPU utilization percentage for EC2 instances running the specified machine
image.

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Graph Metrics

Graph Metrics for Your Instances
After you launch an instance, you can go to the Amazon EC2 console and view the instance's
monitoring graphs. They're displayed when you select the instance on the Instances page in the EC2
Dashboard. A Monitoring tab is displayed next to the instance's Description tab. The following graphs
are available:
• Average CPU Utilization (Percent)
• Average Disk Reads (Bytes)
• Average Disk Writes (Bytes)
• Maximum Network In (Bytes)
• Maximum Network Out (Bytes)
• Summary Disk Read Operations (Count)
• Summary Disk Write Operations (Count)
• Summary Status (Any)
• Summary Status Instance (Count)
• Summary Status System (Count)
Each graph is based on one of the available Amazon EC2 metrics. For more information about the
metrics and the data they provide to the graphs, see List the Available CloudWatch Metrics for Your
Instances (p. 421).
You can also use the CloudWatch console to graph metric data generated by Amazon EC2 and other
AWS services to make it easier to see what's going on. You can use the following procedures to graph
metrics in CloudWatch.
Contents
• Graph a Metric (p. 441)
• Graph a Metric Across Resources (p. 442)

Graph a Metric
You can select a metric and create a graph of the data in CloudWatch. For example, you can select
the CPUUtilization metric for an Amazon EC2 instance and display a graph of CPU usage over time for
that instance.

To graph a metric
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

If necessary, from the navigation bar, change the region to match the region where you have your
instances.

In the navigation pane, click Metrics.

In the CloudWatch Metrics by Category pane, use the Search Metrics box and categories to
find a metric by metric name, AWS resource, or other metadata.

Use the scroll bar and next and previous arrows above the metrics list to page through the full list
of metrics

Select the metric to view, for example, CPUUtilization. A graph appears in the details pane.

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To save this graph and access it later, in the details pane, under Tools, click Copy URL, and then
in the Copy Graph URL dialog box, select the URL and paste it into your browser.

Graph a Metric Across Resources
You can graph a metric across all resources to see everything on one graph. For example, you can
graph the CPUUtilization metric for all Amazon EC2 instances on one graph.

To graph a metric across resources
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

If necessary, from the navigation bar, change the region to match the region where you have your
instances.

In the navigation pane, click Metrics.

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In the CloudWatch Metrics by Category pane, select a metric category. For example, under EC2
Metrics, select Per-Instance Metrics.

In the metric list, in the Metric Name column, click a metric. For example CPUUtilization.

At the top of the metric list, click Select All.
The graph shows all data for all occurrences of the selected metric. In the example below,
CPUUtilization for all Amazon EC2 instances is shown.

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Create a CloudWatch Alarm

To save this graph and access it later, in the details pane, under Tools, click Copy URL, and then
in the Copy Graph URL dialog box, select the URL and paste it into your browser.

Create a CloudWatch Alarm
You can create an Amazon CloudWatch alarm that monitors any one of your Amazon EC2 instance's
CloudWatch metrics. CloudWatch will automatically send you a notification when the metric reaches a
threshold you specify. You can create a CloudWatch alarm on the Amazon EC2 console of the AWS
Management Console, or you can use the CloudWatch console and configure more advanced options.
Contents
• Send Email Based on CPU Usage Alarm (p. 444)
• Send Email Based on Load Balancer Alarm (p. 446)
• Send Email Based on Storage Throughput Alarm (p. 448)

Send Email Based on CPU Usage Alarm
This scenario walks you through how to use the AWS Management Console or the command line
interface to create an Amazon CloudWatch alarm that sends an Amazon Simple Notification Service
email message when the alarm changes state from OK to ALARM.
In this scenario, you configure the alarm to change to the ALARM state when the average CPU use of
an EC2 instance exceeds 70 percent for two consecutive five-minute periods.

AWS Management Console
To create an alarm that sends email based on CPU usage
1.
2.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.
If necessary, from the navigation bar, change the region to match the region where you have your
instances.

3.
4.

In the navigation pane, click Alarms.
Click Create Alarm, and then in CloudWatch Metrics by Category, select a metric category, for
example, EC2 Metrics.
In the list of metrics, select a row that contains CPUUtilization for a specific instance ID.

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Create a CloudWatch Alarm

A graph showing average CPUUtilization for a single instance appears in the lower pane.

Select Average from the Statistic drop-down list.

Select a period from the Period drop-down list, for example: 5 minutes.

Click Next, and then under Alarm Threshold, in the Name field, enter a unique name for the
alarm, for example: myHighCpuAlarm.

In the Description field, enter a description of the alarm, for example: CPU usage exceeds 70
percent.

10. In the is drop-down list, select >.
11. In the box next to the is drop-down list, enter 70 and in the for field, enter 10.
A graphical representation of the threshold is shown under Alarm Preview.
12. Under Actions, in the Whenever this alarm drop-down list, select State is ALARM.
13. In the Send notification to drop-down list, select an existing Amazon SNS topic or create a new
one.
14. To create a new Amazon SNS topic, select New list.
In the Send notification to field, enter a name for the new Amazon SNS topic for example:
myHighCpuAlarm, and in the Email list field, enter a comma-separated list of email addresses to
be notified when the alarm changes to the ALARM state.
15. Click Create Alarm to complete the alarm creation process.

AWS Command Line Interface
To send an Amazon Simple Notification Service email message when CPU utilization
exceeds 70 percent
1.

Set up an Amazon Simple Notification Service topic or retrieve the Topic Resource Name of the
topic you intend to use. For help on setting up an Amazon Simple Notification Service topic, see
Set Up Amazon Simple Notification Service.

Create an alarm using the put-metric-alarm command as follows.

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$ aws cloudwatch put-metric-alarm --alarm-name cpu-mon --alarmdescription "Alarm when CPU exceeds 70%" --metric-name CPUUtilization
--namespace AWS/EC2 --statistic Average --period 300 --threshold
70 --comparison-operator GreaterThanThreshold --dimensions
Name=InstanceId,Value=i-1234567890abcdef0 --evaluation-periods 2 --alarmactions arn:aws:sns:us-east-1:111122223333:MyTopic --unit Percent

Test the alarm by forcing an alarm state change with the set-alarm-state command.
a.

Change the alarm state from INSUFFICIENT_DATA to OK:
$ aws cloudwatch set-alarm-state
"initializing" --state-value OK

--alarm-name cpu-mon --state-reason

Change the alarm state from OK to ALARM:
$ aws cloudwatch set-alarm-state --alarm-name cpu-mon --state-reason
"initializing" --state-value ALARM

Check that an email has been received.

Send Email Based on Load Balancer Alarm
This scenario walks you through how to use the AWS Management Console or the command line
interface to set up an Amazon Simple Notification Service notification and configure an alarm that
monitors load balancer latency exceeding 100 ms.

AWS Management Console
To create a load balancer alarm that sends email
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

If necessary, from the navigation bar, change the region to match the region where you have your
instances.

In the navigation pane, click Alarms.

Click Create Alarm, and then in the CloudWatch Metrics by Category pane, select a metric
category, for example, ELB Metrics.

In the list of metrics, select a row that contains Latency for a specific load balancer.
A graph showing average Latency for a single load balancer appears in the lower pane.

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Select Average from the Statistic drop-down list.

Select 1 Minute from the Period drop-down list.

Click Next, and then under Alarm Threshold, in the Name field, enter a unique name for the
alarm, for example: myHighCpuAlarm.

In the Description field, enter a description of the alarm, for example: Alarm when Latency
exceeds 100ms.

10. In the is drop-down list, select >.
11. In the box next to the is drop-down list, enter 0.1 and in the for field, enter 3.
A graphical representation of the threshold is shown under Alarm Preview.
12. Under Actions, in the Whenever this alarm drop-down list, select State is ALARM.
13. In the Send notification to drop-down list, select an existing Amazon SNS topic or create a new
one.
14. To create a new Amazon SNS topic, select New list.
In the Send notification to field, enter a name for the new Amazon SNS topic for example:
myHighCpuAlarm, and in the Email list field, enter a comma-separated list of email addresses to
be notified when the alarm changes to the ALARM state.
15. Click Create Alarm to complete the alarm creation process.

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AWS Command Line Interface
To send an Amazon Simple Notification Service email message when LoadBalancer
Latency Exceeds 100 milliseconds
1.

Create an Amazon Simple Notification Service topic. See instructions for creating an Amazon SNS
topic in Set Up Amazon Simple Notification Service.

Use the put-metric-alarm command as follows.
$ aws cloudwatch put-metric-alarm --alarm-name lb-mon --alarm-description
"Alarm when Latency exceeds 100ms" --metric-name Latency --namespace
AWS/ELB --statistic Average --period 60 --threshold 100 --comparisonoperator GreaterThanThreshold --dimensions Name=LoadBalancerName,Value=myserver --evaluation-periods 3 --alarm-actions arn:aws:sns:useast-1:1234567890:my-topic --unit Milliseconds

Test the alarm.
• Force an alarm state change to ALARM:
$ aws cloudwatch set-alarm-state --alarm-name lb-mon --state-reason
"initializing" --state-value OK

$ aws cloudwatch set-alarm-state --alarm-name lb-mon --state-reason
"initializing" --state-value ALARM

• Check that you have received an email notification about the alarm.

Send Email Based on Storage Throughput Alarm
This scenario walks you through how to use the AWS Management Console or the command line
interface to set up an Amazon Simple Notification Service notification and to configure an alarm that
sends email when EBS exceeds 100 MB throughput.

AWS Management Console
To create a storage throughput alarm that sends email
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

If necessary, from the navigation bar, change the region to match the region where you have your
instances.

In the navigation pane, click Alarms.

Click Create Alarm, and then in the CloudWatch Metrics by Category pane, select a metric
category, for example, EBS Metrics.

In the list of metrics, select a row that contains VolumeWriteBytes for a specific VolumeId.
A graph showing average VolumeWriteBytes for a single volume appears in the lower pane.

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Select Average from the Statistic drop-down list.

Select 5 Minutes from the Period drop-down list.

Click Next, and then under Alarm Threshold, in the Name field, enter a unique name for the
alarm, for example: myHighWriteAlarm.

In the Description field, enter a description of the alarm, for example: VolumeWriteBytes
exceeds 100,000 KiB/s.

10. In the is drop-down list, select >.
11. In the box next to the is drop-down list, enter 100000 and in the for field, enter 15.
A graphical representation of the threshold is shown under Alarm Preview.
12. Under Actions, in the Whenever this alarm drop-down list, select State is ALARM.
13. In the Send notification to drop-down list, select an existing Amazon SNS topic or create a new
one.
14. To create a new Amazon SNS topic, select New list.
In the Send notification to field, enter a name for the new Amazon SNS topic for example:
myHighCpuAlarm, and in the Email list field, enter a comma-separated list of email addresses to
be notified when the alarm changes to the ALARM state.
15. Click Create Alarm to complete the alarm creation process.

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Create Alarms That Stop, Terminate,
Reboot, or Recover an Instance

AWS Command Line Interface
To send an Amazon Simple Notification Service email message when EBS exceeds 100
MB throughput
1.

Create an Amazon Simple Notification Service topic. See instructions for creating an Amazon SNS
topic in Set Up Amazon Simple Notification Service.

Use the put-metric-alarm command as follows.
$ aws cloudwatch put-metric-alarm --alarm-name ebs-mon --alarmdescription "Alarm when EBS volume exceeds 100MB throughput" --metricname VolumeReadBytes --namespace AWS/EBS --statistic Average --period
300 --threshold 100000000 --comparison-operator GreaterThanThreshold
--dimensions Name=VolumeId,Value=my-volume-id --evaluation-periods
3 --alarm-actions arn:aws:sns:us-east-1:1234567890:my-alarm-topic
--insufficient-data-actions arn:aws:sns:us-east-1:1234567890:myinsufficient-data-topic

Test the alarm.
• Force an alarm state change to ALARM.
$ aws cloudwatch set-alarm-state --alarm-name lb-mon --state-reason
"initializing" --state-value OK

$ aws cloudwatch set-alarm-state --alarm-name lb-mon --state-reason
"initializing" --state-value ALARM

$ aws cloudwatch set-alarm-state --alarm-name lb-mon --state-reason
"initializing" --state-value INSUFFICIENT_DATA

• Check that you have received two email notifications about the alarm.

Create Alarms That Stop, Terminate, Reboot, or
Recover an Instance
Using Amazon CloudWatch alarm actions, you can create alarms that automatically stop, terminate,
reboot, or recover your Amazon Elastic Compute Cloud (Amazon EC2) instances. You can use the
stop or terminate actions to help you save money when you no longer need an instance to be running.
You can use the reboot and recover actions to automatically reboot those instances or recover them
onto new hardware if a system impairment occurs.
Every alarm action you create uses alarm action ARNs. One set of ARNs is more secure because it
requires you to have the EC2ActionsAccess IAM role in your account. This IAM role enables you to
perform stop, terminate, or reboot actions--previously you could not execute an action if you were using
an IAM role. Existing alarms that use the previous alarm action ARNs do not require this IAM role,
however it is recommended that you change the ARN and add the role when you edit an existing alarm
that uses these ARNs.
The EC2ActionsAccess IAM role enables AWS to perform alarm actions on your behalf. When you
create an alarm action for the first time using the Amazon EC2 or Amazon CloudWatch consoles, AWS
automatically creates this role for you. In addition, you must create the EC2ActionsAccess role using
either console before it's available for use from the CLI.

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Create Alarms That Stop, Terminate,
Reboot, or Recover an Instance
There are a number of scenarios in which you might want to automatically stop or terminate your
instance. For example, you might have instances dedicated to batch payroll processing jobs or
scientific computing tasks that run for a period of time and then complete their work. Rather than letting
those instances sit idle (and accrue charges), you can stop or terminate them which can help you
to save money. The main difference between using the stop and the terminate alarm actions is that
you can easily restart a stopped instance if you need to run it again later, and you can keep the same
instance ID and root volume. However, you cannot restart a terminated instance. Instead, you must
launch a new instance.

You can create an alarm that automatically recovers an Amazon EC2 instance when the instance
becomes impaired due to an underlying hardware failure a problem that requires AWS involvement to
repair. Examples of problems that cause system status checks to fail include:
• Loss of network connectivity
• Loss of system power
• Software issues on the physical host
• Hardware issues on the physical host

Important
The recover action is only supported on:
• C3, C4, M3, M4, R3, T2, and X1 instance types.
• Instances in a VPC. If your instance has a public IP address, it will retain the same public IP
address after recovery.
• Instances with shared tenancy (where the tenancy attribute of the instance is set to
default).
• Instances that use Amazon EBS storage exclusively.
Currently, the recover action is not supported for EC2-Classic instances, dedicated tenancy
instances, instances running on Dedicated hosts, and instances that use any instance store
volumes.
You can add the stop, terminate, reboot, or recover actions to any alarm that is set on an Amazon EC2
per-instance metric, including basic and detailed monitoring metrics provided by Amazon CloudWatch
(in the AWS/EC2 namespace), as well as any custom metrics that include the “InstanceId=” dimension,
as long as the InstanceId value refers to a valid running Amazon EC2 instance.
Contents
• Adding Stop Actions to Amazon CloudWatch Alarms (p. 451)
• Adding Terminate Actions to Amazon CloudWatch Alarms (p. 454)
• Adding Reboot Actions to Amazon CloudWatch Alarms (p. 456)
• Adding Recover Actions to Amazon CloudWatch Alarms (p. 459)
• Using the Amazon CloudWatch Console to View the History of Triggered Alarms and
Actions (p. 461)
• Using the CLI or the API to Create an Alarm to Stop, Terminate, Reboot, or Recover an
Instance (p. 462)
• Amazon CloudWatch Alarm Action Scenarios (p. 467)

Adding Stop Actions to Amazon CloudWatch Alarms
You can configure the stop alarm action using the Amazon EC2 console, the Amazon CloudWatch
console, the Amazon CloudWatch command line interface (CLI), the CloudWatch API, or the AWS

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SDKs. For information about using the Amazon CloudWatch API with the AWS SDKs, see Sample
Code & Libraries.

You can create an alarm that stops an Amazon EC2 instance when a certain threshold has been met.
For example, you may run development or test instances and occasionally forget to shut them off. You
can create an alarm that is triggered when the average CPU utilization percentage has been lower
than 10 percent for 24 hours, signaling that it is idle and no longer in use. You can adjust the threshold,
duration, and period to suit your needs, plus you can add an Amazon Simple Notification Service
(Amazon SNS) notification, so that you will receive an email when the alarm is triggered.
Amazon EC2 instances that use an Amazon Elastic Block Store volume as the root device can be
stopped or terminated, whereas instances that use the instance store as the root device can only be
terminated.

Note
If you are using an AWS Identity and Access Management (IAM) account to create or modify
an alarm, you must have the following Amazon EC2 permissions:
• ec2:DescribeInstanceStatus and ec2:DescribeInstances for all alarms on
Amazon EC2 instance status metrics.
• ec2:StopInstances for alarms with stop actions.
• ec2:TerminateInstances for alarms with terminate actions.
• ec2:DescribeInstanceRecoveryAttribute, and ec2:RecoverInstances for alarms
with recover actions.
If you have read/write permissions for Amazon CloudWatch but not for Amazon EC2, you can
still create an alarm but the stop or terminate actions won't be performed on the Amazon EC2
instance. However, if you are later granted permission to use the associated Amazon EC2
APIs, the alarm actions you created earlier will be performed. For more information about IAM
permissions, see Permissions and Policies in the IAM User Guide.
If you want to use an IAM role to stop, terminate, or reboot an instance using an alarm action,
you can only use the EC2ActionsAccess role. Other IAM roles are not supported. If you are
using another IAM role, you cannot stop, terminate, or reboot the instance. However, you can
still see the alarm state and perform any other actions such as Amazon SNS notifications or
Auto Scaling policies.
If you are using temporary security credentials granted using the AWS Security Token Service
(AWS STS), you cannot recover an Amazon EC2 instance using alarm actions.

Using the Amazon EC2 Console to Create an Alarm to Stop an Instance
To create an alarm to stop an idle instance
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

If necessary, change the region. From the navigation bar, select the region where your instance is
running. For more information, see Regions and Endpoints.

In the navigation pane, under INSTANCES, click Instances.

In the contents pane, right-click an instance, select CloudWatch Monitoring, and then click Add/
Edit Alarms.
Or, you can also select the instance, and then in the lower pane on the Monitoring tab, click
Create Alarm.

In the Alarm Details for dialog box, click Create Alarm.

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If you create a new topic, in the Send a notification to box type a name for the topic, and then
in the With these recipients box, type the email addresses of the recipients (separated by
commas). Later, after you create the alarm, you will receive a subscription confirmation email that
you must accept before you will get email for this topic.

Select the Take the action check box, and then choose the Stop this instance radio button.

If prompted, select the Create IAM role: EC2ActionsAccess check box to automatically create
an IAM role so that AWS can automatically stop the instance on your behalf when the alarm is
triggered.

In the Whenever boxes, choose the statistic you want to use and then select the metric. In this
example, choose Average and CPU Utilization.

10. In the Is boxes, define the metric threshold. In this example, enter 10 percent.
11. In the For at least box, choose the sampling period for the alarm. In this example, enter 24
consecutive periods of one hour.
12. To change the name of the alarm, in the Name this alarm box, type a new name.
If you don't type a name for the alarm, Amazon CloudWatch will automatically create one for you.

Note
You can adjust the alarm configuration based on your own requirements before creating
the alarm, or you can edit them later. This includes the metric, threshold, duration, action,
and notification settings. However, after you create an alarm, you cannot edit its name
later.
13. Click Create Alarm.

Using the Amazon CloudWatch Console to Create an Alarm that Stops an
Instance
To create an alarm to stop an idle instance
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

If necessary, change the region. From the navigation bar, select the region where your instance is
running. For more information, see Regions and Endpoints.

In the navigation pane, click Alarms.

Click Create Alarm, and then in CloudWatch Metrics by Category, under EC2 Metrics, select
Per-Instance Metrics.

In the list of metrics, select the instance and metric you want to create an alarm for. You can also
type an instance ID in the search box to go the instance that you want.

Select Average from the Statistic drop-down list.

Select a period from the Period drop-down list, for example: 1 Day.

Click Next, and then under Alarm Threshold, in the Name field, enter a unique name for the
alarm, for example: Stop EC2 instance.

In the Description field, enter a description of the alarm, for example: Stop EC2 instance
when CPU is idle for too long.

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15. If prompted, select the Create IAM role: EC2ActionsAccess check box to automatically create
an IAM role so that AWS can automatically stop the instance on your behalf when the alarm is
triggered.

16. Click Notification, and then in the Send notification to drop-down list, select an existing Amazon
SNS topic or create a new one.
17. To create a new Amazon SNS topic, select New list.
In the Send notification to field, enter a name for the new Amazon SNS topic for example:
Stop_EC2_Instance, and in the Email list field, enter a comma-separated list of email
addresses to be notified when the alarm changes to the ALARM state.

Important
If you are creating a new topic or adding email addresses to an existing topic, each
email address that you add will be sent a topic subscription confirmation email. You must
confirm the subscription by clicking the included link before notifications will be sent to a
new email address.
18. In the navigation pane, click Create Alarm to complete the alarm creation process.

Adding Terminate Actions to Amazon CloudWatch Alarms
You can configure the terminate alarm action using the Amazon EC2 console, the Amazon
CloudWatch console, the Amazon CloudWatch command line interface (CLI), the CloudWatch API, or
the AWS SDKs. For information about using the Amazon CloudWatch API with the AWS SDKs, see
Sample Code & Libraries.
You can create an alarm that terminates an EC2 instance automatically when a certain threshold has
been met (as long as termination protection is not enabled for the instance). For example, you might
want to terminate an instance when it has completed its work, and you don’t need the instance again.
If you might want to use the instance later, you should stop the instance instead of terminating it. For
information on enabling and disabling termination protection for an instance, see Enabling Termination
Protection for an Instance in the Amazon EC2 User Guide for Linux Instances.

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Create Alarms That Stop, Terminate,
Reboot, or Recover an Instance

Using the Amazon EC2 Console to Create an Alarm that Terminates an
Instance
To create an alarm to terminate an idle instance
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

If necessary, change the region. From the navigation bar, select the region where your instance is
running. For more information, see Regions and Endpoints.

In the navigation pane, under INSTANCES, click Instances.

In the upper pane, right-click an instance, select CloudWatch Monitoring, and then click Add/
Edit Alarms.
Or, select the instance and then in the lower pane, on the Monitoring tab, click Create Alarm.

In the Alarm Details for dialog box, click Create Alarm.

If you want to receive an email when the alarm is triggered, in the Create Alarm for dialog box,
in the Send a notification to box, select an existing Amazon SNS topic, or click Create Topic to
create a new one.
If you create a new topic, in the Send a notification to box type a name for the topic, and then
in the With these recipients box, type the email addresses of the recipients (separated by
commas). Later, after you create the alarm, you will receive a subscription confirmation email that
you must accept before you will get email for this topic.

Select the Take the action check box, and then choose the Terminate this instance radio
button.

If prompted, select the Create IAM role: EC2ActionsAccess check box to automatically create
an IAM role so that AWS can automatically stop the instance on your behalf when the alarm is
triggered.

In the Whenever boxes, choose the statistic you want to use and then select the metric. In this
example, choose Average and CPU Utilization.

Using the Amazon CloudWatch Console to Create an Alarm to Terminate
an Idle Instance
To create an alarm to terminate an idle instance
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

If necessary, change the region. From the navigation bar, select the region where your instance is
running. For more information, see Regions and Endpoints.

In the navigation pane, click Alarms.
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Click Create Alarm, and then in CloudWatch Metrics by Category, under EC2 Metrics, select
Per-Instance Metrics.

In the list of metrics, select the instance and metric you want to create an alarm for. You can also
type an instance ID in the search box to go the instance that you want.

Select Average from the Statistic drop-down list.

Select a period from the Period drop-down list, for example: 1 Day.

Click Next, and then under Alarm Threshold, in the Name field, enter a unique name for the
alarm, for example: Terminate EC2 instance.

In the Description field, enter a description of the alarm, for example: Terminate EC2
instance when CPU is idle for too long.

10. In the is drop-down list, select <.
11. In the box next to the is drop-down list, enter 10 and in the for field, enter 1440.
A graphical representation of the threshold is shown under Alarm Preview.
12. Under Actions, click EC2 Action.
13. In the Whenever this alarm drop-down list, select State is ALARM.
14. In the Take this action drop-down list, select Terminate this instance.
15. If prompted, select the Create IAM role: EC2ActionsAccess check box to automatically create
an IAM role so that AWS can automatically stop the instance on your behalf when the alarm is
triggered.
16. Click Notification, and then in the Send notification to drop-down list, select an existing Amazon
SNS topic or create a new one.
17. To create a new Amazon SNS topic, select New list.
In the Send notification to field, enter a name for the new Amazon SNS topic for example:
Terminate_EC2_Instance, and in the Email list field, enter a comma-separated list of email
addresses to be notified when the alarm changes to the ALARM state.

Adding Reboot Actions to Amazon CloudWatch Alarms
You can configure the reboot alarm action using the Amazon EC2 console, the Amazon CloudWatch
console, the Amazon CloudWatch command line interface (CLI), the CloudWatch API, or the AWS
SDKs. For information about using the Amazon CloudWatch API with the AWS SDKs, see Sample
Code & Libraries.
You can create an Amazon CloudWatch alarm that monitors an Amazon EC2 instance and
automatically reboots the instance. The reboot alarm action is recommended for Instance Health
Check failures (as opposed to the recover alarm action, which is suited for System Health Check
failures). An instance reboot is equivalent to an operating system reboot. In most cases, it takes only
a few minutes to reboot your instance. When you reboot an instance, it remains on the same physical
host, so your instance keeps its public DNS name, private IP address, and any data on its instance
store volumes.
Rebooting an instance doesn't start a new instance billing hour, unlike stopping and restarting your
instance. For more information about rebooting an instance, see Reboot Your Instance in the Amazon
EC2 User Guide for Linux Instances.

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Important
To avoid a race condition between the reboot and recover actions, we recommend that you
set the alarm threshold to 3 for 1 minute when creating alarms that reboot an Amazon EC2
instance.

Using the Amazon EC2 Console to Create an Alarm to Reboot an
Instance
To create an alarm to reboot an instance
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

If necessary, change the region. From the navigation bar, select the region where your instance is
running. For more information, see Regions and Endpoints.

In the navigation pane, under INSTANCES, click Instances.

In the Alarm Details for dialog box, click Create Alarm.

Select the Take the action check box, and then choose the Reboot this instance radio button.

If prompted, select the Create IAM role: EC2ActionsAccess check box to automatically create
an IAM role so that AWS can automatically stop the instance on your behalf when the alarm is
triggered.

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In the Whenever box, choose Status Check Failed (Instance).

10. In the For at least field, enter 2.
11. In the consecutive period(s) of box, select 1 minute.
12. To change the name of the alarm, in the Name of alarm box, type a new name.
If you don't type a name for the alarm, Amazon CloudWatch will automatically create one for you.
13. Click Create Alarm.

Using the Amazon CloudWatch Console to Create an Alarm to Reboot an
Instance
To create an alarm to reboot an instance
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

If necessary, change the region. From the navigation bar, select the region where your instance is
running. For more information, see Regions and Endpoints.

In the navigation pane, click Alarms.

Click Create Alarm, and then in CloudWatch Metrics by Category, under EC2 Metrics, select
Per-Instance Metrics.

In the list of metrics, select the instance and StatusCheckFailed_Instance metric you want to
create an alarm for. You can also type an instance ID in the search box to go the instance that you
want.

Select Minimum from the Statistic drop-down list.

Note
This is the only statistic that is currently supported.
7.

Select a period from the Period drop-down list, for example: 1 Minute.

Click Next, and then under Alarm Threshold, in the Name field, enter a unique name for the
alarm, for example: Reboot EC2 instance.

In the Description field, enter a description of the alarm, for example: Reboot EC2 instance
when health checks fail.

10. In the is drop-down list, select >.
11. In the box next to the is drop-down list, enter 0 and in the for field, enter 2.
A graphical representation of the threshold is shown under Alarm Preview.
12. Under Actions, click EC2 Action.
13. In the Whenever this alarm drop-down list, select State is ALARM.
14. In the Take this action drop-down list, select Reboot this instance.
15. Click Notification, and then in the Send notification to drop-down list, select an existing Amazon
SNS topic or create a new one.
16. To create a new Amazon SNS topic, select New list.
In the Send notification to field, enter a name for the new Amazon SNS topic for example:
Reboot_EC2_Instance, and in the Email list field, enter a comma-separated list of email
addresses to be notified when the alarm changes to the ALARM state.

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Create Alarms That Stop, Terminate,
Reboot, or Recover an Instance
17. In the navigation pane, click Create Alarm to complete the alarm creation process.

Adding Recover Actions to Amazon CloudWatch Alarms
You can configure the recover alarm action using the Amazon EC2 console, the Amazon CloudWatch
console, the Amazon CloudWatch command line interface (CLI), the CloudWatch API, or the AWS
SDKs. For information about using the Amazon CloudWatch API with the AWS SDKs, see Sample
Code & Libraries.
You can create an Amazon CloudWatch alarm that monitors an Amazon EC2 instance and
automatically recovers the instance if it becomes impaired due to an underlying hardware failure or
a problem that requires AWS involvement to repair. Terminated instances cannot be recovered. A
recovered instance is identical to the original instance, including the instance ID, private IP addresses,
Elastic IP addresses, and all instance metadata.
When the StatusCheckFailed_System alarm is triggered, and the recover action is initiated, you
will be notified by the Amazon SNS topic that you selected when you created the alarm and associated
the recover action. During instance recovery, the instance is migrated during an instance reboot, and
any data that is in-memory is lost. When the process is complete, information is published to the SNS
topic you've configured for the alarm. Anyone who is subscribed to this SNS topic will receive an email
notification that includes the status of the recovery attempt and any further instructions. You will notice
an instance reboot on the recovered instance.
Examples of problems that cause system status checks to fail include:
• Loss of network connectivity
• Loss of system power
• Software issues on the physical host
• Hardware issues on the physical host

Important
The recover action is only supported on:
• C3, C4, M3, M4, R3, T2, and X1 instance types.
• Instances in a VPC. Dedicated instances or instances running on Dedicated hosts are not
supported. If your instance has a public IP address, it will retain the same public IP address
after recovery.
• Instances that use EBS-backed storage. Instance storage is not supported. Automatic
recovery of the instance will fail if any instance storage is attached.

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instance. However, if you are later granted permission to use the associated Amazon EC2
APIs, the alarm actions you created earlier will be performed. For more information about IAM
permissions, see Permissions and Policies in the IAM User Guide.
If you want to use an IAM role to stop, terminate, or reboot an instance using an alarm action,
you can only use the EC2ActionsAccess role. Other IAM roles are not supported. If you are
using another IAM role, you cannot stop, terminate, or reboot the instance. However, you can
still see the alarm state and perform any other actions such as Amazon SNS notifications or
Auto Scaling policies.
If you are using temporary security credentials granted using the AWS Security Token Service
(AWS STS), you cannot recover an Amazon EC2 instance using alarm actions.

Important
To avoid a race condition between the reboot and recover actions, we recommend that you
set the alarm threshold to 2 for 1 minute when creating alarms that recover an Amazon EC2
instance.

Create an Alarm from the Amazon EC2 Console
To create an alarm to recover an instance
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

If necessary, change the region. From the navigation bar, select the region where your instance is
running. For more information, see Regions and Endpoints.

In the navigation pane, under INSTANCES, click Instances.

In the Alarm Details for dialog box, click Create Alarm.

Select the Take the action check box, and then choose the Recover this instance radio button.

If prompted, select the Create IAM role: EC2ActionsAccess check box to automatically create
an IAM role so that AWS can automatically stop the instance on your behalf when the alarm is
triggered.

In the Whenever box, choose Status Check Failed (System).

Create an Alarm from the Amazon CloudWatch Console
To create an alarm to recover an instance
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

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If necessary, change the region. From the navigation bar, select the region where your instance is
running. For more information, see Regions and Endpoints.

In the navigation pane, click Alarms.

Click Create Alarm, and then in CloudWatch Metrics by Category, under EC2 Metrics, select
Per-Instance Metrics.

In the list of metrics, select the instance and StatusCheckFailed_System metric you want to
create an alarm for. You can also type an instance ID in the search box to go the instance that you
want.

Select Minimum from the Statistic drop-down list.

Note
This is the only statistic that is currently supported.
7.

Select a period from the Period drop-down list, for example: 1 Minute.

Click Next, and then under Alarm Threshold, in the Name field, enter a unique name for the
alarm, for example: Recover EC2 instance.

In the Description field, enter a description of the alarm, for example: Recover EC2 instance
when health checks fail.

10. In the is drop-down list, select >.
11. In the box next to the is drop-down list, enter 0 and in the for field, enter 2.
A graphical representation of the threshold is shown under Alarm Preview.
12. Under Actions, click EC2 Action.
13. In the Whenever this alarm drop-down list, select State is ALARM.
14. In the Take this action drop-down list, select Recover this instance.
15. Click Notification, and then in the Send notification to drop-down list, select an existing Amazon
SNS topic or create a new one.
16. To create a new Amazon SNS topic, select New list.
In the Send notification to field, enter a name for the new Amazon SNS topic for example:
Recover_EC2_Instance, and in the Email list field, enter a comma-separated list of email
addresses to be notified when the alarm changes to the ALARM state.

Important
If you are creating a new topic or adding email addresses to an existing topic, each
email address that you add will be sent a topic subscription confirmation email. You must
confirm the subscription by clicking the included link before notifications will be sent to a
new email address.
17. In the navigation pane, click Create Alarm to complete the alarm creation process.

Using the Amazon CloudWatch Console to View the
History of Triggered Alarms and Actions
You can view alarm and action history in the Amazon CloudWatch console. Amazon CloudWatch
keeps the last two weeks’ worth of alarm and action history.

To view the history of triggered alarms and actions
1.

Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

If necessary, change the region. From the navigation bar, select the region where your instance is
running. For more information, see Regions and Endpoints.

In the navigation pane, click Alarms.

In the upper pane, select the alarm with the history that you want to view.

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In the lower pane, the Details tab shows the most recent state transition along with the time and
metric values.

Click the History tab to view the most recent history entries.

Using the CLI or the API to Create an Alarm to Stop,
Terminate, Reboot, or Recover an Instance
If you are using either the AWS CLI or the Amazon CloudWatch API, or if you are using the AWS SDKs
with the API, you can create a CloudWatch alarm using an Amazon EC2 per-instance metric, and then
add an action using the action’s dedicated Amazon Resource Name (ARN). You can add the action to
any alarm state, and you can specify the region for each action. The region must match the region to
which you send the put-metric-alarm request.
Action

ARN (with region)

ARN (for use with IAM role)

Stop

arn:aws:automate:useast-1:ec2:stop

arn:aws:swf:useast-1:{customeraccount}:action/actions/
AWS_EC2.InstanceId.Stop/1.0

Note
You must create at
least one stop alarm
using the Amazon
EC2 or CloudWatch
console to create the
EC2ActionsAccess
IAM role. After this IAM
role is created, you
can create stop alarms
using the CLI.
Terminate

arn:aws:automate:useast-1:ec2:terminate

arn:aws:swf:useast-1:{customeraccount}:action/actions/
AWS_EC2.InstanceId.Terminate/1.0

Note
You must create at
least one terminate
alarm using the
Amazon EC2
or CloudWatch
console to create the
EC2ActionsAccess
IAM role. After this IAM
role is created, you can
create terminate alarms
using the CLI.
Reboot

n/a

arn:aws:swf:useast-1:{customeraccount}:action/actions/
AWS_EC2.InstanceId.Reboot/1.0

Note
You must create at
least one reboot alarm

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Action

ARN (with region)

ARN (for use with IAM role)
using the Amazon
EC2 or CloudWatch
console to create the
EC2ActionsAccess
IAM role. After this IAM
role is created, you can
create reboot alarms
using the CLI.

Recover

arn:aws:automate:useast-1:ec2:recover

n/a

For information about using the Amazon CloudWatch API with the AWS SDKs, see Sample Code &
Libraries.

To create an alarm to stop an instance using the CLI
You can use the arn:aws:automate:us-east-1:ec2:stop ARN to stop an Amazon EC2 instance.
The following example shows how to stop an instance if the average CPU utilization is less than 10
percent over a 24 hour period.
•

At a command prompt, type:
% aws cloudwatch put-metric-alarm --alarm-name my-Alarm --alarmdescription "Stop the instance when it is idle for a day" --namespace
"AWS/EC2" --dimensions Name=InstanceId,Value="i-1234567890abcdef0" -statistic Average --metric-name CPUUtilization --comparison-operator
LessThanThreshold --threshold 10 --period 21600 --evaluation-periods 4 -alarm-actions arn:aws:automate:us-east-1:ec2:stop

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Reboot, or Recover an Instance

To create an alarm to terminate an instance using the CLI
•

At a command prompt, type:
% aws cloudwatch put-metric-alarm --alarm-name my-Alarm --alarmdescription "Terminate the instance when it is idle for a day" --namespace
"AWS/EC2" --dimensions Name=InstanceId,Value="i-1234567890abcdef0" -statistic Average --metric-name CPUUtilization --comparison-operator
LessThanThreshold --threshold 1 --period 21600 --evaluation-periods 4 -alarm-actions arn:aws:automate:us-east-1:ec2:terminate

To create an alarm to reboot an instance using the CLI
•

At a command prompt, type:
% aws cloudwatch put-metric-alarm --alarm-name my-Alarm --alarmdescription "Reboot the instance" --namespace "AWS/EC2" --dimensions
Name=InstanceId,Value="i-1234567890abcdef0" --statistic Minimum
--metric-name StatusCheckFailed_Instance --comparison-operator
GreaterThanThreshold --threshold 0 --period 60 --evaluation-periods 2
--alarm-actions arn:aws:swf:us-east-1:{customer-account}:action/actions/
AWS_EC2.InstanceId.Reboot/1.0

To create an alarm to recover an instance using the CLI
Note
Terminated instances cannot be recovered.
•

At a command prompt, type:
% aws cloudwatch put-metric-alarm --alarm-name my-Alarm --alarmdescription "Recover the instance" --namespace "AWS/EC2" --dimensions
Name=InstanceId,Value="i-1234567890abcdef0" --statistic Average
--metric-name StatusCheckFailed_System --comparison-operator
GreaterThanThreshold --threshold 0 --period 60 --evaluation-periods 2 -alarm-actions arn:aws:automate:us-east-1:ec2:recover

To create an alarm to stop an instance using the API
The following example request shows how to create an alarm that stops an Amazon EC2 instance:
•

http://monitoring.amazonaws.com/
?SignatureVersion=2
&Action=PutMetricAlarm
&Version=2009-05-15
&Namespace=AWS/EC2
&MetricName=CPUUtilization
&Dimension.member.1.Name=instance-id

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&Dimension.member.1.Value=i-1234567890abcdef0
&Period=21600
&Statistic=Average
&AlarmName=Stop-EC2-Instance
&ComparisonOperator=LessThanThreshold
&Threshold=10
&EvaluationPeriods=4
&StartTime=2009-01-16T00:00:00
&EndTime=2009-01-16T00:02:00
&Timestamp=2009-01-08-18
&AWSAccessKeyId=XXX YOUR ACCESS KEY XXX
&Signature=%XXX YOUR SIGNATURE XXX%3D
&AlarmActions.member.1=arn:aws:automate:us-east-1:ec2:stop

To create an alarm to terminate an instance using the API
The following example request shows how to create an alarm that terminates an Amazon EC2
instance:
•

http://monitoring.amazonaws.com/
?SignatureVersion=2
&Action=PutMetricAlarm
&Version=2009-05-15
&Namespace=AWS/EC2
&MetricName=CPUUtilization
&Dimension.member.1.Name=instance-id
&Dimension.member.1.Value=i-1234567890abcdef0
&Period=21600
&Statistic=Average
&AlarmName=Terminate-EC2-Instance
&ComparisonOperator=LessThanThreshold
&Threshold=10

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&EvaluationPeriods=4
&StartTime=2009-01-16T00:00:00
&EndTime=2009-01-16T00:02:00
&Timestamp=2009-01-08-18
&AWSAccessKeyId=XXX YOUR ACCESS KEY XXX
&Signature=%XXX YOUR SIGNATURE XXX%3D
&AlarmActions.member.1=arn:aws:automate:us-east-1:ec2:terminate

To create an alarm to reboot an instance using the API
The following example request shows how to create an alarm that reboots an Amazon EC2 instance:
•

http://monitoring.amazonaws.com/
?SignatureVersion=2
&Action=PutMetricAlarm
&Version=2009-05-15
&Namespace=AWS/EC2
&MetricName=StatusCheckFailed_Instance
&Dimension.member.1.Name=instance-id
&Dimension.member.1.Value=i-1234567890abcdef0
&Period=60
&Statistic=Average
&AlarmName=Reboot-EC2-Instance
&ComparisonOperator=GreaterThanThreshold
&Threshold=0
&EvaluationPeriods=2
&StartTime=2009-01-16T00:00:00
&EndTime=2009-01-16T00:02:00
&Timestamp=2009-01-08-18
&AWSAccessKeyId=XXX YOUR ACCESS KEY XXX
&Signature=%XXX YOUR SIGNATURE XXX%3D

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&AlarmActions.member.1=arn:aws:aws:swf:us-east-1:{customeraccount}:action/actions/AWS_EC2.InstanceId.Reboot/1.0

To create an alarm to recover an instance using the API
The following example request shows how to create an alarm that recovers an Amazon EC2 instance:
•

http://monitoring.amazonaws.com/
?SignatureVersion=2
&Action=PutMetricAlarm
&Version=2009-05-15
&Namespace=AWS/EC2
&MetricName=StatusCheckFailed_System
&Dimension.member.1.Name=instance-id
&Dimension.member.1.Value=i-1234567890abcdef0
&Period=60
&Statistic=Average
&AlarmName=Terminate-EC2-Instance
&ComparisonOperator=GreaterThanThreshold
&Threshold=0
&EvaluationPeriods=2
&StartTime=2009-01-16T00:00:00
&EndTime=2009-01-16T00:02:00
&Timestamp=2009-01-08-18
&AWSAccessKeyId=XXX YOUR ACCESS KEY XXX
&Signature=%XXX YOUR SIGNATURE XXX%3D
&AlarmActions.member.1=arn:aws:automate:us-east-1:ec2:recover

Amazon CloudWatch Alarm Action Scenarios
You can use the Amazon EC2 console to create alarm actions that stop or terminate an Amazon EC2
instance when certain conditions are met. In the following screen capture of the console page where
you set the alarm actions, we've numbered the settings. We've also numbered the settings in the
scenarios that follow, to help you create the appropriate actions.

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Scenario 1: Stop Idle Development and Test Instances
Create an alarm that stops an instance used for software development or testing when it has been idle
for at least an hour.
Setting
Value
Stop
Maximum
CPUUtilization
<=
10%
60 minutes
1

Scenario 2: Stop Idle Instances
Create an alarm that stops an instance and sends an email when the instance has been idle for 24
hours.

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Setting
Value
Stop and email
Average
CPUUtilization
<=
5%
60 minutes
24

Scenario 3: Send Email About Web Servers with Unusually High Traffic
Create an alarm that sends email when an instance exceeds 10 GB of outbound network traffic per
day.
Setting
Value
Email
Sum
NetworkOut
>
10 GB
1 day
1

Scenario 4: Stop Web Servers with Unusually High Traffic
Create an alarm that stops an instance and send a text message (SMS) if outbound traffic exceeds 1
GB per hour.
Setting
Value
Stop and send SMS
Sum
NetworkOut
>
1 GB
1 hour
1

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Scenario 5: Stop an Instance Experiencing a Memory Leak
Create an alarm that stops an instance when memory utilization reaches or exceeds 90%, so that
application logs can be retrieved for troubleshooting.

Note
The MemoryUtilization metric is a custom metric. In order to use the MemoryUtilization metric,
you must install the Perl scripts for Linux instances. For more information, see Monitoring
Memory and Disk Metrics for Amazon EC2 Linux Instances.
Setting
Value
Stop
Maximum
MemoryUtilization
>=
90%
1 minute
1

Scenario 6: Stop an Impaired Instance
Create an alarm that stops an instance that fails three consecutive status checks (performed at 5minute intervals).
Setting
Value
Stop
Average
StatusCheckFailed_System
>=
1
15 minutes
1

Scenario 7: Terminate Instances When Batch Processing Jobs Are
Complete
Create an alarm that terminates an instance that runs batch jobs when it is no longer sending results
data.
Setting
Value
Terminate
Maximum

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Setting
Value
NetworkOut
<=
100,000 bytes
5 minutes
1

Scenarios Using the CloudWatch Console
The previous scenarios can also be performed using the Amazon CloudWatch console. We've
numbered the settings on the console to match the numbered settings in the Amazon EC2 console and
the scenarios that we covered earlier, so you can make a comparison and create an alarm with the
appropriate actions.

Monitoring Memory and Disk Metrics for
Amazon EC2 Linux Instances
The Amazon CloudWatch Monitoring Scripts for Amazon Elastic Compute Cloud (Amazon EC2) Linuxbased instances demonstrate how to produce and consume Amazon CloudWatch custom metrics.

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These sample Perl scripts comprise a fully functional example that reports memory, swap, and disk
space utilization metrics for a Linux instance. You can download the Amazon CloudWatch Monitoring
Scripts for Linux from the AWS sample code library.

Important
These scripts are examples only. They are provided "as is" and are not supported.
These monitoring scripts are intended for use with Amazon EC2 instances running Linux operating
systems. The scripts have been tested on the following Amazon Machine Images (AMIs) for both 32-bit
and 64-bit versions:
• Amazon Linux 2014.09.2
• Red Hat Enterprise Linux 6.6
• SUSE Linux Enterprise Server 12
• Ubuntu Server 14.04

Note
Standard Amazon CloudWatch free tier quantities and usage charges for custom metrics
apply to your use of these scripts. For more information, see the Amazon CloudWatch pricing
page.
You can use EC2Config on Amazon EC2 instances running Windows to monitor memory and disk
metrics by sending this data to CloudWatch Logs. To get started with CloudWatch Logs on an Amazon
EC2 instance running Windows, see Sending Performance Counters to CloudWatch and Logs to
CloudWatch Logs in the Amazon EC2 User Guide for Windows Instances.
Contents
• Prerequisites (p. 472)
• Getting Started (p. 474)
• mon-put-instance-data.pl (p. 475)
• mon-get-instance-stats.pl (p. 477)
• Viewing Your Custom Metrics in the Console (p. 479)

Prerequisites
You must perform additional steps on some versions of Linux.

Note
The CloudWatchClient.pm module included in the script package locally caches instance
metadata. If you create an AMI from an instance where you have run the scripts, any
instances launched from this AMI within the cache TTL (default: six hours, 24 hours for Auto
Scaling groups) will emit metrics using the original instance's ID. After the cache TTL time
period passes, the script will retrieve fresh data and the scripts will use the current instance's
ID. To immediately correct this, remove the cached data using: $ rm /var/tmp/aws-mon/
instance-id.
Amazon Linux AMI
If you are running Amazon Linux AMI, version 2014.03 or later, you’ll need to add some additional Perl
modules in order for the monitoring scripts to work. Use the following procedures to configure your
server.

To install the scripts for the first time
1.

Log on to your Amazon Linux AMI instance.

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At a command prompt, install the following package:
$ sudo yum install perl-Switch perl-DateTime perl-Sys-Syslog perl-LWPProtocol-https

Red Hat Enterprise Linux
If you are running Red Hat Enterprise Linux, you’ll need to add some additional Perl modules in order
for the monitoring scripts to work. Use the following procedures to configure your server.

To install the scripts for the first time
1.

Log on to your Red Hat Enterprise Linux instance.

At a command prompt, install the following packages:
$ sudo yum install perl-Switch perl-DateTime perl-Sys-Syslog perl-LWPProtocol-https perl-Digest-SHA -y

$ sudo yum install zip unzip

SUSE Linux Enterprise Server
If you are running SUSE Linux Enterprise Server, you’ll need to add some additional Perl modules in
order for the monitoring scripts to work. Use the following procedures to configure your server.

To install the scripts for the first time
1.

Log on to your SUSE Linux Enterprise Server instance.

At a command prompt, install the following packages:
$ sudo zypper install perl-Switch perl-DateTime

$ sudo zypper install –y "perl(LWP::Protocol::https)"

Ubuntu Server
If you are running Ubuntu Server, use the following procedures to configure your server.

To install the scripts for the first time
1.

Log on to your Ubuntu Server instance.

At a command prompt, install the following packages:
$ sudo apt-get update

$ sudo apt-get install unzip

$ sudo apt-get install libwww-perl libdatetime-perl

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For information about connecting to Amazon EC2 Linux instances, see Connect to Your Linux
Instance (p. 289).

Getting Started
The following steps show you how to download, uncompress, and configure the CloudWatch
Monitoring Scripts on an EC2 Linux instance.

To download, install, and configure the script
1.

Open a command prompt, move to a folder where you want to store the scripts and then type the
following:
curl http://aws-cloudwatch.s3.amazonaws.com/downloads/
CloudWatchMonitoringScripts-1.2.1.zip -O
unzip CloudWatchMonitoringScripts-1.2.1.zip
rm CloudWatchMonitoringScripts-1.2.1.zip
cd aws-scripts-mon

The CloudWatchMonitoringScripts-1.2.1.zip package contains these files:
• CloudWatchClient.pm—Shared Perl module that simplifies calling Amazon CloudWatch from
other scripts.
• mon-put-instance-data.pl—Collects system metrics on an Amazon EC2 instance (memory,
swap, disk space utilization) and sends them to Amazon CloudWatch.
• mon-get-instance-stats.pl—Queries Amazon CloudWatch and displays the most recent
utilization statistics for the EC2 instance on which this script is executed.
• awscreds.template—File template for AWS credentials that stores your access key ID and
secret access key.
• LICENSE.txt—Text file containing the Apache 2.0 license.
• NOTICE.txt—copyright notice.
2.

If you already have an AWS Identity and Access Management (IAM) role associated with your
instance, make sure that it has permissions to perform the following operations:
• cloudwatch:PutMetricData
• cloudwatch:GetMetricStatistics
• cloudwatch:ListMetrics
• ec2:DescribeTags
Otherwise, you can create a new IAM role with permissions to perform CloudWatch operations
and associate that role when you launch a new instance. For more information, see Controlling
User Access to Your AWS Account.

Optional: If you aren't using an IAM role, update the awscreds.template file that you
downloaded earlier. The content of this file should use the following format:
AWSAccessKeyId=YourAccessKeyID
AWSSecretKey=YourSecretAccessKey

Note
This step is optional if you have already created a file for credentials. You can use an
existing file by specifying its location on the command line when you call the scripts.
Alternatively, you can set the environment variable AWS_CREDENTIAL_FILE to point to
the file with your AWS credentials.
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mon-put-instance-data.pl

For instructions on how to access your credentials, see Creating, Modifying, and Viewing
User Security Credentials in the IAM User Guide.

mon-put-instance-data.pl
This script collects memory, swap, and disk space utilization data on the current system. It then makes
a remote call to Amazon CloudWatch to report the collected data as custom metrics.

Options
Name

Description

--mem-util

Collects and sends the MemoryUtilization metrics in percentages.
This option reports only memory allocated by applications and the
operating system, and excludes memory in cache and buffers.

--mem-used

Collects and sends the MemoryUsed metrics, reported in
megabytes. This option reports only memory allocated by
applications and the operating system, and excludes memory in
cache and buffers.

--mem-avail

Collects and sends the MemoryAvailable metrics, reported in
megabytes. This option reports memory available for use by
applications and the operating system.

--swap-util

Collects and sends SwapUtilization metrics, reported in
percentages.

--swap-used

Collects and sends SwapUsed metrics, reported in megabytes.

--disk-path=PATH

Selects the disk on which to report.
PATH can specify a mount point or any file located on a mount
point for the filesystem that needs to be reported. For selecting
multiple disks, specify a --disk-path=PATH for each one of
them.
To select a disk for the filesystems mounted on / and /home, use
the following parameters:
--disk-path=/ --disk-path=/home

--disk-space-util

Collects and sends the DiskSpaceUtilization metric for the selected
disks. The metric is reported in percentages.

--disk-space-used

Collects and sends the DiskSpaceUsed metric for the selected
disks. The metric is reported by default in gigabytes.
Due to reserved disk space in Linux operating systems, disk space
used and disk space available might not accurately add up to the
amount of total disk space.

--disk-space-avail

Collects and sends the DiskSpaceAvailable metric for the selected
disks. The metric is reported in gigabytes.
Due to reserved disk space in the Linux operating systems, disk
space used and disk space available might not accurately add up
to the amount of total disk space.

--memory-units=UNITS

Specifies units in which to report memory usage. If not specified,
memory is reported in megabytes. UNITS may be one of the
following: bytes, kilobytes, megabytes, gigabytes.

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mon-put-instance-data.pl

Name

Description

--disk-spaceunits=UNITS

Specifies units in which to report disk space usage. If not specified,
disk space is reported in gigabytes. UNITS may be one of the
following: bytes, kilobytes, megabytes, gigabytes.

--aws-credentialfile=PATH

Provides the location of the file containing AWS credentials.
This parameter cannot be used with the --aws-access-key-id
and --aws-secret-key parameters.

--aws-access-keyid=VALUE

Specifies the AWS access key ID to use to identify the caller. Must
be used together with the --aws-secret-key option. Do not use
this option with the --aws-credential-file parameter.

--aws-secret-key=VALUE

Specifies the AWS secret access key to use to sign the request
to CloudWatch. Must be used together with the --aws-accesskey-id option. Do not use this option with --aws-credentialfile parameter.

--aws-iam-role=VALUE

Specifies the IAM role used to provide AWS credentials. The value
=VALUE is required. If no credentials are specified, the default IAM
role associated with the EC2 instance is applied. Only one IAM
role can be used. If no IAM roles are found, or if more than one
IAM role is found, the script will return an error.
Do not use this option with the --aws-credential-file, -aws-access-key-id, or --aws-secret-key parameters.

--aggregated[=only]

Adds aggregated metrics for instance type, AMI ID, and overall
for the region. The value =only is optional; if specified, the script
reports only aggregated metrics.

--auto-scaling[=only]

Adds aggregated metrics for the Auto Scaling group. The value
=only is optional; if specified, the script reports only Auto Scaling
metrics. The IAM policy associated with the IAM account or role
using the scripts need to have permissions to call the EC2 action
DescribeTags.

--verify

Performs a test run of the script that collects the metrics, prepares
a complete HTTP request, but does not actually call CloudWatch
to report the data. This option also checks that credentials are
provided. When run in verbose mode, this option outputs the
metrics that will be sent to CloudWatch.

--from-cron

Use this option when calling the script from cron. When this option
is used, all diagnostic output is suppressed, but error messages
are sent to the local system log of the user account.

--verbose

Displays detailed information about what the script is doing.

--help

Displays usage information.

--version

Displays the version number of the script.

Examples
The following examples assume that you have already updated the awscreds.template file with
valid AWS credentials. If you are not using the awscreds.template file, provide credentials using the
--aws-access-key-id and --aws-secret-key arguments.

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mon-get-instance-stats.pl

To perform a simple test run without posting data to CloudWatch
•

Run the following command:
./mon-put-instance-data.pl --mem-util --verify --verbose

To collect all available memory metrics and send them to CloudWatch
•

Run the following command:
./mon-put-instance-data.pl --mem-util --mem-used --mem-avail

To set a cron schedule for metrics reported to CloudWatch
1.

Start editing the crontab using the following command:
crontab -e

Add the following command to report memory and disk space utilization to CloudWatch every five
minutes:
*/5 * * * * ~/aws-scripts-mon/mon-put-instance-data.pl --mem-util --diskspace-util --disk-path=/ --from-cron

If the script encounters an error, the script will write the error message in the system log.

To collect aggregated metrics for an Auto Scaling group and send them to Amazon
CloudWatch without reporting individual instance metrics
•

Run the following command:
./mon-put-instance-data.pl --mem-util --mem-used --mem-avail --autoscaling=only

To collect aggregated metrics for instance type, AMI ID and region, and send them to
Amazon CloudWatch without reporting individual instance metrics
•

Run the following command:
./mon-put-instance-data.pl --mem-util --mem-used --mem-avail -aggregated=only

mon-get-instance-stats.pl
This script queries CloudWatch for statistics on memory, swap, and disk space metrics within the time
interval provided using the number of most recent hours. This data is provided for the Amazon EC2
instance on which this script is executed.

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mon-get-instance-stats.pl

Options
Name

Description

--recent-hours=N

Specifies the number of recent hours to report on, as represented
by N where N is an integer.

--aws-credentialfile=PATH

Provides the location of the file containing AWS credentials.

--aws-access-keyid=VALUE

Specifies the AWS access key ID to use to identify the caller. Must
be used together with the --aws-secret-key option. Do not use
this option with the --aws-credential-file option.

--aws-secret-key=VALUE

Specifies the AWS secret access key to use to sign the request
to CloudWatch. Must be used together with the --aws-accesskey-id option. Do not use this option with --aws-credentialfile option.

--aws-iam-role=VALUE

--verify

--verbose

Displays detailed information about what the script is doing.

--help

Displays usage information.

--version

Displays the version number of the script.

Examples
To get utilization statistics for the last 12 hours
•

Run the following command:
./mon-get-instance-stats.pl --recent-hours=12

The returned response will be similar to the following example output:
Instance metric statistics for the last 12 hours.
CPU Utilization
Average: 1.06%, Minimum: 0.00%, Maximum: 15.22%
Memory Utilization
Average: 6.84%, Minimum: 6.82%, Maximum: 6.89%

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Viewing Your Custom Metrics in the Console
Swap Utilization
Average: N/A, Minimum: N/A, Maximum: N/A
Disk Space Utilization on /dev/xvda1 mounted as /
Average: 9.69%, Minimum: 9.69%, Maximum: 9.69%

Viewing Your Custom Metrics in the Console
If you successfully call the mon-put-instance-data.pl script, you can use the AWS Management
Console to view your posted custom metrics in the Amazon CloudWatch console.

To view custom metrics
1.
2.

Execute mon-put-instance-data.pl, as described earlier.
Sign in to the AWS Management Console and open the CloudWatch console at https://
console.aws.amazon.com/cloudwatch/.

3.
4.

Click View Metrics.
In the Viewing list, your custom metrics posted by the script are displayed with the prefix System/
Linux.

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Network and Security

Amazon EC2 provides the following network and security features.
Features
• Amazon EC2 Key Pairs (p. 481)
• Amazon EC2 Security Groups for Linux Instances (p. 489)
• Controlling Access to Amazon EC2 Resources (p. 498)
• Amazon EC2 and Amazon Virtual Private Cloud (p. 543)
• Amazon EC2 Instance IP Addressing (p. 570)
• Elastic IP Addresses (p. 581)
• Elastic Network Interfaces (ENI) (p. 588)
• Placement Groups (p. 602)
• Network Maximum Transmission Unit (MTU) for Your EC2 Instance (p. 605)
• Enhanced Networking on Linux (p. 608)
If you access Amazon EC2 using the command line tools or an API, you'll need your access key ID
and secret access key. For more information, see How Do I Get Security Credentials? in the Amazon
Web Services General Reference.
You can launch an instance into one of two platforms: EC2-Classic or EC2-VPC. An instance that's
launched into EC2-Classic or a default VPC is automatically assigned a public IP address. An instance
that's launched into a nondefault VPC can be assigned a public IP address on launch. For more
information about EC2-Classic and EC2-VPC, see Supported Platforms (p. 549).
Instances can fail or terminate for reasons outside of your control. If an instance fails and you launch a
replacement instance, the replacement has a different public IP address than the original. However, if
your application needs a static IP address, you can use an Elastic IP address.
You can use security groups to control who can access your instances. These are analogous to an
inbound network firewall that enables you to specify the protocols, ports, and source IP ranges that are
allowed to reach your instances. You can create multiple security groups and assign different rules to
each group. You can then assign each instance to one or more security groups, and we use the rules
to determine which traffic is allowed to reach the instance. You can configure a security group so that
only specific IP addresses or specific security groups have access to the instance.

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Key Pairs

Amazon EC2 Key Pairs
Amazon EC2 uses public–key cryptography to encrypt and decrypt login information. Public–key
cryptography uses a public key to encrypt a piece of data, such as a password, then the recipient uses
the private key to decrypt the data. The public and private keys are known as a key pair.
To log in to your instance, you must create a key pair, specify the name of the key pair when you
launch the instance, and provide the private key when you connect to the instance. Linux instances
have no password, and you use a key pair to log in using SSH. With Windows instances, you use a key
pair to obtain the administrator password and then log in using RDP.
Creating a Key Pair
You can use Amazon EC2 to create your key pair. For more information, see Creating Your Key Pair
Using Amazon EC2 (p. 482).
Alternatively, you could use a third-party tool and then import the public key to Amazon EC2. For more
information, see Importing Your Own Key Pair to Amazon EC2 (p. 482).
Each key pair requires a name. Be sure to choose a name that is easy to remember. Amazon EC2
associates the public key with the name that you specify as the key name.
Amazon EC2 stores the public key only, and you store the private key. Anyone who possesses your
private key can decrypt your login information, so it's important that you store your private keys in a
secure place.
The keys that Amazon EC2 uses are 2048-bit SSH-2 RSA keys. You can have up to five thousand key
pairs per region.
Launching and Connecting to Your Instance
When you launch an instance, you should specify the name of the key pair you plan to use to connect
to the instance. If you don't specify the name of an existing key pair when you launch an instance,
you won't be able to connect to the instance. When you connect to the instance, you must specify the
private key that corresponds to the key pair you specified when you launched the instance.

Note
Amazon EC2 doesn't keep a copy of your private key; therefore, if you lose a private key,
there is no way to recover it. If you lose the private key for an instance store-backed instance,
you can't access the instance; you should terminate the instance and launch another instance
using a new key pair. If you lose the private key for an EBS-backed Linux instance, you can
regain access to your instance. For more information, see Connecting to Your Linux Instance
if You Lose Your Private Key (p. 486).
Key Pairs for Multiple Users
If you have several users that require access to a single instance, you can add user accounts to your
instance. For more information, see Managing User Accounts on Your Linux Instance (p. 320). You can
create a key pair for each user, and add the public key information from each key pair to the .ssh/
authorized_keys file for each user on your instance. You can then distribute the private key files
to your users. That way, you do not have to distribute the same private key file that's used for the root
account to multiple users.
Contents
• Creating Your Key Pair Using Amazon EC2 (p. 482)
• Importing Your Own Key Pair to Amazon EC2 (p. 482)
• Retrieving the Public Key for Your Key Pair on Linux (p. 484)
• Retrieving the Public Key for Your Key Pair on Windows (p. 485)

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Creating Your Key Pair Using Amazon EC2

• Verifying Your Key Pair's Fingerprint (p. 485)
• Deleting Your Key Pair (p. 486)
• Connecting to Your Linux Instance if You Lose Your Private Key (p. 486)

Creating Your Key Pair Using Amazon EC2
You can create a key pair using the Amazon EC2 console or the command line. After you create a
key pair, you can specify it when you launch your instance. You can also add the key pair to a running
instance to enable another user to connect to the instance. For more information, see Managing User
Accounts on Your Linux Instance (p. 320).

To create your key pair using the Amazon EC2 console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, under NETWORK & SECURITY, choose Key Pairs.

Tip
The navigation pane is on the left side of the Amazon EC2 console. If you do not see the
pane, it might be minimized; choose the arrow to expand the pane.
3.

Choose Create Key Pair.

Enter a name for the new key pair in the Key pair name field of the Create Key Pair dialog box,
and then choose Create.

To create your key pair using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• create-key-pair (AWS CLI)
• New-EC2KeyPair (AWS Tools for Windows PowerShell)

Importing Your Own Key Pair to Amazon EC2
If you used Amazon EC2 to create your key pair, as described in the previous section, you are ready to
launch an instance. Otherwise, instead of using Amazon EC2 to create your key pair, you can create
an RSA key pair using a third-party tool and then import the public key to Amazon EC2. For example,
you can use ssh-keygen (a tool provided with the standard OpenSSH installation) to create a key pair.
Alternatively, Java, Ruby, Python, and many other programming languages provide standard libraries
that you can use to create an RSA key pair.
Amazon EC2 accepts the following formats:

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Importing Your Own Key Pair to Amazon EC2

• OpenSSH public key format (the format in ~/.ssh/authorized_keys)
• Base64 encoded DER format
• SSH public key file format as specified in RFC4716
Amazon EC2 does not accept DSA keys. Make sure your key generator is set up to create RSA keys.
Supported lengths: 1024, 2048, and 4096.

To create a key pair using a third-party tool
1.

Generate a key pair with a third-party tool of your choice.

Save the public key to a local file. For example, ~/.ssh/my-key-pair.pub (Linux) or C:\keys
\my-key-pair.pub (Windows). The file name extension for this file is not important.

Save the private key to a different local file that has the .pem extension. For example, ~/.ssh/
my-key-pair.pem (Linux) or C:\keys\my-key-pair.pem (Windows). Save the private key file
in a safe place. You'll need to provide the name of your key pair when you launch an instance and
the corresponding private key each time you connect to the instance.

Use the following steps to import your key pair using the Amazon EC2 console.

To import the public key
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.
4.

In the navigation pane, under NETWORK & SECURITY, choose Key Pairs.
Choose Import Key Pair.
In the Import Key Pair dialog box, choose Browse, and select the public key file that you saved
previously. Enter a name for the key pair in the Key pair name field, and choose Import.

To import your key pair using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• import-key-pair (AWS CLI)
• Import-EC2KeyPair (AWS Tools for Windows PowerShell)
After the public key file is imported, you can verify that the key pair was imported successfully using the
Amazon EC2 console as follows.

To verify that your key pair was imported
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.
4.

From the navigation bar, select the region in which you created the key pair.
In the navigation pane, under NETWORK & SECURITY, choose Key Pairs.
Verify that the key pair that you imported is in the displayed list of key pairs.

To view your key pair using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• describe-key-pairs (AWS CLI)
• Get-EC2KeyPair (AWS Tools for Windows PowerShell)

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Retrieving the Public Key for Your Key Pair on Linux

Retrieving the Public Key for Your Key Pair on
Linux
On a Linux instance, the public key content is placed in an entry within ~/.ssh/authorized_keys.
This is done at boot time and enables you to securely access your instance without passwords. You
can open this file in an editor to view the public key for your key pair. The following is an example entry
for the key pair named my-key-pair. It consists of the public key followed by the name of the key
pair. For example:
ssh-rsa
AAAAB3NzaC1yc2EAAAADAQABAAABAQClKsfkNkuSevGj3eYhCe53pcjqP3maAhDFcvBS7O6V
hz2ItxCih+PnDSUaw+WNQn/mZphTk/a/gU8jEzoOWbkM4yxyb/wB96xbiFveSFJuOp/
d6RJhJOI0iBXr
lsLnBItntckiJ7FbtxJMXLvvwJryDUilBMTjYtwB+QhYXUMOzce5Pjz5/i8SeJtjnV3iAoG/cQk
+0FzZ
qaeJAAHco+CY/5WrUBkrHmFJr6HcXkvJdWPkYQS3xqC0+FmUZofz221CBt5IMucxXPkX4rWi
+z7wB3Rb
BQoQzd8v7yeb7OzlPnWOyN0qFU0XA246RA8QFYiCNYwI3f05p6KLxEXAMPLE my-key-pair

You can use ssh-keygen to get the public key for your key pair. Run the following command on a
computer to which you've downloaded your private key:
$ ssh-keygen -y

When prompted to enter the file in which the key is, specify the path to your .pem file; for example:
/path_to_key_pair/my-key-pair.pem

The command returns the public key:
ssh-rsa
AAAAB3NzaC1yc2EAAAADAQABAAABAQClKsfkNkuSevGj3eYhCe53pcjqP3maAhDFcvBS7O6V
hz2ItxCih+PnDSUaw+WNQn/mZphTk/a/gU8jEzoOWbkM4yxyb/wB96xbiFveSFJuOp/
d6RJhJOI0iBXr
lsLnBItntckiJ7FbtxJMXLvvwJryDUilBMTjYtwB+QhYXUMOzce5Pjz5/i8SeJtjnV3iAoG/cQk
+0FzZ
qaeJAAHco+CY/5WrUBkrHmFJr6HcXkvJdWPkYQS3xqC0+FmUZofz221CBt5IMucxXPkX4rWi
+z7wB3Rb
BQoQzd8v7yeb7OzlPnWOyN0qFU0XA246RA8QFYiCNYwI3f05p6KLxEXAMPLE

If this command fails, ensure that you've changed the permissions on your key pair file so that only you
can view it by running the following command:
$ chmod 400 my-key-pair.pem

The public key that you specified when you launched an instance is also available to you through its
instance metadata. To view the public key that you specified when launching the instance, use the
following command from your instance:
$ GET http://169.254.169.254/latest/meta-data/public-keys/0/openssh-key
ssh-rsa
AAAAB3NzaC1yc2EAAAADAQABAAABAQClKsfkNkuSevGj3eYhCe53pcjqP3maAhDFcvBS7O6V

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Retrieving the Public Key for
Your Key Pair on Windows
hz2ItxCih+PnDSUaw+WNQn/mZphTk/a/gU8jEzoOWbkM4yxyb/wB96xbiFveSFJuOp/
d6RJhJOI0iBXr
lsLnBItntckiJ7FbtxJMXLvvwJryDUilBMTjYtwB+QhYXUMOzce5Pjz5/i8SeJtjnV3iAoG/cQk
+0FzZ
qaeJAAHco+CY/5WrUBkrHmFJr6HcXkvJdWPkYQS3xqC0+FmUZofz221CBt5IMucxXPkX4rWi
+z7wB3Rb
BQoQzd8v7yeb7OzlPnWOyN0qFU0XA246RA8QFYiCNYwI3f05p6KLxEXAMPLE my-key-pair

For more information, see Retrieving Instance Metadata (p. 338).
Note that if you change the key pair that you use to connect to the instance, as shown in the last
section on this page, we don't update the instance metadata to show the new public key; you'll
continue to see the public key for the key pair you specified when you launched the instance in the
instance metadata.

Retrieving the Public Key for Your Key Pair on
Windows
On Windows, you can use PuTTYgen to get the public key for your key pair. Start PuTTYgen, click
Load, and select the .ppk or .pem file. PuTTYgen displays the public key.
The public key that you specified when you launched an instance is also available to you through its
instance metadata. To view the public key that you specified when launching the instance, use the
following command from your instance:
$ GET http://169.254.169.254/latest/meta-data/public-keys/0/openssh-key
ssh-rsa
AAAAB3NzaC1yc2EAAAADAQABAAABAQClKsfkNkuSevGj3eYhCe53pcjqP3maAhDFcvBS7O6V
hz2ItxCih+PnDSUaw+WNQn/mZphTk/a/gU8jEzoOWbkM4yxyb/wB96xbiFveSFJuOp/
d6RJhJOI0iBXr
lsLnBItntckiJ7FbtxJMXLvvwJryDUilBMTjYtwB+QhYXUMOzce5Pjz5/i8SeJtjnV3iAoG/cQk
+0FzZ
qaeJAAHco+CY/5WrUBkrHmFJr6HcXkvJdWPkYQS3xqC0+FmUZofz221CBt5IMucxXPkX4rWi
+z7wB3Rb
BQoQzd8v7yeb7OzlPnWOyN0qFU0XA246RA8QFYiCNYwI3f05p6KLxEXAMPLE my-key-pair

For more information, see Retrieving Instance Metadata (p. 338).

Verifying Your Key Pair's Fingerprint
On the Key Pairs page in the Amazon EC2 console, the Fingerprint column displays the fingerprints
generated from your key pairs. AWS calculates the fingerprint differently depending on whether the key
pair was generated by AWS or a third-party tool. If you created the key pair using AWS, the fingerprint
is calculated using an SHA-1 hash function. If you created the key pair with a third-party tool and
uploaded the public key to AWS, or if you generated a new public key from an existing AWS-created
private key and uploaded it to AWS, the fingerprint is calculated using an MD5 hash function.
You can use the fingerprint that's displayed on the Key Pairs page to verify that the private key you
have on your local machine matches the public key that's stored in AWS.
If you created your key pair using AWS, you can use the OpenSSL tools to generate a fingerprint from
the private key file:
$ openssl pkcs8 -in path_to_private_key -inform PEM -outform DER -topk8 nocrypt | openssl sha1 -c

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Deleting Your Key Pair

If you created your key pair using a third-party tool and uploaded the public key to AWS, you can use
the OpenSSL tools to generate a fingerprint from the private key file on your local machine:
$ openssl rsa -in path_to_private_key -pubout -outform DER | openssl md5 -c

The output should match the fingerprint that's displayed in the console.

Deleting Your Key Pair
When you delete a key pair, you are only deleting Amazon EC2's copy of the public key. Deleting a
key pair doesn't affect the private key on your computer or the public key on any instances already
launched using that key pair. You can't launch a new instance using a deleted key pair, but you can
continue to connect to any instances that you launched using a deleted key pair, as long as you still
have the private key (.pem) file.

Note
If you're using an Auto Scaling group (for example, in an Elastic Beanstalk environment),
ensure that the key pair you're deleting is not specified in your launch configuration. Auto
Scaling launches a replacement instance if it detects an unhealthy instance; however, the
instance launch fails if the key pair cannot be found.
You can delete a key pair using the Amazon EC2 console or the command line.

To delete your key pair using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, under NETWORK & SECURITY, choose Key Pairs.

Select the key pair and choose Delete.

When prompted, choose Yes.

To delete your key pair using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• delete-key-pair (AWS CLI)
• Remove-EC2KeyPair (AWS Tools for Windows PowerShell)

Note
If you create a Linux AMI from an instance, and then use the AMI to launch a new instance
in a different region or account, the new instance includes the public key from the original
instance. This enables you to connect to the new instance using the same private key file
as your original instance. You can remove this public key from your instance by removing
its entry from the .ssh/authorized_keys file using a text editor of your choice. For more
information about managing users on your instance and providing remote access using a
specific key pair, see Managing User Accounts on Your Linux Instance (p. 320).

Connecting to Your Linux Instance if You Lose
Your Private Key
If you lose the private key for an EBS-backed instance, you can regain access to your instance. You
must stop the instance, detach its root volume and attach it to another instance as a data volume,
modify the authorized_keys file, move the volume back to the original instance, and restart the

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instance. For more information about launching, connecting to, and stopping instances, see Instance
Lifecycle (p. 275).

This procedure isn't supported for instance store-backed instances. To determine the root device type
of your instance, open the Amazon EC2 console, choose Instances, select the instance, and check
the value of Root device type in the details pane. The value is either ebs or instance store. If
the root device is an instance store volume, you must have the private key in order to connect to the
instance.
Prerequisites
Create a new key pair using either the Amazon EC2 console or a third-party tool.

To connect to an EBS-backed instance with a different key pair
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

Choose Instances in the navigation pane, and then select the instance that you'd like to connect
to. (We'll refer to this as the original instance.)

Save the following information that you'll need to complete this procedure.
• Write down the instance ID, AMI ID, and Availability Zone of the original instance.
• Choose the entry for sda1 (the root volume) under Block devices in the details pane and write
down the volume ID in the EBS ID field (vol-xxxxxxxx).
• [EC2-Classic] If the original instance has an associated Elastic IP address, write down the
Elastic IP address shown in the Elastic IP field in the details pane.

Choose Actions, select Instance State, and then select Stop. If Stop is disabled, either the
instance is already stopped or its root device is an instance store volume.

Choose Launch Instance, and then use the launch wizard to launch a temporary instance with
the following options:
• On the Choose an AMI page, select the same AMI that you used to launch the original
instance. If this AMI is unavailable, you can create an AMI that you can use from the stopped
instance. For more information, see Creating an Amazon EBS-Backed Linux AMI (p. 89) .
• On the Choose an Instance Type page, leave the default instance type that the wizard selects
for you.
• On the Configure Instance Details page, specify the same Availability Zone as the instance
you'd like to connect to. If you're launching an instance in a VPC, select a subnet in this
Availability Zone.
• On the Tag Instance page, add the tag Name=Temporary to the instance to indicate that this is
a temporary instance.
• On the Review page, choose Launch. Create a new key pair, download it to a safe location on
your computer, and then choose Launch Instances.

In the navigation pane, choose Volumes and select the root device volume for the original
instance (you wrote down its volume ID in a previous step). Choose Actions, and then select
Detach Volume. Wait for the state of the volume to become available. (You might need to
choose the Refresh icon.)

With the volume still selected, choose Actions, and then select Attach Volume. Select the
instance ID of the temporary instance, write down the device name specified under Device (for
example, /dev/sdf), and then choose Yes, Attach.

Connect to the temporary instance.
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From the temporary instance, mount the volume that you attached to the instance so that you can
access its file system. For example, if the device name is /dev/sdf, use the following commands
to mount the volume as /mnt/tempvol.

Note
The device name may appear differently on your instance. For example, devices mounted
as /dev/sdf may show up as /dev/xvdf on the instance. Some versions of Red Hat
(or its variants, such as CentOS) may even increment the trailing letter by 4 characters,
where /dev/sdf becomes /dev/xvdk.
a.

Use the lsblk command to determine if the volume is partitioned.
[ec2-user ~]$ lsblk
NAME
MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda
202:0
0
8G 0 disk
##xvda1 202:1
0
8G 0 part /
xvdf
202:80
0 101G 0 disk
##xvdf1 202:81
0 101G 0 part
xvdg
202:96
0
30G 0 disk

In the above example, /dev/xvda and /dev/xvdf are partitioned volumes, and /dev/xvdg
is not. If your volume is partitioned, you mount the partition (/dev/xvdf1) instead of the raw
device (/dev/xvdf) in the next steps.
b.

Create a temporary directory to mount the volume.
[ec2-user ~]$ sudo mkdir /mnt/tempvol

Mount the volume (or partition) at the temporary mount point, using the volume name or
device name you identified earlier.
[ec2-user ~]$ sudo mount /dev/xvdf1 /mnt/tempvol

10. From the temporary instance, use the following command to update authorized_keys on the
mounted volume with the new public key from the authorized_keys for the temporary instance
(you may need to substitute a different user name in the following command, such as ubuntu for
Ubuntu instances):
[ec2-user ~]$ cp .ssh/authorized_keys /mnt/tempvol/home/ec2-user/.ssh/
authorized_keys

If this copy succeeded, you can go to the next step.
(Optional) Otherwise, if you don't have permission to edit files in /mnt/tempvol, you'll need to
update the file using sudo and then check the permissions on the file to verify that you'll be able to
log into the original instance. Use the following command to check the permissions on the file:
[ec2-user ~]$ sudo ls -l /mnt/tempvol/home/ec2-user/.ssh
total 4
-rw------- 1 222 500 398 Sep 13 22:54 authorized_keys

In this example output, 222 is the user ID and 500 is the group ID. Next, use sudo to re-run the
copy command that failed:
[ec2-user ~]$ sudo cp .ssh/authorized_keys /mnt/tempvol/home/ec2user/.ssh/authorized_keys

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Run the following command again to determine whether the permissions changed:
[ec2-user ~]$ sudo ls -l /mnt/tempvol/home/ec2-user/.ssh

If the user ID and group ID have changed, use the following command to restore them:
[ec2-user ~]$ sudo chown 222:500 /mnt/tempvol/home/ec2-user/.ssh/
authorized_keys

11. From the temporary instance, unmount the volume that you attached so that you can reattach it to
the original instance. For example, use the following command to unmount the volume at /mnt/
tempvol:
[ec2-user ~]$ sudo umount /mnt/tempvol

12. From the Amazon EC2 console, select the volume with the volume ID that you wrote down,
choose Actions, and then select Detach Volume. Wait for the state of the volume to become
available. (You might need to choose the Refresh icon.)
13. With the volume still selected, choose Actions, and then select Attach Volume. Select the
instance ID of the original instance, specify the device name /dev/sda1, and then choose Yes,
Attach.

Warning
If you don't specify sda1 as the device name, you'll be unable to start the original
instance. This is because Amazon EC2 expects the root device volume at sda1.
14. Select the original instance, choose Actions, select Instance State, and then choose Start. After
the instance enters the running state, you can connect to it using the private key file for your new
key pair.
15. [EC2-Classic] If the original instance had an associated Elastic IP address before you stopped it,
you must re-associate it with the instance as follows:
a.
b.
c.

In the navigation pane, choose Elastic IPs.
Select the Elastic IP address that you wrote down at the beginning of this procedure.
Choose Actions, and then select Associate Address.

d. Select the ID of the original instance, and then choose Associate.
16. (Optional) You can terminate the temporary instance if you have no further use for it. Select the
temporary instance, choose Actions, select Instance State, and then choose Terminate.

Amazon EC2 Security Groups for Linux
Instances
A security group acts as a virtual firewall that controls the traffic for one or more instances. When you
launch an instance, you associate one or more security groups with the instance. You add rules to
each security group that allow traffic to or from its associated instances. You can modify the rules for a
security group at any time; the new rules are automatically applied to all instances that are associated
with the security group. When we decide whether to allow traffic to reach an instance, we evaluate all
the rules from all the security groups that are associated with the instance.
If you need to allow traffic to a Windows instance, see Amazon EC2 Security Groups for Windows
Instances in the Amazon EC2 User Guide for Windows Instances.
Topics

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• Security Groups for EC2-Classic (p. 490)
• Security Groups for EC2-VPC (p. 490)
• Security Group Rules (p. 491)
• Default Security Groups (p. 492)
• Custom Security Groups (p. 493)
• Creating a Security Group (p. 494)
• Describing Your Security Groups (p. 495)
• Adding Rules to a Security Group (p. 495)
• Deleting Rules from a Security Group (p. 496)
• Deleting a Security Group (p. 496)
• API and Command Overview (p. 497)
If you have requirements that aren't met by security groups, you can maintain your own firewall on any
of your instances in addition to using security groups.

Security Groups for EC2-Classic
If you're using EC2-Classic, you must use security groups created specifically for EC2-Classic. When
you launch an instance in EC2-Classic, you must specify a security group in the same region as the
instance. You can't specify a security group that you created for a VPC when you launch an instance in
EC2-Classic.
After you launch an instance in EC2-Classic, you can't change its security groups. However, you can
add rules to or remove rules from a security group, and those changes are automatically applied to all
instances that are associated with the security group.

Note
In EC2-Classic, you can associate an instance with up to 500 security groups and add up to
100 rules to a security group.

Security Groups for EC2-VPC
If you're using EC2-VPC, you must use security groups created specifically for your VPC. When you
launch an instance in a VPC, you must specify a security group for that VPC. You can't specify a
security group that you created for EC2-Classic when you launch an instance in a VPC.
After you launch an instance in a VPC, you can change its security groups. Security groups are
associated with network interfaces. Changing an instance's security groups changes the security
groups associated with the primary network interface (eth0). For more information, see Changing an
Instance's Security Groups in the Amazon VPC User Guide. You can also change the security groups
associated with any other network interface. For more information, see Changing the Security Group of
an Elastic Network Interface (p. 598).
You can change the rules of a security group, and those changes are automatically applied to all
instances that are associated with the security group.

Note
In EC2-VPC, you can associate a network interface with up to 5 security groups and add up to
50 rules to a security group.
When you specify a security group for a nondefault VPC to the CLI or the API actions, you must use
the security group ID and not the security group name to identify the security group.
Security groups for EC2-VPC have additional capabilities that aren't supported by security groups for
EC2-Classic. For more information about security groups for EC2-VPC, see Security Groups for Your

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VPC, and Differences Between Security Groups for EC2-Classic and EC2-VPC in the Amazon VPC
User Guide.

Security Group Rules
The rules of a security group control the inbound traffic that's allowed to reach the instances that are
associated with the security group and the outbound traffic that's allowed to leave them.
The following are the characteristics of security group rules:
• By default, security groups allow all outbound traffic.
• Security group rules are always permissive; you can't create rules that deny access.
• You can add and remove rules at any time. You can't change the outbound rules for EC2-Classic.
If you're using the Amazon EC2 console, you can modify existing rules, and you can copy the rules
from an existing security group to a new security group.
• When you add or remove rules, your changes are automatically applied to the instances associated
with the security group after a short period, depending on the connection tracking for the traffic. For
more information, see Connection Tracking (p. 492).
• Security groups are stateful — if you send a request from your instance, the response traffic for that
request is allowed to flow in regardless of inbound security group rules. For VPC security groups,
this also means that responses to allowed inbound traffic are allowed to flow out, regardless of
outbound rules. For more information, see Connection Tracking (p. 492).

Note
If your instance (host A) initiates traffic to host B and uses a protocol other than TCP,
UDP, or ICMP, your instance’s firewall only tracks the IP address and protocol number
for the purpose of allowing response traffic from host B. If host B initiates traffic to your
instance in a separate request within 600 seconds of the original request or response, your
instance accepts it regardless of inbound security group rules, because it’s regarded as
response traffic. For VPC security groups, you can control this by modifying your security
group’s outbound rules to permit only certain types of outbound traffic. Alternatively, you
can use a network ACL for your subnet — network ACLs are stateless and therefore do
not automatically allow response traffic. For more information, see Network ACLs in the
Amazon VPC User Guide.
For each rule, you specify the following:
• The protocol to allow (such as TCP, UDP, or ICMP)
• TCP and UDP, or a custom protocol: The range of ports to allow
• ICMP: The ICMP type and code
• One of the following options for the source (inbound rules) or destination (outbound rules):
• An individual IP address, in CIDR notation. Be sure to use the /32 prefix after the IP address; if
you use the /0 prefix after the IP address, this opens the port to everyone. For example, specify
the IP address 203.0.113.1 as 203.0.113.1/32.
• An IP address range, in CIDR notation (for example, 203.0.113.0/24).
• The name (EC2-Classic) or ID (EC2-Classic or EC2-VPC) of a security group. This allows
instances associated with the specified security group to access instances associated with this
security group. (Note that this does not add rules from the source security group to this security
group.) You can specify one of the following security groups:
• The current security group.
• EC2-Classic: A different security group for EC2-Classic in the same region.
• EC2-Classic: A security group for another AWS account in the same region (add the AWS
account ID as a prefix; for example, 111122223333/sg-edcd9784).
• EC2-VPC: A different security group for the same VPC or a peer VPC.

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When you specify a security group as the source or destination for a rule, the rule affects all
instances associated with the security group. Incoming traffic is allowed based on the private IP
addresses of the instances that are associated with the source security group (and not the public IP
or Elastic IP addresses). For more information about IP addresses, see Amazon EC2 Instance IP
Addressing (p. 570). If your security group rule references a security group in a peer VPC, and the
referenced security group or VPC peering connection is deleted, the rule is marked as stale. For more
information, see Working with Stale Security Group Rules in the Amazon VPC Peering Guide.
If there is more than one rule for a specific port, we apply the most permissive rule. For example, if you
have a rule that allows access to TCP port 22 (SSH) from IP address 203.0.113.1 and another rule
that allows access to TCP port 22 from everyone, everyone has access to TCP port 22.
When you associate multiple security groups with an instance, the rules from each security group are
effectively aggregated to create one set of rules. We use this set of rules to determine whether to allow
access.

Caution
Because you can assign multiple security groups to an instance, an instance can have
hundreds of rules that apply. This might cause problems when you access the instance.
Therefore, we recommend that you condense your rules as much as possible.
For more information about creating security group rules to ensure that Path MTU Discovery can
function correctly, see Path MTU Discovery (p. 606).

Connection Tracking
Your security groups use connection tracking to track information about traffic to and from the instance.
Rules are applied based on the connection state of the traffic to determine if the traffic is allowed or
denied. This allows security groups to be stateful — responses to inbound traffic are allowed to flow out
of the instance regardless of outbound security group rules, and vice versa. For example, if you initiate
an ICMP ping command to your instance from your home computer, and your inbound security group
rules allow ICMP traffic, information about the connection (including the port information) is tracked.
Response traffic from the instance for the ping command is not tracked as new request, but rather
as an established connection and is allowed to flow out of the instance, even if your outbound security
group rules restrict outbound ICMP traffic.
Not all flows of traffic are tracked. If a security group rule permits TCP or UDP flows for all traffic
(0.0.0.0/0) and there is a corresponding rule in the other direction that permits the response traffic, then
that flow of traffic is not tracked. The response traffic is therefore allowed to flow based on the inbound
or outbound rule that permits the response traffic, and not on tracking information.
An existing flow of traffic that is tracked may not be interrupted when you remove the security group
rule that enables that flow. Instead, the flow is interrupted when it's stopped by you or the other host
for at least a few minutes (or up to 5 days for established TCP connections). For UDP, this may
require terminating actions on the remote side of the flow. An untracked flow of traffic is immediately
interrupted if the rule that enables the flow is removed or modified. For example, if you remove a rule
that allows all inbound SSH traffic (0.0.0.0/0) to the instance, then your existing SSH connections to the
instance are immediately dropped.
If you want to ensure that traffic is immediately interrupted when you remove a security group rule,
you can use a network ACL for your subnet — network ACLs are stateless and therefore do not
automatically allow response traffic. For more information, see Network ACLs in the Amazon VPC User
Guide.

Default Security Groups
Your AWS account automatically has a default security group per region for EC2-Classic. When you
create a VPC, we automatically create a default security group for the VPC. If you don't specify a

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different security group when you launch an instance, the instance is automatically associated with the
appropriate default security group.
A default security group is named default, and it has an ID assigned by AWS. The following are the
initial settings for each default security group:
• Allow inbound traffic only from other instances associated with the default security group
• Allow all outbound traffic from the instance
The default security group specifies itself as a source security group in its inbound rules. This is what
allows instances associated with the default security group to communicate with other instances
associated with the default security group.
You can change the rules for a default security group. For example, you can add an inbound rule to
allow SSH connections so that specific hosts can manage the instance.
You can't delete a default security group. If you try to delete the EC2-Classic default security group,
you'll get the following error: Client.InvalidGroup.Reserved: The security group
'default' is reserved. If you try to delete a VPC default security group, you'll get the following
error: Client.CannotDelete: the specified group: "sg-51530134" name: "default"
cannot be deleted by a user.

Custom Security Groups
If you don't want all your instances to use the default security group, you can create your own security
groups and specify them when you launch your instances. You can create multiple security groups
to reflect the different roles that your instances play; for example, a web server or a database server.
For instructions that help you create security groups for web servers and database servers, see
Recommended Security Groups in the Amazon VPC User Guide.

Note
In EC2-Classic, you can create up to 500 security groups in each region for each account. In
EC2-VPC, you can create up to 500 security groups per VPC. The security groups for EC2Classic do not count against the security group limit for EC2-VPC.
When you create a security group, you must provide it with a name and a description. Security
group names and descriptions can be up to 255 characters in length, and are limited to the following
characters:
• EC2-Classic: ASCII characters
• EC2-VPC: a-z, A-Z, 0-9, spaces, and ._-:/()#,@[]+=&;{}!$*
AWS assigns each security group a unique ID in the form sg-xxxxxxxx. The following are the initial
settings for a security group that you create:
• Allow no inbound traffic
• Allow all outbound traffic
After you've created a security group, you can change its inbound rules to reflect the type of inbound
traffic that you want to reach the associated instances. In EC2-VPC, you can also change its outbound
rules.
To allow instances that have the same security group to communicate with each other, you must
explicitly add rules for this. The following table describes the rules that you must add to your security
group to enable instances in EC2-Classic to communicate with each other.

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Inbound
Source

Protocol

Port Range

Comments

The ID of the security group

ICMP

All

Allow inbound ICMP access from
other instances associated with this
security group

The ID of the security group

TCP

0 - 65535

Allow inbound TCP access from
other instances associated with this
security group

The ID of the security group

UDP

0 - 65535

Allow inbound UDP access from
other instances associated with this
security group

The following table describes the rules that you must add to your security group to enable instances in
a VPC to communicate with each other.
Inbound
Source

Protocol

Port Range

Comments

The ID of the security group

All

Allow inbound traffic from other
instances associated with this
security group

Creating a Security Group
To create a new security group
1.
2.
3.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Security Groups.
Choose Create Security Group.

Specify a name and description for the security group. For VPC, choose No VPC to create a
security group for EC2-Classic, or choose a VPC ID to create a security group for that VPC.
You can start adding rules, or you can choose Create to create the security group now (you can
always add rules later). For more information about adding rules, see Adding Rules to a Security
Group (p. 495).

To copy a security group
1.
2.
3.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Security Groups.
Select the security group you want to copy, choose Actions, and then Copy to new.

The Create Security Group dialog opens, and is populated with the rules from the existing
security group. Specify a name and description for your new security group. In the VPC list,
choose No VPC to create a security group for EC2-Classic, or choose a VPC ID to create a
security group for that VPC. When you are done, choose Create.

You can assign a security group to an instance when you launch the instance. When you add or
remove rules, those changes are automatically applied to all instances to which you've assigned the
security group.

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After you launch an instance in EC2-Classic, you can't change its security groups. After you launch
an instance in a VPC, you can change its security groups. For more information, see Changing an
Instance's Security Groups in the Amazon VPC User Guide.

Describing Your Security Groups
To describe your security groups for EC2-Classic
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.
4.

In the navigation pane, choose Security Groups.
Select Network Platforms from the filter list, then choose EC2-Classic.
Select a security group. We display general information in the Description tab and inbound rules
on the Inbound tab.

To describe your security groups for EC2-VPC
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Security Groups.

3.
4.

Select Network Platforms from the filter list, then choose EC2-VPC.
Select a security group. We display general information in the Description tab, inbound rules on
the Inbound tab, and outbound rules on the Outbound tab.

Adding Rules to a Security Group
When you add a rule to a security group, the new rule is automatically applied to any instances
associated with the security group.

To add rules to a security group
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.

In the navigation pane, choose Security Groups.
Choose the security group.

You can allow web servers to receive all inbound HTTP and HTTPS traffic. On the Inbound tab,
choose Edit. In the dialog, choose Add Rule. Select HTTP from the Type list, and leave the
source as Anywhere (0.0.0.0/0). Add a similar rule for the HTTPS protocol.
To connect to a Linux instance, you need to allow SSH traffic. Choose Add Rule, and then select
SSH from the Type list.

In the Source field, specify the public IP address of your computer, in CIDR notation. For example,
if your IP address is 203.0.113.25, specify 203.0.113.25/32 to list this single IP address
in CIDR notation. If your company allocates addresses from a range, specify the entire range,
such as 203.0.113.0/24. You can select My IP to from the Source list to let us automatically
populate the field with your computer's IP address. However, if you are connecting through an
ISP or from behind your firewall without a static IP address, you need to find out the range of IP
addresses used by client computers.

Caution
If you use 0.0.0.0/0, you enable all IP addresses to access your instance using SSH.
This is acceptable for a short time in a test environment, but it's unsafe for production
environments. In production, you'll authorize only a specific IP address or range of
addresses to access your instance.
6.

You can allow communication between all instances associated with this security group, or
between instances associated with another security group and instances associated with this
security group. Choose Add Rule, select All ICMP, then start entering the ID of the security group

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in Source; this provides you with a list of security groups. Select the security group from the list.
Repeat the steps for the TCP and UDP protocols. Choose Save when you are done.

If you are creating a security group for a VPC, you can also specify outbound rules. For an
example, see Adding and Removing Rules in the Amazon VPC User Guide.

Deleting Rules from a Security Group
When you delete a rule from a security group, the change is automatically applied to any instances
associated with the security group.

To delete a security group rule
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Security Groups.

Select a security group.

Choose Edit, and then choose Delete (a cross icon) next to each rule that you need to delete.

Choose Save.

Deleting a Security Group
You can't delete a security group that is associated with an instance. You can't delete the default
security group. You can't delete a security group that is referenced by a rule in another security group.
If your security group is referenced by one of its own rules, you must delete the rule before you can
delete the security group.

To delete a security group
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

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In the navigation pane, choose Security Groups.

Select a security group and choose Delete.

Choose Yes, Delete.

API and Command Overview
You can perform the tasks described on this page using the command line or an API. For more
information about the command line interfaces and a list of available APIs, see Accessing Amazon
EC2 (p. 3).

Create a security group
• create-security-group (AWS CLI)
• New-EC2SecurityGroup (AWS Tools for Windows PowerShell)

Add one or more ingress rules to a security group
• authorize-security-group-ingress (AWS CLI)
• Grant-EC2SecurityGroupIngress (AWS Tools for Windows PowerShell)

[EC2-VPC] Add one or more egress rules to a security group
• authorize-security-group-egress (AWS CLI)
• Grant-EC2SecurityGroupIngress (AWS Tools for Windows PowerShell)

Describe one or more security groups
• describe-security-groups (AWS CLI)
• Get-EC2SecurityGroup (AWS Tools for Windows PowerShell)

[EC2-VPC] Modify the security groups for an instance
• modify-instance-attribute (AWS CLI)
• Edit-EC2InstanceAttribute (AWS Tools for Windows PowerShell)

Remove one or more ingress rules from a security group
• revoke-security-group-ingress (AWS CLI)
• Revoke-EC2SecurityGroupIngress (AWS Tools for Windows PowerShell)

[EC2-VPC] Remove one or more egress rules from a security group
• revoke-security-group-egress(AWS CLI)
• Revoke-EC2SecurityGroupEgress (AWS Tools for Windows PowerShell)

Delete a security group
• delete-security-group (AWS CLI)
• Remove-EC2SecurityGroup (AWS Tools for Windows PowerShell)

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Controlling Access to Amazon EC2 Resources
Your security credentials identify you to services in AWS and grant you unlimited use of your AWS
resources, such as your Amazon EC2 resources. You can use features of Amazon EC2 and AWS
Identity and Access Management (IAM) to allow other users, services, and applications to use your
Amazon EC2 resources without sharing your security credentials. You can use IAM to control how
other users use resources in your AWS account, and you can use security groups to control access
to your Amazon EC2 instances. You can choose to allow full use or limited use of your Amazon EC2
resources.
Contents
• Network Access to Your Instance (p. 498)
• Amazon EC2 Permission Attributes (p. 498)
• IAM and Amazon EC2 (p. 498)
• IAM Policies for Amazon EC2 (p. 500)
• IAM Roles for Amazon EC2 (p. 536)
• Authorizing Inbound Traffic for Your Linux Instances (p. 541)

Network Access to Your Instance
A security group acts as a firewall that controls the traffic allowed to reach one or more instances.
When you launch an instance, you assign it one or more security groups. You add rules to each
security group that control traffic for the instance. You can modify the rules for a security group at any
time; the new rules are automatically applied to all instances to which the security group is assigned.
For more information, see Authorizing Inbound Traffic for Your Linux Instances (p. 541).

Amazon EC2 Permission Attributes
Your organization might have multiple AWS accounts. Amazon EC2 enables you to specify additional
AWS accounts that can use your Amazon Machine Images (AMIs) and Amazon EBS snapshots. These
permissions work at the AWS account level only; you can't restrict permissions for specific users within
the specified AWS account. All users in the AWS account that you've specified can use the AMI or
snapshot.
Each AMI has a LaunchPermission attribute that controls which AWS accounts can access the AMI.
For more information, see Making an AMI Public (p. 78).
Each Amazon EBS snapshot has a createVolumePermission attribute that controls which
AWS accounts can use the snapshot. For more information, see Sharing an Amazon EBS
Snapshot (p. 691).

IAM and Amazon EC2
IAM enables you to do the following:
• Create users and groups under your AWS account
• Assign unique security credentials to each user under your AWS account
• Control each user's permissions to perform tasks using AWS resources
• Allow the users in another AWS account to share your AWS resources

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• Create roles for your AWS account and define the users or services that can assume them
• Use existing identities for your enterprise to grant permissions to perform tasks using AWS
resources
By using IAM with Amazon EC2, you can control whether users in your organization can perform a task
using specific Amazon EC2 API actions and whether they can use specific AWS resources.
This topic helps you answer the following questions:
• How do I create groups and users in IAM?
• How do I create a policy?
• What IAM policies do I need to carry out tasks in Amazon EC2?
• How do I grant permissions to perform actions in Amazon EC2?
• How do I grant permissions to perform actions on specific resources in Amazon EC2?

Creating an IAM Group and Users
To create an IAM group
1.

In the navigation pane, choose Groups and then choose Create New Group.

In the Group Name box, enter a name for your group, and then choose Next Step.

On the Attach Policy page, select an AWS managed policy. For example, for Amazon EC2, one
of the following AWS managed policies might meet your needs:
• PowerUserAccess
• ReadOnlyAccess
• AmazonEC2FullAccess
• AmazonEC2ReadOnlyAccess

Choose Next Step and then choose Create Group.

Your new group is listed under Group Name.

To create an IAM user, add the user to your group, and create a password for the user
1.

In the navigation pane, choose Users and then choose Create New Users.

In box 1, enter a user name and then choose Create.

Choose Download Credentials and save your access key in a secure place. You will need your
access key for programmatic access to AWS using the AWS CLI, the AWS SDKs, or the HTTP
APIs.

Note
You cannot retrieve the secret access key after you complete this step; if you misplace it
you must create a new one.
After you have downloaded your access key, choose Close.
4.

Under User Name, choose the name of the user you just created.

In the Groups tab, choose Add User to Groups.

Select the group you created earlier, and then choose Add to Groups.

Choose Security Credentials and then Manage Password.
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Select Assign a custom password and then enter and confirm a password. When you are
finished, choose Apply.

Give each user his or her credentials (access keys and password); this enables them to use
services based on the permissions you specified for the IAM group

Related Topics
For more information about IAM, see the following:
• IAM Policies for Amazon EC2 (p. 500)
• IAM Roles for Amazon EC2 (p. 536)
• Identity and Access Management (IAM)
• IAM User Guide

IAM Policies for Amazon EC2
By default, IAM users don't have permission to create or modify Amazon EC2 resources, or perform
tasks using the Amazon EC2 API. (This means that they also can't do so using the Amazon EC2
console or CLI.) To allow IAM users to create or modify resources and perform tasks, you must create
IAM policies that grant IAM users permission to use the specific resources and API actions they'll need,
and then attach those policies to the IAM users or groups that require those permissions.
When you attach a policy to a user or group of users, it allows or denies the users permission to
perform the specified tasks on the specified resources. For more general information about IAM
policies, see Permissions and Policies in the IAM User Guide. For more information about managing
and creating custom IAM policies, see Managing IAM Policies.
Getting Started
An IAM policy must grant or deny permission to use one or more Amazon EC2 actions. It must also
specify the resources that can be used with the action, which can be all resources, or in some cases,
specific resources. The policy can also include conditions that you apply to the resource.
Amazon EC2 partially supports resource-level permissions. This means that for some EC2 API actions,
you cannot specify which resource a user is allowed to work with for that action; instead, you have to
allow users to work with all resources for that action.
Task

Topic

Understand the basic structure of a policy

Policy Syntax (p. 501)

Define actions in your policy

Actions for Amazon EC2 (p. 502)

Define specific resources in your policy

Amazon Resource Names for Amazon
EC2 (p. 502)

Apply conditions to the use of the resources

Condition Keys for Amazon EC2 (p. 504)

Work with the available resource-level
permissions for Amazon EC2

Supported Resource-Level Permissions for
Amazon EC2 API Actions (p. 507)

Test your policy

Checking that Users Have the Required
Permissions (p. 507)

Example policies for a CLI or SDK

Example Policies for Working With the AWS CLI
or an AWS SDK (p. 520)

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Task

Topic

Example policies for the Amazon EC2 console

Example Policies for Working in the Amazon EC2
Console (p. 530)

Policy Structure
The following topics explain the structure of an IAM policy.
Topics
• Policy Syntax (p. 501)
• Actions for Amazon EC2 (p. 502)
• Amazon Resource Names for Amazon EC2 (p. 502)
• Condition Keys for Amazon EC2 (p. 504)
• Checking that Users Have the Required Permissions (p. 507)

Policy Syntax
An IAM policy is a JSON document that consists of one or more statements. Each statement is
structured as follows:
{
"Statement":[{
"Effect":"effect",
"Action":"action",
"Resource":"arn",
"Condition":{
"condition":{
"key":"value"
}
}
}
]
}

There are various elements that make up a statement:
• Effect: The effect can be Allow or Deny. By default, IAM users don't have permission to use
resources and API actions, so all requests are denied. An explicit allow overrides the default. An
explicit deny overrides any allows.
• Action: The action is the specific API action for which you are granting or denying permission. To
learn about specifying action, see Actions for Amazon EC2 (p. 502).
• Resource: The resource that's affected by the action. Some Amazon EC2 API actions allow you to
include specific resources in your policy that can be created or modified by the action. To specify a
resource in the statement, you need to use its Amazon Resource Name (ARN). For more information
about specifying the arn value, see Amazon Resource Names for Amazon EC2 (p. 502). For
more information about which API actions support which ARNs, see Supported Resource-Level
Permissions for Amazon EC2 API Actions (p. 507). If the API action does not support ARNs, use
the * wildcard to specify that all resources can be affected by the action.
• Condition: Conditions are optional. They can be used to control when your policy will be in effect.
For more information about specifying conditions for Amazon EC2, see Condition Keys for Amazon
EC2 (p. 504).

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For more information about example IAM policy statements for Amazon EC2, see Example Policies for
Working With the AWS CLI or an AWS SDK (p. 520).

Actions for Amazon EC2
In an IAM policy statement, you can specify any API action from any service that supports IAM.
For Amazon EC2, use the following prefix with the name of the API action: ec2:. For example:
ec2:RunInstances and ec2:CreateImage.
To specify multiple actions in a single statement, separate them with commas as follows:
"Action": ["ec2:action1", "ec2:action2"]

You can also specify multiple actions using wildcards. For example, you can specify all actions whose
name begins with the word "Describe" as follows:
"Action": "ec2:Describe*"

To specify all Amazon EC2 API actions, use the * wildcard as follows:
"Action": "ec2:*"

For a list of Amazon EC2 actions, see Actions in the Amazon EC2 API Reference.

Amazon Resource Names for Amazon EC2
Each IAM policy statement applies to the resources that you specify using their ARNs.

Important
Currently, not all API actions support individual ARNs; we'll add support for additional API
actions and ARNs for additional Amazon EC2 resources later. For information about which
ARNs you can use with which Amazon EC2 API actions, as well as supported condition
keys for each ARN, see Supported Resource-Level Permissions for Amazon EC2 API
Actions (p. 507).
An ARN has the following general syntax:
arn:aws:[service]:[region]:[account]:resourceType/resourcePath

service
The service (for example, ec2).
region
The region for the resource (for example, us-east-1).
account
The AWS account ID, with no hyphens (for example, 123456789012).
resourceType
The type of resource (for example, instance).
resourcePath
A path that identifies the resource. You can use the * wildcard in your paths.
For example, you can indicate a specific instance (i-1234567890abcdef0) in your statement using
its ARN as follows:

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"Resource": "arn:aws:ec2:us-east-1:123456789012:instance/i-1234567890abcdef0"

You can also specify all instances that belong to a specific account by using the * wildcard as follows:
"Resource": "arn:aws:ec2:us-east-1:123456789012:instance/*"

To specify all resources, or if a specific API action does not support ARNs, use the * wildcard in the
Resource element as follows:
"Resource": "*"

The following table describes the ARNs for each type of resource used by the Amazon EC2 API
actions.
Resource Type

ARN

All Amazon EC2 resources

arn:aws:ec2:*

All Amazon EC2 resources
owned by the specified account
in the specified region

arn:aws:ec2:region:account:*

Customer gateway

arn:aws:ec2:region:account:customer-gateway/cgw-id
Where cgw-id is cgw-xxxxxxxx

DHCP options set

arn:aws:ec2:region:account:dhcp-options/dhcp-options-id
Where dhcp-options-id is dopt-xxxxxxxx

Image

arn:aws:ec2:region::image/image-id
Where image-id is the ID of the AMI, AKI, or ARI, and account isn't
used

Instance

arn:aws:ec2:region:account:instance/instance-id
Where instance-id is i-xxxxxxxx or i-xxxxxxxxxxxxxxxxx

Instance profile

arn:aws:iam::account:instance-profile/instance-profile-name
Where instance-profile-name is the name of the instance profile,
and region isn't used

Internet gateway

arn:aws:ec2:region:account:internet-gateway/igw-id
Where igw-id is igw-xxxxxxxx

Key pair

arn:aws:ec2:region:account:key-pair/key-pair-name
Where key-pair-name is the key pair name (for example, gsgkeypair)

Network ACL

arn:aws:ec2:region:account:network-acl/nacl-id
Where nacl-id is acl-xxxxxxxx

Network interface

arn:aws:ec2:region:account:network-interface/eni-id
Where eni-id is eni-xxxxxxxx

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Resource Type

ARN

Placement group

arn:aws:ec2:region:account:placement-group/placement-groupname
Where placement-group-name is the placement group name (for
example, my-cluster)

Route table

arn:aws:ec2:region:account:route-table/route-table-id
Where route-table-id is rtb-xxxxxxxx

Security group

arn:aws:ec2:region:account:security-group/security-group-id
Where security-group-id is sg-xxxxxxxx

Snapshot

arn:aws:ec2:region::snapshot/snapshot-id
Where snapshot-id is snap-xxxxxxxx or snap-xxxxxxxxxxxxxxxxx,
and account isn't used

Subnet

arn:aws:ec2:region:account:subnet/subnet-id
Where subnet-id is subnet-xxxxxxxx

Volume

arn:aws:ec2:region:account:volume/volume-id
Where volume-id is vol-xxxxxxxx or vol-xxxxxxxxxxxxxxxxx

VPC

arn:aws:ec2:region:account:vpc/vpc-id
Where vpc-id is vpc-xxxxxxxx

VPC peering connection

arn:aws:ec2:region:account:vpc-peering-connection/vpc-peeringconnection-id
Where vpc-peering connection-id is pcx-xxxxxxxx

Many Amazon EC2 API actions involve multiple resources. For example, AttachVolume attaches an
Amazon EBS volume to an instance, so an IAM user must have permission to use the volume and the
instance. To specify multiple resources in a single statement, separate their ARNs with commas, as
follows:
"Resource": ["arn1", "arn2"]

For more general information about ARNs, see Amazon Resource Names (ARN) and AWS Service
Namespaces in the Amazon Web Services General Reference. For more information about the
resources that are created or modified by the Amazon EC2 actions, and the ARNs that you can
use in your IAM policy statements, see Granting IAM Users Required Permissions for Amazon EC2
Resources in the Amazon EC2 API Reference.

Condition Keys for Amazon EC2
In a policy statement, you can optionally specify conditions that control when it is in effect. Each
condition contains one or more key-value pairs. Condition keys are not case sensitive. We've defined
AWS-wide condition keys, plus additional service-specific condition keys.
If you specify multiple conditions, or multiple keys in a single condition, we evaluate them using a
logical AND operation. If you specify a single condition with multiple values for one key, we evaluate
the condition using a logical OR operation. For permission to be granted, all conditions must be met.

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You can also use placeholders when you specify conditions. For example, you can grant an IAM user
permission to use resources with a tag that specifies his or her IAM user name. For more information,
see Policy Variables in the IAM User Guide.
Amazon EC2 implements the AWS-wide condition keys (see Available Keys), plus the following
service-specific condition keys. (We'll add support for additional service-specific condition keys for
Amazon EC2 later.)

Important
Many condition keys are specific to a resource, and some API actions use multiple resources.
If you write a policy with a condition key, use the Resource element of the statement to
specify the resource to which the condition key applies. If not, the policy may prevent users
from performing the action at all, because the condition check fails for the resources to which
the condition key does not apply. If you do not want to specify a resource, or if you've written
the Action element of your policy to include multiple API actions, then you must use the
...IfExists condition type to ensure that the condition key is ignored for resources that do
not use it. For more information, see ...IfExists Conditions in the IAM User Guide.
Condition Key

Key/Value Pair

Evaluation
Types

ec2:AccepterVpc

"ec2:AccepterVpc":"vpc-arn"

ARN, Null

Where vpc-arn is the VPC ARN for the peer VPC
ec2:AvailabilityZone "ec2:AvailabilityZone":"az-api-name"

String, Null

Where az-api-name is the name of the Availability Zone (for
example, us-west-2a)
To list your Availability Zones, use describe-availabilityzones
ec2:EbsOptimized

"ec2:EbsOptimized":"optimized-flag"

Boolean, Null

Where optimized-flag is true | false
ec2:ImageType

"ec2:ImageType":"image-type-api-name"

String, Null

Where image-type-api-name is ami | aki | ari
ec2:InstanceProfile "ec2:InstanceProfile":"instance-profile-arn"

ARN, Null

Where instance-profile-arn is the instance profile ARN
ec2:InstanceType

"ec2:InstanceType":"instance-type-api-name"

String, Null

Where instance-type-api-name is the name of the instance
type.
ec2:Owner

"ec2:Owner":"account-id"

String, Null

Where account-id is amazon | aws-marketplace | awsaccount-id
ec2:ParentSnapshot"ec2:ParentSnapshot":"snapshot-arn"

ARN, Null

Where snapshot-arn is the snapshot ARN
ec2:ParentVolume "ec2:ParentVolume":"volume-arn"
Where volume-arn is the volume ARN

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Condition Key

Key/Value Pair

Evaluation
Types

ec2:PlacementGroup"ec2:PlacementGroup":"placement-group-arn"

ARN, Null

Where placement-group-arn is the placement group ARN
ec2:PlacementGroupStrategy
"ec2:PlacementGroupStrategy":"placement-group-strategy"

String, Null

Where placement-group-strategy is cluster
ec2:ProductCode

"ec2:ProductCode":"product-code"

String, Null

Where product-code is the product code
ec2:Public

"ec2:Public":"public-flag"

Boolean, Null

Where public-flag for an AMI is true | false
ec2:Region

"ec2:Region":"region-name"

String, Null

Where region-name is the name of the region (for example,
us-west-2). To list your regions, use describe-regions.
ec2:RequesterVpc "ec2:RequesterVpc":"vpc-arn"

ARN, Null

Where vpc-arn is the VPC ARN for the requester's VPC
ec2:ResourceTag/ "ec2:ResourceTag/tag-key":"tag-value"
tag-key
Where tag-key and tag-value are the tag-key pair

String, Null

ec2:RootDeviceType"ec2:RootDeviceType":"root-device-type-name"

String, Null

Where root-device-type-name is ebs | instance-store
ec2:Subnet

"ec2:Subnet":"subnet-arn"

ARN, Null

Where subnet-arn is the subnet ARN
ec2:Tenancy

"ec2:Tenancy":"tenancy-attribute"

String, Null

Where tenancy-attribute is default | dedicated | host
ec2:VolumeIops

"ec2:VolumeIops":"volume-iops"

Numeric, Null

Where volume-iops is the input/output operations per
second (IOPS); the range is 100 to 20,000
ec2:VolumeSize

"ec2:VolumeSize":"volume-size"

Numeric, Null

Where volume-size is the size of the volume, in GiB
ec2:VolumeType

"ec2:VolumeType":"volume-type-name"
Where volume-type-name is gp2 for General Purpose SSD
volumes, io1 for Provisioned IOPS SSD volumes, st1 for
Throughput Optimized HDD volumes, sc1 for Cold HDD
volumes, or standard for Magnetic volumes.

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Condition Key

Key/Value Pair

Evaluation
Types

ec2:Vpc

"ec2:Vpc":"vpc-arn"

ARN, Null

Where vpc-arn is the VPC ARN

For information about which condition keys you can use with which Amazon EC2 resources,
on an action-by-action basis, see Supported Resource-Level Permissions for Amazon EC2 API
Actions (p. 507). For example policy statements for Amazon EC2, see Example Policies for Working
With the AWS CLI or an AWS SDK (p. 520).

Checking that Users Have the Required Permissions
After you've created an IAM policy, we recommend that you check whether it grants users the
permissions to use the particular API actions and resources they need before you put the policy into
production.
First, create an IAM user for testing purposes, and then attach the IAM policy that you created to the
test user. Then, make a request as the test user.
If the action that you are testing creates or modifies a resource, you should make the request using
the DryRun parameter (or run the CLI command with the --auth-dry-run option). In this case,
the call completes the authorization check, but does not complete the operation. For example, you
can check whether the user can terminate a particular instance without actually terminating it. If the
test user has the required permissions, the request returns DryRunOperation; otherwise, it returns
UnauthorizedOperation.
If the policy doesn't grant the user the permissions that you expected, or is overly permissive, you can
adjust the policy as needed and retest until you get the desired results.

Important
It can take several minutes for policy changes to propagate before they take effect. Therefore,
we recommend that you allow five minutes to pass before you test your policy updates.
If an authorization check fails, the request returns an encoded message with diagnostic information.
You can decode the message using the DecodeAuthorizationMessage action. For more
information, see DecodeAuthorizationMessage in the AWS Security Token Service API Reference, and
decode-authorization-message in the AWS Command Line Interface Reference.

Supported Resource-Level Permissions for Amazon EC2
API Actions
Resource-level permissions refers to the ability to specify which resources users are allowed to
perform actions on. Amazon EC2 has partial support for resource-level permissions. This means
that for certain Amazon EC2 actions, you can control when users are allowed to use those actions
based on conditions that have to be fulfilled, or specific resources that users are allowed to use. For
example, you can grant users permission to launch instances, but only of a specific type, and only
using a specific AMI.
The following table describes the Amazon EC2 API actions that currently support resource-level
permissions, as well as the supported resources (and their ARNs) and condition keys for each action.
When specifying an ARN, you can use the * wildcard in your paths; for example, when you cannot or
do not want to specify exact resource IDs. For examples of using wildcards, see Example Policies for
Working With the AWS CLI or an AWS SDK (p. 520).

Important
If an Amazon EC2 API action is not listed in this table, then it does not support resource-level
permissions. If an Amazon EC2 API action does not support resource-level permissions, you

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can grant users permission to use the action, but you have to specify a * for the resource
element of your policy statement. For an example of how to do this, see 1: Read-only
access (p. 520). We'll add support for additional actions, ARNs, and condition keys later. For
a list of Amazon EC2 API actions that currently do not support resource-level permissions, see
Unsupported Resource-Level Permissions in the Amazon EC2 API Reference.
API Action

Resources

Condition Keys

AcceptVpcPeeringConnection
VPC peering connection
arn:aws:ec2:region:account:vpcpeering-connection/*

ec2:AccepterVpc
ec2:Region
ec2:ResourceTag/tag-key

arn:aws:ec2:region:account:vpcpeering-connection/vpc-peeringconnection-id

ec2:RequesterVpc

VPC

ec2:ResourceTag/tag-key

arn:aws:ec2:region:account:vpc/*

ec2:Region

arn:aws:ec2:region:account:vpc/vpc-id

ec2:Tenancy

Where vpc-id is a VPC owned by the
accepter.
AttachClassicLinkVpc

Instance

ec2:AvailabilityZone

arn:aws:ec2:region:account:instance/*

ec2:EbsOptimized

arn:aws:ec2:region:account:instance/
instance-id

ec2:InstanceProfile
ec2:InstanceType
ec2:PlacementGroup
ec2:Region
ec2:ResourceTag/tag-key
ec2:RootDeviceType
ec2:Tenancy

Security group
arn:aws:ec2:region:account:securitygroup/*

ec2:Region
ec2:ResourceTag/tag-key
ec2:Vpc

arn:aws:ec2:region:account:securitygroup/security-group-id
Where the security group is the security
group for the VPC.
VPC
arn:aws:ec2:region:account:vpc/*
arn:aws:ec2:region:account:vpc/vpc-id

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API Action

Resources

Condition Keys

AttachVolume

Instance

ec2:AvailabilityZone

arn:aws:ec2:region:account:instance/*

ec2:EbsOptimized

arn:aws:ec2:region:account:instance/
instance-id

ec2:InstanceProfile
ec2:InstanceType
ec2:PlacementGroup
ec2:Region
ec2:ResourceTag/tag-key
ec2:RootDeviceType
ec2:Tenancy

Volume

ec2:AvailabilityZone

arn:aws:ec2:region:account:volume/*

ec2:ParentSnapshot

arn:aws:ec2:region:account:volume/
volume-id

ec2:Region
ec2:ResourceTag/tag-key
ec2:VolumeIops
ec2:VolumeSize
ec2:VolumeType

AuthorizeSecurityGroupEgress
Security group

ec2:Region

arn:aws:ec2:region:account:securitygroup/*

ec2:ResourceTag/tag-key
ec2:Vpc

arn:aws:ec2:region:account:securitygroup/security-group-id
AuthorizeSecurityGroupIngress
Security group

ec2:Region

arn:aws:ec2:region:account:securitygroup/*

ec2:ResourceTag/tag-key
ec2:Vpc

arn:aws:ec2:region:account:securitygroup/security-group-id
CreateVpcPeeringConnection
VPC

ec2:ResourceTag/tag-key

arn:aws:ec2:region:account:vpc/*

ec2:Region

arn:aws:ec2:region:account:vpc/vpc-id

ec2:Tenancy

Where vpc-id is a requester VPC.

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API Action

Resources

Condition Keys

VPC peering connection

ec2:AccepterVpc

arn:aws:ec2:region:account:vpcpeering-connection/*

ec2:Region
ec2:RequesterVpc

DeleteCustomerGateway Customer gateway
arn:aws:ec2:region:account:customergateway/*

ec2:Region
ec2:ResourceTag/tag-key

arn:aws:ec2:region:account:customergateway/cgw-id
DeleteDhcpOptions

DHCP options set

ec2:Region

arn:aws:ec2:region:account:dhcpoptions/*

ec2:ResourceTag/tag-key

arn:aws:ec2:region:account:dhcpoptions/dhcp-options-id
DeleteInternetGateway

Internet gateway

ec2:Region

arn:aws:ec2:region:account:internetgateway/*

ec2:ResourceTag/tag-key

arn:aws:ec2:region:account:internetgateway/igw-id
DeleteNetworkAcl

Network ACL

ec2:Region

arn:aws:ec2:region:account:networkacl/*

ec2:ResourceTag/tag-key
ec2:Vpc

arn:aws:ec2:region:account:networkacl/nacl-id
DeleteNetworkAclEntry

Network ACL

ec2:Region

arn:aws:ec2:region:account:networkacl/*

ec2:ResourceTag/tag-key
ec2:Vpc

arn:aws:ec2:region:account:networkacl/nacl-id
DeleteRoute

Route table

ec2:Region

arn:aws:ec2:region:account:route-table/
*

ec2:ResourceTag/tag-key
ec2:Vpc

arn:aws:ec2:region:account:routetable/route-table-id

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API Action

Resources

Condition Keys

DeleteRouteTable

Route table

ec2:Region

arn:aws:ec2:region:account:route-table/
*

ec2:ResourceTag/tag-key
ec2:Vpc

arn:aws:ec2:region:account:routetable/route-table-id
DeleteSecurityGroup

Security group

ec2:Region

arn:aws:ec2:region:account:securitygroup/security-group-id

ec2:ResourceTag/tag-key
ec2:Vpc

DeleteVolume

Volume

ec2:AvailabilityZone

arn:aws:ec2:region:account:volume/*

ec2:ParentSnapshot

arn:aws:ec2:region:account:volume/
volume-id

ec2:Region
ec2:ResourceTag/tag-key
ec2:VolumeIops
ec2:VolumeSize
ec2:VolumeType

DeleteVpcPeeringConnection
VPC peering connection
arn:aws:ec2:region:account:vpcpeering-connection/*

ec2:AccepterVpc
ec2:Region
ec2:ResourceTag/tag-key

DetachClassicLinkVpc

arn:aws:ec2:region:account:vpcpeering-connection/vpc-peeringconnection-id

ec2:RequesterVpc

Instance

ec2:AvailabilityZone

arn:aws:ec2:region:account:instance/*

ec2:EbsOptimized

arn:aws:ec2:region:account:instance/
instance-id

ec2:InstanceProfile
ec2:InstanceType
ec2:PlacementGroup
ec2:Region
ec2:ResourceTag/tag-key
ec2:RootDeviceType
ec2:Tenancy

VPC
arn:aws:ec2:region:account:vpc/*
arn:aws:ec2:region:account:vpc/vpc-id

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API Action

Resources

Condition Keys

DetachVolume

Instance

ec2:AvailabilityZone

arn:aws:ec2:region:account:instance/*

ec2:EbsOptimized

arn:aws:ec2:region:account:instance/
instance-id

ec2:InstanceProfile
ec2:InstanceType
ec2:PlacementGroup
ec2:Region
ec2:ResourceTag/tag-key
ec2:RootDeviceType
ec2:Tenancy

Volume

ec2:AvailabilityZone

arn:aws:ec2:region:account:volume/*

ec2:ParentSnapshot

arn:aws:ec2:region:account:volume/
volume-id

ec2:Region
ec2:ResourceTag/tag-key
ec2:VolumeIops
ec2:VolumeSize
ec2:VolumeType

DisableVpcClassicLink

VPC
arn:aws:ec2:region:account:vpc/*

ec2:Region
ec2:ResourceTag/tag-key
ec2:Tenancy

arn:aws:ec2:region:account:vpc/vpc-id
EnableVpcClassicLink

VPC
arn:aws:ec2:region:account:vpc/*
arn:aws:ec2:region:account:vpc/vpc-id

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API Action

Resources

Condition Keys

GetConsoleScreenshot

Instance

ec2:AvailabilityZone

arn:aws:ec2:region:account:instance/*

ec2:EbsOptimized

arn:aws:ec2:region:account:instance/
instance-id

ec2:InstanceProfile
ec2:InstanceType
ec2:PlacementGroup
ec2:Region
ec2:ResourceTag/tag-key
ec2:RootDeviceType
ec2:Tenancy

RebootInstances

Instance

ec2:AvailabilityZone

arn:aws:ec2:region:account:instance/*

ec2:EbsOptimized

arn:aws:ec2:region:account:instance/
instance-id

ec2:InstanceProfile
ec2:InstanceType
ec2:PlacementGroup
ec2:Region
ec2:ResourceTag/tag-key
ec2:RootDeviceType
ec2:Tenancy

RejectVpcPeeringConnection
VPC peering connection
arn:aws:ec2:region:account:vpcpeering-connection/*

ec2:AccepterVpc
ec2:Region
ec2:ResourceTag/tag-key

arn:aws:ec2:region:account:vpcpeering-connection/vpc-peeringconnection-id
RevokeSecurityGroupEgress
Security group

ec2:RequesterVpc

ec2:Region

arn:aws:ec2:region:account:securitygroup/*

ec2:ResourceTag/tag-key
ec2:Vpc

arn:aws:ec2:region:account:securitygroup/security-group-id
RevokeSecurityGroupIngress
Security group

ec2:Region

arn:aws:ec2:region:account:securitygroup/*

ec2:ResourceTag/tag-key
ec2:Vpc

arn:aws:ec2:region:account:securitygroup/security-group-id

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API Action

Resources

Condition Keys

RunInstances

Image

ec2:ImageType

arn:aws:ec2:region::image/*

ec2:Owner

arn:aws:ec2:region::image/image-id

ec2:Public
ec2:Region
ec2:RootDeviceType
ec2:ResourceTag/tag-key

Instance

ec2:AvailabilityZone

arn:aws:ec2:region:account:instance/*

ec2:EbsOptimized
ec2:InstanceProfile
ec2:InstanceType
ec2:PlacementGroup
ec2:Region
ec2:RootDeviceType
ec2:Tenancy

Key pair

ec2:Region

arn:aws:ec2:region:account:key-pair/*
arn:aws:ec2:region:account:keypair/key-pair-name
Network interface

ec2:AvailabilityZone

arn:aws:ec2:region:account:networkinterface/*

ec2:Region
ec2:Subnet

arn:aws:ec2:region:account:networkinterface/eni-id

ec2:ResourceTag/tag-key
ec2:Vpc

Placement group

ec2:Region

arn:aws:ec2:region:account:placementgroup/*

ec2:PlacementGroupStrategy

arn:aws:ec2:region:account:placementgroup/placement-group-name
Security group

ec2:Region

arn:aws:ec2:region:account:securitygroup/*

ec2:ResourceTag/tag-key
ec2:Vpc

arn:aws:ec2:region:account:securitygroup/security-group-id

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API Action

Resources

Condition Keys

Snapshot

ec2:Owner

arn:aws:ec2:region::snapshot/*

ec2:ParentVolume

arn:aws:ec2:region::snapshot/snapshot- ec2:Region
id
ec2:SnapshotTime
ec2:ResourceTag/tag-key
ec2:VolumeSize
Subnet

ec2:AvailabilityZone

arn:aws:ec2:region:account:subnet/*

ec2:Region

arn:aws:ec2:region:account:subnet/
subnet-id

ec2:ResourceTag/tag-key
ec2:Vpc

Volume

ec2:AvailabilityZone

arn:aws:ec2:region:account:volume/*

ec2:ParentSnapshot
ec2:Region
ec2:VolumeIops
ec2:VolumeSize
ec2:VolumeType

StartInstances

Instance

ec2:AvailabilityZone

arn:aws:ec2:region:account:instance/*

ec2:EbsOptimized

arn:aws:ec2:region:account:instance/
instance-id

ec2:InstanceProfile
ec2:InstanceType
ec2:PlacementGroup
ec2:Region
ec2:ResourceTag/tag-key
ec2:RootDeviceType
ec2:Tenancy

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API Action

Resources

Condition Keys

StopInstances

Instance

ec2:AvailabilityZone

arn:aws:ec2:region:account:instance/*

ec2:EbsOptimized

arn:aws:ec2:region:account:instance/
instance-id

ec2:InstanceProfile
ec2:InstanceType
ec2:PlacementGroup
ec2:Region
ec2:ResourceTag/tag-key
ec2:RootDeviceType
ec2:Tenancy

TerminateInstances

Instance

ec2:AvailabilityZone

arn:aws:ec2:region:account:instance/*

ec2:EbsOptimized

arn:aws:ec2:region:account:instance/
instance-id

ec2:InstanceProfile
ec2:InstanceType
ec2:PlacementGroup
ec2:Region
ec2:ResourceTag/tag-key
ec2:RootDeviceType
ec2:Tenancy

Resource-Level Permissions for RunInstances
The RunInstances API action launches one or more instances, and creates and uses a number
of Amazon EC2 resources. The action requires an AMI and creates an instance; and the instance
must be associated with a security group. Launching into a VPC requires a subnet, and creates a
network interface. Launching from an Amazon EBS-backed AMI creates a volume. The user must have
permission to use these resources, so they must be specified in the Resource element of any policy
that uses resource-level permissions for the ec2:RunInstances action. If you don't intend to use
resource-level permissions with the ec2:RunInstances action, you can specify the * wildcard in the
Resource element of your statement instead of individual ARNs.
If you are using resource-level permissions, the following table describes the minimum resources
required to use the ec2:RunInstances action.
Type of launch

Resources required

Condition keys

Launching into EC2-Classic
using an instance store-backed
AMI

arn:aws:ec2:region:account:instance/
ec2:AvailabilityZone
*
ec2:EbsOptimized
ec2:InstanceProfile
ec2:InstanceType

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Type of launch

Resources required

Condition keys
ec2:PlacementGroup
ec2:Region
ec2:RootDeviceType
ec2:Tenancy

arn:aws:ec2:region::image/* (or
a specific AMI ID)

ec2:ImageType
ec2:Owner
ec2:Public
ec2:Region
ec2:RootDeviceType
ec2:ResourceTag/tag-key

arn:aws:ec2:region:account:securityec2:Region
group/* (or a specific security
ec2:ResourceTag/tag-key
group ID)
ec2:Vpc
Launching into EC2-Classic
using an Amazon EBS-backed
AMI

arn:aws:ec2:region:account:instance/
ec2:AvailabilityZone
*
ec2:EbsOptimized
ec2:InstanceProfile
ec2:InstanceType
ec2:PlacementGroup
ec2:Region
ec2:RootDeviceType
ec2:Tenancy
arn:aws:ec2:region::image/* (or
a specific AMI ID)

ec2:ImageType
ec2:Owner
ec2:Public
ec2:Region
ec2:RootDeviceType
ec2:ResourceTag/tag-key

arn:aws:ec2:region:account:securityec2:Region
group/* (or a specific security
ec2:ResourceTag/tag-key
group ID)
ec2:Vpc

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Type of launch

Resources required

Condition keys

arn:aws:ec2:region:account:volume/
ec2:AvailabilityZone
*
ec2:ParentSnapshot
ec2:Region
ec2:VolumeIops
ec2:VolumeSize
ec2:VolumeType
Launching into a VPC using an
instance store-backed AMI

ec2:ImageType
ec2:Owner
ec2:Public
ec2:Region
ec2:RootDeviceType
ec2:ResourceTag/tag-key

arn:aws:ec2:region:account:securityec2:Region
group/* (or a specific security
ec2:ResourceTag/tag-key
group ID)
ec2:Vpc
arn:aws:ec2:region:account:networkec2:AvailabilityZone
interface/* (or a specific
ec2:Region
network interface ID)
ec2:Subnet
ec2:ResourceTag/tag-key
ec2:Vpc

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Type of launch

Resources required

Condition keys

arn:aws:ec2:region:account:subnet/
ec2:AvailabilityZone
* (or a specific subnet ID)
ec2:Region
ec2:ResourceTag/tag-key
ec2:Vpc
Launching into a VPC using an
Amazon EBS-backed AMI

ec2:ImageType
ec2:Owner
ec2:Public
ec2:Region
ec2:RootDeviceType
ec2:ResourceTag/tag-key

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Type of launch

Resources required

Condition keys

arn:aws:ec2:region:account:volume/
ec2:AvailabilityZone
*
ec2:ParentSnapshot
ec2:Region
ec2:VolumeIops
ec2:VolumeSize
ec2:VolumeType
arn:aws:ec2:region:account:subnet/
ec2:AvailabilityZone
* (or a specific subnet ID)
ec2:Region
ec2:ResourceTag/tag-key
ec2:Vpc

We recommend that you also specify the key pair resource in your policy — even though it's not
required to launch an instance, you cannot connect to your instance without a key pair. For examples
of using resource-level permissions with the ec2:RunInstances action, see 4: Launching instances
(RunInstances) (p. 523).
For additional information about resource-level permissions in Amazon EC2, see the following AWS
Security Blog post: Demystifying EC2 Resource-Level Permissions.

Example Policies for Working With the AWS CLI or an
AWS SDK
The following examples show policy statements that you could use to control the permissions that IAM
users have to Amazon EC2. These policies are designed for requests that are made with the AWS CLI
or an AWS SDK. For example policies for working in the Amazon EC2 console, see Example Policies
for Working in the Amazon EC2 Console (p. 530). For examples of IAM policies specific to Amazon
VPC, see Controlling Access to Amazon VPC Resources
• 1: Read-only access (p. 520)
• 2: Working with instances (p. 521)
• 3. Working with volumes (p. 522)
• 4: Launching instances (RunInstances) (p. 523)
• 5. Working with ClassicLink (p. 527)
• 6. Working with Reserved Instances (p. 529)

Example 1: Read-only access
The following policy grants users permission to use all Amazon EC2 API actions whose names
begin with Describe. The Resource element uses a wildcard to indicate that users can specify all
resources with these API actions. The * wildcard is also necessary in cases where the API action does
not support resource-level permissions. For more information about which ARNs you can use with
which Amazon EC2 API actions, see Supported Resource-Level Permissions for Amazon EC2 API
Actions (p. 507).
Users don't have permission to perform any actions on the resources (unless another statement grants
them permission to do so) because they're denied permission to use API actions by default.

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{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": "ec2:Describe*",
"Resource": "*"
}
]
}

Example 2: Working with instances
a. Describe, launch, stop, start, and terminate all instances
The following policy grants users permission to use the API actions specified in the Action element.
The Resource element uses a * wildcard to indicate that users can specify all resources with these
API actions. The * wildcard is also necessary in cases where the API action does not support resourcelevel permissions. For more information about which ARNs you can use with which Amazon EC2 API
actions, see Supported Resource-Level Permissions for Amazon EC2 API Actions (p. 507).
The users don't have permission to use any other API actions (unless another statement grants them
permission to do so) because users are denied permission to use API actions by default.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": [
"ec2:DescribeInstances", "ec2:DescribeImages",
"ec2:DescribeKeyPairs", "ec2:DescribeSecurityGroups",
"ec2:DescribeAvailabilityZones",
"ec2:RunInstances", "ec2:TerminateInstances",
"ec2:StopInstances", "ec2:StartInstances"
],
"Resource": "*"
}
]
}

b. Describe all instances, and stop, start, and terminate only particular instances
The following policy allows users to describe all instances, to start and stop only instances
i-1234567890abcdef0 and i-0598c7d356eba48d7, and to terminate only instances in the US East (N.
Virginia) Region (us-east-1) with the resource tag "purpose=test".
The first statement uses a * wildcard for the Resource element to indicate that users can specify
all resources with the action; in this case, they can list all instances. The * wildcard is also
necessary in cases where the API action does not support resource-level permissions (in this case,
ec2:DescribeInstances). For more information about which ARNs you can use with which Amazon
EC2 API actions, see Supported Resource-Level Permissions for Amazon EC2 API Actions (p. 507).
The second statement uses resource-level permissions for the StopInstances and
StartInstances actions. The specific instances are indicated by their ARNs in the Resource
element.
The third statement allows users to terminate all instances in the US East (N. Virginia) Region
(us-east-1) that belong to the specified AWS account, but only where the instance has the tag
"purpose=test". The Condition element qualifies when the policy statement is in effect.

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{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "ec2:DescribeInstances",
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"ec2:StopInstances",
"ec2:StartInstances"
],
"Resource": [
"arn:aws:ec2:us-east-1:123456789012:instance/i-1234567890abcdef0",
"arn:aws:ec2:us-east-1:123456789012:instance/i-0598c7d356eba48d7"
]
},
{
"Effect": "Allow",
"Action": "ec2:TerminateInstances",
"Resource": "arn:aws:ec2:us-east-1:123456789012:instance/*",
"Condition": {
"StringEquals": {
"ec2:ResourceTag/purpose": "test"
}
}
}
]
}

Example 3. Working with volumes
When an API action requires a caller to specify multiple resources, you must create a policy statement
that allows users to access all required resources. If you need to use a Condition element with one
or more of these resources, you must create multiple statements as shown in this example.
The following policy allows users to attach volumes with the tag "volume_user=iam-user-name" to
instances with the tag "department=dev", and to detach those volumes from those instances. If you
attach this policy to an IAM group, the aws:username policy variable gives each IAM user in the group
permission to attach or detach volumes from the instances with a tag named volume_user that has
his or her IAM user name as a value.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": [
"ec2:AttachVolume",
"ec2:DetachVolume"
],
"Resource": "arn:aws:ec2:us-east-1:123456789012:instance/*",
"Condition": {
"StringEquals": {
"ec2:ResourceTag/department": "dev"
}

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}
},
{
"Effect": "Allow",
"Action": [
"ec2:AttachVolume",
"ec2:DetachVolume"
],
"Resource": "arn:aws:ec2:us-east-1:123456789012:volume/*",
"Condition": {
"StringEquals": {
"ec2:ResourceTag/volume_user": "${aws:username}"
}
}
}
]
}

Example 4: Launching instances (RunInstances)
The RunInstances API action launches one or more instances. RunInstances requires an AMI and
creates an instance; and users can specify a key pair and security group in the request. Launching into
EC2-VPC requires a subnet, and creates a network interface. Launching from an Amazon EBS-backed
AMI creates a volume. Therefore, the user must have permission to use these Amazon EC2 resources.
The caller can also configure the instance using optional parameters to RunInstances, such as
the instance type and a subnet. You can create a policy statement that requires users to specify an
optional parameter, or restricts users to particular values for a parameter. The examples in this section
demonstrate some of the many possible ways that you can control the configuration of an instance that
a user can launch.
Note that by default, users don't have permission to describe, start, stop, or terminate the resulting
instances. One way to grant the users permission to manage the resulting instances is to create a
specific tag for each instance, and then create a statement that enables them to manage instances
with that tag. For more information, see 2: Working with instances (p. 521).
a. AMI
The following policy allows users to launch instances using only the AMIs that have the specified
tag, "department=dev", associated with them. The users can't launch instances using other AMIs
because the Condition element of the first statement requires that users specify an AMI that has this
tag. The users also can't launch into a subnet, as the policy does not grant permissions for the subnet
and network interface resources. They can, however, launch into EC2-Classic. The second statement
uses a wildcard to enable users to create instance resources, and requires users to specify the key
pair project_keypair and the security group sg-1a2b3c4d. Users are still able to launch instances
without a key pair.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": "ec2:RunInstances",
"Resource": [
"arn:aws:ec2:region::image/ami-*"
],
"Condition": {
"StringEquals": {
"ec2:ResourceTag/department": "dev"
}

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}
},
{
"Effect": "Allow",
"Action": "ec2:RunInstances",
"Resource": [
"arn:aws:ec2:region:account:instance/*",
"arn:aws:ec2:region:account:volume/*",
"arn:aws:ec2:region:account:key-pair/project_keypair",
"arn:aws:ec2:region:account:security-group/sg-1a2b3c4d"
]
}
]
}

Alternatively, the following policy allows users to launch instances using only the specified AMIs,
ami-9e1670f7 and ami-45cf5c3c. The users can't launch an instance using other AMIs (unless
another statement grants the users permission to do so), and the users can't launch an instance into a
subnet.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": "ec2:RunInstances",
"Resource": [
"arn:aws:ec2:region::image/ami-9e1670f7",
"arn:aws:ec2:region::image/ami-45cf5c3c",
"arn:aws:ec2:region:account:instance/*",
"arn:aws:ec2:region:account:volume/*",
"arn:aws:ec2:region:account:key-pair/*",
"arn:aws:ec2:region:account:security-group/*"
]
}
]
}

Alternatively, the following policy allows users to launch instances from all AMIs owned by Amazon.
The Condition element of the first statement tests whether ec2:Owner is amazon. The users can't
launch an instance using other AMIs (unless another statement grants the users permission to do so).
The users are able to launch an instance into a subnet.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": "ec2:RunInstances",
"Resource": [
"arn:aws:ec2:region::image/ami-*"
],
"Condition": {
"StringEquals": {
"ec2:Owner": "amazon"
}
}
},
{

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"Effect": "Allow",
"Action": "ec2:RunInstances",
"Resource": [
"arn:aws:ec2:region:account:instance/*",
"arn:aws:ec2:region:account:subnet/*",
"arn:aws:ec2:region:account:volume/*",
"arn:aws:ec2:region:account:network-interface/*",
"arn:aws:ec2:region:account:key-pair/*",
"arn:aws:ec2:region:account:security-group/*"
]
}
]
}

b. Instance type
The following policy allows users to launch instances using only the t2.micro or t2.small instance
type, which you might do to control costs. The users can't launch larger instances because the
Condition element of the first statement tests whether ec2:InstanceType is either t2.micro or
t2.small.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": "ec2:RunInstances",
"Resource": [
"arn:aws:ec2:region:account:instance/*"
],
"Condition": {
"StringEquals": {
"ec2:InstanceType": ["t2.micro", "t2.small"]
}
}
},
{
"Effect": "Allow",
"Action": "ec2:RunInstances",
"Resource": [
"arn:aws:ec2:region::image/ami-*",
"arn:aws:ec2:region:account:subnet/*",
"arn:aws:ec2:region:account:network-interface/*",
"arn:aws:ec2:region:account:volume/*",
"arn:aws:ec2:region:account:key-pair/*",
"arn:aws:ec2:region:account:security-group/*"
]
}
]
}

Alternatively, you can create a policy that denies users permission to launch any instances except
t2.micro and t2.small instance types.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Deny",
"Action": "ec2:RunInstances",

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"Resource": [
"arn:aws:ec2:region:account:instance/*"
],
"Condition": {
"StringNotEquals": {
"ec2:InstanceType": ["t2.micro", "t2.small"]
}
}
},
{
"Effect": "Allow",
"Action": "ec2:RunInstances",
"Resource": [
"arn:aws:ec2:region::image/ami-*",
"arn:aws:ec2:region:account:network-interface/*",
"arn:aws:ec2:region:account:instance/*",
"arn:aws:ec2:region:account:subnet/*",
"arn:aws:ec2:region:account:volume/*",
"arn:aws:ec2:region:account:key-pair/*",
"arn:aws:ec2:region:account:security-group/*"
]
}
]
}

c. Subnet
The following policy allows users to launch instances using only the specified subnet,
subnet-12345678. The group can't launch instances into any another subnet (unless another
statement grants the users permission to do so). Users are still able to launch instances into EC2Classic.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": "ec2:RunInstances",
"Resource": [
"arn:aws:ec2:region:account:subnet/subnet-12345678",
"arn:aws:ec2:region:account:network-interface/*",
"arn:aws:ec2:region:account:instance/*",
"arn:aws:ec2:region:account:volume/*",
"arn:aws:ec2:region::image/ami-*",
"arn:aws:ec2:region:account:key-pair/*",
"arn:aws:ec2:region:account:security-group/*"
]
}
]
}

Alternatively, you could create a policy that denies users permission to launch an instance into any
other subnet. The statement does this by denying permission to create a network interface, except
where subnet subnet-12345678 is specified. This denial overrides any other policies that are created
to allow launching instances into other subnets. Users are still able to launch instances into EC2Classic.
{
"Version": "2012-10-17",

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"Statement": [{
"Effect": "Deny",
"Action": "ec2:RunInstances",
"Resource": [
"arn:aws:ec2:region:account:network-interface/*"
],
"Condition": {
"ArnNotEquals": {
"ec2:Subnet": "arn:aws:ec2:region:account:subnet/subnet-12345678"
}
}
},
{
"Effect": "Allow",
"Action": "ec2:RunInstances",
"Resource": [
"arn:aws:ec2:region::image/ami-*",
"arn:aws:ec2:region:account:network-interface/*",
"arn:aws:ec2:region:account:instance/*",
"arn:aws:ec2:region:account:subnet/*",
"arn:aws:ec2:region:account:volume/*",
"arn:aws:ec2:region:account:key-pair/*",
"arn:aws:ec2:region:account:security-group/*"
]
}
]
}

Example 5. Working with ClassicLink
You can enable a VPC for ClassicLink and then link an EC2-Classic instance to the VPC.
You can also view your ClassicLink-enabled VPCs, and all of your EC2-Classic instances
that are linked to a VPC. You can create policies with resource-level permission for the
ec2:EnableVpcClassicLink, ec2:DisableVpcClassicLink, ec2:AttachClassicLinkVpc,
and ec2:DetachClassicLinkVpc actions to control how users are able to use those actions.
Resource-level permissions are not supported for ec2:Describe* actions.
a. Full permission to work with ClassicLink
The following policy grants users permission to view ClassicLink-enabled VPCs and linked EC2Classic instances, to enable and disable a VPC for ClassicLink, and to link and unlink instances from a
ClassicLink-enabled VPC.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": [
"ec2:DescribeClassicLinkInstances", "ec2:DescribeVpcClassicLink",
"ec2:EnableVpcClassicLink", "ec2:DisableVpcClassicLink",
"ec2:AttachClassicLinkVpc", "ec2:DetachClassicLinkVpc"
],
"Resource": "*"
}
]
}

b. Enable and disable a VPC for ClassicLink

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The following policy allows user to enable and disable VPCs for ClassicLink that have the specific tag
'purpose=classiclink'. Users cannot enable or disable any other VPCs for ClassicLink.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "ec2:*VpcClassicLink",
"Resource": "arn:aws:ec2:region:account:vpc/*",
"Condition": {
"StringEquals": {
"ec2:ResourceTag/purpose":"classiclink"
}
}
}
]
}

c. Link instances
The following policy grants users permission to link instances to a VPC only if the instance is an
m3.large instance type. The second statement allows users to use the VPC and security group
resources, which are required to link an instance to a VPC.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "ec2:AttachClassicLinkVpc",
"Resource": "arn:aws:ec2:region:account:instance/*",
"Condition": {
"StringEquals": {
"ec2:InstanceType":"m3.large"
}
}
},
{
"Effect": "Allow",
"Action": "ec2:AttachClassicLinkVpc",
"Resource": [
"arn:aws:ec2:region:account:vpc/*",
"arn:aws:ec2:region:account:security-group/*"
]
}
]
}

The following policy grants users permission to link instances to a specific VPC (vpc-1a2b3c4d) only,
and to associate only specific security groups from the VPC to the instance (sg-1122aabb and sgaabb2233). Users cannot link an instance to any other VPC, and they cannot specify any other of the
VPC security groups to associate with the instance in the request.
{
"Version": "2012-10-17",
"Statement": [
{

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IAM Policies
"Effect": "Allow",
"Action": "ec2:AttachClassicLinkVpc",
"Resource": [
"arn:aws:ec2:region:account:vpc/vpc-1a2b3c4d",
"arn:aws:ec2:region:account:instance/*",
"arn:aws:ec2:region:account:security-group/sg-1122aabb",
"arn:aws:ec2:region:account:security-group/sg-aabb2233"
]
}
]
}

d. Unlink instances
The following grants users permission to unlink any linked EC2-Classic instance from a VPC, but only
if the instance has the tag "unlink=true". The second statement grants users permission to use the
VPC resource, which is required to unlink an instance from a VPC.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": "ec2:DetachClassicLinkVpc",
"Resource": [
"arn:aws:ec2:region:account:instance/*"
],
"Condition": {
"StringEquals": {
"ec2:ResourceTag/unlink":"true"
}
}
},
{
"Effect": "Allow",
"Action": "ec2:DetachClassicLinkVpc",
"Resource": [
"arn:aws:ec2:region:account:vpc/*"
]
}
]
}

Example 6. Working with Reserved Instances
The following policy gives users permission to view, modify, and purchase Reserved Instances in your
account.
It is not possible to set resource-level permissions for individual Reserved Instances. This policy means
that users have access to all the Reserved Instances in the account.
The Resource element uses a * wildcard to indicate that users can specify all resources with the
action; in this case, they can list and modify all Reserved Instances in the account. They can also
purchase Reserved Instances using the account credentials. The * wildcard is also necessary in cases
where the API action does not support resource-level permissions.
{
"Version": "2012-10-17",
"Statement": [{

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"Effect": "Allow",
"Action": [
"ec2:DescribeReservedInstances", "ec2:ModifyReservedInstances",
"ec2:PurchaseReservedInstancesOffering",
"ec2:DescribeAvailabilityZones",
"ec2:DescribeReservedInstancesOfferings"
],
"Resource": "*"
}
]
}

To allow users to view and modify the Reserved Instances in your account, but not purchase new
Reserved Instances.
{
""Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": [
"ec2:DescribeReservedInstances", "ec2:ModifyReservedInstances",
"ec2:DescribeAvailabilityZones"
],
"Resource": "*"
}
]
}

Example Policies for Working in the Amazon EC2 Console
You can use IAM policies to grant users permissions to view and work with specific resources in the
Amazon EC2 console. You can use the example policies in the previous section; however, they are
designed for requests that are made with the AWS CLI or an AWS SDK. The console uses additional
API actions for its features, so these policies may not work as expected. For example, a user that has
permission to use only the DescribeVolumes API action will encounter errors when trying to view
volumes in the console. This section demonstrates policies that enable users to work with specific parts
of the console.
• 1: Read-only access (p. 531)
• 2: Using the EC2 launch wizard (p. 532)
• 3: Working with volumes (p. 533)
• 4: Working with security groups (p. 534)
• 5: Working with Elastic IP addresses (p. 535)
• 6: Working with Reserved Instances (p. 536)

Note
To help you work out which API actions are required to perform tasks in the console, you
can use a service such as AWS CloudTrail. For more information, see the AWS CloudTrail
User Guide. If your policy does not grant permission to create or modify a specific resource,
the console displays an encoded message with diagnostic information. You can decode the
message using the DecodeAuthorizationMessage API action for AWS STS, or the decodeauthorization-message command in the AWS CLI.
For additional information about creating policies for the Amazon EC2 console, see the following AWS
Security Blog post: Granting Users Permission to Work in the Amazon EC2 Console.

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IAM Policies

Example 1: Read-only access
To allow users to view all resources in the Amazon EC2 console, you can use the same policy as
the following example: 1: Read-only access (p. 520). Users cannot perform any actions on those
resources or create new resources, unless another statement grants them permission to do so.
a. View instances, AMIs, and snapshots
Alternatively, you can provide read-only access to a subset of resources. To do this, replace the *
wildcard in the ec2:Describe API action with specific ec2:Describe actions for each resource. The
following policy allows users to view all instances, AMIs, and snapshots in the Amazon EC2 console.
The ec2:DescribeTags action allows users to view public AMIs. The console requires the tagging
information to display public AMIs; however, you can remove this action if you want users to view only
private AMIs.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": [
"ec2:DescribeInstances", "ec2:DescribeImages",
"ec2:DescribeTags", "ec2:DescribeSnapshots"
],
"Resource": "*"
}
]
}

Note
Currently, the Amazon EC2 ec2:Describe* API actions do not support resource-level
permissions, so you cannot control which individual resources users can view in the console.
Therefore, the * wildcard is necessary in the Resource element of the above statement. For
more information about which ARNs you can use with which Amazon EC2 API actions, see
Supported Resource-Level Permissions for Amazon EC2 API Actions (p. 507).
b. View instances and CloudWatch metrics
The following policy allows users to view instances in the Amazon EC2 console, as well as
CloudWatch alarms and metrics in the Monitoring tab of the Instances page. The Amazon EC2
console uses the CloudWatch API to display the alarms and metrics, so you must grant users
permission to use the cloudwatch:DescribeAlarms and cloudwatch:GetMetricStatistics
actions.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": [
"ec2:DescribeInstances",
"cloudwatch:DescribeAlarms",
"cloudwatch:GetMetricStatistics"
],
"Resource": "*"
}
]
}

531

The Amazon EC2 launch wizard is a series of screens with options to configure and launch an
instance. Your policy must include permission to use the API actions that allow users to work with the
{
wizard's options. If your policy does not include permission to use those actions, some items in the
"Version": "2012-10-17",
wizard
cannot load properly, and users cannot complete a launch.
"Statement": [{
Amazon Elastic Compute Cloud
"Effect": "Allow",
User Guide for Linux Instances
"Action": [
IAM Policies
"ec2:DescribeInstances", "ec2:DescribeImages",
"ec2:DescribeSubnets",
Example "ec2:DescribeKeyPairs","ec2:DescribeVpcs",
2: Using the EC2 launch wizard
"ec2:DescribeSecurityGroups"
],
{
"Resource":
"*"
"Version":
"2012-10-17",
The
statement
grantstousers
to viewmore
the options
launch
as demonstrated
You first
can
add API actions
your permission
policy to provide
options in
forthe
users,
for wizard,
example:
},
"Statement":
in the
example above.[{
The second statement grants users permission to use the network interface,
{ "Effect": "Allow",
• ec2:DescribeAvailabilityZones
: If launching
to view and select
specific
volume,
key pair, security group, and subnet
resourcesinto
for EC2-Classic,
the ec2:RunInstances
action,awhich
are
"Effect":
"Allow",
"Action":
Availability
Zone.an[instance into a VPC. For more information about using the ec2:RunInstances
required
to launch
"Action":
"ec2:RunInstances",
"ec2:DescribeInstances",
"ec2:DescribeImages",
action,
see 4:
Launching instances (RunInstances)
(p. into
523).
and and
fourth
statements
• ec2:DescribeNetworkInterfaces
: If launching
a The
VPC,third
to view
select
existinggrant
network
"Resource":
"*"users to launch
The following
policy
allows
m1.small
instances
using"ec2:DescribeSubnets",
AMIs
owned
Amazon,
and
"ec2:DescribeKeyPairs","ec2:DescribeVpcs",
users
permission
to
use
the
instance
and
AMI
resources
respectively,
but
only
if the by
instance
is an
interfaces
for the selected subnet.
}
"ec2:DescribeSecurityGroups"
only
into a specific
subnet
(subnet-1a2b3c4d
). Users
can only launch in the sa-east-1 region. If users
m1.small
instance,
and
only
if
the
AMI
is
owned
by
Amazon.
]
•select
ec2:CreateSecurityGroup
Todifferent
create ainstance
new security
group;
example,
createwizard,
the
],a different region, or select: a
type, AMI,
orfor
subnet
in thetolaunch
the
} wizard's
suggested
launch-wizard-x
security
group.
However,
this
action
alone
only
creates
"Resource":
"*"
launch
fails.
the
},security group; it does not add or modify any rules. To add inbound rules, users must be
granted
permission to use the ec2:AuthorizeSecurityGroupIngress API action. To
{ Important
add outbound
togranting
VPC security
users
beec2:CreateTags
granted permissionaction.
to useThis
the
Be
carefulrules
about
users groups,
permission
to must
use the
"Effect":
"Allow",
ec2:AuthorizeSecurityGroupEgress
API action.
To modify
existing
users must
limits
your ability to use the ec2:ResourceTag
condition
keyortodelete
restrict
the userules,
of other
"Action":"ec2:RunInstances",
granted
permission
to use
the relevant
ec2:RevokeSecurityGroup*
action.
b. be
Restrict
access
to specific
instance
type,
subnet,
and region
resources;
users
can
change
a resource's
tag in order
to bypass thoseAPI
restrictions.
"Resource":
[
"arn:aws:ec2:sa-east-1:111122223333:network-interface/*",
• ec2:CreateTags
: To add a tag to the instance. By default, the launch wizard attempts to add
a tag with"arn:aws:ec2:sa-east-1:111122223333:volume/*",
a key of Name to an instance. Users that do not have permission to use this action will
encounter"arn:aws:ec2:sa-east-1:111122223333:key-pair/*",
a warning that this tag could not be applied to an instance; however, this does not
Currently,
the
Amazon
Describe*
API
actions
dogrant
not support
resource-level
permissions,
"arn:aws:ec2:sa-east-1:111122223333:security-group/*",
affect the
success
of EC2
the launch,
so you
should
only
users permission
to use
this action ifsoit'syou
cannot
restrict
which
individual
resources
users
can
view
in
the
launch
wizard.
However,
you can apply
"arn:aws:ec2:sa-east-1:111122223333:subnet/subnet-1a2b3c4d"
absolutely necessary.
resource-level
permissions on the ec2:RunInstances API action to restrict which resources users
]
can },
use to launch an instance. The launch fails if users select options that they are not authorized to
use.{
"Effect": "Allow",
"Action": "ec2:RunInstances",
"Resource": [
"arn:aws:ec2:sa-east-1:111122223333:instance/*"
],
"Condition": {
"StringEquals": {
"ec2:InstanceType": "m1.small"
}
}
},
{
"Effect": "Allow",
"Action": "ec2:RunInstances",
"Resource": [
"arn:aws:ec2:sa-east-1::image/ami-*"
],
"Condition": {
"StringEquals": {
"ec2:Owner": "amazon"
}
}
}
]
}

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Example 3: Working with volumes
The following policy grants users permission to view and create volumes, and attach and detach
volumes to specific instances.
Users can attach any volume to instances that have the tag "purpose=test", and also detach
volumes from those instances. To attach a volume using the Amazon EC2 console, it is helpful for
users to have permission to use the ec2:DescribeInstances action, as this allows them to select
an instance from a pre-populated list in the Attach Volume dialog box. However, this also allows users
to view all instances on the Instances page in the console, so you can omit this action.
In the first statement, the ec2:DescribeVolumeStatus and ec2:DescribeAvailabilityZones
actions are necessary to ensure that volumes display correctly in the console.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": [
"ec2:DescribeVolumes", "ec2:DescribeVolumeStatus",
"ec2:DescribeAvailabilityZones", "ec2:CreateVolume",
"ec2:DescribeInstances"
],
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"ec2:AttachVolume",
"ec2:DetachVolume"
],
"Resource": "arn:aws:ec2:region:111122223333:instance/*",
"Condition": {
"StringEquals": {
"ec2:ResourceTag/purpose": "test"
}
}
},
{
"Effect": "Allow",
"Action": [
"ec2:AttachVolume",
"ec2:DetachVolume"
],
"Resource": "arn:aws:ec2:region:111122223333:volume/*"
}
]
}

533

"Resource":
Department=Test
. "*"
},
{
a. View "Effect":
security groups
and add and remove rules
"Allow",
Amazon Elastic Compute Cloud
"Action": [
User Guide for Linux Instances
"ec2:AuthorizeSecurityGroupIngress",
IAM Policies
"ec2:RevokeSecurityGroupIngress",
"ec2:AuthorizeSecurityGroupEgress", "ec2:RevokeSecurityGroupEgress"
Example
], 4: Working with security groups
"Resource": [
You can create
a policy that allows users to work with the Create Security Group dialog box in the
"arn:aws:ec2:region:111122223333:security-group/*"
Amazon],
EC2 console. To use this dialog box, users must be granted permission to use at the least the
following"Condition":
API actions:
{
"StringEquals": {
• ec2:CreateSecurityGroup: To create a new security group.
"ec2:ResourceTag/Department": "Test"
Working }with the Create
Security
Group
dialog
box
•b. ec2:DescribeVpcs
: To view
a list of
existing
VPCs
in the VPC list. This action is required even if
you are
} not creating a security group for a VPC.
}
]
With
these permissions, users can create a new security group successfully, but they cannot add any
}
rules to it. To work with rules in the Create Security Group dialog box, you can add the following API
actions to your policy:

• ec2:AuthorizeSecurityGroupIngress: To add inbound rules.
• ec2:AuthorizeSecurityGroupEgress: To add outbound rules to VPC security groups.
• ec2:RevokeSecurityGroupIngress: To modify or delete existing inbound rules. This is useful
if you want to allow users to use the Copy to new feature in the console. This feature opens the
Create Security Group dialog box and populates it with the same rules as the security group that
was selected.
• ec2:RevokeSecurityGroupEgress: To modify or delete outbound rules for VPC security groups.
This is useful to allow users to modify or delete the default outbound rule that allows all outbound
traffic.
• ec2:DeleteSecurityGroup: To cater for scenarios where invalid rules cannot be saved. If a
user creates a security group with an invalid rule, the console first creates the security group, then
attempts to add the rules to it. After that fails, the security group is deleted. The user remains in the
Create Security Group dialog box, where an error is displayed. The rules remain listed, so the user
can correct the invalid rule and try to create the security group again. This API action is not required,
but if a user is not granted permission to use it and attempts to create a security group with invalid
The
following
policy grants
users
permission
use
the Create
dialog
box, and
rules,
the security
group is
created
without to
any
rules,
and theSecurity
user mustGroup
add them
afterward.
to create inbound and outbound rules for security groups that are associated with a specific VPC
(vpc-1a2b3c4d). Users can create security groups for EC2-Classic or another VPC, but they cannot
{
Currently,
the ec2:CreateSecurityGroup
doestonot
support
resource-level
permissions;
add any rules
to them. Similarly, users cannotAPI
addaction
any rules
any
existing
security group
that's not
"Version":
"2012-10-17",
however,
you
can
apply
resource-level
permissions
to
the
ec2:AuthorizeSecurityGroupIngress
associated with VPC vpc-1a2b3c4d. Users are also granted permission to view all security groups
"Statement":
[{
and
ec2:AuthorizeSecurityGroupEgress
how
usersto
can
create
rules.
in
the
console. This makes
it easier for users to actions
identify to
thecontrol
security
groups
which
they
can add
"Allow",
inbound"Effect":
rules. This policy
also grants users permission to delete security groups that are associated
"Action":
[ .
with VPC
vpc-1a2b3c4d
"ec2:DescribeSecurityGroups", "ec2:CreateSecurityGroup",
"ec2:DescribeVpcs"
],
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"ec2:DeleteSecurityGroup", "ec2:AuthorizeSecurityGroupIngress",
"ec2:AuthorizeSecurityGroupEgress"
],
"Resource": "arn:aws:ec2:region:111122223333:security-group/*",
"Condition":{
"ArnEquals": {
"ec2:Vpc": "arn:aws:ec2:region:111122223333:vpc/vpc-1a2b3c4d"
}
}
}
]
}

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Example 5: Working with Elastic IP addresses
The following policy grants users permission to view Elastic IP addresses in the Amazon EC2 console.
The console uses the ec2:DescribeInstances action to display information about instances with
which the Elastic IP addresses are associated. If users are not granted permission to use this action,
the Elastic IP addresses page cannot load properly.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": [
"ec2:DescribeAddresses", "ec2:DescribeInstances"
],
"Resource": "*"
}
]
}

To allow users to work with Elastic IP addresses, you can add the following actions to your policy
• ec2:AllocateAddress: To allocate an address for use in VPC or EC2-Classic.
• ec2:ReleaseAddress: To release an Elastic IP address.
• ec2:DescribeNetworkInterfaces: To work with the Associate Address dialog box. The dialog
box displays the available network interfaces to which you can associate an Elastic IP address, and
will not open if users are not granted permission to use this action. However, this only applies to
EC2-VPC; this action is not required for associating an Elastic IP address to an instance in EC2Classic.
• ec2:AssociateAddress: To associate an Elastic IP address with an instance or a network
interface.
• ec2:DisassociateAddress: To disassociate an Elastic IP address from an instance or a network
interface,

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IAM Roles

Example 6: Working with Reserved Instances
The following policy can be attached to an IAM user. It gives the user access to view and modify
Reserved Instances in your account, as well as purchase new Reserved Instances in the AWS
Management Console.
This policy allows users to view all the Reserved Instances, as well as On-Demand Instances, in the
account. It's not possible to set resource-level permissions for individual Reserved Instances.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": [
"ec2:DescribeReservedInstances", "ec2:ModifyReservedInstances",
"ec2:PurchaseReservedInstancesOffering", "ec2:DescribeInstances",
"ec2:DescribeAvailabilityZones",
"ec2:DescribeReservedInstancesOfferings"
],
"Resource": "*"
}
]
}

The ec2:DescribeAvailabilityZones action is necessary to ensure that the Amazon EC2
console can display information about the Availability Zones in which you can purchase Reserved
Instances. The ec2:DescribeInstances action is not required, but ensures that the user can view
the instances in the account and purchase reservations to match the correct specifications.
You can adjust the API actions to limit user access, for example removing ec2:DescribeInstances
and ec2:DescribeAvailabilityZones means the user has read-only access.

IAM Roles for Amazon EC2
Applications must sign their API requests with AWS credentials. Therefore, if you are an application
developer, you need a strategy for managing credentials for your applications that run on EC2
instances. For example, you can securely distribute your AWS credentials to the instances, enabling
the applications on those instances to use your credentials to sign requests, while protecting them
from other users. However, it's challenging to securely distribute credentials to each instance,
especially those that AWS creates on your behalf, such as Spot instances or instances in Auto Scaling
groups. You must also be able to update the credentials on each instance when you rotate your AWS
credentials.
We designed IAM roles so that your applications can securely make API requests from your instances,
without requiring you to manage the security credentials that the applications use. Instead of creating
and distributing your AWS credentials, you can delegate permission to make API requests using IAM
roles as follows:
1. Create an IAM role.
2. Define which accounts or AWS services can assume the role.
3. Define which API actions and resources the application can use after assuming the role.
4. Specify the role when you launch your instances.
5. Have the application retrieve a set of temporary credentials and use them.
For example, you can use IAM roles to grant permissions to applications running on your instances that
needs to use a bucket in Amazon S3.

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IAM Roles

Note
Amazon EC2 uses an instance profile as a container for an IAM role. When you create an
IAM role using the console, the console creates an instance profile automatically and gives it
the same name as the role it corresponds to. If you use the AWS CLI, API, or an AWS SDK
to create a role, you create the role and instance profile as separate actions, and you might
give them different names. To launch an instance with an IAM role, you specify the name of
its instance profile. When you launch an instance using the Amazon EC2 console, you can
select a role to associate with the instance; however, the list that's displayed is actually a list
of instance profile names. For more information, see Instance Profiles in the IAM User Guide.
You can specify permissions for IAM roles by creating a policy in JSON format. These are similar to the
policies that you create for IAM users. If you make a change to a role, the change is propagated to all
instances, simplifying credential management.

Note
You can't assign a role to an existing instance; you can only specify a role when you launch a
new instance.
For more information about creating and using IAM roles, see Roles in the IAM User Guide.
Topics
• Retrieving Security Credentials from Instance Metadata (p. 537)
• Granting an IAM User Permission to Launch an Instance with an IAM Role (p. 538)
• Creating an IAM Role Using the Console (p. 538)
• Launching an Instance with an IAM Role Using the Console (p. 539)
• Creating an IAM Role Using the AWS CLI (p. 539)
• Launching an Instance with an IAM Role Using the AWS CLI (p. 541)

Retrieving Security Credentials from Instance Metadata
An application on the instance retrieves the security credentials provided by the role from the instance
metadata item iam/security-credentials/role-name. The application is granted the permissions
for the actions and resources that you've defined for the role through the security credentials
associated with the role. These security credentials are temporary and we rotate them automatically.
We make new credentials available at least five minutes prior to the expiration of the old credentials.

Warning
If you use services that use instance metadata with IAM roles, ensure that you don't expose
your credentials when the services make HTTP calls on your behalf. The types of services
that could expose your credentials include HTTP proxies, HTML/CSS validator services, and
XML processors that support XML inclusion.
The following command retrieves the security credentials for an IAM role named s3access.
$ curl http://169.254.169.254/latest/meta-data/iam/security-credentials/
s3access

The following is example output.
{
"Code" : "Success",
"LastUpdated" : "2012-04-26T16:39:16Z",
"Type" : "AWS-HMAC",
"AccessKeyId" : "AKIAIOSFODNN7EXAMPLE",
"SecretAccessKey" : "wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY",
"Token" : "token",
"Expiration" : "2012-04-27T22:39:16Z"

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}

For applications, AWS CLI, and Tools for Windows PowerShell commands that run on the instance,
you do not have to explicitly get the temporary security credentials — the AWS SDKs, AWS CLI, and
Tools for Windows PowerShell automatically get the credentials from the EC2 instance metadata
service and use them. To make a call outside of the instance using temporary security credentials (for
example, to test IAM policies), you must provide the access key, secret key, and the session token. For
more information, see Using Temporary Security Credentials to Request Access to AWS Resources in
the IAM User Guide.
For more information about instance metadata, see Instance Metadata and User Data (p. 337).

Granting an IAM User Permission to Launch an Instance
with an IAM Role
To enable an IAM user to launch an instance with an IAM role, you must grant the user permission to
pass the role to the instance.
For example, the following IAM policy grants users permission to launch an instance with the IAM role
named s3access.
{
"Version": "2012-10-17",
"Statement": [{
"Effect": "Allow",
"Action": "iam:PassRole",
"Resource": "arn:aws:iam::123456789012:role/s3access"
}]
}

Alternatively, you could grant IAM users access to all your roles by specifying the resource as "*" in this
policy. However, consider whether users who launch instances with your roles (ones that exist or that
you'll create later on) might be granted permissions that they don't need or shouldn't have.
For more information, see Permissions Required for Using Roles with Amazon EC2 in the IAM User
Guide.

Creating an IAM Role Using the Console
You must create an IAM role before you can launch an instance with that role.

To create an IAM role using the IAM console
1.

2.
3.
4.
5.

In the navigation pane, choose Roles, and then choose Create New Role.
On the Set Role Name page, enter a name for the role and choose Next Step.
On the Select Role Type page, choose Select next to Amazon EC2.
On the Attach Policy page, select an AWS managed policy. For example, for Amazon EC2, one
of the following AWS managed policies might meet your needs:
• PowerUserAccess
• ReadOnlyAccess
• AmazonEC2FullAccess

• AmazonEC2ReadOnlyAccess
Review the role information, edit the role as needed, and then choose Create Role.

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Launching an Instance with an IAM Role Using the
Console
After you've created an IAM role, you can launch an instance, and associate that role with the instance
during launch.

Important
After you create an IAM role, it may take several seconds for the permissions to propagate.
If your first attempt to launch an instance with a role fails, wait a few seconds before trying
again. For more information, see Troubleshooting Working with Roles in the IAM User Guide.

To launch an instance with an IAM role
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

On the dashboard, choose Launch Instance.

3.
4.

Select an AMI, then select an instance type and choose Next: Configure Instance Details.
On the Configure Instance Details page, select the IAM role you created from the IAM role list.

Note

6.
7.

The IAM role list displays the name of the instance profile that you created when you
created your IAM role. If you created your IAM role using the console, the instance profile
was created for you and given the same name as the role. If you created your IAM role
using the AWS CLI, API, or an AWS SDK, you may have named your instance profile
differently.
Configure any other details, then follow the instructions through the rest of the wizard, or choose
Review and Launch to accept default settings and go directly to the Review Instance Launch
page.
Review your settings, then choose Launch to choose a key pair and launch your instance.
If you are using the Amazon EC2 API actions in your application, retrieve the AWS security
credentials made available on the instance and use them to sign the requests. Note that the AWS
SDK does this for you.
$ curl http://169.254.169.254/latest/meta-data/iam/securitycredentials/role_name

Creating an IAM Role Using the AWS CLI
You must create an IAM role before you can launch an instance with that role.

To create an IAM role using the AWS CLI
•

Create an IAM role with a policy that allows the role to use an Amazon S3 bucket.
a.

Create the following trust policy and save it in a text file named ec2-role-trustpolicy.json.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": { "Service": "ec2.amazonaws.com"},
"Action": "sts:AssumeRole"
}
]

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}

Create the s3access role and specify the trust policy that you created.
$ aws iam create-role --role-name s3access --assume-role-policydocument file://ec2-role-trust-policy.json
{
"Role": {
"AssumeRolePolicyDocument": {
"Version": "2012-10-17",
"Statement": [
{
"Action": "sts:AssumeRole",
"Effect": "Allow",
"Principal": {
"Service": "ec2.amazonaws.com"
}
}
]
},
"RoleId": "AROAIIZKPBKS2LEXAMPLE",
"CreateDate": "2013-12-12T23:46:37.247Z",
"RoleName": "s3access",
"Path": "/",
"Arn": "arn:aws:iam::123456789012:role/s3access"
}
}

Create an access policy and save it in a text file named ec2-role-access-policy.json.
For example, this policy grants administrative permissions for Amazon S3 to applications
running on the instance.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": ["s3:*"],
"Resource": ["*"]
}
]
}

Attach the access policy to the role.
$ aws iam put-role-policy --role-name s3access --policy-name S3Permissions --policy-document file://ec2-role-access-policy.json

Create an instance profile named s3access-profile.
$ aws iam create-instance-profile --instance-profile-name s3accessprofile
{
"InstanceProfile": {
"InstanceProfileId": "AIPAJTLBPJLEGREXAMPLE",
"Roles": [],
"CreateDate": "2013-12-12T23:53:34.093Z",
"InstanceProfileName": "s3access-profile",
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"Path": "/",
"Arn": "arn:aws:iam::123456789012:instance-profile/s3accessprofile"
}
}

Add the s3access role to the s3access-profile instance profile.
$ aws iam add-role-to-instance-profile --instance-profile-name
s3access-profile --role-name s3access

For more information about these commands, see create-role, put-role-policy, and createinstance-profile in the AWS Command Line Interface Reference.

Launching an Instance with an IAM Role Using the AWS
CLI
After you've created an IAM role, you can launch an instance, and associate that role with the instance
during launch.

To launch an instance with an IAM role using the AWS CLI
1.

Launch an instance using the instance profile. The following example shows how to launch an
instance with the instance profile.
$ aws ec2 run-instances --image-id ami-11aa22bb --iam-instance-profile
Name="s3access-profile" --key-name my-key-pair --security-groups mysecurity-group --subnet-id subnet-1a2b3c4d

For more information, see run-instances in the AWS Command Line Interface Reference.
2.

If you are using the Amazon EC2 API actions in your application, retrieve the AWS security
credentials made available on the instance and use them to sign the requests. Note that the AWS
SDK does this for you.
$ curl http://169.254.169.254/latest/meta-data/iam/securitycredentials/role_name

Authorizing Inbound Traffic for Your Linux
Instances
Security groups enable you to control traffic to your instance, including the kind of traffic that can reach
your instance. For example, you can allow computers from only your home network to access your
instance using SSH. If your instance is a web server, you can allow all IP addresses to access your
instance via HTTP, so that external users can browse the content on your web server.

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Network Access

To enable network access to your instance, you must allow inbound traffic to your instance. To open a
port for inbound traffic, add a rule to a security group that you associated with your instance when you
launched it.
To connect to your instance, you must set up a rule to authorize SSH traffic from your computer's
public IP address. To allow SSH traffic from additional IP address ranges, add another rule for each
range you need to authorize.
If you need to enable network access to a Windows instance, see Authorizing Inbound Traffic for Your
Windows Instances in the Amazon EC2 User Guide for Windows Instances.

Before You Start
Decide who requires access to your instance; for example, a single host or a specific network that
you trust. In this case, we use your local system's public IP address. You can get the public IP
address of your local computer using a service. For example, we provide the following service: http://
checkip.amazonaws.com. To locate another service that provides your IP address, use the search
phrase "what is my IP address". If you are connecting through an ISP or from behind your firewall
without a static IP address, you need to find out the range of IP addresses used by client computers.

Adding a Rule for Inbound SSH Traffic to a Linux Instance
Security groups act as a firewall for associated instances, controlling both inbound and outbound traffic
at the instance level. You must add rules to a security group that enable you to connect to your Linux
instance from your IP address using SSH.

To add a rule to a security group for inbound SSH traffic using the console
1.

In the navigation pane of the Amazon EC2 console, choose Instances. Select your instance and
look at the Description tab; Security groups lists the security groups that are associated with the
instance. Choose view rules to display a list of the rules that are in effect for the instance.

In the navigation pane, choose Security Groups. Select one of the security groups associated
with your instance.

In the details pane, on the Inbound tab, choose Edit. In the dialog, choose Add Rule, and then
choose SSH from the Type list.

Choose Save.

To add a rule to a security group using the command line
You can use one of the following commands. Be sure to run this command on your local system,
not on the instance itself. For more information about these command line interfaces, see Accessing
Amazon EC2 (p. 3).

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• authorize-security-group-ingress (AWS CLI)
• Grant-EC2SecurityGroupIngress (AWS Tools for Windows PowerShell)

Assigning a Security Group to an Instance
You can assign a security group to an instance when you launch the instance. When you add or
remove rules, those changes are automatically applied to all instances to which you've assigned the
security group.
After you launch an instance in EC2-Classic, you can't change its security groups. After you launch
an instance in a VPC, you can change its security groups. For more information, see Changing an
Instance's Security Groups in the Amazon VPC User Guide.

Amazon EC2 and Amazon Virtual Private
Cloud
Amazon Virtual Private Cloud (Amazon VPC) enables you to define a virtual network in your own
logically isolated area within the AWS cloud, known as a virtual private cloud (VPC). You can launch
your AWS resources, such as instances, into your VPC. Your VPC closely resembles a traditional
network that you might operate in your own data center, with the benefits of using AWS's scalable
infrastructure. You can configure your VPC; you can select its IP address range, create subnets, and
configure route tables, network gateways, and security settings. You can connect instances in your
VPC to the Internet. You can connect your VPC to your own corporate data center, making the AWS
cloud an extension of your data center. To protect the resources in each subnet, you can use multiple
layers of security, including security groups and network access control lists. For more information, see
the Amazon VPC User Guide.
Your account may support both the EC2-VPC and EC2-Classic platforms, on a region-by-region basis.
If you created your account after 2013-12-04, it supports EC2-VPC only. To find out which platforms
your account supports, see Supported Platforms (p. 549). If your accounts supports EC2-VPC only,
we create a default VPC for you. A default VPC is a VPC that is already configured and ready for you
to use. You can launch instances into your default VPC immediately. For more information, see Your
Default VPC and Subnets in the Amazon VPC User Guide. If your account supports EC2-Classic and
EC2-VPC, you can launch instances into either platform. Regardless of which platforms your account
supports, you can create your own nondefault VPC, and configure it as you need.
Contents
• Benefits of Using a VPC (p. 543)
• Differences Between EC2-Classic and EC2-VPC (p. 544)
•
•
•
•

Sharing and Accessing Resources Between EC2-Classic and EC2-VPC (p. 546)
Instance Types Available Only in a VPC (p. 548)
Amazon VPC Documentation (p. 548)
Supported Platforms (p. 549)

• ClassicLink (p. 550)
• Migrating from a Linux Instance in EC2-Classic to a Linux Instance in a VPC (p. 560)

Benefits of Using a VPC
By launching your instances into a VPC instead of EC2-Classic, you gain the ability to:
• Assign static private IP addresses to your instances that persist across starts and stops

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• Assign multiple IP addresses to your instances
• Define network interfaces, and attach one or more network interfaces to your instances
• Change security group membership for your instances while they're running
• Control the outbound traffic from your instances (egress filtering) in addition to controlling the
inbound traffic to them (ingress filtering)
• Add an additional layer of access control to your instances in the form of network access control lists
(ACL)
• Run your instances on single-tenant hardware

Differences Between EC2-Classic and EC2-VPC
The following table summarizes the differences between instances launched in EC2-Classic, instances
launched in a default VPC, and instances launched in a nondefault VPC.
Characteristic EC2-Classic

Default VPC

Nondefault VPC

Public IP
address (from
Amazon's
public IP
address pool)

Your instance receives a
public IP address.

Your instance launched in
a default subnet receives
a public IP address by
default, unless you specify
otherwise during launch,
or you modify the subnet's
public IP address attribute.

Your instance doesn't
receive a public IP
address by default, unless
you specify otherwise
during launch, or you
modify the subnet's public
IP address attribute.

Private IP
address

Your instance receives a
private IP address from
the EC2-Classic range
each time it's started.

Your instance receives a
static private IP address
from the address range of
your default VPC.

Your instance receives a
static private IP address
from the address range of
your VPC.

Multiple
private IP
addresses

We select a single
private IP address for
your instance; multiple
IP addresses are not
supported.

You can assign multiple
private IP addresses to
your instance.

Elastic IP
address

An EIP is disassociated
from your instance when
you stop it.

An EIP remains
associated with your
instance when you stop it.

DNS
hostnames

DNS hostnames are
enabled by default.

DNS hostnames are
disabled by default.

Security
group

A security group can
reference security groups
that belong to other AWS
accounts.

A security group can
reference security groups
for your VPC only.

You can create up to 100
security groups per VPC.

You can assign up to
5 security groups to an
instance.

You can assign security
groups to your instance

You can create up to 500
security groups in each
region.
Security
group
association

You can assign an
unlimited number of
security groups to an
instance when you launch
it.

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Characteristic EC2-Classic

Security
group rules

Default VPC

Nondefault VPC

You can't change the
when you launch it and
security groups of your
while it's running.
running instance. You
can either modify the
rules of the assigned
security groups, or replace
the instance with a new
one (create an AMI from
the instance, launch a
new instance from this
AMI with the security
groups that you need,
disassociate any Elastic IP
address from the original
instance and associate it
with the new instance, and
then terminate the original
instance).

when you launch it and
while it's running.

You can add rules for
inbound traffic only.

You can add rules for
inbound and outbound
traffic.

You can add up to 50
rules to a security group.

You can add up to 100
rules to a security group.
Tenancy

Your instance runs on
shared hardware.

You can run your instance
on shared hardware or
single-tenant hardware.

Accessing the
Internet

Your instance can access
the Internet. Your instance
automatically receives a
public IP address, and
can access the Internet
directly through the AWS
network edge.

By default, your instance
can access the Internet.
Your instance receives
a public IP address
by default. An Internet
gateway is attached to
your default VPC, and
your default subnet has
a route to the Internet
gateway.

By default, your instance
cannot access the
Internet. Your instance
doesn't receive a public IP
address by default. Your
VPC may have an Internet
gateway, depending on
how it was created.

The following diagram shows instances in each platform. Note the following:
• Instances C1, C2, C3, and C4 are in the EC2-Classic platform. C1 and C2 were launched by one
account, and C3 and C4 were launched by a different account. These instances can communicate
with each other, can access the Internet directly.
• Instances V1 and V2 are in different subnets in the same VPC in the EC2-VPC platform. They were
launched by the account that owns the VPC; no other account can launch instances in this VPC.
These instances can communicate with each other and can access instances in EC2-Classic and the
Internet through the Internet gateway.

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Sharing and Accessing Resources
Between EC2-Classic and EC2-VPC

Sharing and Accessing Resources Between
EC2-Classic and EC2-VPC
Some resources and features in your AWS account can be shared or accessed between the EC2Classic and EC2-VPC platforms, for example, through ClassicLink. For more information about
ClassicLink, see ClassicLink (p. 550).
If your account supports EC2-Classic, you might have set up resources for use in EC2-Classic. If you
want to migrate from EC2-Classic to a VPC, you must recreate those resources in your VPC. For more
information about migrating from EC2-Classic to a VPC, see Migrating from a Linux Instance in EC2Classic to a Linux Instance in a VPC (p. 560).
The following resources can be shared or accessed between EC2-Classic and a VPC.

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Resource

Notes

AMI
Bundle task
EBS volume
Elastic IP address

You can migrate an Elastic IP address from EC2Classic to EC2-VPC. You can't migrate an Elastic
IP address that was originally allocated for use
in a VPC to EC2-Classic. For more information,
see Migrating an Elastic IP Address from EC2Classic to EC2-VPC (p. 583).

Instance

An EC2-Classic instance can communicate
with instances in a VPC using public IP
addresses, or you can use ClassicLink to enable
communication over private IP addresses.
You can't migrate an instance from EC2-Classic
to a VPC. However, you can migrate your
application from an instance in EC2-Classic to
an instance in a VPC. For more information, see
Migrating from a Linux Instance in EC2-Classic to
a Linux Instance in a VPC (p. 560).

Key pair
Load balancer

If you're using ClassicLink, you can register a
linked EC2-Classic instance with a load balancer
in a VPC, provided that the VPC has a subnet in
the same Availability Zone as the instance.
You can't migrate a load balancer from EC2Classic to a VPC. You can't register an instance
in a VPC with a load balancer in EC2-Classic.

Placement group
Reserved Instance

You can change the network platform for your
Reserved Instances from EC2-Classic to EC2VPC. For more information, see Modifying Your
Reserved Instances (p. 210).

Security group

A linked EC2-Classic instance can use a VPC
security groups through ClassicLink to control
traffic to and from the VPC. VPC instances can't
use EC2-Classic security groups.
You can't migrate a security group from EC2Classic to a VPC. You can copy rules from a
security group in EC2-Classic to a security group
in a VPC. For more information, see Creating a
Security Group (p. 494).

Snapshot

The following resources can't be shared or moved between EC2-Classic and a VPC:

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Instance Types Available Only in a VPC

• Spot instances

Instance Types Available Only in a VPC
Instances of the following instance types are not supported in EC2-Classic and must be launched in a
VPC:
• C4
• M4
• T2
• X1
If your account supports EC2-Classic but you have not created a nondefault VPC, you can do one of
the following to launch a VPC-only instance:
• Create a nondefault VPC and launch your VPC-only instance into it by specifying a subnet ID or a
network interface ID in the request. Note that you must create a nondefault VPC if you do not have a
default VPC and you are using the AWS CLI, Amazon EC2 API, or AWS SDK to launch a VPC-only
instance. For more information, see Create a Virtual Private Cloud (VPC) (p. 23).
• Launch your VPC-only instance using the Amazon EC2 console. The Amazon EC2 console creates
a nondefault VPC in your account and launches the instance into the subnet in the first Availability
Zone. Note that the console creates the VPC with the following attributes:
• One subnet in each Availability Zone, with the public IP addressing attribute set to true so that
instances receive a public IP address. For more information, see IP Addressing in Your VPC in the
Amazon VPC User Guide.
• An Internet gateway, and a main route table that routes traffic in the VPC to the Internet gateway.
This enables the instances you launch in the VPC to communicate over the Internet. For more
information, see Internet Gateways in the Amazon VPC User Guide.
• A default security group for the VPC and a default network ACL that is associated with each
subnet. For more information, see Security in Your VPC in the Amazon VPC User Guide.
If you have other resources in EC2-Classic, you can take steps to migrate them to EC2-VPC. For
more information, see Migrating from a Linux Instance in EC2-Classic to a Linux Instance in a
VPC (p. 560).

Amazon VPC Documentation
For more information about Amazon VPC, see the following documentation.
Guide

Description

Amazon VPC Getting Started Guide

Provides a hands-on introduction to Amazon
VPC.

Amazon VPC User Guide

Provides detailed information about how to use
Amazon VPC.

Amazon VPC Network Administrator Guide

Helps network administrators configure your
customer gateway.

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Supported Platforms

Supported Platforms
Amazon EC2 supports the following platforms. Your AWS account is capable of launching instances
either into both platforms or only into EC2-VPC, on a region by region basis.
Platform

Introduced In

Description

EC2Classic

The original release of
Amazon EC2

Your instances run in a single, flat network that you share
with other customers.

EC2-VPC

The original release of
Amazon VPC

Your instances run in a virtual private cloud (VPC) that's
logically isolated to your AWS account.

For more information about the availability of either platform in your account, see Availability in the
Amazon VPC User Guide. For more information about the differences between EC2-Classic and EC2VPC, see Differences Between EC2-Classic and EC2-VPC (p. 544).

Supported Platforms in the Amazon EC2 Console
The Amazon EC2 console indicates which platforms you can launch instances into for the selected
region, and whether you have a default VPC in that region.
Verify that the region you'll use is selected in the navigation bar. On the Amazon EC2 console
dashboard, look for Supported Platforms under Account Attributes. If there are two values, EC2 and
VPC, you can launch instances into either platform. If there is one value, VPC, you can launch instances
only into EC2-VPC.
If you can launch instances only into EC2-VPC, we create a default VPC for you. Then, when you
launch an instance, we launch it into your default VPC, unless you create a nondefault VPC and
specify it when you launch the instance.

EC2-VPC
The dashboard displays the following under Account Attributes to indicate that the account supports
only the EC2-VPC platform, and has a default VPC with the identifier vpc-1a2b3c4d.

If your account supports only EC2-VPC, you can select a VPC from the Network list, and a subnet
from the Subnet list when you launch an instance using the launch wizard.

EC2-Classic, EC2-VPC
The dashboard displays the following under Account Attributes to indicate that the account supports
both the EC2-Classic and EC2-VPC platforms.

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ClassicLink

If your account supports EC2-Classic and EC2-VPC, you can launch into EC2-Classic using the launch
wizard by selecting Launch into EC2-Classic from the Network list. To launch into a VPC, you can
select a VPC from the Network list, and a subnet from the Subnet list.

Related Topic
For more information about how you can tell which platforms you can launch instances into, see
Detecting Your Supported Platforms in the Amazon VPC User Guide.

ClassicLink
ClassicLink allows you to link your EC2-Classic instance to a VPC in your account, within the same
region. This allows you to associate the VPC security groups with the EC2-Classic instance, enabling
communication between your EC2-Classic instance and instances in your VPC using private IP
addresses. ClassicLink removes the need to make use of public IP addresses or Elastic IP addresses
to enable communication between instances in these platforms. For more information about private
and public IP addresses, see IP Addressing in Your VPC.
ClassicLink is available to all users with accounts that support the EC2-Classic platform, and can be
used with any EC2-Classic instance. To find out which platform your account supports, see Supported
Platforms (p. 549). For more information about the benefits of using a VPC, see Amazon EC2 and
Amazon Virtual Private Cloud (p. 543). For more information about migrating your resources to a
VPC, see Migrating from a Linux Instance in EC2-Classic to a Linux Instance in a VPC (p. 560).
There is no additional charge for using ClassicLink. Standard charges for data transfer and instance
hour usage apply.
Topics
• ClassicLink Basics (p. 550)
• ClassicLink Limitations (p. 553)
• Working with ClassicLink (p. 553)
• API and CLI Overview (p. 557)
• Example: ClassicLink Security Group Configuration for a Three-Tier Web Application (p. 558)

ClassicLink Basics
There are two steps to linking an EC2-Classic instance to a VPC using ClassicLink. First, you must
enable the VPC for ClassicLink. By default, all VPCs in your account are not enabled for ClassicLink,
to maintain their isolation. After you've enabled the VPC for ClassicLink, you can then link any running
EC2-Classic instance in the same region in your account to that VPC. Linking your instance includes
selecting security groups from the VPC to associate with your EC2-Classic instance. After you've linked
the instance, it can communicate with instances in your VPC using their private IP addresses, provided
the VPC security groups allow it. Your EC2-Classic instance does not lose its private IP address when
linked to the VPC.

Note
Linking your instance to a VPC is sometimes referred to as attaching your instance.
A linked EC2-Classic instance can communicate with instances in a VPC, but it does not form part of
the VPC. If you list your instances and filter by VPC, for example, through the DescribeInstances
API request, or by using the Instances screen in the Amazon EC2 console, the results do not return
any EC2-Classic instances that are linked to the VPC. For more information about viewing your
linked EC2-Classic instances, see Viewing Your ClassicLink-Enabled VPCs and Linked EC2-Classic
Instances (p. 555).
By default, if you use a public DNS hostname to address an instance in a VPC from a linked EC2Classic instance, the hostname resolves to the instance's public IP address. The same occurs if you

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use a public DNS hostname to address a linked EC2-Classic instance from an instance in the VPC. If
you want the public DNS hostname to resolve to the private IP address, you can enable ClassicLink
DNS support for the VPC. For more information, see Enabling ClassicLink DNS Support (p. 555).
If you no longer require a ClassicLink connection between your instance and the VPC, you can
unlink the EC2-Classic instance from the VPC. This disassociates the VPC security groups from the
EC2-Classic instance. A linked EC2-Classic instance is automatically unlinked from a VPC when
it's stopped. After you've unlinked all linked EC2-Classic instances from the VPC, you can disable
ClassicLink for the VPC.

Using Other AWS Services in Your VPC With ClassicLink
Linked EC2-Classic instances can access the following AWS services in the VPC: Amazon Redshift,
Amazon ElastiCache, Elastic Load Balancing, and Amazon RDS. However, instances in the VPC
cannot access the AWS services provisioned by the EC2-Classic platform using ClassicLink.
If you use Elastic Load Balancing in your VPC, you can register your linked EC2-Classic instance with
the load balancer, provided that the instance is in an Availability Zone in which your VPC has a subnet.
If you terminate the linked EC2-Classic instance, the load balancer deregisters the instance. For more
information about working with load balancers in a VPC, see Elastic Load Balancing in Amazon VPC in
the Elastic Load Balancing User Guide.
If you use Auto Scaling, you can create an Auto Scaling group with instances that are automatically
linked to a specified ClassicLink-enabled VPC at launch. For more information, see Linking EC2Classic Instances to a VPC in the Auto Scaling User Guide.
If you use Amazon RDS instances or Amazon Redshift clusters in your VPC, and they are publicly
accessible (accessible from the Internet), the endpoint you use to address those resources from a
linked EC2-Classic instance by default resolves to a public IP address. If those resources are not
publicly accessible, the endpoint resolves to a private IP address. To address a publicly accessible
RDS instance or Redshift cluster over private IP using ClassicLink, you must use their private IP
address or private DNS hostname, or you must enable ClassicLink DNS support for the VPC.
If you use a private DNS hostname or a private IP address to address an RDS instance, the linked
EC2-Classic instance cannot use the failover support available for Multi-AZ deployments.
You can use the Amazon EC2 console to find the private IP addresses of your Amazon Redshift,
Amazon ElastiCache, or Amazon RDS resources.

To locate the private IP addresses of AWS resources in your VPC
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Network Interfaces.

Check the descriptions of the network interfaces in the Description column. A network interface
that's used by Amazon Redshift, Amazon ElastiCache, or Amazon RDS will have the name of the
service in the description. For example, a network interface that's attached to an Amazon RDS
instance will have the following description: RDSNetworkInterface.

Select the required network interface.

In the details pane, get the private IP address from the Primary private IP field.

Controlling the Use of ClassicLink
By default, IAM users do not have permission to work with ClassicLink. You can create an IAM
policy that grants users permissions to enable or disable a VPC for ClassicLink, link or unlink an
instance to a ClassicLink-enabled VPC, and to view ClassicLink-enabled VPCs and linked EC2-Classic
instances. For more information about IAM policies for Amazon EC2, see IAM Policies for Amazon
EC2 (p. 500).

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For more information about policies for working with ClassicLink, see the following example: 5. Working
with ClassicLink (p. 527).

Security Groups in ClassicLink
Linking your EC2-Classic instance to a VPC does not affect your EC2-Classic security groups. They
continue to control all traffic to and from the instance. This excludes traffic to and from instances in
the VPC, which is controlled by the VPC security groups that you associated with the EC2-Classic
instance. EC2-Classic instances that are linked to the same VPC cannot communicate with each
other through the VPC; regardless of whether they are associated with the same VPC security group.
Communication between EC2-Classic instances is controlled by the EC2-Classic security groups
associated with those instances. For an example of a security group configuration, see Example:
ClassicLink Security Group Configuration for a Three-Tier Web Application (p. 558).
After you've linked your instance to a VPC, you cannot change which VPC security groups are
associated with the instance. To associate different security groups with your instance, you must first
unlink the instance, and then link it to the VPC again, choosing the required security groups.

Routing for ClassicLink
When you enable a VPC for ClassicLink, a static route is added to all of the VPC route tables with
a destination of 10.0.0.0/8 and a target of local. This allows communication between instances
in the VPC and any EC2-Classic instances that are then linked to the VPC. If you add a custom
route table to a ClassicLink-enabled VPC, a static route is automatically added with a destination
of 10.0.0.0/8 and a target of local. When you disable ClassicLink for a VPC, this route is
automatically deleted in all of the VPC route tables.
VPCs that are in the 10.0.0.0/16 and 10.1.0.0/16 IP address ranges can be enabled for
ClassicLink only if they do not have any existing static routes in route tables in the 10.0.0.0/8 IP
address range, excluding the local routes that were automatically added when the VPC was created.
Similarly, if you've enabled a VPC for ClassicLink, you may not be able to add any more specific routes
to your route tables within the 10.0.0.0/8 IP address range.

Important
If your VPC CIDR block is a publicly routable IP address range, consider the security
implications before you link an EC2-Classic instance to your VPC. For example, if your linked
EC2-Classic instance receives an incoming Denial of Service (DoS) request flood attack from
a source IP address that falls within the VPC’s IP address range, the response traffic is sent
into your VPC. We strongly recommend that you create your VPC using a private IP address
range as specified in RFC 1918.
For more information about route tables and routing in your VPC, see Route Tables in the Amazon
VPC User Guide.

Enabling a VPC Peering Connection for ClassicLink
If you have a VPC peering connection between two VPCs, and there are one or more EC2-Classic
instances that are linked to one or both of the VPCs via ClassicLink, you can extend the VPC peering
connection to enable communication between the EC2-Classic instances and the instances in the
VPC on the other side of the VPC peering connection. This enables the EC2-Classic instances and
the instances in the VPC to communicate using private IP addresses. To do this, you can enable a
local VPC to communicate with a linked EC2-Classic instance in a peer VPC, or you can enable a local
linked EC2-Classic instance to communicate with instances in a peer VPC.
If you enable a local VPC to communicate with a linked EC2-Classic instance in a peer VPC, a static
route is automatically added to your route tables with a destination of 10.0.0.0/8 and a target of
local.
For more information and examples, see Configurations With ClassicLink in the Amazon VPC Peering
Guide.

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ClassicLink Limitations
To use the ClassicLink feature, you need to be aware of the following limitations:
• You can link an EC2-Classic instance to only one VPC at a time.
• If you stop your linked EC2-Classic instance, it's automatically unlinked from the VPC, and the VPC
security groups are no longer associated with the instance. You can link your instance to the VPC
again after you've restarted it.
• You cannot link an EC2-Classic instance to a VPC that's in a different region, or a different AWS
account.
• VPCs configured for dedicated hardware tenancy cannot be enabled for ClassicLink. Contact AWS
support to request that your dedicated tenancy VPC be allowed to be enabled for ClassicLink.

Important
EC2-Classic instances are run on shared hardware. If you've set the tenancy of your VPC
to dedicated because of regulatory or security requirements, then linking an EC2-Classic
instance to your VPC may not conform to those requirements, as you will be allowing
a shared tenancy resource to address your isolated resources directly using private IP
addresses. If you want to enable your dedicated VPC for ClassicLink, provide a detailed
motivation in your request to AWS support.
• VPCs with routes that conflict with the EC2-Classic private IP address range of 10/8 cannot be
enabled for ClassicLink. This does not include VPCs with 10.0.0.0/16 and 10.1.0.0/16 IP
address ranges that already have local routes in their route tables. For more information, see
Routing for ClassicLink (p. 552).
• You cannot associate a VPC Elastic IP address with a linked EC2-Classic instance.
• You can link a running Spot instance to a VPC. To indicate in a Spot instance request that the
instance should be linked to a VPC when the request is fulfilled, you must use the launch wizard in
the Amazon EC2 console.
• ClassicLink does not support transitive relationships out of the VPC. Your linked EC2-Classic
instance will not have access to any VPN connection, VPC endpoint, or Internet gateway associated
with the VPC. Similarly, resources on the other side of a VPN connection, or an Internet gateway will
not have access to a linked EC2-Classic instance.
• You cannot use ClassicLink to link a VPC instance to a different VPC, or to a EC2-Classic resource.
To establish a private connection between VPCs, you can use a VPC peering connection. For more
information, see VPC Peering in the Amazon VPC User Guide.
• If you link your EC2-Classic instance to a VPC in the 172.16.0.0/16 range, and you have a DNS
server running on the 172.16.0.23/32 IP address within the VPC, then your linked EC2-Classic
instance will not be able to access the VPC DNS server. To work around this issue, run your DNS
server on a different IP address within the VPC.

Working with ClassicLink
You can use the Amazon EC2 and Amazon VPC consoles to work with the ClassicLink feature. You
can enable or disable a VPC for ClassicLink, and link and unlink EC2-Classic instances to a VPC.

Note
The ClassicLink features are only visible in the consoles for accounts and regions that support
EC2-Classic.
Topics
• Enabling a VPC for ClassicLink (p. 554)
• Linking an Instance to a VPC (p. 554)
• Creating a VPC with ClassicLink Enabled (p. 554)
• Linking an EC2-Classic Instance to a VPC at Launch (p. 555)

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• Viewing Your ClassicLink-Enabled VPCs and Linked EC2-Classic Instances (p. 555)
• Enabling ClassicLink DNS Support (p. 555)
• Disabling ClassicLink DNS Support (p. 556)
• Unlinking a EC2-Classic Instance from a VPC (p. 556)
• Disabling ClassicLink for a VPC (p. 556)

Enabling a VPC for ClassicLink
To link an EC2-Classic instance to a VPC, you must first enable the VPC for ClassicLink. You cannot
enable a VPC for ClassicLink if the VPC has routing that conflicts with the EC2-Classic private IP
address range. For more information, see Routing for ClassicLink (p. 552).

To enable a VPC for ClassicLink
1.

Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

In the navigation pane, choose Your VPCs.

Choose a VPC, and then choose Actions, Enable ClassicLink.

In the confirmation dialog box, choose Yes, Enable.

Linking an Instance to a VPC
After you've enabled a VPC for ClassicLink, you can link an EC2-Classic instance to it.

Note
You can only link a running EC2-Classic instance to a VPC. You cannot link an instance that's
in the stopped state.

To link an instance to a VPC
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances.

Select the running EC2-Classic instance, choose Actions, ClassicLink, Link to VPC. You can
select more than one instance to link to the same VPC.

In the dialog box that displays, select a VPC from the list. Only VPCs that have been enabled for
ClassicLink are displayed.

Select one or more of the VPC security groups to associate with your instance. When you are
done, choose Link to VPC.

Creating a VPC with ClassicLink Enabled
You can create a new VPC and immediately enable it for ClassicLink by using the VPC wizard in the
Amazon VPC console.

To create a VPC with ClassicLink enabled
1.

Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

From the Amazon VPC dashboard, choose Start VPC Wizard.

Select one of the VPC configuration options and choose Select.

On the next page of the wizard, choose Yes for Enable ClassicLink. Complete the rest of the
steps in the wizard to create your VPC. For more information about using the VPC wizard, see
Scenarios for Amazon VPC in the Amazon VPC User Guide.

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Linking an EC2-Classic Instance to a VPC at Launch
You can use the launch wizard in the Amazon EC2 console to launch an EC2-Classic instance and
immediately link it to a ClassicLink-enabled VPC.

To link an instance to a VPC at launch
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.

From the Amazon EC2 dashboard, choose Launch Instance.
Select an AMI, and then choose an instance type. On the Configure Instance Details page,
ensure that you select Launch into EC2-Classic from the Network list.

Note

Some instance types, such as T2 instance types, can only be launched into a VPC.
Ensure that you select an instance type that can be launched into EC2-Classic.
In the Link to VPC (ClassicLink) section, select a VPC from Link to VPC. Only ClassicLinkenabled VPCs are displayed. Select the security groups from the VPC to associate with the
instance. Complete the other configuration options on the page, and then complete the rest of the
steps in the wizard to launch your instance. For more information about using the launch wizard,
see Launching Your Instance from an AMI (p. 279).

Viewing Your ClassicLink-Enabled VPCs and Linked EC2-Classic
Instances
You can view all of your ClassicLink-enabled VPCs in the Amazon VPC console, and your linked EC2Classic instances in the Amazon EC2 console.

To view your ClassicLink-enabled VPCs
1.
2.

Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.
In the navigation pane, choose Your VPCs.

Select a VPC, and in the Summary tab, look for the ClassicLink field. A value of Enabled
indicates that the VPC is enabled for ClassicLink.
Alternatively, look for the ClassicLink column, and view the value that's displayed for each VPC
(Enabled or Disabled). If the column is not visible, choose Edit Table Columns (the gear-shaped
icon), select the ClassicLink attribute, and then choose Close.

To view your linked EC2-Classic instances
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Instances.

Select an EC2-Classic instance, and in the Description tab, look for the ClassicLink field. If the
instance is linked to a VPC, the field displays the ID of the VPC to which the instance is linked. If
the instance is not linked to any VPC, the field displays Unlinked.
Alternatively, you can filter your instances to display only linked EC2-Classic instances for a
specific VPC or security group. In the search bar, start typing ClassicLink, select the relevant
ClassicLink resource attribute, and then select the security group ID or the VPC ID.

Enabling ClassicLink DNS Support
You can enable ClassicLink DNS support for your VPC so that DNS hostnames that are addressed
between linked EC2-Classic instances and instances in the VPC resolve to private IP addresses and
not public IP addresses. For this feature to work, your VPC must be enabled for DNS hostnames and
DNS resolution.

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Note
If you enable ClassicLink DNS support for your VPC, your linked EC2-Classic instance can
access any private hosted zone associated with the VPC. For more information, see Working
with Private Hosted Zones in the Amazon Route 53 Developer Guide.

To enable ClassicLink DNS support
1.

Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

In the navigation pane, choose Your VPCs.

Select your VPC, and choose Actions, Edit ClassicLink DNS Support.

Choose Yes to enable ClassicLink DNS support, and choose Save.

Disabling ClassicLink DNS Support
You can disable ClassicLink DNS support for your VPC so that DNS hostnames that are addressed
between linked EC2-Classic instances and instances in the VPC resolve to public IP addresses and
not private IP addresses.

To disable ClassicLink DNS support
1.

Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

In the navigation pane, choose Your VPCs.

Select your VPC, and choose Actions, Edit ClassicLink DNS Support.

Choose No to disable ClassicLink DNS support, and choose Save.

Unlinking a EC2-Classic Instance from a VPC
If you no longer require a ClassicLink connection between your EC2-Classic instance and your VPC,
you can unlink the instance from the VPC. Unlinking the instance disassociates the VPC security
groups from the instance.

Note
A stopped instance is automatically unlinked from a VPC.

To unlink an instance from a VPC
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances, and select your instance.

In the Actions list, select ClassicLink, Unlink Instance. You can select more than one instance
to unlink from the same VPC.

Choose Yes in the confirmation dialog box.

Disabling ClassicLink for a VPC
If you no longer require a connection between EC2-Classic instances and your VPC, you can disable
ClassicLink on the VPC. You must first unlink all linked EC2-Classic instances that are linked to the
VPC.

To disable ClassicLink for a VPC
1.

Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

In the navigation pane, choose Your VPCs.

Select your VPC, then choose Actions, Disable ClassicLink.

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In the confirmation dialog box, choose Yes, Disable.

API and CLI Overview
You can perform the tasks described on this page using the command line or the Query API. For
more information about the command line interfaces and a list of available API actions, see Accessing
Amazon EC2 (p. 3).

Enable a VPC for ClassicLink
• enable-vpc-classic-link (AWS CLI)
• Enable-EC2VpcClassicLink (AWS Tools for Windows PowerShell)
• EnableVpcClassicLink (Amazon EC2 Query API)

Link (attach) an EC2-Classic instance to a VPC
• attach-classic-link-vpc (AWS CLI)
• Add-EC2ClassicLinkVpc (AWS Tools for Windows PowerShell)
• AttachClassicLinkVpc (Amazon EC2 Query API)

Unlink (detach) an EC2-Classic instance from a VPC
• detach-classic-link-vpc (AWS CLI)
• Dismount-EC2ClassicLinkVpc (AWS Tools for Windows PowerShell)
• DetachClassicLinkVpc (Amazon EC2 Query API)

Disable ClassicLink for a VPC
• disable-vpc-classic-link (AWS CLI)
• Disable-EC2VpcClassicLink (AWS Tools for Windows PowerShell)
• DisableVpcClassicLink (Amazon EC2 Query API)

Describe the ClassicLink status of VPCs
• describe-vpc-classic-link (AWS CLI)
• Get-EC2VpcClassicLink (AWS Tools for Windows PowerShell)
• DescribeVpcClassicLink (Amazon EC2 Query API)

Describe linked EC2-Classic instances
• describe-classic-link-instances (AWS CLI)
• Get-EC2ClassicLinkInstance (AWS Tools for Windows PowerShell)
• DescribeClassicLinkInstances (Amazon EC2 Query API)

Enable a VPC peering connection for ClassicLink
• modify-vpc-peering-connection-options (AWS CLI)
• Edit-EC2VpcPeeringConnectionOption (AWS Tools for Windows PowerShell)
• ModifyVpcPeeringConnectionOptions(Amazon EC2 Query API)

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Enable a VPC for ClassicLink DNS support
• enable-vpc-classic-link-dns-support (AWS CLI)
• Enable-EC2VpcClassicLinkDnsSupport (AWS Tools for Windows PowerShell)
• EnableVpcClassicLinkDnsSupport (Amazon EC2 Query API)

Disable a VPC for ClassicLink DNS support
• disable-vpc-classic-link-dns-support (AWS CLI)
• Disable-EC2VpcClassicLinkDnsSupport (AWS Tools for Windows PowerShell)
• DisableVpcClassicLinkDnsSupport (Amazon EC2 Query API)

Describe ClassicLink DNS support for VPCs
• describe-vpc-classic-link-dns-support (AWS CLI)
• Get-EC2VpcClassicLinkDnsSupport (AWS Tools for Windows PowerShell)
• DescribeVpcClassicLinkDnsSupport (Amazon EC2 Query API)

Example: ClassicLink Security Group Configuration for a
Three-Tier Web Application
In this example, you have an application with three instances: a public-facing web server, an
application server, and a database server. Your web server accepts HTTPS traffic from the Internet,
and then communicates with your application server over TCP port 6001. Your application server
then communicates with your database server over TCP port 6004. You're in the process of migrating
your entire application to a VPC in your account. You've already migrated your application server and
your database server to your VPC. Your web server is still in EC2-Classic and linked to your VPC via
ClassicLink.
You want a security group configuration that allows traffic to flow only between these instances. You
have four security groups: two for your web server (sg-1a1a1a1a and sg-2b2b2b2b), one for your
application server (sg-3c3c3c3c), and one for your database server (sg-4d4d4d4d).
The following diagram displays the architecture of your instances, and their security group
configuration.

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Security Groups for Your Web Server (sg-1a1a1a1a and sg-2b2b2b2b)
You have one security group in EC2-Classic, and the other in your VPC. You associated the
VPC security group with your web server instance when you linked the instance to your VPC via
ClassicLink. The VPC security group enables you to control the outbound traffic from your web server
to your application server.
The following are the security group rules for the EC2-Classic security group (sg-1a1a1a1a).
Inbound
Source

Type

Port Range

Comments

0.0.0.0/0

HTTPS

443

Allows Internet traffic to reach your
web server.

The following are the security group rules for the VPC security group (sg-2b2b2b2b).
Outbound
Destination

Type

Port Range

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sg-3c3c3c3c

TCP

6001

Allows outbound traffic from your
web server to your application server
in your VPC (or to any other instance
associated with sg-3c3c3c3c).

Security Group for Your Application Server (sg-3c3c3c3c)
The following are the security group rules for the VPC security group that's associated with your
application server.
Inbound
Source

Type

PortComments
Range

sg-2b2b2b2b

TCP

6001Allows the specified type of traffic from your
web server (or any other instance associated
with sg-2b2b2b2b) to reach your application
server.

Destination

Type

PortComments
Range

sg-4d4d4d4d

TCP

6004Allows outbound traffic from the application
server to the database server (or to any other
instance associated with sg-4d4d4d4d).

Outbound

Security Group for Your Database Server (sg-4d4d4d4d)
The following are the security group rules for the VPC security group that's associated with your
database server.
Inbound
Source

Type

Port Range

Comments

sg-3c3c3c3c

TCP

6004

Allows the specified type of traffic
from your application server (or
any other instance associated
with sg-3c3c3c3c) to reach your
database server.

Migrating from a Linux Instance in EC2-Classic
to a Linux Instance in a VPC
Your AWS account might support both EC2-Classic and EC2-VPC, depending on when you created
your account and which regions you've used. For more information, and to find out which platform
your account supports, see Supported Platforms (p. 549). For more information about the benefits of
using a VPC, and the differences between EC2-Classic and EC2-VPC, see Amazon EC2 and Amazon
Virtual Private Cloud (p. 543).
You create and use resources in your AWS account. Some resources and features, such as enhanced
networking and T2 instances, can be used only in a VPC. Some resources can be shared between

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EC2-Classic and a VPC, while some can't. For more information, see Sharing and Accessing
Resources Between EC2-Classic and EC2-VPC (p. 546).
If your account supports EC2-Classic, you might have set up resources for use in EC2-Classic. If you
want to migrate from EC2-Classic to a VPC, you must recreate those resources in your VPC.
There are two ways of migrating to a VPC. You can do a full migration, or you can do an incremental
migration over time. The method you choose depends on the size and complexity of your application
in EC2-Classic. For example, if your application consists of one or two instances running a static
website, and you can afford a short period of downtime, you can do a full migration. If you have a multitier application with processes that cannot be interrupted, you can do an incremental migration using
ClassicLink. This allows you to transfer functionality one component at a time until your application is
running fully in your VPC.
If you need to migrate a Windows instance, see Migrating a Windows Instance from EC2-Classic to a
VPC in the Amazon EC2 User Guide for Windows Instances.
Contents
• Full Migration to a VPC (p. 561)
• Incremental Migration to a VPC Using ClassicLink (p. 567)

Full Migration to a VPC
Complete the following tasks to fully migrate your application from EC2-Classic to a VPC.
Tasks
• Step 1: Create a VPC (p. 561)
• Step 2: Configure Your Security Group (p. 562)
• Step 3: Create an AMI from Your EC2-Classic Instance (p. 562)
• Step 4: Launch an Instance Into Your VPC (p. 563)
• Example: Migrating a Simple Web Application (p. 565)

Step 1: Create a VPC
To start using a VPC, ensure that you have one in your account. You can create one using one of
these methods:
• Use a new, EC2-VPC-only AWS account. Your EC2-VPC-only account comes with a default VPC
in each region, which is ready for you to use. Instances that you launch are by default launched into
this VPC, unless you specify otherwise. For more information about your default VPC, see Your
Default VPC and Subnets. Use this option if you'd prefer not to set up a VPC yourself, or if you do
not need specific requirements for your VPC configuration.
• In your existing AWS account, open the Amazon VPC console and use the VPC wizard to create a
new VPC. For more information, see Scenarios for Amazon VPC. Use this option if you want to set
up a VPC quickly in your existing EC2-Classic account, using one of the available configuration sets
in the wizard. You'll specify this VPC each time you launch an instance.
• In your existing AWS account, open the Amazon VPC console and set up the components of a VPC
according to your requirements. For more information, see Your VPC and Subnets. Use this option if
you have specific requirements for your VPC, such as a particular number of subnets. You'll specify
this VPC each time you launch an instance.

Note
T2 instance types must be launched into a VPC. If you do not have any VPCs in your EC2Classic account, and you use the launch wizard in the Amazon EC2 console to launch a

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T2 instance, the wizard creates a nondefault VPC for you. For more information about T2
instance types, see T2 Instances (p. 160). Your T2 instance will not be able to communicate
with your EC2-Classic instances using private IP addresses. Consider migrating your existing
instances to the same VPC using the methods outlined in this topic.

Step 2: Configure Your Security Group
You cannot use the same security groups between EC2-Classic and a VPC. However, if you want your
instances in your VPC to have the same security group rules as your EC2-Classic instances, you can
use the Amazon EC2 console to copy your existing EC2-Classic security group rules to a new VPC
security group.

Important
You can only copy security group rules to a new security group in the same AWS account in
the same region. If you've created a new AWS account, you cannot use this method to copy
your existing security group rules to your new account. You'll have to create a new security
group, and add the rules yourself. For more information about creating a new security group,
see Amazon EC2 Security Groups for Linux Instances (p. 489).

To copy your security group rules to a new security group
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Security Groups.

Select the security group that's associated with your EC2-Classic instance, then choose Actions
and select Copy to new.

In the Create Security Group dialog box, specify a name and description for your new security
group. Select your VPC from the VPC list.

The Inbound tab is populated with the rules from your EC2-Classic security group. You can
modify the rules as required. In the Outbound tab, a rule that allows all outbound traffic has
automatically been created for you. For more information about modifying security group rules, see
Amazon EC2 Security Groups for Linux Instances (p. 489).

Note
If you've defined a rule in your EC2-Classic security group that references another
security group, you will not be able to use the same rule in your VPC security group.
Modify the rule to reference a security group in the same VPC.
6.

Choose Create.

Step 3: Create an AMI from Your EC2-Classic Instance
An AMI is a template for launching your instance. You can create your own AMI based on an existing
EC2-Classic instance, then use that AMI to launch instances into your VPC.
The method you use to create your AMI depends on the root device type of your instance, and the
operating system platform on which your instance runs. To find out the root device type of your
instance, go to the Instances page, select your instance, and look at the information in the Root
device type field in the Description tab. If the value is ebs, then your instance is EBS-backed. If
the value is instance-store, then your instance is instance store-backed. You can also use the
describe-instances AWS CLI command to find out the root device type.
The following table provides options for you to create your AMI based on the root device type of your
instance, and the software platform.

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AMI offers. If your AMI supports PV virtualization, and you want to use an instance type that
supports HVM virtualization, you may have to reinstall your software on a base HVM AMI. For
more information about PV and HVM virtualization, see Linux AMI Virtualization Types (p. 74).
Instance Root Device
Type

Action

EBS

Create an EBS-backed AMI from your instance. For more information, see
Creating an Amazon EBS-Backed Linux AMI (p. 89).

Instance store

Create an instance store-backed AMI from your instance using the AMI
tools. For more information, see Creating an Instance Store-Backed Linux
AMI (p. 92).

Instance store

Transfer your instance data to an EBS volume, then take a snapshot of the
volume, and create an AMI from the snapshot. For more information, see
Converting your Instance Store-Backed AMI to an Amazon EBS-Backed
AMI (p. 129).

Note
This method converts an instance store-backed instance to an
EBS-backed instance.

(Optional) Store Your Data on Amazon EBS Volumes
You can create an Amazon EBS volume and use it to back up and store the data on your instance
—like you would use a physical hard drive. Amazon EBS volumes can be attached and detached
from any instance in the same Availability Zone. You can detach a volume from your instance in EC2Classic, and attach it to a new instance that you launch into your VPC in the same Availability Zone.
For more information about Amazon EBS volumes, see the following topics:
• Amazon EBS Volumes (p. 636)
• Creating an Amazon EBS Volume (p. 650)
• Attaching an Amazon EBS Volume to an Instance (p. 654)
To back up the data on your Amazon EBS volume, you can take periodic snapshots of your volume. If
you need to, you can restore an Amazon EBS volume from your snapshot. For more information about
Amazon EBS snapshots, see the following topics:
• Amazon EBS Snapshots (p. 685)
• Creating an Amazon EBS Snapshot (p. 686)
• Restoring an Amazon EBS Volume from a Snapshot (p. 652)

Step 4: Launch an Instance Into Your VPC
After you've created an AMI, you can launch an instance into your VPC. The instance will have the
same data and configurations as your existing EC2-Classic instance.
You can either launch your instance into a VPC that you've created in your existing account, or into a
new, VPC-only AWS account.

Using Your Existing EC2-Classic Account
You can use the Amazon EC2 launch wizard to launch an instance into your VPC.

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To launch an instance into your VPC
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

On the dashboard, choose Launch Instance.

On the Choose an Amazon Machine Image page, select the My AMIs category, and select the
AMI you created.

On the Choose an Instance Type page, select the type of instance, and choose Next: Configure
Instance Details.

Select Select an existing group, and select the security group you created earlier. Choose
Review and Launch.

Review your instance details, then choose Launch to specify a key pair and launch your instance.

For more information about the parameters you can configure in each step of the wizard, see
Launching an Instance (p. 279).

Using Your New, VPC-Only Account
To launch an instance in your new AWS account, you'll first have to share the AMI you created with
your new account. You can then use the Amazon EC2 launch wizard to launch an instance into your
default VPC.

To share an AMI with your new AWS account
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

Switch to the account in which you created your AMI.

In the navigation pane, choose AMIs.

In the Filter list, ensure Owned by me is selected, then select your AMI.

In the Permissions tab, choose Edit. Enter the account number of your new AWS account,
choose Add Permission, and then choose Save.

To launch an instance into your default VPC
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

Switch to your new AWS account.

In the navigation pane, choose AMIs.

In the Filter list, select Private images. Select the AMI that you shared from your EC2-Classic
account, then choose Launch.

On the Choose an Instance Type page, select the type of instance, and choose Next: Configure
Instance Details.

On the Configure Instance Details page, your default VPC should be selected in the Network
list. Configure any other details you require, then go through the next pages of the wizard until you
reach the Configure Security Group page.

Select Select an existing group, and select the security group you created earlier. Choose
Review and Launch.

Review your instance details, then choose Launch to specify a key pair and launch your instance.

For more information about the parameters you can configure in each step of the wizard, see
Launching an Instance (p. 279).

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Example: Migrating a Simple Web Application
In this example, you use AWS to host your gardening website. To manage your website, you have
three running instances in EC2-Classic. Instances A and B host your public-facing web application, and
you use an Elastic Load Balancer to load balance the traffic between these instances. You've assigned
Elastic IP addresses to instances A and B so that you have static IP addresses for configuration and
administration tasks on those instances. Instance C holds your MySQL database for your website.
You've registered the domain name www.garden.example.com, and you've used Amazon Route 53
to create a hosted zone with an alias record set that's associated with the DNS name of your load
balancer.

The first part of migrating to a VPC is deciding what kind of VPC architecture will suit your needs. In
this case, you've decided on the following: one public subnet for your web servers, and one private
subnet for your database server. As your website grows, you can add more web servers and database
servers to your subnets. By default, instances in the private subnet cannot access the Internet;
however, you can enable Internet access through a Network Address Translation (NAT) device in the
public subnet. You may want to set up a NAT device to support periodic updates and patches from the
Internet for your database server. You'll migrate your Elastic IP addresses to EC2-VPC, and create an
Elastic Load Balancer in your public subnet to load balance the traffic between your web servers.

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To migrate your web application to a VPC, you can follow these steps:
• Create a VPC: In this case, you can use the VPC wizard in the Amazon VPC console to create
your VPC and subnets. The second wizard configuration creates a VPC with one private and one
public subnet, and launches and configures a NAT device in your public subnet for you. For more
information, see Scenario 2: VPC with Public and Private Subnets in the Amazon VPC User Guide.
• Create AMIs from your instances: Create an AMI from one of your web servers, and a second AMI
from your database server. For more information, see Step 3: Create an AMI from Your EC2-Classic
Instance (p. 562).
• Configure your security groups: In your EC2-Classic environment, you have one security group
for your web servers, and another security group for your database server. You can use the Amazon
EC2 console to copy the rules from each security group into new security groups for your VPC. For
more information, see Step 2: Configure Your Security Group (p. 562).

Tip
Create the security groups that are referenced by other security groups first.
• Launch an instance into your new VPC: Launch replacement web servers into your public subnet,
and launch your replacement database server into your private subnet. For more information, see
Step 4: Launch an Instance Into Your VPC (p. 563).
• Configure your NAT device: If you are using a NAT instance, you must create security group for
it that allows HTTP and HTTPS traffic from your private subnet. For more information, see NAT
Instances. If you are using a NAT gateway, traffic from your private subnet is automatically allowed.

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• Configure your database: When you created an AMI from your database server in EC2-Classic, all
the configuration information that was stored in that instance was copied to the AMI. You may have
to connect to your new database server and update the configuration details; for example, if you
configured your database to grant full read, write, and modification permissions to your web servers
in EC2-Classic, you'll have to update the configuration files to grant the same permissions to your
new VPC web servers instead.
• Configure your web servers: Your web servers will have the same configuration settings as your
instances in EC2-Classic. For example, if you configured your web servers to use the database in
EC2-Classic, update your web servers' configuration settings to point to your new database instance.

Note
By default, instances launched into a nondefault subnet are not assigned a public IP
address, unless you specify otherwise at launch. Your new database server may not
have a public IP address. In this case, you can update your web servers' configuration file
to use your new database server's private DNS name. Instances in the same VPC can
communicate with each other via private IP address.
• Migrate your Elastic IP addresses: Disassociate your Elastic IP addresses from your web servers
in EC2-Classic, and then migrate them to EC2-VPC. After you've migrated them, you can associate
them with your new web servers in your VPC. For more information, see Migrating an Elastic IP
Address from EC2-Classic to EC2-VPC (p. 583).
• Create a new load balancer: To continue using Elastic Load Balancing to load balance the traffic to
your instances, make sure you understand the various ways you can configure your load balancer in
VPC. For more information, see Elastic Load Balancing in Amazon VPC.
• Update your DNS records: After you've set up your load balancer in your public subnet, ensure
that your www.garden.example.com domain points to your new load balancer. To do this, you'll
need to update your DNS records and update your alias record set in Amazon Route 53. For more
information about using Amazon Route 53, see Getting Started with Amazon Route 53.
• Shut down your EC2-Classic resources: After you've verified that your web application is working
from within the VPC architecture, you can shut down your EC2-Classic resources to stop incurring
charges for them. Terminate your EC2-Classic instances, and release your EC2-Classic Elastic IP
addresses.

Incremental Migration to a VPC Using ClassicLink
The ClassicLink feature makes it easier to manage an incremental migration to a VPC. ClassicLink
allows you to link an EC2-Classic instance to a VPC in your account in the same region, allowing your
new VPC resources to communicate with the EC2-Classic instance using private IP addresses. You
can then migrate functionality to the VPC one step at a time. This topic provides some basic steps for
managing an incremental migration from EC2-Classic to a VPC.
For more information about ClassicLink, see ClassicLink (p. 550).
Topics
• Step 1: Prepare Your Migration Sequence (p. 568)
• Step 2: Create a VPC (p. 568)
• Step 3: Enable Your VPC for ClassicLink (p. 568)
• Step 4: Create an AMI from Your EC2-Classic Instance (p. 568)
• Step 5: Launch an Instance Into Your VPC (p. 569)
• Step 6: Link Your EC2-Classic Instances to Your VPC (p. 570)
• Step 7: Complete the VPC Migration (p. 570)

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Step 1: Prepare Your Migration Sequence
To use ClassicLink effectively, you must first identify the components of your application that must be
migrated to the VPC, and then confirm the order in which to migrate that functionality.
For example, you have an application that relies on a presentation web server, a backend database
server, and authentication logic for transactions. You may decide to start the migration process with the
authentication logic, then the database server, and finally, the web server.

Step 2: Create a VPC
To start using a VPC, ensure that you have one in your account. You can create one using one of
these methods:
• In your existing AWS account, open the Amazon VPC console and use the VPC wizard to create a
new VPC. For more information, see Scenarios for Amazon VPC. Use this option if you want to set
up a VPC quickly in your existing EC2-Classic account, using one of the available configuration sets
in the wizard. You'll specify this VPC each time you launch an instance.
• In your existing AWS account, open the Amazon VPC console and set up the components of a VPC
according to your requirements. For more information, see Your VPC and Subnets. Use this option if
you have specific requirements for your VPC, such as a particular number of subnets. You'll specify
this VPC each time you launch an instance.

Step 3: Enable Your VPC for ClassicLink
After you've created a VPC, you can enable it for ClassicLink. For more information about ClassicLink,
see ClassicLink (p. 550).

To enable a VPC for ClassicLink
1.
2.

Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.
In the navigation pane, choose Your VPCs.

3.
4.

Select your VPC, and then select Enable ClassicLink from the Actions list.
In the confirmation dialog box, choose Yes, Enable.

Step 4: Create an AMI from Your EC2-Classic Instance
An AMI is a template for launching your instance. You can create your own AMI based on an existing
EC2-Classic instance, then use that AMI to launch instances into your VPC.
The method you use to create your AMI depends on the root device type of your instance, and the
operating system platform on which your instance runs. To find out the root device type of your
instance, go to the Instances page, select your instance, and look at the information in the Root
device type field in the Description tab. If the value is ebs, then your instance is EBS-backed. If
the value is instance-store, then your instance is instance store-backed. You can also use the
describe-instances AWS CLI command to find out the root device type.
The following table provides options for you to create your AMI based on the root device type of your
instance, and the software platform.

Important
Some instance types support both PV and HVM virtualization, while others support only
one or the other. If you plan to use your AMI to launch a different instance type than your
current instance type, check that the instance type supports the type of virtualization that your
AMI offers. If your AMI supports PV virtualization, and you want to use an instance type that
supports HVM virtualization, you may have to reinstall your software on a base HVM AMI. For
more information about PV and HVM virtualization, see Linux AMI Virtualization Types (p. 74).

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Instance Root Device
Type

Action

EBS

Create an EBS-backed AMI from your instance. For more information, see
Creating an Amazon EBS-Backed Linux AMI (p. 89).

Instance store

Create an instance store-backed AMI from your instance using the AMI
tools. For more information, see Creating an Instance Store-Backed Linux
AMI (p. 92).

Instance store

Note
This method converts an instance store-backed instance to an
EBS-backed instance.

Step 5: Launch an Instance Into Your VPC
The next step in the migration process is to launch instances into your VPC so that you can start
transferring functionality to them. You can use the AMIs that you created in the previous step to launch
instances into your VPC. The instances will have the same data and configurations as your existing
EC2-Classic instances.

To launch an instance into your VPC using your custom AMI
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

On the dashboard, choose Launch Instance.

On the Choose an Amazon Machine Image page, select the My AMIs category, and select the
AMI you created.

On the Choose an Instance Type page, select the type of instance, and choose Next: Configure
Instance Details.

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6.
7.

On the Configure Instance Details page, select your VPC from the Network list. Select the
required subnet from the Subnet list. Configure any other details you require, then go through the
next pages of the wizard until you reach the Configure Security Group page.
Select Select an existing group, and select the security group you created earlier. Choose
Review and Launch.
Review your instance details, then choose Launch to specify a key pair and launch your instance.

For more information about the parameters you can configure in each step of the wizard, see
Launching an Instance (p. 279).
After you've launched your instance and it's in the running state, you can connect to it and configure it
as required.

Step 6: Link Your EC2-Classic Instances to Your VPC
After you've configured your instances and made the functionality of your application available in the
VPC, you can use ClassicLink to enable private IP communication between your new VPC instances
and your EC2-Classic instances.

To link an instance to a VPC
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.

In the navigation pane, choose Instances.
Select your EC2-Classic instance, then choose Actions, ClassicLink, and Link to VPC.

Note
4.
5.

Ensure that your instance is in the running state.
In the dialog box, select your ClassicLink-enabled VPC (only VPCs that are enabled for
ClassicLink are displayed).
Select one or more of the VPC security groups to associate with your instance. When you are
done, choose Link to VPC.

Step 7: Complete the VPC Migration
Depending on the size of your application and the functionality that must be migrated, repeat steps 4 to
6 until you've moved all the components of your application from EC2-Classic into your VPC.
After you've enabled internal communication between the EC2-Classic and VPC instances, you must
update your application to point to your migrated service in your VPC, instead of your service in the
EC2-Classic platform. The exact steps for this depend on your application’s design. Generally, this
includes updating your destination IP addresses to point to the IP addresses of your VPC instances
instead of your EC2-Classic instances. You can migrate your Elastic IP addresses that you are
currently using in the EC2-Classic platform to the EC2-VPC platform. For more information, see
Migrating an Elastic IP Address from EC2-Classic to EC2-VPC (p. 583).
After you've completed this step and you've tested that the application is functioning from your VPC,
you can terminate your EC2-Classic instances, and disable ClassicLink for your VPC. You can also
clean up any EC2-Classic resources that you may no longer need to avoid incurring charges for them;
for example, you can release Elastic IP addresses, and delete the volumes that were associated with
your EC2-Classic instances.

Amazon EC2 Instance IP Addressing
We provide your instances with IP addresses and DNS hostnames. These can vary depending on
whether you launched the instance in the EC2-Classic platform or in a virtual private cloud (VPC).

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For information about the EC2-Classic and EC2-VPC platforms, see Supported Platforms (p. 549).
For information about Amazon VPC, see What is Amazon VPC? in the Amazon VPC User Guide.
Contents
• Private IP Addresses and Internal DNS Hostnames (p. 571)
• Public IP Addresses and External DNS Hostnames (p. 572)
• Elastic IP Addresses (p. 573)
• Amazon DNS Server (p. 573)
• IP Address Differences Between EC2-Classic and EC2-VPC (p. 573)
• Determining Your Public, Private, and Elastic IP Addresses (p. 574)
• Assigning a Public IP Address (p. 575)
• Multiple Private IP Addresses (p. 576)

Private IP Addresses and Internal DNS
Hostnames
A private IP address is an IP address that's not reachable over the Internet. You can use private IP
addresses for communication between instances in the same network (EC2-Classic or a VPC). For
more information about the standards and specifications of private IP addresses, see RFC 1918.

Note
You can create a VPC with a publicly-routable CIDR block that falls outside of the private IP
address ranges specified in RFC 1918. However, for the purposes of this documentation, we
refer to private IP addresses as the IP addresses that are within the CIDR range of your VPC.
When you launch an instance, we allocate a private IP address for the instance using DHCP. Each
instance is also given an internal DNS hostname that resolves to the private IP address of the instance;
for example, ip-10-251-50-12.ec2.internal. You can use the internal DNS hostname for
communication between instances in the same network, but we can't resolve the DNS hostname
outside the network that the instance is in.
An instance launched in a VPC is given a primary private IP address in the address range of the
subnet. For more information, see Subnet Sizing in the Amazon VPC User Guide. If you don't specify
a primary private IP address when you launch the instance, we select an available IP address in
the subnet's range for you. Each instance in a VPC has a default network interface (eth0) that is
assigned the primary private IP address. You can also specify additional private IP addresses,
known as secondary private IP addresses. Unlike primary private IP addresses, secondary private IP
addresses can be reassigned from one instance to another. For more information, see Multiple Private
IP Addresses (p. 576).
For instances launched in EC2-Classic, we release the private IP address when the instance is
stopped or terminated. If you restart your stopped instance, it receives a new private IP address.
For instances launched in a VPC, a private IP address remains associated with the network interface
when the instance is stopped and restarted, and is released when the instance is terminated.
If you create a custom firewall configuration in EC2-Classic, you must create a rule in your firewall that
allows inbound traffic from port 53 (DNS)—with a destination port from the ephemeral range—from
the address of the Amazon DNS server; otherwise, internal DNS resolution from your instances fails.
If your firewall doesn't automatically allow DNS query responses, then you need to allow traffic from
the IP address of the Amazon DNS server. To get the IP address of the Amazon DNS server, use the
following command from within your instance:
• Linux

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grep nameserver /etc/resolv.conf

Public IP Addresses and External DNS
Hostnames
A public IP address is reachable from the Internet. You can use public IP addresses for communication
between your instances and the Internet.
Each instance that receives a public IP address is also given an external DNS hostname; for example,
ec2-203-0-113-25.compute-1.amazonaws.com. We resolve an external DNS hostname to the
public IP address of the instance outside the network of the instance, and to the private IP address of
the instance from within the network of the instance. The public IP address is mapped to the primary
private IP address through network address translation (NAT). For more information about NAT, see
RFC 1631: The IP Network Address Translator (NAT).
When you launch an instance in EC2-Classic, we automatically assign a public IP address to the
instance from the EC2-Classic public IP address pool. You cannot modify this behavior. When you
launch an instance into a VPC, your subnet has an attribute that determines whether instances
launched into that subnet receive a public IP address from the EC2-VPC public IP address pool. By
default, we assign a public IP address to instances launched in a default VPC, and we don't assign a
public IP address to instances launched in a nondefault subnet.
You can control whether your instance in a VPC receives a public IP address by doing the following:
• Modifying the public IP addressing attribute of your subnet. For more information, see Modifying
Your Subnet's Public IP Addressing Behavior in the Amazon VPC User Guide.
• Enabling or disabling the public IP addressing feature during launch, which overrides the subnet's
public IP addressing attribute. For more information, see Assigning a Public IP Address (p. 575).
A public IP address is assigned to your instance from Amazon's pool of public IP addresses, and is not
associated with your AWS account. When a public IP address is disassociated from your instance, it is
released back into the public IP address pool, and you cannot reuse it.
You cannot manually associate or disassociate a public IP address from your instance. Instead, in
certain cases, we release the public IP address from your instance, or assign it a new one:
• We release the public IP address for your instance when it's stopped or terminated. Your stopped
instance receives a new public IP address when it's restarted.
• We release the public IP address for your instance when you associate an Elastic IP address with
your instance, or when you associate an Elastic IP address with the primary network interface (eth0)
of your instance in a VPC. When you disassociate the Elastic IP address from your instance, it
receives a new public IP address.
• If the public IP address of your instance in a VPC has been released, it will not receive a new one if
there is more than one network interface attached to your instance.
If you require a persistent public IP address that can be associated to and from instances as you
require, use an Elastic IP address instead. For example, if you use dynamic DNS to map an existing
DNS name to a new instance's public IP address, it might take up to 24 hours for the IP address to
propagate through the Internet. As a result, new instances might not receive traffic while terminated
instances continue to receive requests. To solve this problem, use an Elastic IP address. You can
allocate your own Elastic IP address, and associate it with your instance. For more information, see
Elastic IP Addresses (p. 581).

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If your instance is in a VPC and you assign it an Elastic IP address, it receives a DNS hostname if DNS
hostnames are enabled. For more information, see Using DNS with Your VPC in the Amazon VPC
User Guide.

Note
Instances that access other instances through their public NAT IP address are charged for
regional or Internet data transfer, depending on whether the instances are in the same region.

Elastic IP Addresses
An Elastic IP address is a public IP address that you can allocate to your account. You can associate
it to and from instances as you require, and it's allocated to your account until you choose to
release it. For more information about Elastic IP addresses and how to use them, see Elastic IP
Addresses (p. 581).

Amazon DNS Server
Amazon provides a DNS server that resolves DNS hostnames to IP addresses. In EC2-Classic, the
Amazon DNS server is located at 172.16.0.23. In EC2-VPC, the Amazon DNS server is located at
the base of your VPC network range plus two. For more information, see Amazon DNS Server in the
Amazon VPC User Guide.

IP Address Differences Between EC2-Classic
and EC2-VPC
The following table summarizes the differences between IP addresses for instances launched in EC2Classic, instances launched in a default subnet, and instances launched in a nondefault subnet.
CharacteristicEC2-Classic

Default Subnet

Nondefault Subnet

Public IP
address
(from
Amazon's
public IP
address
pool)

Your instance receives a
public IP address.

Your instance receives
a public IP address by
default, unless you specify
otherwise during launch,
or you modify the subnet's
public IP address attribute.

Your instance doesn't
receive a public IP address
by default, unless you
specify otherwise during
launch, or you modify the
subnet's public IP address
attribute.

Private IP
address

Your instance receives a
private IP address from the
EC2-Classic range each
time it's started.

Your instance receives a
static private IP address
from the address range of
your default subnet.

Your instance receives a
static private IP address
from the address range of
your subnet.

Multiple IP
addresses

We select a single
private IP address for
your instance; multiple
IP addresses are not
supported.

You can assign multiple
private IP addresses to
your instance.

Network
interfaces

IP addresses are
associated with the
instance; network
interfaces aren't supported.

IP addresses are
associated with a network
interface. Each instance
has one or more network
interfaces.

Elastic IP
address

An Elastic IP address is
disassociated from your
instance when you stop it.

An Elastic IP address
remains associated with

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Private, and Elastic IP Addresses

CharacteristicEC2-Classic

DNS
hostnames

DNS hostnames are
enabled by default.

Default Subnet

Nondefault Subnet

your instance when you
stop it.

DNS hostnames are
enabled by default.

DNS hostnames are
disabled by default, except
if you've created your VPC
using the VPC wizard in the
Amazon VPC console.

Determining Your Public, Private, and Elastic IP
Addresses
You can use the Amazon EC2 console to determine the private IP addresses, public IP addresses, and
Elastic IP addresses of your instances. You can also determine the public and private IP addresses
of your instance from within your instance by using instance metadata. For more information, see
Instance Metadata and User Data (p. 337).

To determine your instance's private IP addresses using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances.

Select your instance. In the details pane, get the private IP address from the Private IPs field, and
get the internal DNS hostname from the Private DNS field.

(VPC only) If you have one or more secondary private IP addresses assigned to network
interfaces that are attached to your instance, get those IP addresses from the Secondary private
IPs field.

(VPC only) Alternatively, in the navigation pane, choose Network Interfaces, and then select the
a network interface that's associated with your instance.

Get the primary private IP address from the Primary private IP field, and the internal DNS
hostname from the Private DNS field.

If you've assigned secondary private IP addresses to the network interface, get those IP
addresses from the Secondary private IPs field.

To determine your instance's public IP addresses using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances.

Select your instance. In the details pane, get the public IP address from the Public IP field, and
get the external DNS hostname from the Public DNS field.

If an Elastic IP address has been associated with the instance, get the Elastic IP address from the
Elastic IP field.

Note
If you've associated an Elastic IP address with your instance, the Public IP field also
displays the Elastic IP address.
5.

(VPC only) Alternatively, in the navigation pane, choose Network Interfaces, and then select a
network interface that's associated with your instance.

Get the public IP address from the Public IPs field. An asterisk (*) indicates the public IP address
or Elastic IP address that's mapped to the primary private IP address.

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Note
The public IP address is displayed as a property of the network interface in the console,
but it's mapped to the primary private IP address through NAT. Therefore, if you inspect
the properties of your network interface on your instance, for example, through ifconfig
(Linux) or ipconfig (Windows), the public IP address is not displayed. To determine
your instance's public IP address from within the instance, you can use instance
metadata.

To determine your instance's IP addresses using instance metadata
1.

Connect to your instance.

Use the following command to access the private IP address:
•

Linux
$ curl http://169.254.169.254/latest/meta-data/local-ipv4

•

Windows
$ wget http://169.254.169.254/latest/meta-data/local-ipv4

Use the following command to access the public IP address:
•

Linux
$ curl http://169.254.169.254/latest/meta-data/public-ipv4

•

Windows
$ wget http://169.254.169.254/latest/meta-data/public-ipv4

Note that if an Elastic IP address is associated with the instance, the value returned is that of the
Elastic IP address.

Assigning a Public IP Address
If you launch an instance in EC2-Classic, it is assigned a public IP address by default. You can't modify
this behavior.
In a VPC, all subnets have an attribute that determines whether instances launched into that subnet
are assigned a public IP address. By default, nondefault subnets have this attribute set to false, and
default subnets have this attribute set to true. When you launch an instance, a public IP addressing
feature is also available for you to control whether your instance is assigned a public IP address; you
can override the default behavior of the subnet's IP addressing attribute. The public IP address is
assigned from Amazon's pool of public IP addresses, and is assigned to the network interface with the
device index of eth0. This feature depends on certain conditions at the time you launch your instance.

Important
You can't manually disassociate the public IP address from your instance after launch.
Instead, it's automatically released in certain cases, after which you cannot reuse it. For
more information, see Public IP Addresses and External DNS Hostnames (p. 572). If you
require a persistent public IP address that you can associate or disassociate at will, assign an
Elastic IP address to the instance after launch instead. For more information, see Elastic IP
Addresses (p. 581).

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To access the public IP addressing feature when launching an instance
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

Choose Launch Instance.

Select an AMI and an instance type, and then choose Next: Configure Instance Details.

On the Configure Instance Details page, select a VPC from the Network list. An Auto-assign
Public IP list is displayed. Choose Enable or Disable to override the default setting for the subnet.

Important
You cannot auto-assign a public IP address if you specify more than one network
interface. Additionally, you cannot override the subnet setting using the auto-assign public
IP feature if you specify an existing network interface for eth0.
5.

Follow the steps on the next pages of the wizard to complete your instance's setup. For more
information about the wizard configuration options, see Launching an Instance (p. 279). On the
final Review Instance Launch page, review your settings, and then choose Launch to choose a
key pair and launch your instance.

On the Instances page, select your new instance and view its public IP address in Public IP field
in the details pane.

The public IP addressing feature is only available during launch. However, whether you assign a public
IP address to your instance during launch or not, you can associate an Elastic IP address with your
instance after it's launched. For more information, see Elastic IP Addresses (p. 581). You can also
modify your subnet's public IP addressing behavior. For more information, see Modifying Your Subnet's
Public IP Addressing Behavior.

API and Command Line Tools for Public IP Addressing
To enable or disable the public IP addressing feature, use one of the methods in the table below. For
more information about these command line interfaces, see Accessing Amazon EC2 (p. 3).
Method

Parameter

AWS CLI

Use the --associate-public-ip-address or the --noassociate-public-ip-address option with the run-instances
command.

AWS Tools for Windows
PowerShell

Use the -AssociatePublicIp parameter with the NewEC2Instance command.

Query API

Use the NetworkInterface.n.AssociatePublicIpAddress
parameter with the RunInstances request.

Multiple Private IP Addresses
In EC2-VPC, you can specify multiple private IP addresses for your instances. The number of network
interfaces and private IP addresses that you can specify for an instance depends on the instance type.
For more information, see Private IP Addresses Per Network Interface Per Instance Type (p. 589).
It can be useful to assign multiple private IP addresses to an instance in your VPC to do the following:
• Host multiple websites on a single server by using multiple SSL certificates on a single server and
associating each certificate with a specific IP address.
• Operate network appliances, such as firewalls or load balancers, that have multiple private IP
addresses for each network interface.

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• Redirect internal traffic to a standby instance in case your instance fails, by reassigning the
secondary private IP address to the standby instance.
Contents
• How Multiple IP Addresses Work (p. 577)
• Assigning a Secondary Private IP Address (p. 577)
• Configuring the Operating System on Your Instance to Recognize the Secondary Private IP
Address (p. 579)
• Associating an Elastic IP Address with the Secondary Private IP Address (p. 580)
• Viewing Your Secondary Private IP Addresses (p. 580)
• Unassigning a Secondary Private IP Address (p. 580)

How Multiple IP Addresses Work
The following list explains how multiple IP addresses work with network interfaces:
• You can assign a secondary private IP address to any network interface. The network interface can
be attached to or detached from the instance.
• You must choose a secondary private IP address that's in the CIDR block range of the subnet for the
network interface.
• Security groups apply to network interfaces, not to IP addresses. Therefore, IP addresses are
subject to the security group of the network interface in which they're specified.
• Secondary private IP addresses can be assigned and unassigned to elastic network interfaces
attached to running or stopped instances.
• Secondary private IP addresses that are assigned to a network interface can be reassigned to
another one if you explicitly allow it.
• When assigning multiple secondary private IP addresses to a network interface using the command
line tools or API, the entire operation fails if one of the secondary private IP addresses can't be
assigned.
• Primary private IP addresses, secondary private IP addresses, and any associated Elastic IP
addresses remain with the network interface when it is detached from an instance or attached to
another instance.
• Although you can't move the primary network interface from an instance, you can reassign the
secondary private IP address of the primary network interface to another network interface.
• You can move any additional network interface from one instance to another.
The following list explains how multiple IP addresses work with Elastic IP addresses:
• Each private IP address can be associated with a single Elastic IP address, and vice versa.
• When a secondary private IP address is reassigned to another interface, the secondary private IP
address retains its association with an Elastic IP address.
• When a secondary private IP address is unassigned from an interface, an associated Elastic IP
address is automatically disassociated from the secondary private IP address.

Assigning a Secondary Private IP Address
You can assign the secondary private IP address to the network interface for an instance as you
launch the instance, or after the instance is running. This section includes the following procedures.

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• To assign a secondary private IP address when launching an instance in EC2-VPC (p. 578)
• To assign a secondary IP address during launch using the command line (p. 578)
• To assign a secondary private IP to an existing instance (p. 579)
• To assign a secondary private IP to an existing instance using the command line (p. 579)

To assign a secondary private IP address when launching an instance in EC2-VPC
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

Choose Launch Instance.

Select an AMI, then choose an instance type and choose Next: Configure Instance Details.

On the Configure Instance Details page, select a VPC from the Network list, and a subnet from
the Subnet list.

In the Network Interfaces section, do the following, and then choose Next: Add Storage:
a.

Choose Add Device to add another network interface. The console enables you to specify
up to two network interfaces when you launch an instance. After you launch the instance,
choose Network Interfaces in the navigation pane to add additional network interfaces. The
total number of network interfaces that you can attach varies by instance type. For more
information, see Private IP Addresses Per Network Interface Per Instance Type (p. 589).

Important
When you add a second network interface, the system can no longer auto-assign a
public IP address. You will not be able to connect to the instance unless you assign
an Elastic IP address to the primary network interface (eth0). You can assign the
Elastic IP address after you complete the Launch wizard. For more information, see
Working with Elastic IP Addresses (p. 584).
b.

For each network interface, you can specify a primary private IP address, and one or more
secondary private IP addresses. For this example, however, accept the IP address that we
automatically assign.

Under Secondary IP addresses, choose Add IP, and then enter a private IP address in the
subnet range, or accept the default, Auto-assign, to let us select an address.

Important
After you have added a secondary private IP address to a network interface, you
must connect to the instance and configure the secondary private IP address on the
instance itself. For more information, see Configuring the Operating System on Your
Instance to Recognize the Secondary Private IP Address (p. 579).
6.

On the next Add Storage page, you can specify volumes to attach to the instance besides the
volumes specified by the AMI (such as the root device volume), and then choose Next: Tag
Instance.

On the Tag Instance page, specify tags for the instance, such as a user-friendly name, and then
choose Next: Configure Security Group.

On the Configure Security Group page, select an existing security group or create a new one.
Choose Review and Launch.

On the Review Instance Launch page, review your settings, and then choose Launch to choose
a key pair and launch your instance. If you're new to Amazon EC2 and haven't created any key
pairs, the wizard prompts you to create one.

To assign a secondary IP address during launch using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• The --secondary-private-ip-addresses option with the run-instances command (AWS CLI)

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• Define -NetworkInterface and specify the PrivateIpAddresses parameter with the NewEC2Instance command (AWS Tools for Windows PowerShell).

To assign a secondary private IP to an existing instance
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Network Interfaces, and then select the network interface
attached to the instance.

Choose Actions, Manage Private IP Addresses.

In the Manage Private IP Addresses dialog box, do the following:
a.

Choose Assign new IP.

Enter a specific IP address that's within the subnet range for the instance, or leave the field
blank and we select an IP address for you.

(Optional) Choose Allow reassignment to allow the secondary private IP address to be
reassigned if it is already assigned to another network interface.

Choose Yes, Update, Close.

Note that alternatively, you can assign a secondary private IP address to an instance. Choose
Instances in the navigation pane, select the instance, and then choose Actions, Networking,
Manage Private IP Addresses. You can configure the same information in the dialog as you did
in the steps above.

To assign a secondary private IP to an existing instance using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• assign-private-ip-addresses (AWS CLI)
• Register-EC2PrivateIpAddress (AWS Tools for Windows PowerShell)

Configuring the Operating System on Your Instance to
Recognize the Secondary Private IP Address
After you assign a secondary private IP address to your instance, you need to configure the operating
system on your instance to recognize the secondary private IP address.
• If you are using Amazon Linux, the ec2-net-utils package can take care of this step for you. It
configures additional network interfaces that you attach while the instance is running, refreshes
secondary IP addresses during DHCP lease renewal, and updates the related routing rules. You
can immediately refresh the list of interfaces by using the command sudo service network
restart and then view the up-to-date list using ip addr li. If you require manual control over
your network configuration, you can remove the ec2-net-utils package. For more information, see
Configuring Your Network Interface Using ec2-net-utils (p. 593).
• If you are using another Linux distribution, see the documentation for your Linux distribution. Search
for information about configuring additional network interfaces and secondary IP addresses. If the
instance has two or more interfaces on the same subnet, search for information about using routing
rules to work around asymmetric routing.
For information about configuring a Windows instance, see Configuring a Secondary Private IP
Address for Your Windows Instance in a VPC in the Amazon EC2 User Guide for Windows Instances.

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Associating an Elastic IP Address with the Secondary
Private IP Address
To associate an Elastic IP address with a secondary private IP address in EC2-VPC
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Elastic IPs.

3.
4.

Choose Actions, Associate Address.
In the Associate Address dialog box, select the network interface from the Network Interface
list, and then select the secondary IP address from the Private IP address list.

Choose Associate.

To associate an Elastic IP address with a secondary private IP address using the
command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• associate-address (AWS CLI)
• Register-EC2Address (AWS Tools for Windows PowerShell)

Viewing Your Secondary Private IP Addresses
To view the private IP addresses assigned to a network interface in EC2-VPC
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Network Interfaces.

3.
4.

Select the network interface whose private IP addresses you want to view.
On the Details tab in the details pane, check the Primary private IP and Secondary private IPs
fields for the primary private IP address and any secondary private IP addresses assigned to the
network interface.

To view the private IP addresses assigned to an instance
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.
4.

In the navigation pane, choose Instances.
Select the instance whose private IP addresses you want to view.
On the Description tab in the details pane, check the Private IPs and Secondary private IPs
fields for the primary private IP address and any secondary private IP addresses assigned to the
instance through its network interface.

Unassigning a Secondary Private IP Address
If you no longer require a secondary private IP address, you can unassign it from the instance or
the network interface. When a secondary private IP address is unassigned from an elastic network
interface, the Elastic IP address (if it exists) is also disassociated.

To unassign a secondary private IP address from an instance
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Instances.

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Select an instance, choose Actions, Networking, Manage Private IP Addresses.

In the Manage Private IP Addresses dialog box, beside the secondary private IP address to
unassign, choose Unassign.
Choose Yes, Update, and then close the dialog box.

To unassign a secondary private IP address from a network interface
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Network Interfaces.

Select the network interface, choose Actions, Manage Private IP Addresses.

In the Manage Private IP Addresses dialog box, beside the secondary private IP address to
unassign, choose Unassign.

Choose Yes, Update, Close.

To unassign a secondary private IP address using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• unassign-private-ip-addresses (AWS CLI)
• Unregister-EC2PrivateIpAddress (AWS Tools for Windows PowerShell)

Elastic IP Addresses
An Elastic IP address is a static IP address designed for dynamic cloud computing. An Elastic IP
address is associated with your AWS account. With an Elastic IP address, you can mask the failure of
an instance or software by rapidly remapping the address to another instance in your account.
An Elastic IP address is a public IP address, which is reachable from the Internet. If your instance does
not have a public IP address, you can associate an Elastic IP address with your instance to enable
communication with the Internet; for example, to connect to your instance from your local computer.
Topics
• Elastic IP Address Basics (p. 581)
• Elastic IP Address Differences for EC2-Classic and EC2-VPC (p. 582)
• Working with Elastic IP Addresses (p. 584)
• Using Reverse DNS for Email Applications (p. 587)
• Elastic IP Address Limit (p. 587)

Elastic IP Address Basics
The following are the basic characteristics of an Elastic IP address:
• To use an Elastic IP address, you first allocate one to your account, and then associate it with your
instance or a network interface.
• When you associate an Elastic IP address with an instance or its primary network interface,
the instance's public IP address (if it had one) is released back into Amazon's pool of public IP
addresses. You cannot reuse a public IP address. For more information, see Public IP Addresses
and External DNS Hostnames (p. 572).
• You can disassociate an Elastic IP address from a resource, and reassociate it with a different
resource.

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• A disassociated Elastic IP address remains allocated to your account until you explicitly release it.

• To ensure efficient use of Elastic IP addresses, we impose a small hourly charge if an Elastic IP
address is not associated with a running instance, or if it is associated with a stopped instance or an
unattached network interface. While your instance is running, you are not charged for one Elastic IP
address associated with the instance, but you are charged for any additional Elastic IP addresses
associated with the instance. For more information, see Amazon EC2 Pricing.
• An Elastic IP address is for use in a specific region only.
• When you associate an Elastic IP address with an instance that previously had a public IP address,
the public DNS hostname of the instance changes to match the Elastic IP address.
• We resolve a public DNS hostname to the public IP address or the Elastic IP address of the instance
outside the network of the instance, and to the private IP address of the instance from within the
network of the instance.
If your account supports EC2-Classic, the use and behavior of Elastic IP addresses for EC2-Classic
and EC2-VPC may differ. For more information, see Elastic IP Address Differences for EC2-Classic
and EC2-VPC (p. 582).

Elastic IP Address Differences for EC2-Classic
and EC2-VPC
If your account supports EC2-Classic, there's one pool of Elastic IP addresses for use with the EC2Classic platform and another for use with the EC2-VPC platform. You can't associate an Elastic
IP address that you allocated for use with a VPC with an instance in EC2-Classic, and vice-versa.
However, you can migrate an Elastic IP address you've allocated for use in the EC2-Classic platform
to the EC2-VPC platform. You cannot migrate an Elastic IP address to another region. For more
information about EC2-Classic and EC2-VPC, see Supported Platforms (p. 549).
When you associate an Elastic IP address with an instance in EC2-Classic, a default VPC, or
an instance in a nondefault VPC in which you assigned a public IP to the eth0 network interface
during launch, the instance's current public IP address is released back into the public IP address
pool. If you disassociate an Elastic IP address from the instance, the instance is automatically
assigned a new public IP address within a few minutes. However, if you have attached a second
network interface to an instance in a VPC, the instance is not automatically assigned a new public IP
address. For more information about public IP addresses, see Public IP Addresses and External DNS
Hostnames (p. 572).
For information about using an Elastic IP address with an instance in a VPC, see Elastic IP Addresses
in the Amazon VPC User Guide.
The following table lists the differences between Elastic IP addresses on EC2-Classic and EC2-VPC.
For more information about the differences between private and public IP addresses, see IP Address
Differences Between EC2-Classic and EC2-VPC (p. 573).
Characteristic

EC2-Classic

EC2-VPC

Allocating an
Elastic IP address

When you allocate an Elastic IP
When you allocate an Elastic IP
address, it's for use in EC2-Classic;
address, it's for use only in a VPC.
however, you can migrate an Elastic
IP address to the EC2-VPC platform.
For more information, see Migrating an
Elastic IP Address from EC2-Classic to
EC2-VPC (p. 583).

Associating an
Elastic IP address

You associate an Elastic IP address
with an instance.

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Elastic IP Address Differences
for EC2-Classic and EC2-VPC

Characteristic

EC2-Classic

EC2-VPC
can associate an Elastic IP address
with an instance by updating the ENI
attached to the instance. For more
information, see Elastic Network
Interfaces (ENI) (p. 588).

Reassociating an
Elastic IP address

If you try to associate an Elastic IP
address that's already associated
with another instance, the address is
automatically associated with the new
instance.

If your account supports EC2-VPC
only, and you try to associate an
Elastic IP address that's already
associated with another instance, the
address is automatically associated
with the new instance. If you're using
a VPC in an EC2-Classic account,
and you try to associate an Elastic IP
address that's already associated with
another instance, it succeeds only if
you allowed reassociation.

Stopping an
instance

If you stop an instance, its Elastic
IP address is disassociated, and
you must reassociate the Elastic IP
address when you restart the instance.

If you stop an instance, its Elastic IP
address remains associated.

Assigning multiple
IP addresses

Instances support only a single private
IP address and a corresponding
Elastic IP address.

Instances support multiple IP
addresses, and each one can have a
corresponding Elastic IP address. For
more information, see Multiple Private
IP Addresses (p. 576).

Migrating an Elastic IP Address from EC2-Classic to EC2VPC
If your account supports EC2-Classic, you can migrate Elastic IP addresses that you've allocated for
use in the EC2-Classic platform to the EC2-VPC platform, within the same region. This can assist you
to migrate your resources from EC2-Classic to a VPC; for example, you can launch new web servers
in your VPC, and then use the same Elastic IP addresses that you used for your web servers in EC2Classic for your new VPC web servers.
After you've migrated an Elastic IP address to EC2-VPC, you cannot use it in the EC2-Classic platform;
however, if required, you can restore it to EC2-Classic. After you've restored an Elastic IP address
to EC2-Classic, you cannot use it in EC2-VPC until you migrate it again. You can only migrate an
Elastic IP address from EC2-Classic to EC2-VPC. You cannot migrate an Elastic IP address that was
originally allocated for use in EC2-VPC to EC2-Classic.
To migrate an Elastic IP address, it must not be associated with an instance. For more information
about disassociating an Elastic IP address from an instance, see Disassociating an Elastic IP Address
and Reassociating it with a Different Instance (p. 585).
You can migrate as many EC2-Classic Elastic IP addresses as you can have in your account.
However, when you migrate an Elastic IP address to EC2-VPC, it counts against your Elastic IP
address limit for EC2-VPC. You cannot migrate an Elastic IP address if it will result in you exceeding
your limit. Similarly, when you restore an Elastic IP address to EC2-Classic, it counts against your
Elastic IP address limit for EC2-Classic. For more information, see Elastic IP Address Limit (p. 587).
You cannot migrate an Elastic IP address that has been allocated to your account for less than 24
hours.

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For more information, see Moving an Elastic IP Address (p. 586).

Working with Elastic IP Addresses
The following sections describe how you can work with Elastic IP addresses.
Topics
• Allocating an Elastic IP Address (p. 584)
• Describing Your Elastic IP Addresses (p. 584)
• Associating an Elastic IP Address with a Running Instance (p. 585)
• Disassociating an Elastic IP Address and Reassociating it with a Different Instance (p. 585)
• Moving an Elastic IP Address (p. 586)
• Releasing an Elastic IP Address (p. 587)

Allocating an Elastic IP Address
You can allocate an Elastic IP address using the Amazon EC2 console or the command line. If your
account supports EC2-Classic, you can allocate an address for use in EC2-Classic or in EC2-VPC.

To allocate an Elastic IP address for use in EC2-VPC using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.

In the navigation pane, choose Elastic IPs.
Choose Allocate New Address.

(EC2-Classic accounts) In the Allocate New Address dialog box, select VPC from EIP used in,
and then choose Yes, Allocate. Close the confirmation dialog box.

(VPC-only accounts) Choose Yes, Allocate, and close the confirmation dialog box.

To allocate an Elastic IP address for use in EC2-Classic using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.

In the navigation pane, choose Elastic IPs.
Choose Allocate New Address.

Select EC2, and then choose Yes, Allocate. Close the confirmation dialog box.

To allocate an Elastic IP address using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• allocate-address (AWS CLI)
• New-EC2Address (AWS Tools for Windows PowerShell)

Describing Your Elastic IP Addresses
You can describe an Elastic IP address using the Amazon EC2 or the command line.

To describe your Elastic IP addresses using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Elastic IPs.

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Select a filter from the Resource Attribute list to begin searching. You can use multiple filters in a
single search.

To describe your Elastic IP addresses using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• describe-addresses (AWS CLI)
• Get-EC2Address (AWS Tools for Windows PowerShell)

Associating an Elastic IP Address with a Running Instance
You can associate an Elastic IP address to an instance using the Amazon EC2 console or the
command line.
(VPC only) If you're associating an Elastic IP address with your instance to enable communication with
the Internet, you must also ensure that your instance is in a public subnet. For more information, see
Internet Gateways in the Amazon VPC User Guide.

To associate an Elastic IP address with an instance using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Elastic IPs.

Select an Elastic IP address, choose Actions, and then select Associate Address.

In the Associate Address dialog box, select the instance from Instance and then choose
Associate.

To associate an Elastic IP address using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• associate-address (AWS CLI)
• Register-EC2Address (AWS Tools for Windows PowerShell)

Disassociating an Elastic IP Address and Reassociating it
with a Different Instance
You can disassociate an Elastic IP address and then reassociate it using the Amazon EC2 console or
the command line.

To disassociate and reassociate an Elastic IP address using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Elastic IPs.

Select the Elastic IP address, choose Actions, and then select Disassociate Address.

Choose Yes, Disassociate when prompted for confirmation.

Select the address that you disassociated in the previous step. For Actions, choose Associate
Address.

In the Associate Address dialog box, select the new instance from Instance, and then choose
Associate.

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To disassociate an Elastic IP address using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• disassociate-address (AWS CLI)
• Unregister-EC2Address (AWS Tools for Windows PowerShell)

Moving an Elastic IP Address
Currently, you can migrate an Elastic IP address to EC2-VPC or restore it to EC2-Classic using the
Amazon EC2 Query API, an AWS SDK, or the AWS CLI only.
After you've performed the command to move or restore your Elastic IP address, the process of
migrating the Elastic IP address can take a few minutes. Use the describe-moving-addresses
command to check whether your Elastic IP address is still moving, or has completed moving.
If the Elastic IP address is in a moving state for longer than 5 minutes, contact http://aws.amazon.com/
premiumsupport/.

To move an Elastic IP address using the Amazon EC2 Query API or AWS CLI
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• move-address-to-vpc (AWS CLI)
• MoveAddressToVpc (Amazon EC2 Query API)
• Move-EC2AddressToVpc (AWS Tools for Windows PowerShell)

To restore an Elastic IP address to EC2-Classic using the Amazon EC2 Query API or
AWS CLI
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• restore-address-to-classic (AWS CLI)
• RestoreAddressToClassic (Amazon EC2 Query API)
• Restore-EC2AddressToClassic (AWS Tools for Windows PowerShell)

To describe the status of your moving addresses using the Amazon EC2 Query API or
AWS CLI
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• describe-moving-addresses (AWS CLI)
• DescribeMovingAddresses (Amazon EC2 Query API)

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• Get-EC2Address (AWS Tools for Windows PowerShell)

To retrieve the allocation ID for your migrated Elastic IP address in EC2-VPC
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• describe-addresses (AWS CLI)
• DescribeAddresses (Amazon EC2 Query API)
• Get-EC2Address (AWS Tools for Windows PowerShell)

Releasing an Elastic IP Address
If you no longer need an Elastic IP address, we recommend that you release it (the address must not
be associated with an instance). You incur charges for any Elastic IP address that's allocated for use
with EC2-Classic but not associated with an instance.
You can release an Elastic IP address using the Amazon EC2 console or the command line.

To release an Elastic IP address using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.

In the navigation pane, choose Elastic IPs.
Select the Elastic IP address, choose Actions, and then select Release Addresses. Choose Yes,
Release when prompted.

To release an Elastic IP address using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• release-address (AWS CLI)
• Remove-EC2Address (AWS Tools for Windows PowerShell)

Using Reverse DNS for Email Applications
If you intend to send email to third parties from an instance, we suggest you provision one or
more Elastic IP addresses and provide them to us. AWS works with ISPs and Internet anti-spam
organizations to reduce the chance that your email sent from these addresses will be flagged as spam.
In addition, assigning a static reverse DNS record to your Elastic IP address used to send email can
help avoid having email flagged as spam by some anti-spam organizations. Note that a corresponding
forward DNS record (record type A) pointing to your Elastic IP address must exist before we can create
your reverse DNS record.
If a reverse DNS record is associated with an Elastic IP address, the Elastic IP address is locked to
your account and cannot be released from your account until the record is removed.
To remove email sending limits, or to provide us with your Elastic IP addresses and reverse DNS
records, go to the Request to Remove Email Sending Limitations page.

Elastic IP Address Limit
By default, all AWS accounts are limited to 5 Elastic IP addresses per region, because public (IPv4)
Internet addresses are a scarce public resource. We strongly encourage you to use an Elastic IP

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address primarily for the ability to remap the address to another instance in the case of instance failure,
and to use DNS hostnames for all other inter-node communication.
If you feel your architecture warrants additional Elastic IP addresses, please complete the Amazon
EC2 Elastic IP Address Request Form. We will ask you to describe your use case so that we can
understand your need for additional addresses.

Elastic Network Interfaces (ENI)
An elastic network interface (ENI) is a virtual network interface that you can attach to an instance in a
VPC. ENIs are available only for instances running in a VPC.
An ENI can include the following attributes:
• A primary private IP address.
• One or more secondary private IP addresses.
• One Elastic IP address per private IP address.
• One public IP address, which can be auto-assigned to the elastic network interface for eth0
when you launch an instance. For more information, see Public IP Addresses for Network
Interfaces (p. 591).
• One or more security groups.
• A MAC address.
• A source/destination check flag.
• A description.
You can create an elastic network interface, attach it to an instance, detach it from an instance, and
attach it to another instance. The attributes of an elastic network interface follow it as it's attached or
detached from an instance and reattached to another instance. When you move an elastic network
interface from one instance to another, network traffic is redirected to the new instance.
Each instance in a VPC has a default elastic network interface (the primary network interface,
eth0) that is assigned a private IP address from the IP address range of your VPC. You cannot
detach a primary network interface from an instance. You can create and attach additional elastic
network interfaces. The maximum number of elastic network interfaces that you can use varies by
instance type. For more information, see Private IP Addresses Per Network Interface Per Instance
Type (p. 589).
Attaching multiple elastic network interfaces to an instance is useful when you want to:
• Create a management network.
• Use network and security appliances in your VPC.
• Create dual-homed instances with workloads/roles on distinct subnets.
• Create a low-budget, high-availability solution.
Contents
•
•
•
•
•

Private IP Addresses Per Network Interface Per Instance Type (p. 589)
Public IP Addresses for Network Interfaces (p. 591)
Creating a Management Network (p. 591)
Use Network and Security Appliances in Your VPC (p. 592)
Creating Dual-homed Instances with Workloads/Roles on Distinct Subnets (p. 592)

• Create a Low Budget High Availability Solution (p. 592)
• Monitoring IP Traffic on Your Network Interface (p. 593)

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Interface Per Instance Type
• Best Practices for Configuring Elastic Network Interfaces (p. 593)

• Configuring Your Network Interface Using ec2-net-utils (p. 593)
• Creating an Elastic Network Interface (p. 594)
• Deleting an Elastic Network Interface (p. 595)
• Viewing Details about an Elastic Network Interface (p. 595)
• Attaching an Elastic Network Interface When Launching an Instance (p. 596)
• Attaching an Elastic Network Interface to a Stopped or Running Instance (p. 597)
• Detaching an Elastic Network Interface from an Instance (p. 598)
• Changing the Security Group of an Elastic Network Interface (p. 598)
• Changing the Source/Destination Checking of an Elastic Network Interface (p. 599)
• Associating an Elastic IP Address with an Elastic Network Interface (p. 599)
• Disassociating an Elastic IP Address from an Elastic Network Interface (p. 600)
• Changing Termination Behavior for an Elastic Network Interface (p. 600)
• Adding or Editing a Description for an Elastic Network Interface (p. 601)
• Adding or Editing Tags for an Elastic Network Interface (p. 601)

Private IP Addresses Per Network Interface Per
Instance Type
The following table lists the maximum number of elastic network interfaces (ENI) per instance type,
and the maximum number of private IP addresses per ENI. ENIs and multiple private IP addresses
are only available for instances running in a VPC. For more information, see Multiple Private IP
Addresses (p. 576).
Instance Type

Maximum Elastic Network
Interfaces

IP Addresses per Interface

c1.medium

c1.xlarge

c3.large

c3.xlarge

c3.2xlarge

c3.4xlarge

c3.8xlarge

c4.large

c4.xlarge

c4.2xlarge

c4.4xlarge

c4.8xlarge

cc2.8xlarge

cg1.4xlarge

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Interface Per Instance Type

Instance Type

Maximum Elastic Network
Interfaces

IP Addresses per Interface

cr1.8xlarge

d2.xlarge

d2.2xlarge

d2.4xlarge

d2.8xlarge

g2.2xlarge

g2.8xlarge

hi1.4xlarge

hs1.8xlarge

i2.xlarge

i2.2xlarge

i2.4xlarge

i2.8xlarge

m1.small

m1.medium

m1.large

m1.xlarge

m2.xlarge

m2.2xlarge

m2.4xlarge

m3.medium

m3.large

m3.xlarge

m3.2xlarge

m4.large

m4.xlarge

m4.2xlarge

m4.4xlarge

m4.10xlarge

r3.large

r3.xlarge

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Instance Type

Maximum Elastic Network
Interfaces

IP Addresses per Interface

r3.2xlarge

r3.4xlarge

r3.8xlarge

t1.micro

t2.nano

t2.micro

t2.small

t2.medium

t2.large

x1.32xlarge

Public IP Addresses for Network Interfaces
In a VPC, all subnets have a modifiable attribute that determines whether instances launched into that
subnet are assigned a public IP address. For more information, see IP Addressing Behavior for Your
Subnet in the Amazon VPC User Guide. The public IP address is assigned from Amazon's pool of
public IP addresses, and is assigned to the network interface with the device index of eth0 (the primary
network interface).
When you create a network interface, it inherits the public IP addressing attribute from the subnet. If
you subsequently modify the public IP addressing attribute of the subnet, the network interface keeps
the setting that was in effect when it was created. If you launch an instance and specify an existing
network interface for eth0, the public IP addressing attribute is determined by the network interface.
For more information, see Public IP Addresses and External DNS Hostnames (p. 572).

Creating a Management Network
You can create a management network using elastic network interfaces. In this scenario, the
secondary elastic network interface on the instance handles public-facing traffic and the primary elastic
network interface handles back-end management traffic and is connected to a separate subnet in
your VPC that has more restrictive access controls. The public facing interface, which may or may
not be behind a load balancer, has an associated security group that allows access to the server from
the Internet (for example, allow TCP port 80 and 443 from 0.0.0.0/0, or from the load balancer)
while the private facing interface has an associated security group allowing SSH access only from an
allowed range of IP addresses either within the VPC or from the Internet, a private subnet within the
VPC or a virtual private gateway.
To ensure failover capabilities, consider using a secondary private IP for incoming traffic on an elastic
network interface. In the event of an instance failure, you can move the interface and/or secondary
private IP address to a standby instance.

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Use Network and Security Appliances in Your
VPC
Some network and security appliances, such as load balancers, network address translation (NAT)
servers, and proxy servers prefer to be configured with multiple elastic network interfaces. You can
create and attach secondary elastic network interfaces to instances in a VPC that are running these
types of applications and configure the additional interfaces with their own public and private IP
addresses, security groups, and source/destination checking.

Creating Dual-homed Instances with Workloads/
Roles on Distinct Subnets
You can place an elastic network interface on each of your web servers that connects to a mid-tier
network where an application server resides. The application server can also be dual-homed to a backend network (subnet) where the database server resides. Instead of routing network packets through
the dual-homed instances, each dual-homed instance receives and processes requests on the front
end, initiates a connection to the back end, and then sends requests to the servers on the back-end
network.

Create a Low Budget High Availability Solution
If one of your instances serving a particular function fails, its elastic network interface can be attached
to a replacement or hot standby instance pre-configured for the same role in order to rapidly recover
the service. For example, you can use an ENI as your primary or secondary network interface to a
critical service such as a database instance or a NAT instance. If the instance fails, you (or more likely,
the code running on your behalf) can attach the ENI to a hot standby instance. Because the interface
maintains its private IP addresses, Elastic IP addresses, and MAC address, network traffic will begin
flowing to the standby instance as soon as you attach the ENI to the replacement instance. Users will
experience a brief loss of connectivity between the time the instance fails and the time that the ENI
is attached to the standby instance, but no changes to the VPC route table or your DNS server are
required.

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Monitoring IP Traffic on Your Network Interface
You can enable a VPC flow log on your elastic network interface to capture information about the IP
traffic going to and from the interface. After you've created a flow log, you can view and retrieve its data
in Amazon CloudWatch Logs.
For more information, see VPC Flow Logs in the Amazon VPC User Guide.

Best Practices for Configuring Elastic Network
Interfaces
• You can attach an elastic network interface to an instance when it's running (hot attach), when it's
stopped (warm attach), or when the instance is being launched (cold attach).
• You can detach secondary (ethN) elastic network interfaces when the instance is running or stopped.
However, you can't detach the primary (eth0) interface.
• You can attach an elastic network interface in one subnet to an instance in another subnet in the
same VPC; however, both the elastic network interface and the instance must reside in the same
Availability Zone.
• When launching an instance from the CLI or API, you can specify the elastic network interfaces to
attach to the instance for both the primary (eth0) and additional elastic network interfaces.
• Launching an Amazon Linux or Windows Server instance with multiple network interfaces
automatically configures interfaces, private IP addresses, and route tables on the operating system
of the instance.
• A warm or hot attach of an additional elastic network interface may require you to manually bring
up the second interface, configure the private IP address, and modify the route table accordingly.
Instances running Amazon Linux or Windows Server automatically recognize the warm or hot attach
and configure themselves.
• Attaching another elastic network interface to an instance is not a method to increase or double the
network bandwidth to or from the dual-homed instance.
• If you attach two or more network interfaces from the same subnet to an instance, you may
encounter networking issues such as asymmetric routing. If possible, use a secondary private IP
address on the primary network interface instead. For more information, see Assigning a Secondary
Private IP Address (p. 577).

Configuring Your Network Interface Using ec2net-utils
Amazon Linux AMIs may contain additional scripts installed by AWS, known as ec2-net-utils. These
scripts optionally automate the configuration of your elastic network interfaces (ENIs). These scripts
are available for Amazon Linux only.
Use the following command to install the package on Amazon Linux if it's not already installed, or
update it if it's installed and additional updates are available:
$ yum install ec2-net-utils

The following components are part of ec2-net-utils:
udev rules (/etc/udev/rules.d)
Identifies network interfaces when they are attached, detached, or reattached to a running
instance, and ensures that the hotplug script runs (53-ec2-network-interfaces.rules).

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Maps the MAC address to a device name (75-persistent-net-generator.rules, which
generates 70-persistent-net.rules).
hotplug script
Generates an interface configuration file suitable for use with DHCP (/etc/sysconfig/
network-scripts/ifcfg-ethN). Also generates a route configuration file (/etc/sysconfig/
network-scripts/route-ethN).
DHCP script
Whenever the elastic network interface receives a new DHCP lease, this script queries the
instance metadata for Elastic IP addresses. For each Elastic IP address, it adds a rule to the
routing policy database to ensure that outbound traffic from that address uses the correct network
interface. It also adds each private IP address to the elastic network interface as a secondary
address.
ec2ifup ethN
Extends the functionality of the standard ifup. After this script rewrites the configuration files
ifcfg-ethN and route-ethN, it runs ifup.
ec2ifdown ethN
Extends the functionality of the standard ifdown. After this script removes any rules for the elastic
network interface from the routing policy database, it runs ifdown.
ec2ifscan
Checks for network interfaces that have not been configured and configures them.
Note that this script isn't available in the initial release of ec2-net-utils.
To list any configuration files that were generated by ec2-net-utils, use the following command:
$ ls -l /etc/sysconfig/network-scripts/*-eth?

To disable the automation on a per-instance basis, you can add EC2SYNC=no to the corresponding
ifcfg-ethN file. For example, use the following command to disable the automation for the eth1
interface:
$ sed -i -e 's/^EC2SYNC=yes/EC2SYNC=no/' /etc/sysconfig/network-scripts/
ifcfg-eth1

If you want to disable the automation completely, you can remove the package using the following
command:
$ yum remove ec2-net-utils

Creating an Elastic Network Interface
You can create an elastic network interface using the Amazon EC2 console or the command line.

To create an elastic network interface using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Network Interfaces.

Choose Create Network Interface.

In the Create Network Interface dialog box, provide the following information for the elastic
network interface and choose Yes, Create.

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For Description, enter a descriptive name.

For Subnet, select the subnet. Note that you can't move the elastic network interface to
another subnet after it's created, and you can only attach the interface to instances in the
same Availability Zone.

For Private IP, enter the primary private IP address. If you don't specify an IP address, we'll
select an available private IP address from within the selected subnet.

For Security groups, select one or more security groups.

To create an elastic network interface using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• create-network-interface (AWS CLI)
• New-EC2NetworkInterface (AWS Tools for Windows PowerShell)

Deleting an Elastic Network Interface
You must first detach an elastic network interface from an instance before you can delete it. Deleting
an elastic network interface releases all attributes associated with the interface and releases any
private IP addresses or Elastic IP addresses to be used by another instance.
You can delete an elastic network interface using the Amazon EC2 console or the command line.

To delete an elastic network interface using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Network Interfaces.

Select an elastic network interface and choose Delete.

In the Delete Network Interface dialog box, choose Yes, Delete.

To delete an elastic network interface using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• delete-network-interface (AWS CLI)
• Remove-EC2NetworkInterface (AWS Tools for Windows PowerShell)

Viewing Details about an Elastic Network
Interface
You can describe an elastic network interface using the Amazon EC2 console or the command line.

To describe an elastic network interface using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Network Interfaces.

Select the elastic network interface.

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When Launching an Instance
View the details on the Details tab.

To describe an elastic network interface using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• describe-network-interfaces (AWS CLI)
• Get-EC2NetworkInterface (AWS Tools for Windows PowerShell)

To describe an elastic network interface attribute using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• describe-network-interface-attribute (AWS CLI)
• Get-EC2NetworkInterfaceAttribute (AWS Tools for Windows PowerShell)

Attaching an Elastic Network Interface When
Launching an Instance
You can specify an existing network interface or attach an additional network interface when you
launch an instance. You can do this using the Amazon EC2 console or the command line.

Note
If an error occurs when attaching an elastic network interface to your instance, this causes the
instance launch to fail.

To attach an elastic network interface when launching an instance using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

Choose Launch Instance.

Select an AMI and instance type and choose Next: Configure Instance Details.

On the Configure Instance Details page, select a VPC for Network, and a subnet for Subnet.

In the Network Interfaces section, the console enables you specify up to 2 elastic network
interfaces (new, existing, or a combination) when you launch an instance. You can also enter a
primary IP address and one or more secondary IP addresses for any new interface. When you've
finished, choose Next: Add Storage.
You can add additional network interfaces to the instance after you launch it. The total number of
network interfaces that you can attach varies by instance type. For more information, see Private
IP Addresses Per Network Interface Per Instance Type (p. 589).

Note
You cannot auto-assign a public IP address to your instance if you specify more than one
network interface.
6.

On the Add Storage page, you can specify volumes to attach to the instance besides the volumes
specified by the AMI (such as the root device volume), and then choose Next: Tag Instance.

On the Tag Instance page, specify tags for the instance, such as a user-friendly name, and then
choose Next: Configure Security Group.

On the Configure Security Group page, you can select a security group or create a new one.
Choose Review and Launch.

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to a Stopped or Running Instance

Note
If you specified an existing network interface in step 5, the instance is associated with the
security group for that network interface, regardless of any option you select in this step.
9.

On the Review Instance Launch page, details about the primary and additional network interface
are displayed. Review the settings, and then choose Launch to choose a key pair and launch your
instance. If you're new to Amazon EC2 and haven't created any key pairs, the wizard prompts you
to create one.

To attach an elastic network interface when launching an instance using the command
line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• run-instances (AWS CLI)
• New-EC2Instance (AWS Tools for Windows PowerShell)

Attaching an Elastic Network Interface to a
Stopped or Running Instance
You can attach an elastic network interface to any of your stopped or running instances in your VPC
using either the Instances or Network Interfaces page of the Amazon EC2 console, or using a
command line interface.

Note
If the public IP address on your instance is released, it will not receive a new one if there
is more than one elastic network interface attached to the instance. For more information
about the behavior of public IP addresses, see Public IP Addresses and External DNS
Hostnames (p. 572).

To attach an elastic network interface to an instance using the Instances page
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances.

Choose Actions, Networking, Attach Network Interface.

In the Attach Network Interface dialog box, select the elastic network interface and choose
Attach.

To attach an elastic network interface to an instance using the Network Interfaces page
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Network Interfaces.

Select the elastic network interface and choose Attach.

In the Attach Network Interface dialog box, select the instance and choose Attach.

To attach an elastic network interface to an instance using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• attach-network-interface (AWS CLI)
• Add-EC2NetworkInterface (AWS Tools for Windows PowerShell)

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Interface from an Instance

Detaching an Elastic Network Interface from an
Instance
You can detach a secondary elastic network interface at any time, using either the Instances or
Network Interfaces page of the Amazon EC2 console, or using a command line interface.

To detach an elastic network interface from an instance using the Instances page
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances.

Choose Actions, Networking, Detach Network Interface.

In the Detach Network Interface dialog box, select the elastic network interface and choose
Detach.

To detach an elastic network interface from an instance using the Network Interfaces
page
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Network Interfaces.

Select the elastic network interface and choose Detach.

In the Detach Network Interface dialog box, choose Yes, Detach. If the elastic network interface
fails to detach from the instance, choose Force detachment, and then try again.

To detach an elastic network interface using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• detach-network-interface (AWS CLI)
• Dismount-EC2NetworkInterface (AWS Tools for Windows PowerShell)

Changing the Security Group of an Elastic
Network Interface
You can change the security groups that are associated with an elastic network interface. When you
create the security group, be sure to specify the same VPC as the subnet for the interface.
You can change the security group for your elastic network interfaces using the Amazon EC2 console
or the command line.

Note
To change security group membership for interfaces owned by other services, such as Elastic
Load Balancing, use the console or command line interface for that service.

To change the security group of an elastic network interface using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Network Interfaces.

Select the elastic network interface and choose Actions, Change Security Groups.

In the Change Security Groups dialog box, select the security groups to use, and choose Save.

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Changing the Source/Destination
Checking of an Elastic Network Interface

To change the security group of an elastic network interface using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• modify-network-interface-attribute (AWS CLI)
• Edit-EC2NetworkInterfaceAttribute (AWS Tools for Windows PowerShell)

Changing the Source/Destination Checking of an
Elastic Network Interface
The Source/Destination Check attribute controls whether source/destination checking is enabled
on the instance. Disabling this attribute enables an instance to handle network traffic that isn't
specifically destined for the instance. For example, instances running services such as network
address translation, routing, or a firewall should set this value to disabled. The default value is
enabled.
You can change source/destination checking using the Amazon EC2 console or the command line.

To change source/destination checking for an elastic network interface using the
console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Network Interfaces.

Select the elastic network interface and choose Actions, Change Source/Dest Check.

In the dialog box, choose Enabled (if enabling) or Disabled (if disabling), and Save.

To change source/destination checking for an elastic network interface using the
command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• modify-network-interface-attribute (AWS CLI)
• Edit-EC2NetworkInterfaceAttribute (AWS Tools for Windows PowerShell)

Associating an Elastic IP Address with an
Elastic Network Interface
If you have an Elastic IP address, you can associate it with one of the private IP addresses for the
elastic network interface. You can associate one Elastic IP address with each private IP address.
You can associate an Elastic IP address using the Amazon EC2 console or the command line.

To associate an Elastic IP address using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Network Interfaces.

Select the elastic network interface and choose Actions, Associate Address.

In the Associate Elastic IP Address dialog box, select the Elastic IP address from the Address
list.

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Disassociating an Elastic IP Address
from an Elastic Network Interface
For Associate to private IP address, select the private IP address to associate with the Elastic IP
address.

Choose Allow reassociation to allow the Elastic IP address to be associated with the specified
network interface if it's currently associated with another instance or network interface, and then
choose Associate Address.

Disassociating an Elastic IP Address from an
Elastic Network Interface
If the elastic network interface has an Elastic IP address associated with it, you can disassociate the
address, and then either associate it with another elastic network interface or release it back to the
address pool. Note that this is the only way to associate an Elastic IP address with an instance in a
different subnet or VPC using an elastic network interface, as elastic network interfaces are specific to
a particular subnet.
You can disassociate an Elastic IP address using the Amazon EC2 console or the command line.

To disassociate an Elastic IP address using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Network Interfaces.

Select the elastic network interface and choose Actions, Disassociate Address.

In the Disassociate IP Address dialog box, choose Yes, Disassociate.

Changing Termination Behavior for an Elastic
Network Interface
You can set the termination behavior for an elastic network interface attached to an instance so that it
is automatically deleted when you delete the instance to which it's attached.

Note
By default, elastic network interfaces that are automatically created and attached to instances
using the console are set to terminate when the instance terminates. However, network
interfaces created using the command line interface aren't set to terminate when the instance
terminates.

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Adding or Editing a Description
for an Elastic Network Interface
You can change the terminating behavior for an elastic network interface using the Amazon EC2
console or the command line.

To change the termination behavior for an elastic network interface using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Network Interfaces.

Select the elastic network interface and choose Actions, Change Termination Behavior.

In the Change Termination Behavior dialog box, select the Delete on termination check box if
you want the elastic network interface to be deleted when you terminate an instance.

To change the termination behavior for an elastic network interface using the command
line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• modify-network-interface-attribute (AWS CLI)
• Edit-EC2NetworkInterfaceAttribute (AWS Tools for Windows PowerShell)

Adding or Editing a Description for an Elastic
Network Interface
You can change the description for an elastic network interface using the Amazon EC2 console or the
command line.

To change the description for an elastic network interface using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Network Interfaces.

Select the elastic network interface and choose Actions, Change Description.

In the Change Description dialog box, enter a description for the elastic network interface, and
then choose Save.

To change the description for an elastic network interface using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• modify-network-interface-attribute (AWS CLI)
• Edit-EC2NetworkInterfaceAttribute (AWS Tools for Windows PowerShell)

Adding or Editing Tags for an Elastic Network
Interface
Tags are metadata that you can add to an elastic network interface. Tags are private and are only
visible to your account. Each tag consists of a key and an optional value. For more information about
tags, see Tagging Your Amazon EC2 Resources (p. 751).
You can tag a resource using the Amazon EC2 console or the command line.

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To add or edit tags for an elastic network interface using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Network Interfaces.

Select the elastic network interface.

In the details pane, choose Tags, Add/Edit Tags.

In the Add/Edit Tags dialog box, choose Create Tag for each tag to create, and enter a key and
optional value. When you're done, choose Save.

To add or edit tags for an elastic network interface using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• create-tags (AWS CLI)
• New-EC2Tag (AWS Tools for Windows PowerShell)

Placement Groups
A placement group is a logical grouping of instances within a single Availability Zone. Placement
groups are recommended for applications that benefit from low network latency, high network
throughput, or both. To provide the lowest latency, and the highest packet-per-second network
performance for your placement group, choose an instance type that supports enhanced networking.
For more information, see Enhanced Networking (p. 608).
First, you create a placement group and then you launch multiple instances into the placement group.
We recommend that you launch the number of instances that you need in the placement group in a
single launch request and that you use the same instance type for all instances in the placement group.
If you try to add more instances to the placement group later, or if you try to launch more than one
instance type in the placement group, you increase your chances of getting an insufficient capacity
error.
If you stop an instance in a placement group and then start it again, it still runs in the placement group.
However, the start fails if there isn't enough capacity for the instance.
If you receive a capacity error when launching an instance in a placement group, stop and restart the
instances in the placement group, and then try the launch again.
Contents
• Placement Group Limitations (p. 602)
• Launching Instances into a Placement Group (p. 603)
• Deleting a Placement Group (p. 604)

Placement Group Limitations
Placement groups have the following limitations:
• A placement group can't span multiple Availability Zones.
• The name you specify for a placement group must be unique within your AWS account.
• The following are the only instance types that you can use when you launch an instance into a
placement group:

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• General purpose: m4.large | m4.xlarge | m4.2xlarge | m4.4xlarge | m4.10xlarge
• Compute optimized: c4.large | c4.xlarge | c4.2xlarge | c4.4xlarge | c4.8xlarge |
c3.large | c3.xlarge | c3.2xlarge | c3.4xlarge | c3.8xlarge | cc2.8xlarge
• Memory optimized: cr1.8xlarge | r3.large | r3.xlarge | r3.2xlarge | r3.4xlarge |
r3.8xlarge | x1.32xlarge
• Storage optimized: d2.xlarge | d2.2xlarge | d2.4xlarge | d2.8xlarge | hi1.4xlarge |
hs1.8xlarge | i2.xlarge | i2.2xlarge | i2.4xlarge | i2.8xlarge
• GPU: cg1.4xlarge | g2.2xlarge | g2.8xlarge
• The maximum network throughput speed of traffic between two instances in a placement group
is limited by the slower of the two instances. For applications with high-throughput requirements,
choose an instance type with 10 Gbps or 20 Gbps network connectivity. For more information about
instance type network performance, see the Amazon EC2 Instance Types Matrix.
• Although launching multiple instance types into a placement group is possible, this reduces the
likelihood that the required capacity will be available for your launch to succeed. We recommend
using the same instance type for all instances in a placement group.
• You can't merge placement groups. Instead, you must terminate the instances in one placement
group, and then relaunch those instances into the other placement group.
• A placement group can span peered VPCs; however, you will not get full-bisection bandwidth
between instances in peered VPCs. For more information about VPC peering connections, see VPC
Peering in the Amazon VPC User Guide.
• You can't move an existing instance into a placement group. You can create an AMI from your
existing instance, and then launch a new instance from the AMI into a placement group.
• Reserved Instances provide a capacity reservation for EC2 instances in an Availability Zone. The
capacity reservation can be used by instances in a placement group that are assigned to the same
Availability Zone. However, it is not possible to explicitly reserve capacity for a placement group.
• To ensure that network traffic remains within the placement group, members of the placement group
must address each other via their private IP addresses. If members address each other using their
public IP addresses, throughput drops to 5 Gbps or less.
• Network traffic to and from resources outside the placement group is limited to 5 Gbps.

Launching Instances into a Placement Group
We suggest that you create an AMI specifically for the instances that you'll launch into a placement
group.

To launch instances into a placement group using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

Create an AMI for your instances.
a.

From the Amazon EC2 dashboard, choose Launch Instance. After you complete the wizard,
choose Launch.

Connect to your instance. (For more information, see Connect to Your Linux
Instance (p. 289).)

Install software and applications on the instance, copy data, or attach additional Amazon EBS
volumes.

(Optional) If your instance type supports enhanced networking, ensure that this feature is
enabled by following the procedures in Enhanced Networking on Linux (p. 608).

In the navigation pane, choose Instances, select your instance, choose Actions, Image,
Create Image. Provide the information requested by the Create Image dialog box, and then
choose Create Image.

(Optional) You can terminate this instance if you have no further use for it.

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Create a placement group.
a.
b.
c.

In the navigation pane, choose Placement Groups.
Choose Create Placement Group.
In the Create Placement Group dialog box, provide a name for the placement group that is
unique in the AWS account you're using, and then choose Create.
When the status of the placement group is available, you can launch instances into the
placement group.

Launch instances into your placement group.
a.
b.

In the navigation pane, choose Instances.
Choose Launch Instance. Complete the wizard as directed, taking care to do the following:
• On the Choose an Amazon Machine Image (AMI) page, select the My AMIs tab, and then
select the AMI that you created.
• On the Choose an Instance Type page, select an instance type that can be launched into
a placement group.
• On the Configure Instance Details page, enter the total number of instances that you'll
need in this placement group, as you might not be able to add instances to the placement
group later on.
• On the Configure Instance Details page, select the placement group that you created
from Placement group. If you do not see the Placement group list on this page, verify that
you have selected an instance type that can be launched into a placement group, as this
option is not available otherwise.

To launch instances into a placement group using the command line
1.

Create an AMI for your instances using one of the following commands:
• create-image (AWS CLI)

• New-EC2Image (AWS Tools for Windows PowerShell)
Create a placement group using one of the following commands:
• create-placement-group (AWS CLI)

• New-EC2PlacementGroup (AWS Tools for Windows PowerShell)
Launch instances into your placement group using one of the following options:
• --placement with run-instances (AWS CLI)
• -PlacementGroup with New-EC2Instance (AWS Tools for Windows PowerShell)

Deleting a Placement Group
You can delete a placement group if you need to replace it or no longer need a placement group.
Before you can delete your placement group, you must terminate all instances that you launched into
the placement group.

To delete a placement group using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.

In the navigation pane, choose Instances.
Select and terminate all instances in the placement group. (You can verify that the instance is in a
placement group before you terminate it by checking the value of Placement Group in the details
pane.)

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Network MTU

In the navigation pane, choose Placement Groups.

Select the placement group, and then choose Delete Placement Group.

When prompted for confirmation, choose Yes, Delete.

To delete a placement group using the command line
You can use one of the following sets of commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• terminate-instances and delete-placement-group (AWS CLI)
• Stop-EC2Instance and Remove-EC2PlacementGroup(AWS Tools for Windows PowerShell)

Network Maximum Transmission Unit (MTU)
for Your EC2 Instance
The maximum transmission unit (MTU) of a network connection is the size, in bytes, of the largest
permissible packet that can be passed over the connection. The larger the MTU of a connection, the
more data that can be passed in a single packet. Ethernet packets consist of the frame, or the actual
data you are sending, and the network overhead information that surrounds it.
Ethernet frames can come in different formats, and the most common format is the standard Ethernet
v2 frame format. It supports 1500 MTU, which is the largest Ethernet packet size supported over most
of the Internet. The maximum supported MTU for an instance depends on its instance type. All Amazon
EC2 instance types support 1500 MTU, and many current instance sizes support 9001 MTU, or jumbo
frames.
Contents
• Jumbo Frames (9001 MTU) (p. 605)
• Path MTU Discovery (p. 606)
• Check the Path MTU Between Two Hosts (p. 606)
• Check and Set the MTU on your Amazon EC2 Instance (p. 607)
• Troubleshooting (p. 608)

Jumbo Frames (9001 MTU)
Jumbo frames allow more than 1500 bytes of data by increasing the payload size per packet, and
thus increasing the percentage of the packet that is not packet overhead. Fewer packets are needed
to send the same amount of usable data. However, outside of a given AWS region (EC2-Classic), a
single VPC, or a VPC peering connection, you will experience a maximum path of 1500 MTU. VPN
connections and traffic sent over an Internet gateway are limited to 1500 MTU. If packets are over
1500 bytes, they are fragmented, or they are dropped if the Don't Fragment flag is set in the IP
header.
Jumbo frames should be used with caution for Internet-bound traffic or any traffic that leaves a VPC.
Packets are fragmented by intermediate systems, which slows down this traffic. To use jumbo frames
inside a VPC and not slow traffic that's bound for outside the VPC, you can configure the MTU size by
route, or use multiple elastic network interfaces with different MTU sizes and different routes.
For instances that are collocated inside a placement group, jumbo frames help to achieve the
maximum network throughput possible, and they are recommended in this case. For more information,
see Placement Groups (p. 602).

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The following instances support jumbo frames:
• Compute optimized: C3, C4, CC2
• General purpose: M3, M4, T2
• GPU: CG1, G2
• Memory optimized: CR1, R3
• Storage optimized: D2, HI1, HS1, I2

Path MTU Discovery
Path MTU Discovery is used to determine the path MTU between two devices. The path MTU is the
maximum packet size that's supported on the path between the originating host and the receiving
host. If a host sends a packet that's larger than the MTU of the receiving host or that's larger than the
MTU of a device along the path, the receiving host or device returns the following ICMP message:
Destination Unreachable: Fragmentation Needed and Don't Fragment was Set (Type
3, Code 4). This instructs the original host to adjust the MTU until the packet can be transmitted.
By default, security groups do not allow any inbound ICMP traffic. To ensure that your instance can
receive this message and the packet does not get dropped, you must add a Custom ICMP Rule
with the Destination Unreachable protocol to the inbound security group rules for your instance.
For more information, see the Adding Rules to a Security Group (p. 495) and API and Command
Overview (p. 497) sections in the Amazon EC2 Security Groups topic.

Important
Modifying your instance's security group to allow path MTU discovery does not guarantee
that jumbo frames will not be dropped by some routers. An Internet gateway in your VPC will
forward packets up to 1500 bytes only. 1500 MTU packets are recommended for Internet
traffic.

Check the Path MTU Between Two Hosts
You can check the path MTU between two hosts using the tracepath command, which is part of the
iputils package that is available by default on many Linux distributions, including Amazon Linux.

To check path MTU with tracepath
•

Use the following command to check the path MTU between your Amazon EC2 instance and
another host. You can use a DNS name or an IP address as the destination; this example checks
the path MTU between an EC2 instance and amazon.com.
[ec2-user ~]$ tracepath amazon.com
1?: [LOCALHOST]
pmtu 9001
1: ip-172-31-16-1.us-west-1.compute.internal (172.31.16.1)
0.187ms
pmtu 1500
1: no reply
2: no reply
3: no reply
4: 100.64.16.241 (100.64.16.241)
0.574ms
5: 72.21.222.221 (72.21.222.221)
84.447ms asymm
21
6: 205.251.229.97 (205.251.229.97)
79.970ms asymm
19
7: 72.21.222.194 (72.21.222.194)
96.546ms asymm
16
8: 72.21.222.239 (72.21.222.239)
79.244ms asymm
15

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Check and Set the MTU on your Amazon EC2 Instance
9:
16
...
31:

205.251.225.73 (205.251.225.73)

91.867ms asymm

no reply
Too many hops: pmtu 1500
Resume: pmtu 1500

In this example, the path MTU is 1500.

Check and Set the MTU on your Amazon EC2
Instance
Some AMIs are configured to use jumbo frames on instance that support them, and others are
configured to use standard frame sizes. You may want to use jumbo frames for network traffic within
your VPC or you may want to use standard frames for Internet traffic. Whatever your use case,
we recommend verifying that your instance will behave the way you expect it to. You can use the
procedures in this section to check your network interface's MTU setting and modify it if needed.

To check the MTU setting on a Linux instance
•

If your instance uses a Linux operating system, you can review the MTU value with the ip
command. Run the following command to determine the current MTU value:
[ec2-user ~]$ ip link show eth0
2: eth0: mtu 9001 qdisc pfifo_fast state
UP mode DEFAULT group default qlen 1000
link/ether 02:90:c0:b7:9e:d1 brd ff:ff:ff:ff:ff:ff

In the above example, the mtu 9001 in the output indicates that this instance uses jumbo frames.

To set the MTU value on a Linux instance
1.

If your instance uses a Linux operating system, you can set the MTU value with the ip command.
Run the following command to set the desired MTU value. This procedure sets the MTU to 1500,
but it is the same for 9001.
[ec2-user ~]$ sudo ip link set dev eth0 mtu 1500

(Optional) To persist your network MTU setting after a reboot, modify the following configuration
files, based on your operating system type. This procedure covers Amazon Linux and Ubuntu; for
other distributions, consult their specific documentation.
•

For Amazon Linux, add the following lines to your /etc/dhcp/dhclient-eth0.conf file.
interface "eth0" {
supersede interface-mtu 1500;
}

•

For Ubuntu, add the following line to /etc/network/interfaces.d/eth0.cfg.
post-up /sbin/ifconfig eth0 mtu 1500

(Optional) Reboot your instance and verify that the MTU setting is correct.
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Troubleshooting
If you experience connectivity issues between your EC2 instance and an Amazon Redshift cluster
when using jumbo frames, see Queries Appear to Hang in the Amazon Redshift Cluster Management
Guide

Enhanced Networking on Linux
Enhanced networking uses single root I/O virtualization (SR-IOV) to provide high-performance
networking capabilities on supported instance types (p. 608). SR-IOV is a method of device
virtualization that provides higher I/O performance and lower CPU utilization when compared to
traditional virtualized network interfaces. Enhanced networking provides higher bandwidth, higher
packet per second (PPS) performance, and consistently lower inter-instance latencies. There is no
additional charge for using enhanced networking.
Contents
• Enhanced Networking Types (p. 608)
• Enabling Enhanced Networking on Your Instance (p. 608)
• Enabling Enhanced Networking with the Intel 82599 VF Interface on Linux Instances in a
VPC (p. 609)
• Enabling Enhanced Networking with the Elastic Network Adapter (ENA) on Linux Instances in a
VPC (p. 617)
• Troubleshoooting the Elastic Network Adapter (ENA) (p. 626)

Enhanced Networking Types
Depending on your instance type, enhanced networking can be enabled using one of the following
mechanisms:
Intel 82599 Virtual Function (VF) interface
The Intel 82599 Virtual Function interface supports network speeds of up to 10 Gbps for supported
instance types. For more information, see the Instance Type Matrix.
C3, C4, R3, I2, M4 and D2 instances use the Intel 82599 VF interface for enhanced networking.
Elastic Network Adapter (ENA)
The Elastic Network Adapter (ENA) supports network speeds of up to 20 Gbps.
X1 instances use the Elastic Network Adapter for enhanced networking.

Enabling Enhanced Networking on Your
Instance
If your instance type supports the Intel 82599 VF interface for enhanced networking, follow the
procedures in Enabling Enhanced Networking with the Intel 82599 VF Interface on Linux Instances in a
VPC (p. 609).
If your instance type supports the Elastic Network Adapter for enhanced networking, follow the
procedures in Enabling Enhanced Networking with the Elastic Network Adapter (ENA) on Linux
Instances in a VPC (p. 617).

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Enabling Enhanced Networking with the Intel
82599 VF Interface on Linux Instances in a VPC
Amazon EC2 provides enhanced networking capabilities to C3, C4, R3, I2, M4 and D2 instances with
the Intel 82599 VF interface, which uses the Intel ixgbevf driver.
To prepare for enhanced networking with the Intel 82599 VF interface, set up your instance as follows:
• Launch the instance from an HVM AMI using Linux kernel version of 2.6.32 or later. The latest
Amazon Linux HVM AMIs have the modules required for enhanced networking installed and have
the required attributes set. Therefore, if you launch an Amazon EBS–backed, enhanced networking–
supported instance using a current Amazon Linux HVM AMI, enhanced networking is already
enabled for your instance.
• Launch the instance in a VPC. (You can't enable enhanced networking if the instance is in EC2Classic.)
• Install and configure the AWS CLI on any computer you choose, preferably your local desktop or
laptop. For more information, see Accessing Amazon EC2 (p. 3).Enhanced networking cannot be
manged from the Amazon EC2 console.
• If you have important data on the instance that you want to preserve, you should back that data
up now by creating an AMI from your instance. Updating kernels and kernel modules, as well as
enabling the sriovNetSupport attribute, may render incompatible instances or operating systems
unreachable; if you have a recent backup, your data will still be retained if this happens.
Contents
• Testing Whether Enhanced Networking with the Intel 82599 VF Interface is Enabled (p. 609)
• Enabling Enhanced Networking with the Intel 82599 VF Interface on Amazon Linux (p. 611)
• Enabling Enhanced Networking with the Intel 82599 VF Interface on Ubuntu (p. 613)
• Enabling Enhanced Networking with the Intel 82599 VF Interface on Other Linux
Distributions (p. 615)
• Troubleshooting Connectivity Issues (p. 617)

Testing Whether Enhanced Networking with the Intel
82599 VF Interface is Enabled
To test whether enhanced networking with the Intel 82599 VF interface is already enabled, verify that
the ixgbevf module is installed on your instance and that the sriovNetSupport attribute is set. If
your instance satisfies these two conditions, then the ethtool -i ethn command should show that the
module is in use on the network interface.
Kernel Module (ixgbevf)
To verify that the ixgbevf module is installed and that the version is compatible with enhanced
networking, use the modinfo command as follows:
[ec2-user ~]$ modinfo ixgbevf
filename:
/lib/modules/3.10.48-55.140.amzn1.x86_64/kernel/drivers/
amazon/ixgbevf/ixgbevf.ko
version:
2.14.2
license:
GPL
description:
Intel(R) 82599 Virtual Function Driver
author:
Intel Corporation,

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srcversion:
50CBF6F36B99FE70E56C95A
alias:
pci:v00008086d00001515sv*sd*bc*sc*i*
alias:
pci:v00008086d000010EDsv*sd*bc*sc*i*
depends:
intree:
Y
vermagic:
3.10.48-55.140.amzn1.x86_64 SMP mod_unload modversions
parm:
InterruptThrottleRate:Maximum interrupts per second, per
vector, (956-488281, 0=off, 1=dynamic), default 1 (array of int)

In the above Amazon Linux case, the ixgbevf module is already installed and it is at the minimum
recommended version (2.14.2).
ubuntu:~$ modinfo ixgbevf
filename:
/lib/modules/3.13.0-29-generic/kernel/drivers/net/ethernet/
intel/ixgbevf/ixgbevf.ko
version:
2.11.3-k
license:
GPL
description:
Intel(R) 82599 Virtual Function Driver
author:
Intel Corporation,
srcversion:
0816EA811025C8062A9C269
alias:
pci:v00008086d00001515sv*sd*bc*sc*i*
alias:
pci:v00008086d000010EDsv*sd*bc*sc*i*
depends:
intree:
Y
vermagic:
3.13.0-29-generic SMP mod_unload modversions
signer:
Magrathea: Glacier signing key
sig_key:
66:02:CB:36:F1:31:3B:EA:01:C4:BD:A9:65:67:CF:A7:23:C9:70:D8
sig_hashalgo:
sha512
parm:
debug:Debug level (0=none,...,16=all) (int)

In the above Ubuntu instance, the module is installed, but the version is 2.11.3-k, which does not
have all of the latest bug fixes that the recommended version 2.14.2 does. In this case, the ixgbevf
module would work, but a newer version can still be installed and loaded on the instance for the best
experience.
Instance Attribute (sriovNetSupport)
To check whether an instance has the enhanced networking sriovNetSupport attribute set, use the
following command:
• describe-instance-attribute (AWS CLI)
$ aws ec2 describe-instance-attribute --instance-id instance_id --attribute
sriovNetSupport

If the attribute isn't set, SriovNetSupport is empty; otherwise, it is set as follows:
"SriovNetSupport": {
"Value": "simple"
},

Image Attribute (sriovNetSupport)
To check whether an AMI already has the enhanced networking sriovNetSupport attribute set, use
the following command:

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• describe-image-attribute (AWS CLI)
$ aws ec2 describe-image-attribute --image-id ami_id --attribute
sriovNetSupport

Note
This command only works for images that you own. You receive an AuthFailure error for
images that do not belong to your account.
If the attribute isn't set, SriovNetSupport is empty; otherwise, it is set as follows:
"SriovNetSupport": {
"Value": "simple"
},

Network Interface Driver
Use the following command to verify that the module is being used on a particular interface,
substituting the interface name that you wish to check. If you are using a single interface (default), it will
be eth0.
[ec2-user ~]$ ethtool -i eth0
driver: vif
version:
firmware-version:
bus-info: vif-0
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: no

In the above case, the ixgbevf module is not loaded, because the listed driver is vif.
[ec2-user ~]$ ethtool -i eth0
driver: ixgbevf
version: 2.14.2
firmware-version: N/A
bus-info: 0000:00:03.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: no
supports-register-dump: yes
supports-priv-flags: no

In this case, the ixgbevf module is loaded and at the minimum recommended version. This instance
has enhanced networking properly configured.

Enabling Enhanced Networking with the Intel 82599 VF
Interface on Amazon Linux
The latest Amazon Linux HVM AMIs have the ixgbevf module required for enhanced networking
installed and have the required sriovNetSupport attribute set. Therefore, if you launch a C3, C4,
R3, I2, M4, or D2 instance using a current Amazon Linux HVM AMI, enhanced networking is already

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enabled for your instance. For more information, see Testing Whether Enhanced Networking with the
Intel 82599 VF Interface is Enabled (p. 609).
If you launched your instance using an older Amazon Linux AMI and it does not have enhanced
networking enabled already, use the following procedure to enable enhanced networking.

To enable enhanced networking (EBS-backed instances)
1.

Connect to your instance.

From the instance, run the following command to update your instance with the newest kernel and
kernel modules, including ixgbevf:
[ec2-user ~]$ sudo yum update

From your local computer, reboot your instance using the Amazon EC2 console or the following
command: reboot-instances (AWS CLI).

Connect to your instance again and verify that the ixgbevf module is installed and at the
minimum recommended version using the modinfo ixgbevf command from Testing Whether
Enhanced Networking with the Intel 82599 VF Interface is Enabled (p. 609).

From your local computer, stop the instance using the Amazon EC2 console or the following
command: stop-instances (AWS CLI). If your instance is managed by AWS OpsWorks, you should
stop the instance in the AWS OpsWorks console so that the instance state remains in sync.

Important
If you are using an instance store-backed instance, you can't stop the instance. Instead,
proceed to To enable enhanced networking (instance store-backed instances) (p. 612).
6.

From your local computer, enable the enhanced networking attribute using the following
command.

Warning
There is no way to disable the enhanced networking attribute after you've enabled it.

Warning
Enhanced networking is supported only for HVM instances. Enabling enhanced
networking with a PV instance can make it unreachable. Setting this attribute without the
proper module or module version can also make your instance unreachable.
• modify-instance-attribute (AWS CLI)
$ aws ec2 modify-instance-attribute --instance-id instance_id --sriovnet-support simple

(Optional) Create an AMI from the instance, as described in Creating an Amazon EBS-Backed
Linux AMI (p. 89) . The AMI inherits the enhanced networking attribute from the instance.
Therefore, you can use this AMI to launch another instance with enhanced networking enabled by
default.

From your local computer, start the instance using the Amazon EC2 console or the following
command: start-instances (AWS CLI). If your instance is managed by AWS OpsWorks, you should
start the instance in the AWS OpsWorks console so that the instance state remains in sync.

Connect to your instance and verify that the ixgbevf module is installed and loaded on your
network interface using the ethtool -i ethn command from Testing Whether Enhanced Networking
with the Intel 82599 VF Interface is Enabled (p. 609).

To enable enhanced networking (instance store-backed instances)
If your instance is an instance store–backed instance, follow Step 1 (p. 612) through Step
4 (p. 612) in the previous procedure, and then create a new AMI as described in Creating an

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Instance Store-Backed Linux AMI (p. 92). Be sure to enable the enhanced networking attribute when
you register the AMI.
• register-image (AWS CLI)
$ aws ec2 register-image --sriov-net-support simple ...

Enabling Enhanced Networking with the Intel 82599 VF
Interface on Ubuntu
The following procedure provides the general steps that you'll take when enabling enhanced
networking with the Intel 82599 VF interface on an Ubuntu instance.

To enable enhanced networking on Ubuntu (EBS-backed instances)
1.

Connect to your instance.

Update the package cache and packages.
ubuntu:~$ sudo apt-get update && sudo apt-get upgrade -y

Important
If during the update process, you are prompted to install grub, use /dev/xvda to install
grub onto, and then choose to keep the current version of /boot/grub/menu.lst.
3.

Install the dkms package so that your ixgbevf module is rebuilt every time your kernel is
updated.
ubuntu:~$ sudo apt-get install -y dkms

Download the source for version 2.16.4 of the ixgbevf module on your instance from
Sourceforge at http://sourceforge.net/projects/e1000/files/ixgbevf%20stable/.

Note
Earlier versions of ixgbevf, including the minimum recommended version, 2.14.2, do
not build properly on some versions of Ubuntu. The 2.16.4 version of ixgbevf should be
used for Ubuntu instances.
ubuntu:~$ wget "sourceforge.net/projects/e1000/files/ixgbevf
stable/2.16.4/ixgbevf-2.16.4.tar.gz"

Decompress and unarchive the ixgbevf package.
ubuntu:~$ tar -xzf ixgbevf-2.16.4.tar.gz

Move the ixgbevf package to the /usr/src/ directory so dkms can find it and build it for each
kernel update.
ubuntu:~$ sudo mv ixgbevf-2.16.4 /usr/src/

Create the dkms configuration file with the following values, substituting your version of ixgbevf.
a.

Create the file.
ubuntu:~$ sudo touch /usr/src/ixgbevf-2.16.4/dkms.conf

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Edit the file and add the following values.
ubuntu:~$ sudo vim /usr/src/ixgbevf-2.16.4/dkms.conf
PACKAGE_NAME="ixgbevf"
PACKAGE_VERSION="2.16.4"
CLEAN="cd src/; make clean"
MAKE="cd src/; make BUILD_KERNEL=${kernelver}"
BUILT_MODULE_LOCATION[0]="src/"
BUILT_MODULE_NAME[0]="ixgbevf"
DEST_MODULE_LOCATION[0]="/updates"
DEST_MODULE_NAME[0]="ixgbevf"
AUTOINSTALL="yes"

Add, build, and install the ixgbevf module on your instance with dkms.
a.

Add the module to dkms.
ubuntu:~$ sudo dkms add -m ixgbevf -v 2.16.4

Build the module with dkms.
ubuntu:~$ sudo dkms build -m ixgbevf -v 2.16.4

Install the module with dkms.
ubuntu:~$ sudo dkms install -m ixgbevf -v 2.16.4

Rebuild the initramfs so the correct module is loaded at boot time.
ubuntu:~$ sudo update-initramfs -c -k all

10. Verify that the ixgbevf module is installed and at the minimum recommended version using the
modinfo ixgbevf command from Testing Whether Enhanced Networking with the Intel 82599 VF
Interface is Enabled (p. 609).
ubuntu:~$ modinfo ixgbevf
filename:
/lib/modules/3.13.0-74-generic/updates/dkms/ixgbevf.ko
version:
2.16.4
license:
GPL
description:
Intel(R) 10 Gigabit Virtual Function Network Driver
author:
Intel Corporation,
srcversion:
759A432E3151C8F9F6EA882
alias:
pci:v00008086d00001515sv*sd*bc*sc*i*
alias:
pci:v00008086d000010EDsv*sd*bc*sc*i*
depends:
vermagic:
3.13.0-74-generic SMP mod_unload modversions
parm:
InterruptThrottleRate:Maximum interrupts per second, per
vector, (956-488281, 0=off, 1=dynamic), default 1 (array of int)

11. From your local computer, stop the instance using the Amazon EC2 console or the following
command: stop-instances (AWS CLI). If your instance is managed by AWS OpsWorks, you should
stop the instance in the AWS OpsWorks console so that the instance state remains in sync.

Important
If you are using an instance store-backed instance, you can't stop the instance.
Instead, proceed to To enable enhanced networking on Ubuntu (instance store-backed
instances) (p. 615).
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12. From your local computer, enable the enhanced networking sriovNetSupport attribute using the
following command. Note that there is no way to disable this attribute after you've enabled it.

13. (Optional) Create an AMI from the instance, as described in Creating an Amazon EBS-Backed
Linux AMI (p. 89) . The AMI inherits the enhanced networking sriovNetSupport attribute
from the instance. Therefore, you can use this AMI to launch another instance with enhanced
networking enabled by default.
14. From your local computer, start the instance using the Amazon EC2 console or the following
command: start-instances (AWS CLI). If your instance is managed by AWS OpsWorks, you should
start the instance in the AWS OpsWorks console so that the instance state remains in sync.
15. (Optional) Connect to your instance and verify that the module is installed.
To enable enhanced networking on Ubuntu (instance store-backed instances)
If your instance is an instance store-backed instance, follow Step 1 (p. 613) through Step
10 (p. 614) in the previous procedure, and then create a new AMI as described in Creating an
Instance Store-Backed Linux AMI (p. 92). Be sure to enable the enhanced networking attribute when
you register the AMI.

Warning
Enhanced networking is supported only for HVM instances. Enabling enhanced networking
with a PV instance can make it unreachable. Setting this attribute without the proper module
or module version can also make your instance unreachable.
• register-image (AWS CLI)
$ aws ec2 register-image --sriov-net-support simple ...

Enabling Enhanced Networking with the Intel 82599 VF
Interface on Other Linux Distributions
The following procedure provides the general steps that you'll take when enabling enhanced
networking with the Intel 82599 VF interface on a Linux distribution other than Amazon Linux or
Ubuntu. For more information, such as detailed syntax for commands, file locations, or package and
tool support, see the specific documentation for your Linux distribution.

To enable enhanced networking on Linux (EBS-backed instances)
1.
2.

Connect to your instance.
Download the source for version 2.14.2 of the ixgbevf module on your instance from
Sourceforge at http://sourceforge.net/projects/e1000/files/ixgbevf%20stable/. This is the minimum
version recommended for enhanced networking.

Note
Earlier versions of ixgbevf, including the minimum recommended version, 2.14.2, do
not build properly on some Linux distributions, including certain versions of Ubuntu. If you

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receive build errors, you may try a newer version, such as 2.16.4 (which fixes the build
issue on affected Ubuntu versions).
3.

Compile and install the ixgbevf module on your instance.
If your distribution supports dkms, then you should consider configuring dkms to recompile the
ixgbevf module whenever your system's kernel is updated. If your distribution does not support
dkms natively, you can find it in the EPEL repository (https://fedoraproject.org/wiki/EPEL) for Red
Hat Enterprise Linux variants, or you can download the software at http://linux.dell.com/dkms/. Use
Step 6 (p. 613) through Step 8 (p. 614) in To enable enhanced networking on Ubuntu (EBSbacked instances) (p. 613) for help configuring dkms.

Warning
If you compile the ixgbevf module for your current kernel and then upgrade your kernel
without rebuilding the driver for the new kernel, your system may revert to the distributionspecific ixgbevf module at the next reboot, which could make your system unreachable
if the distribution-specific version is incompatible with enhanced networking.
4.

Run the sudo depmod command to update module dependencies.

Update the initramfs on your instance to ensure that the new module loads at boot time.

Determine if your system uses predictable network interface names by default. Systems that use
systemd or udev versions 197 or greater can rename Ethernet devices and they do not guarantee
that a single network interface will be named eth0. This behavior can cause problems connecting
to your instance. For more information and to see other configuration options, see Predictable
Network Interface Names/ on the freedesktop.org website.
a.

You can check the systemd or udev versions on RPM-based systems with the following
command:
[ec2-user ~]$ rpm -qa | grep -e '^systemd-[0-9]\+\|^udev-[0-9]\+'
systemd-208-11.el7_0.2.x86_64

In the above Red Hat 7 example, the systemd version is 208, so predictable network
interface names must be disabled.
b.

Disable predictable network interface names by adding the net.ifnames=0 option to the
GRUB_CMDLINE_LINUX line in /etc/default/grub.
[ec2-user ~]$ sudo sed -i '/^GRUB\_CMDLINE\_LINUX/s/\"$/\ net\.ifnames
\=0\"/' /etc/default/grub

Rebuild the grub configuration file.
[ec2-user ~]$ sudo grub2-mkconfig -o /boot/grub2/grub.cfg

Important
If you are using an instance store-backed instance, you can't stop the instance.
Instead, proceed to To enabled enhanced networking (instance store–backed
instances) (p. 617)
8.

From your local computer, enable the enhanced networking attribute using the following
command. Note that there is no way to disable the networking attribute after you've enabled it.

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• modify-instance-attribute (AWS CLI)
$ aws ec2 modify-instance-attribute --instance-id instance_id --sriovnet-support simple

Important
If your instance operating system contains an /etc/udev/rules.d/70-persistentnet.rules file, you must delete it before creating the AMI. This file contains the MAC
address for the Ethernet adapter of the original instance. If another instance boots with
this file, the operating system will be unable to find the device and eth0 may fail, causing
boot issues. This file is regenerated at the next boot cycle, and any instances launched
from the AMI create their own version of the file.
10. From your local computer, start the instance using the Amazon EC2 console or the following
command: start-instances (AWS CLI). If your instance is managed by AWS OpsWorks, you should
start the instance in the AWS OpsWorks console so that the instance state remains in sync.
11. (Optional) Connect to your instance and verify that the module is installed.
To enabled enhanced networking (instance store–backed instances)
If your instance is an instance store–backed instance, follow Step 1 (p. 615) through Step
5 (p. 616) in the previous procedure, and then create a new AMI as described in Creating an
Instance Store-Backed Linux AMI (p. 92). Be sure to enable the enhanced networking attribute when
you register the AMI.

Warning
Enhanced networking is supported only for HVM instances. Enabling enhanced networking
with a PV instance can make it unreachable. Setting this attribute without the proper module
or module version can also make your instance unreachable.
• register-image (AWS CLI)
$ aws ec2 register-image --sriov-net-support simple ...

Troubleshooting Connectivity Issues
If you lose connectivity while enabling enhanced networking, the ixgbevf module might be
incompatible with the kernel. Try installing the version of the ixgbevf module included with the
distribution of Linux for your instance.
If you enable enhanced networking for a PV instance or AMI, this can make your instance unreachable.

Enabling Enhanced Networking with the Elastic
Network Adapter (ENA) on Linux Instances in a
VPC
To prepare for enhanced networking with the ENA network adapter, set up your instance as follows:

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• Launch the instance from an HVM AMI using Linux kernel version of 3.2 or later. The latest Amazon
Linux HVM AMIs have the modules required for enhanced networking installed and have the
required attributes set. Therefore, if you launch an Amazon EBS–backed, enhanced networking–
supported instance using a current Amazon Linux HVM AMI, ENA enhanced networking is already
enabled for your instance.
• Launch the instance in a VPC. (You can't enable enhanced networking if the instance is in EC2Classic.)
• Install and configure the AWS CLI on any computer you choose, preferably your local desktop or
laptop. For more information, see Accessing Amazon EC2 (p. 3). Enhanced networking cannot be
managed from the Amazon EC2 console.
• If you have important data on the instance that you want to preserve, you should back that data
up now by creating an AMI from your instance. Updating kernels and kernel modules, as well as
enabling the enaSupport attribute, may render incompatible instances or operating systems
unreachable; if you have a recent backup, your data will still be retained if this happens.
Contents
• Testing Whether Enhanced Networking with ENA Is Enabled (p. 618)
• Enabling Enhanced Networking with ENA on Amazon Linux (p. 620)
• Enabling Enhanced Networking with ENA on Ubuntu (p. 621)
• Enabling Enhanced Networking with ENA on Other Linux Distributions (p. 624)
• Troubleshooting (p. 626)

Testing Whether Enhanced Networking with ENA Is Enabled
To test whether enhanced networking with ENA is already enabled, verify that the ena module is
installed on your instance and that the enaSupport attribute is set. If your instance satisfies these two
conditions, then the ethtool -i ethn command should show that the module is in use on the network
interface.
Kernel Module (ena)
To verify that the ena module is installed, use the modinfo command as follows:
[ec2-user ~]$ modinfo ena
filename:
/lib/modules/4.4.11-23.53.amzn1.x86_64/kernel/drivers/amazon/
net/ena/ena.ko
version:
0.6.6
license:
GPL
description:
Elastic Network Adapter (ENA)
author:
Amazon.com, Inc. or its affiliates
srcversion:
3141E47566402C79D6B8284
alias:
pci:v00001D0Fd0000EC21sv*sd*bc*sc*i*
alias:
pci:v00001D0Fd0000EC20sv*sd*bc*sc*i*
alias:
pci:v00001D0Fd00001EC2sv*sd*bc*sc*i*
alias:
pci:v00001D0Fd00000EC2sv*sd*bc*sc*i*
depends:
intree:
Y
vermagic:
4.4.11-23.53.amzn1.x86_64 SMP mod_unload modversions
parm:
debug:Debug level (0=none,...,16=all) (int)
parm:
push_mode:Descriptor / header push mode
(0=automatic,1=disable,3=enable)
0 - Automatically choose according to device capability (default)
1 - Don't push anything to device memory
3 - Push descriptors and header buffer to device memory (int)

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parm:
enable_wd:Enable keepalive watchdog
(0=disable,1=enable,default=1) (int)
parm:
enable_missing_tx_detection:Enable missing Tx completions.
(default=1) (int)
parm:
numa_node_override_array:Numa node override map
(array of int)
parm:
numa_node_override:Enable/Disable numa node override
(0=disable)
(int)

In the above Amazon Linux case, the ena module is installed.
ubuntu:~$ modinfo ena
ERROR: modinfo: could not find module ena

In the above Ubuntu instance, the module is not installed, so you must first install it. For more
information, see Enabling Enhanced Networking with ENA on Ubuntu (p. 621).
Instance Attribute (enaSupport)
To check whether an instance already has the enhanced networking enaSupport attribute set, use
the following command:
• describe-instances (AWS CLI)
$ aws ec2 describe-instances --instance-id instance_id --query
Reservations[].Instances[].EnaSupport

If the enaSupport attribute isn't set, the returned JSON is empty; otherwise, it is set as follows:
[
true
]

Image Attribute (enaSupport)
To check whether an AMI already already has the enhanced networking enaSupport attribute set, use
the following command:
• describe-image-attribute (AWS CLI)
$ aws ec2 describe-image-attribute --image-id ami_id --attribute enaSupport

Note
This command only works for images that you own. You receive an AuthFailure error for
images that do not belong to your account.
If the attribute isn't set, EnaSupport is empty; otherwise, it is set as follows:
{
"EnaSupport": {
"Value": true
},
"ImageId": "ami_id"
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}

Network Interface Driver
Use the following command to verify that the ena module is being used on a particular interface,
substituting the interface name that you wish to check. If you are using a single interface (default), it will
be eth0.
[ec2-user ~]$ ethtool -i eth0
driver: vif
version:
firmware-version:
bus-info: vif-0
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: no

In the above case, the ena module is not loaded, because the listed driver is vif.
[ec2-user ~]$ ethtool -i eth0
driver: ena
version: 0.6.6
firmware-version:
bus-info: 0000:00:03.0
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: no

In this case, the ena module is loaded and at the minimum recommended version. This instance has
enhanced networking properly configured.

Enabling Enhanced Networking with ENA on Amazon
Linux
The latest Amazon Linux HVM AMIs have the module required for enhanced networking with ENA
installed and have the required enaSupport attribute set. Therefore, if you launch an instance with
the latest Amazon Linux HVM AMI on a supported instance type, enhanced networking with ENA is
already enabled for your instance. For more information, see Testing Whether Enhanced Networking
with ENA Is Enabled (p. 618).
If you launched your instance using an older Amazon Linux AMI and it does not have enhanced
networking enabled already, use the following procedure to enable enhanced networking.

To enable enhanced networking with ENA (EBS-backed instances)
1.

Connect to your instance.

From the instance, run the following command to update your instance with the newest kernel and
kernel modules, including ena:
[ec2-user ~]$ sudo yum update

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3.
4.

From your local computer, reboot your instance using the Amazon EC2 console or the following
command: reboot-instances (AWS CLI).
Connect to your instance again and verify that the ena module is installed and at the minimum
recommended version using the modinfo ena command from Testing Whether Enhanced
Networking with ENA Is Enabled (p. 618).
From your local computer, stop the instance using the Amazon EC2 console or the following
command: stop-instances (AWS CLI). If your instance is managed by AWS OpsWorks, you should
stop the instance in the AWS OpsWorks console so that the instance state remains in sync.

Important
If you are using an instance store-backed instance, you can't stop the instance.
Instead, proceed to To enable enhanced networking with ENA (instance store-backed
instances) (p. 621).
6.

From your local computer, enable the enhanced networking attribute using the following
command.

(Optional) Create an AMI from the instance, as described in Creating an Amazon EBS-Backed
Linux AMI (p. 89). The AMI inherits the enhanced networking enaSupport attribute from the
instance. Therefore, you can use this AMI to launch another instance with enhanced networking
with ENA enabled by default.
From your local computer, start the instance using the Amazon EC2 console or the following
command: start-instances (AWS CLI). If your instance is managed by AWS OpsWorks, you should
start the instance in the AWS OpsWorks console so that the instance state remains in sync.
Connect to your instance and verify that the ena module is installed and loaded on your network
interface using the ethtool -i ethn command from Testing Whether Enhanced Networking with
ENA Is Enabled (p. 618).

Note
If you are unable to connect to your instance after enabling enhanced networking with
ENA, see Troubleshoooting the Elastic Network Adapter (ENA) (p. 626).
To enable enhanced networking with ENA (instance store-backed instances)
If your instance is an instance store–backed instance, follow Step 1 (p. 620) through Step
4 (p. 621) in the previous procedure, and then create a new AMI as described in Creating an
Instance Store-Backed Linux AMI. Be sure to enable the enhanced networking enaSupport attribute
when you register the AMI.
• register-image (AWS CLI)
$ aws ec2 register-image --ena-support ...

Enabling Enhanced Networking with ENA on Ubuntu
The following procedure provides the general steps that you'll take when enabling enhanced
networking with ENA on an Ubuntu instance.

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To enable enhanced networking with ENA on Ubuntu (EBS-backed instances)
1.

Connect to your instance.

Update the package cache and packages.
ubuntu:~$ sudo apt-get update && sudo apt-get upgrade -y

Important
If during the update process you are prompted to install grub, use /dev/xvda to install
grub onto, and then choose to keep the current version of /boot/grub/menu.lst.
3.

Install the build-essential packages to compile the kernel module and the dkms package so
that your ena module is rebuilt every time your kernel is updated.
ubuntu:~$ sudo apt-get install -y build-essential dkms

Clone the source code for the ena module on your instance from GitHub at https://github.com/
amzn/amzn-drivers.
ubuntu:~$ git clone https://github.com/amzn/amzn-drivers

Move the amzn-drivers package to the /usr/src/ directory so dkms can find it and build it for
each kernel update. Append the version number (you can find the current version number in the
release notes) of the source code to the directory name. For example, version 1.0.0 is shown in
the example below.
ubuntu:~$ sudo mv amzn-drivers /usr/src/amzn-drivers-1.0.0

Create the dkms configuration file with the following values, substituting your version of ena.
a.

Create the file.
ubuntu:~$ sudo touch /usr/src/amzn-drivers-1.0.0/dkms.conf

Edit the file and add the following values.
ubuntu:~$ sudo vim /usr/src/amzn-drivers-1.0.0/dkms.conf
PACKAGE_NAME="ena"
PACKAGE_VERSION="1.0.0"
CLEAN="make -C kernel/linux/ena clean"
MAKE="make -C kernel/linux/ena/ BUILD_KERNEL=${kernelver}"
BUILT_MODULE_NAME[0]="ena"
BUILT_MODULE_LOCATION="kernel/linux/ena"
DEST_MODULE_LOCATION[0]="/updates"
DEST_MODULE_NAME[0]="ena"
AUTOINSTALL="yes"

Add, build, and install the ena module on your instance with dkms.
a.

Add the module to dkms.
ubuntu:~$ sudo dkms add -m amzn-drivers -v 1.0.0

Build the module with dkms.

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ubuntu:~$ sudo dkms build -m amzn-drivers -v 1.0.0

Install the module with dkms.
ubuntu:~$ sudo dkms install -m amzn-drivers -v 1.0.0

Rebuild the initramfs so the correct module is loaded at boot time.
ubuntu:~$ sudo update-initramfs -c -k all

Verify that the ena module is installed using the modinfo ena command from Testing Whether
Enhanced Networking with ENA Is Enabled (p. 618).
ubuntu:~$ modinfo ena
filename:
/lib/modules/3.13.0-74-generic/updates/dkms/ena.ko
version:
1.0.0
license:
GPL
description:
Elastic Network Adapter (ENA)
author:
Amazon.com, Inc. or its affiliates
srcversion:
9693C876C54CA64AE48F0CA
alias:
pci:v00001D0Fd0000EC21sv*sd*bc*sc*i*
alias:
pci:v00001D0Fd0000EC20sv*sd*bc*sc*i*
alias:
pci:v00001D0Fd00001EC2sv*sd*bc*sc*i*
alias:
pci:v00001D0Fd00000EC2sv*sd*bc*sc*i*
depends:
vermagic:
3.13.0-74-generic SMP mod_unload modversions
parm:
debug:Debug level (0=none,...,16=all) (int)
parm:
push_mode:Descriptor / header push mode
(0=automatic,1=disable,3=enable)
0 - Automatically choose according to device capability (default)
1 - Don't push anything to device memory
3 - Push descriptors and header buffer to device memory (int)
parm:
enable_wd:Enable keepalive watchdog
(0=disable,1=enable,default=1) (int)
parm:
enable_missing_tx_detection:Enable missing Tx completions.
(default=1) (int)
parm:
numa_node_override_array:Numa node override map
(array of int)
parm:
numa_node_override:Enable/Disable numa node override
(0=disable)
(int)

10. From your local computer, stop the instance using the Amazon EC2 console or the following
command: stop-instances (AWS CLI). If your instance is managed by AWS OpsWorks, you should
stop the instance in the AWS OpsWorks console so that the instance state remains in sync.

Important
If you are using an instance store-backed instance, you can't stop the instance. Instead,
proceed to To enable enhanced networking with ENA on Ubuntu (instance store-backed
instances) (p. 624).
11. From your local computer, enable the enhanced networking attribute using the following
command.

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• modify-instance-attribute (AWS CLI)
$ aws ec2 modify-instance-attribute --instance-id instance_id --enasupport

12. (Optional) Create an AMI from the instance, as described in Creating an Amazon EBS-Backed
Linux AMI (p. 89) . The AMI inherits the enhanced networking attribute from the instance.
Therefore, you can use this AMI to launch another instance with enhanced networking enabled by
default.
13. From your local computer, start the instance using the Amazon EC2 console or the following
command: start-instances (AWS CLI). If your instance is managed by AWS OpsWorks, you should
start the instance in the AWS OpsWorks console so that the instance state remains in sync.
14. (Optional) Connect to your instance and verify that the module is installed.

Note
If you are unable to connect to your instance after enabling enhanced networking with
ENA, see Troubleshoooting the Elastic Network Adapter (ENA) (p. 626).
To enable enhanced networking with ENA on Ubuntu (instance store-backed instances)
If your instance is an instance store-backed instance, follow Step 1 (p. 622) through Step 9 (p. 623)
in the previous procedure, and then create a new AMI as described in Creating an Instance StoreBacked Linux AMI (p. 92). Be sure to enable the enhanced networking enaSupport attribute when
you register the AMI.

Warning
Enhanced networking is supported only for HVM instances. Enabling enhanced networking
with a PV instance can make it unreachable. Setting this attribute without the proper module
or module version can also make your instance unreachable.
• register-image (AWS CLI)
$ aws ec2 register-image --ena-support ...

Enabling Enhanced Networking with ENA on Other Linux
Distributions
The following procedure provides the general steps that you'll take when enabling enhanced
networking with ENA on a Linux distribution other than Amazon Linux or Ubuntu. For more information,
such as detailed syntax for commands, file locations, or package and tool support, see the specific
documentation for your Linux distribution.

To enable enhanced networking with ENA on Linux (EBS-backed instances)
1.

Connect to your instance.

Clone the source code for the ena module on your instance from GitHub at https://github.com/
amzn/amzn-drivers.
ubuntu:~$ git clone https://github.com/amzn/amzn-drivers

Compile and install the ena module on your instance.
If your distribution supports dkms, then you should consider configuring dkms to recompile the
ena module whenever your system's kernel is updated. If your distribution does not support

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dkms natively, you can find it in the EPEL repository (https://fedoraproject.org/wiki/EPEL) for Red
Hat Enterprise Linux variants, or you can download the software at http://linux.dell.com/dkms/.
Use Step 5 (p. 622) through Step 7 (p. 622) in To enable enhanced networking with ENA on
Ubuntu (EBS-backed instances) (p. 622) for help configuring dkms.
4.

Run the sudo depmod command to update module dependencies.

Update the initramfs on your instance to ensure that the new module loads at boot time.

You can check the systemd or udev versions on RPM-based systems with the following
command:
[ec2-user ~]$ rpm -qa | grep -e '^systemd-[0-9]\+\|^udev-[0-9]\+'
systemd-208-11.el7_0.2.x86_64

In the above Red Hat 7 example, the systemd version is 208, so predictable network
interface names must be disabled.
b.

Rebuild the grub configuration file.
[ec2-user ~]$ sudo grub2-mkconfig -o /boot/grub2/grub.cfg

Important
If you are using an instance store-backed instance, you can't stop the instance.
Instead, proceed to To enabled enhanced networking with ENA (instance store–backed
instances) (p. 626)
8.

From your local computer, enable the enhanced networking enaSupport attribute using the
following command.

(Optional) Create an AMI from the instance, as described in Creating an Amazon EBS-Backed
Linux AMI (p. 89) . The AMI inherits the enhanced networking enaSupprt attribute from the
instance. Therefore, you can use this AMI to launch another instance with enhanced networking
enabled by default.
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Note
If you are unable to connect to your instance after enabling enhanced networking with
ENA, see Troubleshoooting the Elastic Network Adapter (ENA) (p. 626).
To enabled enhanced networking with ENA (instance store–backed instances)
If your instance is an instance store–backed instance, follow the Step 1 (p. 624) through the Step
5 (p. 625) in the previous procedure, and then create a new AMI as described in Creating an
Instance Store-Backed Linux AMI (p. 92). Be sure to enable the enhanced networking enaSupport
attribute when you register the AMI.

Warning
Enhanced networking is supported only for HVM instances. Enabling enhanced networking
with a PV instance can make it unreachable. Setting this attribute without the proper module
or module version can also make your instance unreachable.
• register-image (AWS CLI)
$ aws ec2 register-image --ena-support ...

Troubleshooting
For additional information about troubleshooting your ENA adapter, see Troubleshoooting the Elastic
Network Adapter (ENA) (p. 626).

Troubleshoooting the Elastic Network Adapter
(ENA)
The Elastic Network Adapter (ENA) is designed to improve operating system health and reduce
the chances of long-term disruption because of unexpected hardware behavior and or failures. The
ENA architecture keeps device or driver failures as transparent to the system as possible. This topic
provides troubleshooting information for ENA.
If you are unable to connect to your instance, start with the Troubleshooting Connectivity
Issues (p. 627) section.
If you are able to connect to your instance, you can gather diagnostic information by using the failure
detection and recovery mechanisms that are covered in the later sections of this topic.
Contents
• Troubleshooting Connectivity Issues (p. 627)

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• Keep-Alive Mechanism (p. 628)
• Register Read Timeout (p. 629)
• Statistics (p. 629)
• Driver Error Logs in syslog (p. 631)

Troubleshooting Connectivity Issues
If you lose connectivity while enabling enhanced networking, the ena module might be incompatible
with your instance's current running kernel. This can happen if you install the module for a specific
kernel version (without dkms, or with an improperly configured dkms.conf file) and then your instance
kernel is updated. If the instance kernel that is loaded at boot time does not have the ena module
properly installed, your instance will not recognize the network adapter and your instance becomes
unreachable.
If you enable enhanced networking for a PV instance or AMI, this can also make your instance
unreachable.
If your instance becomes unreachable after enabling enhanced networking with ENA, you can disable
the enaSupport attribute for your instance and it will fall back to the stock network adapter.

To disable enhanced networking with ENA (EBS-backed instances)
1.

Important
If you are using an instance store-backed instance, you can't stop the instance.
Instead, proceed to To disable enhanced networking with ENA (instance store-backed
instances) (p. 627).
2.

From your local computer, disable the enhanced networking attribute using the following
command.
• modify-instance-attribute (AWS CLI)
$ aws ec2 modify-instance-attribute --instance-id instance_id --no-enasupport

(Optional) Connect to your instance and try reinstalling the ena module with your current kernel
version by following the steps in Enabling Enhanced Networking with the Elastic Network Adapter
(ENA) on Linux Instances in a VPC (p. 617).

To disable enhanced networking with ENA (instance store-backed instances)
If your instance is an instance store-backed instance, create a new AMI as described in Creating an
Instance Store-Backed Linux AMI (p. 92). Be sure to disable the enhanced networking enaSupport
attribute when you register the AMI.
• register-image (AWS CLI)
$ aws ec2 register-image --no-ena-support ...

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Keep-Alive Mechanism
The ENA device posts keep-alive events at a fixed rate (usually once every second). The ENA
driver implements a watchdog mechanism, which checks every for the presence of these keep-alive
messages. If a message or messages are present, the watchdog is rearmed, otherwise the driver
concludes that the device experienced a failure and then does the following:
• Dumps its current statistics to syslog
• Resets the ENA device
• Resets the ENA driver state
The above reset procedure may result in some traffic loss for a short period of time (TCP connections
should be able to recover), but should not otherwise affect the user.
The ENA device may also indirectly request a device reset procedure, by not sending a keep-alive
notification, for example, if the ENA device reaches an unknown state after loading an irrecoverable
configuration.
Below is an example of the reset procedure:
[18509.800135] ena 0000:00:07.0 eth1: Keep alive watchdog timeout. // The
watchdog process initiates a reset
[18509.815244] ena 0000:00:07.0 eth1: Trigger reset is on
[18509.825589] ena 0000:00:07.0 eth1: tx_timeout: 0 // The driver logs the
current statistics
[18509.834253] ena 0000:00:07.0 eth1: io_suspend: 0
[18509.842674] ena 0000:00:07.0 eth1: io_resume: 0
[18509.850275] ena 0000:00:07.0 eth1: wd_expired: 1
[18509.857855] ena 0000:00:07.0 eth1: interface_up: 1
[18509.865415] ena 0000:00:07.0 eth1: interface_down: 0
[18509.873468] ena 0000:00:07.0 eth1: admin_q_pause: 0
[18509.881075] ena 0000:00:07.0 eth1: queue_0_tx_cnt: 0
[18509.888629] ena 0000:00:07.0 eth1: queue_0_tx_bytes: 0
[18509.895286] ena 0000:00:07.0 eth1: queue_0_tx_queue_stop: 0
.......
........
[18511.280972] ena 0000:00:07.0 eth1: free uncompleted tx skb qid 3 idx
0x7 // At the end of the down process, the driver discards incomplete
packets.
[18511.420112] [ENA_COM: ena_com_validate_version] ena device version:
0.10 //The driver begins its up process
[18511.420119] [ENA_COM: ena_com_validate_version] ena controller version:
0.0.1 implementation version 1
[18511.420127] [ENA_COM: ena_com_admin_init] ena_defs : Version:[b9692e8]
Build date [Wed Apr 6 09:54:21 IDT 2016]
[18512.252108] ena 0000:00:07.0: Device watchdog is Enabled
[18512.674877] ena 0000:00:07.0: irq 46 for MSI/MSI-X
[18512.674933] ena 0000:00:07.0: irq 47 for MSI/MSI-X
[18512.674990] ena 0000:00:07.0: irq 48 for MSI/MSI-X
[18512.675037] ena 0000:00:07.0: irq 49 for MSI/MSI-X
[18512.675085] ena 0000:00:07.0: irq 50 for MSI/MSI-X
[18512.675141] ena 0000:00:07.0: irq 51 for MSI/MSI-X
[18512.675188] ena 0000:00:07.0: irq 52 for MSI/MSI-X
[18512.675233] ena 0000:00:07.0: irq 53 for MSI/MSI-X
[18512.675279] ena 0000:00:07.0: irq 54 for MSI/MSI-X
[18512.772641] [ENA_COM: ena_com_set_hash_function] Feature 10 isn't
supported

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[18512.772647] [ENA_COM: ena_com_set_hash_ctrl] Feature 18 isn't supported
[18512.775945] ena 0000:00:07.0: Device reset completed successfully // The
reset process is complete

Register Read Timeout
The ENA architecture suggests a limited usage of memory mapped I/O (MMIO) read operations. MMIO
registers are accessed by the ENA device driver only during its initialization procedure.
If the driver logs (available in dmesg output) indicate failures of read operations, this may be caused
by an incompatible or incorrectly compiled driver, a busy hardware device, or hardware failure.
Intermittent log entries that indicate failures on read operations should not be considered an issue; the
driver will retry them in this case. However, a sequence of log entries containing read failures indicate a
driver or hardware problem.
Below is an example of driver log entry indicating a read operation failure due to a timeout:
[ 47.113698] [ENA_COM: ena_com_reg_bar_read32] reading reg failed for
timeout. expected: req id[1] offset[88] actual: req id[57006] offset[0]
[ 47.333715] [ENA_COM: ena_com_reg_bar_read32] reading reg failed for
timeout. expected: req id[2] offset[8] actual: req id[57007] offset[0]
[ 47.346221] [ENA_COM: ena_com_dev_reset] Reg read32 timeout occurred

Statistics
If you experience insufficient network performance or latency issues, you should retrieve the device
statistics and examine them. These statistics can be obtained using ethtool, as shown below:
[ec2-user ~]$ ethtool –S ethN
NIC statistics:
tx_timeout: 0
io_suspend: 0
io_resume: 0
wd_expired: 0
interface_up: 1
interface_down: 0
admin_q_pause: 0
queue_0_tx_cnt: 4329
queue_0_tx_bytes: 1075749
queue_0_tx_queue_stop: 0
...

The following command output parameters are described below:
tx_timeout: N
The number of times that the Netdev watchdog was activated.
io_suspend: N
Unsupported. This value should always be zero.
io_resume: N
Unsupported. This value should always be zero.
wd_expired: N
The number of times that the driver did not receive the keep-alive event in the preceding 3
seconds.
interface_up: N
The number of times that the ENA interface was brought up.

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interface_down: N
The number of times that the ENA interface was brought down.
admin_q_pause: N
The admin queue is in an unstable state. This value should always be zero.
queue_N_tx_cnt: N
The number of transmitted packets for queue N.
queue_N_tx_bytes: N
The number of transmitted bytes for queue N.
queue_N_tx_queue_stop: N
The number of times that queue N was full and stopped.
queue_N_tx_queue_wakeup: N
The number of times that queue N resumed after being stopped.
queue_N_tx_dma_mapping_err: N
Direct memory access error count. If this value is not 0, it indicates low system resources.
queue_N_tx_napi_comp: N
The number of times the napi handler called napi_complete for queue N.
queue_N_tx_poll: N
The number of times the napi handler was scheduled for queue N.
queue_N_tx_doorbells: N
The number of transmission doorbells for queue N.
queue_N_tx_linearize: N
The number of times SKB linearization was attempted for queue N.
queue_N_tx_linearize_failed: N
The number of times SKB linearization failed for queue N.
queue_N_tx_prepare_ctx_err: N
The number of times ena_com_prepare_tx failed for queue N. This value should always be zero;
if not, see the driver logs.
queue_N_tx_missing_tx_comp: N
The number of packets that were left uncompleted for queue N. This value should always be zero.
queue_N_tx_bad_req_id: N
Invalid req_id for queue N. The valid req_id is zero, minus the queue_size, minus 1.
queue_N_rx_cnt: N
The number of received packets for queue N.
queue_N_rx_bytes: N
The number of received bytes for queue N.
queue_N_rx_refil_partial: N
The number of times the driver did not succeed in refilling the empty portion of the rx queue with
the buffers for queue N. If this value is not zero, it indicates low memory resources.
queue_N_rx_bad_csum: N
The number of times the rx queue had a bad checksum for queue N (only if rx checksum offload
is supported).
queue_N_rx_page_alloc_fail: N
The number of time that page allocation failed for queue N. If this value is not zero, it indicates low
memory resources.
queue_N_rx_skb_alloc_fail: N
The number of time that SKB allocation failed for queue N. If this value is not zero, it indicates low
system resources.
queue_N_rx_dma_mapping_err: N
Direct memory access error count. If this value is not 0, it indicates low system resources.
queue_N_rx_bad_desc_num: N
Too many buffers per packet. If this value is not 0, it indicates usage of very small buffers.

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queue_N_rx_small_copy_len_pkt: N
Optimization: For packets smaller that this threshold, which is set by sysfs, the packet is copied
directly to the stack to avoid allocation of a new page.
ena_admin_q_aborted_cmd: N
The number of admin commands that were aborted. This usually happens during the autorecovery procedure.
ena_admin_q_submitted_cmd: N
The number of admin queue doorbells.
ena_admin_q_completed_cmd: N
The number of admin queue completions.
ena_admin_q_out_of_space: N
The number of times that the driver tried to submit new admin command, but the queue was full.
ena_admin_q_no_completion: N
The number of times that the driver did not get an admin completion for a command.

Driver Error Logs in syslog
The ENA driver writes log messages to syslog during system boot. You can examine these logs to
look for errors if you are experiencing issues. Below is an example of information logged by the ENA
driver in syslog during system boot, along with some annotations for select messages.
Jun 3 22:37:46 ip-172-31-2-186 kernel: [ 478.416939] [ENA_COM:
ena_com_validate_version] ena device version: 0.10
Jun 3 22:37:46 ip-172-31-2-186 kernel: [ 478.420915] [ENA_COM:
ena_com_validate_version] ena controller version: 0.0.1 implementation
version 1
Jun 3 22:37:46 ip-172-31-2-186 kernel: [ 479.256831] ena 0000:00:03.0:
Device watchdog is Enabled
Jun 3 22:37:46 ip-172-31-2-186 kernel: [ 479.672947] ena 0000:00:03.0:
creating 8 io queues. queue size: 1024
Jun 3 22:37:46 ip-172-31-2-186 kernel: [ 479.680885] [ENA_COM:
ena_com_init_interrupt_moderation] Feature 20 isn't supported // Interrupt
moderation is not supported by the device
Jun 3 22:37:46 ip-172-31-2-186 kernel: [ 479.691609] [ENA_COM:
ena_com_get_feature_ex] Feature 10 isn't supported // RSS HASH function
configuration is not supported by the device
Jun 3 22:37:46 ip-172-31-2-186 kernel: [ 479.694583] [ENA_COM:
ena_com_get_feature_ex] Feature 18 isn't supported //RSS HASH input source
configuration is not supported by the device
Jun 3 22:37:46 ip-172-31-2-186 kernel: [ 479.697433] [ENA_COM:
ena_com_set_host_attributes] Set host attribute isn't supported
Jun 3 22:37:46 ip-172-31-2-186 kernel: [ 479.701064] ena 0000:00:03.0
(unnamed net_device) (uninitialized): Cannot set host attributes
Jun 3 22:37:46 ip-172-31-2-186 kernel: [ 479.704917] ena 0000:00:03.0:
Elastic Network Adapter (ENA) found at mem f3000000, mac addr
02:8a:3c:1e:13:b5 Queues 8
Jun 3 22:37:46 ip-172-31-2-186 kernel: [ 480.805037] EXT4-fs (xvda1): remounted. Opts: (null)
Jun 3 22:37:46 ip-172-31-2-186 kernel: [ 481.025842] NET: Registered
protocol family 10

Which errors can I ignore?
The following warnings that may appear in your system's error logs can be ignored for the Elastic
Network Adapter:

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Set host attribute isn't supported
Host attributes are not supported for this device.
failed to alloc buffer for rx queue
This is a recoverable error, and it indicates that there may have been a memory pressure issue
when the error was thrown.
Feature X isn't supported
The referenced feature is not supported by the Elastic Network Adapter. Possible values for X
include:

• 10: RSS Hash function configuration is not supported for this device.
• 12: RSS Indirection table configuration is not supported for this device.
• 18: RSS Hash Input configuration is not supported for this device.
• 20: Interrupt moderation is not supported for this device.
Failed to config AENQ
The Elastic Network Adapter does not support AENQ configuration.
Trying to set unsupported AENQ events
This error indicates an attempt to set an AENQ events group that is not supported by the Elastic
Network Adapter.

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Storage
Amazon EC2 provides you with flexible, cost effective, and easy-to-use data storage options for your
instances. Each option has a unique combination of performance and durability. These storage options
can be used independently or in combination to suit your requirements.
After reading this section, you should have a good understanding about how you can use the data
storage options supported by Amazon EC2 to meet your specific requirements. These storage options
include the following:
• Amazon Elastic Block Store (Amazon EBS) (p. 634)
• Amazon EC2 Instance Store (p. 715)
• Amazon Simple Storage Service (Amazon S3) (p. 726)
The following figure shows the relationship between these types of storage.

Amazon EBS
Amazon EBS provides durable, block-level storage volumes that you can attach to a running instance
You can use Amazon EBS as a primary storage device for data that requires frequent and granular
updates. For example, Amazon EBS is the recommended storage option when you run a database on
an instance.

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An EBS volume behaves like a raw, unformatted, external block device that you can attach to a
single instance. The volume persists independently from the running life of an instance. After an EBS
volume is attached to an instance, you can use it like any other physical hard drive. As illustrated in
the previous figure, multiple volumes can be attached to an instance. You can also detach an EBS
volume from one instance and attach it to another instance. EBS volumes can also be created as
encrypted volumes using the Amazon EBS encryption feature. For more information, see Amazon EBS
Encryption (p. 695).
To keep a backup copy of your data, you can create a snapshot of an EBS volume, which is stored in
Amazon S3. You can create an EBS volume from a snapshot, and attach it to another instance. For
more information, see Amazon Elastic Block Store (Amazon EBS) (p. 634).
Amazon EC2 Instance Store
Many instances can access storage from disks that are physically attached to the host computer. This
disk storage is referred to as instance store. Instance store provides temporary block-level storage
for instances. The data on an instance store volume persists only during the life of the associated
instance; if you stop or terminate an instance, any data on instance store volumes is lost. For more
information, see Amazon EC2 Instance Store (p. 715).
Amazon S3
Amazon S3 is a repository for Internet data. Amazon S3 provides access to reliable and inexpensive
data storage infrastructure. It is designed to make web-scale computing easier by enabling you to store
and retrieve any amount of data, at any time, from within Amazon EC2 or anywhere on the web. For
example, you can use Amazon S3 to store backup copies of your data and applications. For more
information, see Amazon Simple Storage Service (Amazon S3) (p. 726).
Adding Storage
Every time you launch an instance from an AMI, a root storage device is created for that instance.
The root storage device contains all the information necessary to boot the instance. You can specify
storage volumes in addition to the root device volume when you create an AMI or launch an instance
using block device mapping. For more information, see Block Device Mapping (p. 731).
You can also attach EBS volumes to a running instance. For more information, see Attaching an
Amazon EBS Volume to an Instance (p. 654).

Amazon Elastic Block Store (Amazon EBS)
Amazon Elastic Block Store (Amazon EBS) provides block level storage volumes for use with EC2
instances. EBS volumes are highly available and reliable storage volumes that can be attached to
any running instance that is in the same Availability Zone. EBS volumes that are attached to an EC2
instance are exposed as storage volumes that persist independently from the life of the instance. With
Amazon EBS, you pay only for what you use. For more information about Amazon EBS pricing, see the
Projecting Costs section of the Amazon Elastic Block Store page.
Amazon EBS is recommended when data must be quickly accessible and requires long-term
persistence. EBS volumes are particularly well-suited for use as the primary storage for file systems,
databases, or for any applications that require fine granular updates and access to raw, unformatted,
block-level storage. Amazon EBS is well suited to both database-style applications that rely on random
reads and writes, and to throughput-intensive applications that perform long, continuous reads and
writes.
For simplified data encryption, you can launch your EBS volumes as encrypted volumes. Amazon EBS
encryption offers you a simple encryption solution for your EBS volumes without the need for you to
build, manage, and secure your own key management infrastructure. When you create an encrypted
EBS volume and attach it to a supported instance type, data stored at rest on the volume, disk I/O, and

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snapshots created from the volume are all encrypted. The encryption occurs on the servers that hosts
EC2 instances, providing encryption of data-in-transit from EC2 instances to EBS storage. For more
information, see Amazon EBS Encryption (p. 695).
Amazon EBS encryption uses AWS Key Management Service (AWS KMS) master keys when creating
encrypted volumes and any snapshots created from your encrypted volumes. The first time you create
an encrypted EBS volume in a region, a default master key is created for you automatically. This
key is used for Amazon EBS encryption unless you select a Customer Master Key (CMK) that you
created separately using the AWS Key Management Service. Creating your own CMK gives you
more flexibility, including the ability to create, rotate, disable, define access controls, and audit the
encryption keys used to protect your data. For more information, see the AWS Key Management
Service Developer Guide.
You can attach multiple volumes to the same instance within the limits specified by your AWS account.
Your account has a limit on the number of EBS volumes that you can use, and the total storage
available to you. For more information about these limits, and how to request an increase in your limits,
see Request to Increase the Amazon EBS Volume Limit.
Contents
• Features of Amazon EBS (p. 635)
• Amazon EBS Volumes (p. 636)
• Amazon EBS Snapshots (p. 685)
• Amazon EBS–Optimized Instances (p. 692)
• Amazon EBS Encryption (p. 695)
• Amazon EBS Volume Performance on Linux Instances (p. 699)

Features of Amazon EBS
• You can create EBS General Purpose SSD (gp2), Provisioned IOPS SSD (io1), Throughput
Optimized HDD (st1), and Cold HDD (sc1) volumes up to 16 TiB in size. You can mount these
volumes as devices on your Amazon EC2 instances. You can mount multiple volumes on the same
instance, but each volume can be attached to only one instance at a time. For more information, see
Creating an Amazon EBS Volume (p. 650).
• With General Purpose SSD (gp2) volumes, you can expect base performance of 100 IOPS/GiB, with
the ability to burst to 3,000 IOPS for extended periods of time. Gp2 volumes are ideal for a broad
range of use cases such as boot volumes, small and medium-size databases, and development and
test environments. Gp2 volumes support up to 10,000 IOPS and 160 MB/s of throughput. For more
information, see General Purpose SSD (gp2) Volumes (p. 640).
• With Provisioned IOPS SSD (io1) volumes, you can provision a specific level of I/O performance.
Io1 volumes support up to 20,000 IOPS and 320 MB/s of throughput. This allows you to predictably
scale to tens of thousands of IOPS per EC2 instance. For more information, see Provisioned IOPS
SSD (io1) Volumes (p. 643).
• Throughput Optimized HDD (st1) volumes provide low-cost magnetic storage that defines
performance in terms of throughput rather than IOPS. With throughput of up to 500 MiB/s, this
volume type is a good fit for large, sequential workloads such as Amazon EMR, ETL, data
warehouses, and log processing. For more information, see Throughput Optimized HDD (st1)
Volumes (p. 644).
• Cold HDD (sc1) volumes provide low-cost magnetic storage that defines performance in terms of
throughput rather than IOPS. With throughput of up to 250 MiB/s, sc1 is a good fit ideal for large,
sequential, cold-data workloads. If you require infrequent access to your data and are looking to
save costs, sc1 provides inexpensive block storage. For more information, see Cold HDD (sc1)
Volumes (p. 646).
• EBS volumes behave like raw, unformatted block devices. You can create a file system on top of
these volumes, or use them in any other way you would use a block device (like a hard drive). For

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more information on creating file systems and mounting volumes, see Making an Amazon EBS
Volume Available for Use (p. 655).
• You can use encrypted EBS volumes to meet a wide range of data-at-rest encryption
requirements for regulated/audited data and applications. For more information, see Amazon EBS
Encryption (p. 695).
• You can create point-in-time snapshots of EBS volumes, which are persisted to Amazon S3.
Snapshots protect data for long-term durability, and they can be used as the starting point for
new EBS volumes. The same snapshot can be used to instantiate as many volumes as you wish.
These snapshots can be copied across AWS regions. For more information, see Amazon EBS
Snapshots (p. 685).
• EBS volumes are created in a specific Availability Zone, and can then be attached to any instances
in that same Availability Zone. To make a volume available outside of the Availability Zone, you can
create a snapshot and restore that snapshot to a new volume anywhere in that region. You can copy
snapshots to other regions and then restore them to new volumes there, making it easier to leverage
multiple AWS regions for geographical expansion, data center migration, and disaster recovery. For
more information, see Creating an Amazon EBS Snapshot (p. 686), Restoring an Amazon EBS
Volume from a Snapshot (p. 652), and Copying an Amazon EBS Snapshot (p. 688).
• A large repository of public data set snapshots can be restored to EBS volumes and seamlessly
integrated into AWS cloud-based applications. For more information, see Using Public Data
Sets (p. 740).
• Performance metrics, such as bandwidth, throughput, latency, and average queue length, are
available through the AWS Management Console. These metrics, provided by Amazon CloudWatch,
allow you to monitor the performance of your volumes to make sure that you are providing enough
performance for your applications without paying for resources you don't need. For more information,
see Amazon EBS Volume Performance on Linux Instances (p. 699).

Amazon EBS Volumes
An Amazon EBS volume is a durable, block-level storage device that you can attach to a single EC2
instance. You can use EBS volumes as primary storage for data that requires frequent updates,
such as the system drive for an instance or storage for a database application, or for throughputintensive applications that perform continuous disk scans . EBS volumes persist independently from
the running life of an EC2 instance. After a volume is attached to an instance, you can use it like
any other physical hard drive. Amazon EBS provides the following volume types: General Purpose
SSD (gp2), Provisioned IOPS SSD (io1), Throughput Optimized HDD (st1), Cold HDD (sc1), and
Magnetic (standard). They differ in performance characteristics and price, allowing you to tailor your
storage performance and cost to the needs of your applications. For more information, see Amazon
EBS Volume Types (p. 638).
Contents
• Benefits of Using EBS Volumes (p. 637)
• Amazon EBS Volume Types (p. 638)
• Creating an Amazon EBS Volume (p. 650)
• Restoring an Amazon EBS Volume from a Snapshot (p. 652)
• Attaching an Amazon EBS Volume to an Instance (p. 654)
• Making an Amazon EBS Volume Available for Use (p. 655)
• Viewing Volume Information (p. 657)
• Monitoring the Status of Your Volumes (p. 658)
• Detaching an Amazon EBS Volume from an Instance (p. 669)
• Deleting an Amazon EBS Volume (p. 671)
• Expanding the Storage Space of an EBS Volume on Linux (p. 671)

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• Expanding a Linux Partition (p. 676)

Benefits of Using EBS Volumes
EBS volumes provide several benefits that are not supported by instance store volumes.
• Data availability
When you create an EBS volume in an Availability Zone, it is automatically replicated within that
zone to prevent data loss due to failure of any single hardware component. After you create a
volume, you can attach it to any EC2 instance in the same Availability Zone. After you attach a
volume, it appears as a native block device similar to a hard drive or other physical device. At that
point, the instance can interact with the volume just as it would with a local drive; the instance can
format the EBS volume with a file system, such as ext3, and then install applications.
An EBS volume can be attached to only one instance at a time within the same Availability Zone.
However, multiple volumes can be attached to a single instance. If you attach multiple volumes
to a device that you have named, you can stripe data across the volumes for increased I/O and
throughput performance.
You can get monitoring data for your EBS volumes at no additional charge (this includes data for the
root device volumes for EBS-backed instances). For more information, see Monitoring Volumes with
CloudWatch (p. 658).
• Data persistence
An EBS volume is off-instance storage that can persist independently from the life of an instance.
You continue to pay for the volume usage as long as the data persists.
By default, EBS volumes that are attached to a running instance automatically detach from the
instance with their data intact when that instance is terminated. The volume can then be reattached
to a new instance, enabling quick recovery. If you are using an EBS-backed instance, you can
stop and restart that instance without affecting the data stored in the attached volume. The volume
remains attached throughout the stop-start cycle. This enables you to process and store the data
on your volume indefinitely, only using the processing and storage resources when required. The
data persists on the volume until the volume is deleted explicitly. The physical block storage used
by deleted EBS volumes is overwritten with zeroes before it is allocated to another account. If you
are dealing with sensitive data, you should consider encrypting your data manually or storing the
data on a volume protected by Amazon EBS encryption. For more information, see Amazon EBS
Encryption (p. 695).
By default, EBS volumes that are created and attached to an instance at launch are deleted
when that instance is terminated. You can modify this behavior by changing the value of the flag
DeleteOnTermination to false when you launch the instance. This modified value causes the
volume to persist even after the instance is terminated, and enables you to attach the volume to
another instance.
• Data encryption
For simplified data encryption, you can create encrypted EBS volumes with the Amazon EBS
encryption feature. All EBS volume types support encryption. You can use encrypted EBS volumes
to meet a wide range of data-at-rest encryption requirements for regulated/audited data and
applications. Amazon EBS encryption uses 256-bit Advanced Encryption Standard algorithms
(AES-256) and an Amazon-managed key infrastructure. The encryption occurs on the server that
hosts the EC2 instance, providing encryption of data-in-transit from the EC2 instance to Amazon
EBS storage. For more information, see Amazon EBS Encryption (p. 695).
Amazon EBS encryption uses AWS Key Management Service (AWS KMS) master keys when
creating encrypted volumes and any snapshots created from your encrypted volumes. The first
time you create an encrypted EBS volume in a region, a default master key is created for you

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automatically. This key is used for Amazon EBS encryption unless you select a customer master
key (CMK) that you created separately using AWS KMS. Creating your own CMK gives you more
flexibility, including the ability to create, rotate, disable, define access controls, and audit the
encryption keys used to protect your data. For more information, see the AWS Key Management
Service Developer Guide.
• Snapshots
Amazon EBS provides the ability to create snapshots (backups) of any EBS volume and write a copy
of the data in the volume to Amazon S3, where it is stored redundantly in multiple Availability Zones.
The volume does not need be attached to a running instance in order to take a snapshot. As you
continue to write data to a volume, you can periodically create a snapshot of the volume to use as
a baseline for new volumes. These snapshots can be used to create multiple new EBS volumes,
expand the size of a volume, or move volumes across Availability Zones. Snapshots of encrypted
EBS volumes are automatically encrypted.
When you create a new volume from a snapshot, it's an exact copy of the original volume at the time
the snapshot was taken. EBS volumes that are restored from encrypted snapshots are automatically
encrypted. By optionally specifying a different volume size or a different Availability Zone, you can
use this functionality to increase the size of an existing volume or to create duplicate volumes in
new Availability Zones. The snapshots can be shared with specific AWS accounts or made public.
When you create snapshots, you incur charges in Amazon S3 based on the volume's total size.
For a successive snapshot of the volume, you are only charged for any additional data beyond the
volume's original size.
Snapshots are incremental backups, meaning that only the blocks on the volume that have changed
after your most recent snapshot are saved. If you have a volume with 100 GiB of data, but only 5 GiB
of data have changed since your last snapshot, only the 5 GiB of modified data is written to Amazon
S3. Even though snapshots are saved incrementally, the snapshot deletion process is designed so
that you need to retain only the most recent snapshot in order to restore the volume.
To help categorize and manage your volumes and snapshots, you can tag them with metadata of
your choice. For more information, see Tagging Your Amazon EC2 Resources (p. 751).

Amazon EBS Volume Types
Amazon EBS provides the following volume types, which differ in performance characteristics and
price, so that you can tailor your storage performance and cost to the needs of your applications. The
volumes types fall into two categories:
• SSD-backed volumes optimized for transactional workloads involving frequent read/write operations
with small I/O size, where the dominant performance attribute is IOPS
• HDD-backed volumes optimized for large streaming workloads where throughput (measured in MiB/
s) is a better performance measure than IOPS
The following table describes the use cases and performance characteristics for each volume type:
Solid-State Drives (SSD)

Hard disk Drives (HDD)

Volume Type

General Purpose
SSD (gp2)*

Provisioned IOPS
SSD (io1)

Throughput
Optimized HDD
(st1)

Cold HDD (sc1)

Description

General purpose
SSD volume that
balances price
and performance
for a wide variety

Highestperformance SSD
volume designed
for mission-critical
applications

Low cost HDD
volume designed
for frequently
accessed,
throughput-

Lowest cost HDD
volume designed
for less frequently
accessed
workloads

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Solid-State Drives (SSD)
of transactional
workloads
Use Cases

• Recommended
for most
workloads
• System boot
volumes
• Virtual desktops
• Low-latency
interactive apps
• Development
and test
environments

Hard disk Drives (HDD)
intensive
workloads

• Critical
business
applications
that require
sustained IOPS
performance,
or more than
10,000 IOPS
or 160 MiB/s of
throughput per
volume

• Streaming
workloads
requiring
consistent, fast
throughput at a
low price
• Big data
• Data
warehouses

• Log processing
• Large database • Cannot be a
boot volume
workloads, such
as:

• Throughputoriented
storage for
large volumes
of data that is
infrequently
accessed
• Scenarios
where the
lowest
storage cost is
important
• Cannot be a
boot volume

• MongoDB
• Cassandra
• Microsoft
SQL Server
• MySQL
• PostgreSQL
• Oracle
API Name

gp2

io1

st1

sc1

Volume Size

1 GiB - 16 TiB

4 GiB - 16 TiB

500 GiB - 16 TiB

Max. IOPS**/
Volume

10,000

20,000

500

250

Max.
Throughput/
Volume†

160 MiB/s

320 MiB/s

500 MiB/s

250 MiB/s

Max. IOPS/
Instance

48,000

Max.
Throughput/
Instance

800 MiB/s

Dominant
Performance
Attribute

IOPS

MiB/s

*Default volume type
**gp2/io1 based on 16KiB I/O size, st1/sc1 based on 1 MiB I/O size
† To achieve this throughput, you must have an instance that supports it, such as r3.8xlarge or
x1.32xlarge.
The following table describes previous-generation EBS volume types. If you need higher performance
or performance consistency than previous-generation volumes can provide, we recommend that you

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consider using General Purpose SSD (gp2) or other current volume types. For more information, see
Previous Generation Volumes.
Previous Generation Volumes
Volume Type

EBS Magnetic

Description

Previous generation HDD

Use Cases

Workloads where data is infrequently accessed

API Name

standard

Volume Size

1 GiB-1 TiB

Max. IOPS/Volume

40-200

Max. Throughput/Volume

40-90 MiB/s

Max. IOPS/Instance

48,000

Max. Throughput/Instance

800 MiB/s

Dominant Performance Attribute

IOPS

Note
Linux AMIs require GPT partition tables and GRUB 2 for boot volumes 2 TiB (2048 GiB) or
larger. Many Linux AMIs today use the MBR partitioning scheme, which only supports up
to 2047 GiB boot volumes. If your instance does not boot with a boot volume that is 2 TiB
or larger, the AMI you are using may be limited to a 2047 GiB boot volume size. Non-boot
volumes do not have this limitation on Linux instances.
There are several factors that can affect the performance of EBS volumes, such as instance
configuration, I/O characteristics, and workload demand. For more information about getting the most
out of your EBS volumes, see Amazon EBS Volume Performance on Linux Instances (p. 699).
For more information about pricing for these volume types, see Amazon EBS Pricing.

General Purpose SSD (gp2) Volumes
General Purpose SSD (gp2) volumes offer cost-effective storage that is ideal for a broad range of
workloads. These volumes deliver single-digit millisecond latencies and the ability to burst to 3,000
IOPS for extended periods of time. Between a minimum of 100 IOPS (at 33.33 GiB and below) and a
maximum of 10,000 IOPS (at 3,334 GiB and above), baseline performance scales linearly at 3 IOPS
per GiB of volume size. A gp2 volume can range in size from 1 GiB to 16 TiB.

I/O Credits and Burst Performance
The performance of gp2 volumes is tied to volume size, which determines the baseline performance
level of the volume and how quickly it accumulates I/O credits; larger volumes have higher baseline
performance levels and accumulate I/O credits faster. I/O credits represent the available bandwidth
that your gp2 volume can use to burst large amounts of I/O when more than the baseline performance
is needed. The more credits your volume has for I/O, the more time it can burst beyond its baseline
performance level and the better it performs when more performance is needed. The following diagram
shows the burst-bucket behavior for gp2.

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Each volume receives an initial I/O credit balance of 5.4 million I/O credits, which is enough to sustain
the maximum burst performance of 3,000 IOPS for 30 minutes. This initial credit balance is designed
to provide a fast initial boot cycle for boot volumes and to provide a good bootstrapping experience
for other applications. Volumes earn I/O credits at the baseline performance rate of 3 IOPS per GiB of
volume size. For example, a 100 GiB gp2 volume has a baseline performance of 300 IOPS.

When your volume requires more than the baseline performance I/O level, it draws on I/O credits in the
credit balance to burst to the required performance level, up to a maximum of 3,000 IOPS. Volumes
larger than 1,000 GiB have a baseline performance that is equal or greater than the maximum burst
performance, and their I/O credit balance never depletes. When your volume uses fewer I/O credits
than it earns in a second, unused I/O credits are added to the I/O credit balance. The maximum I/O
credit balance for a volume is equal to the initial credit balance (5.4 million I/O credits).
The following table lists several volume sizes and the associated baseline performance of the volume
(which is also the rate at which it accumulates I/O credits), the burst duration at the 3,000 IOPS
maximum (when starting with a full credit balance), and the time in seconds that the volume would take
to refill an empty credit balance.
Volume size (GiB)

Baseline performance Maximum burst
(IOPS)
duration @ 3,000
IOPS (seconds)

Seconds to fill empty
credit balance

100

1862

54,000

100

300

2,000

18,000

214 (Min. size for max.
throughput)

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2,290

8,412

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Volume size (GiB)

Baseline performance Maximum burst
(IOPS)
duration @ 3,000
IOPS (seconds)

Seconds to fill empty
credit balance

250

750

2,400

7,200

500

1,500

3,600

750

2,250

7,200

2,400

1,000

3,000

N/A*

3,334 (Min. size for
max. IOPS)

10,000

N/A*

16,384 (16 TiB, max.
volume size)

10,000

N/A*

* Bursting and I/O credits are only relevant to volumes under 1,000 GiB, where burst performance
exceeds baseline performance.
The burst duration of a volume is dependent on the size of the volume, the burst IOPS required, and
the credit balance when the burst begins. This is shown in the following equation:

Burst duration

(Credit balance)
-----------------------------------(Burst IOPS) - 3(Volume size in GiB)

What happens if I empty my I/O credit balance?
If your gp2 volume uses all of its I/O credit balance, the maximum IOPS performance of the volume will
remain at the baseline IOPS performance level (the rate at which your volume earns credits) and the
throughput limit is reduced to the baseline IOPS multiplied by the maximum throughput and divided by
3,000, until I/O demand drops below the baseline level and unused credits are added to the I/O credit
balance.
(Max throughput) x
(Baseline IOPS)
Throughput limit with empty I/O credit balance
------------------------------------

=
3,000

For example, a 100 GiB gp2 volume with an empty credit balance has a baseline IOPS performance
limit of 300 IOPS and a throughput limit of 12.8 MiB/s ((128 MiB/s)*300/3000). The larger a volume
is, the greater the baseline performance is and the faster it replenishes the credit balance. For more
information about how IOPS are measured, see I/O Characteristics (p. 704).
If you notice that your volume performance is frequently limited to the baseline level (due to an empty I/
O credit balance), you should consider using a larger gp2 volume (with a higher baseline performance
level) or switching to an io1 volume for workloads that require sustained IOPS performance greater
than 10,000 IOPS.

Throughput Performance
The throughput limit for gp2 volumes is 128 MiB/s for volumes less than or equal to 170 GiB; for
volumes over 170 GiB, this limit increases at the rate of 768 KiB/s per GiB to a maximum of 160 MiB/s
(at 214 GiB and larger).

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Provisioned IOPS SSD (io1) Volumes
Provisioned IOPS SSD (io1) volumes are designed to meet the needs of I/O-intensive workloads,
particularly database workloads, that are sensitive to storage performance and consistency. Instead
of using a bucket and credit model to calculate performance, an io1 volume allows you to specify a
consistent IOPS rate when you create the volume, and Amazon EBS delivers within 10 percent of the
provisioned IOPS performance 99.9 percent of the time over a given year.
An io1 volume can range in size from 4 GiB to 16 TiB and you can provision up to 20,000 IOPS
per volume. The maximum ratio of provisioned IOPS to requested volume size (in GiB) is 50:1. For
example, a 100 GiB volume can be provisioned with up to 5,000 IOPS. Any volume 400 GiB in size or
greater allows provisioning up to the 20,000 IOPS maximum.
The throughput limit of io1 volumes is 256 KiB for each IOPS provisioned, up to a maximum of 320
MiB/s (at 1,280 IOPS).

Your per-I/O latency experience depends on the IOPS provisioned and your workload pattern. For the
best per-I/O latency experience, we recommend that you provision an IOPS-to-GiB ratio greater than
2:1. For example, a 2,000 IOPS volume should be smaller than 1,000 GiB.

Note
Some AWS accounts created before 2012 might have access to Availability Zones in useast-1, us-west-1, or ap-northeast-1 that do not support Provisioned IOPS SSD (io1)
volumes. If you are unable to create an io1 volume (or launch an instance with an io1
volume in its block device mapping) in one of these regions, try a different Availability Zone in
the region. You can verify that an Availability Zone supports io1 volumes by creating a 4 GiB
io1 volume in that zone.

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Throughput Optimized HDD (st1) Volumes
Throughput Optimized HDD (st1) volumes provide low-cost magnetic storage that defines
performance in terms of throughput rather than IOPS. This volume type is a good fit for large,
sequential workloads such as Amazon EMR, ETL, data warehouses, and log processing. Bootable st1
volumes are not supported.

Note
This volume type is optimized for workloads involving large, sequential I/O, and we
recommend that customers with workloads performing small, random I/O use gp2. For more
information, see Inefficiency of Small Read/Writes on HDD (p. 649).

Throughput Credits and Burst Performance
Like gp2, st1 uses a burst-bucket model for performance. Volume size determines the baseline
throughput of your volume, which is the rate at which the volume accumulates throughput credits.
Volume size also determines the burst throughput of your volume, which is the rate at which you can
spend credits when they are available. Larger volumes have higher baseline and burst throughput. The
more credits your volume has, the longer it will be able to drive I/O at the burst level.
The following diagram shows the burst-bucket behavior for st1.

Subject to throughput and throughput-credit caps, the available throughput of an st1 volume is
expressed by the following formula:
(Volume size) x (Credit accumulation rate per TiB) = Baseline Throughput

For a 1 TiB st1 volume, burst throughput is limited to 250 MiB/s, the bucket fills with credits at 40 MiB/
s, and it can hold up to 1 TiB-worth of credits.
Larger volumes scale these limits linearly, with throughput capped at a maximum of 500 MiB/s. After
the bucket is depleted, throughput is limited to the baseline rate of 40 MiB/s per TiB.
On volume sizes ranging from 0.5 to 16 TiB, baseline throughput varies from 20 to a cap of 500 MiB/s,
which is reached at 12.5 TiB because
40 MiB/s
12.5 TiB x ---------- = 500 MiB/s
1 TiB

Burst throughput varies from 125 MiB/s to a cap of 500 MiB/s, which is reached at 2 TiB because
250 MiB/s

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2 TiB x ---------- = 500 MiB/s
1 TiB

The following table states the full range of base and burst throughput values for st1:
Volume Size (TiB)

ST1 Base Throughput (MiB/s)

ST1 Burst Throughput (MiB/s)

0.5

125

250

500

120

500

160

500

200

500

240

500

280

500

320

500

360

500

400

500

440

500

480

500

12.5

500

The following diagram plots the table values:

Note
Throughput for an st1 volume is also capped at the baseline while a snapshot is being
created.

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Cold HDD (sc1) Volumes
Cold HDD (sc1) volumes provide low-cost magnetic storage that defines performance in terms of
throughput rather than IOPS. With a lower throughput limit than st1, sc1 is a good fit ideal for large,
sequential cold-data workloads. If you require infrequent access to your data and are looking to save
costs, sc1 provides inexpensive block storage. Bootable sc1 volumes are not supported.

Throughput Credits and Burst Performance
Like gp2, sc1 uses a burst-bucket model for performance. Volume size determines the baseline
throughput of your volume, which is the rate at which the volume accumulates throughput credits.
Volume size also determines the burst throughput of your volume, which is the rate at which you can
spend credits when they are available. Larger volumes have higher baseline and burst throughput. The
more credits your volume has, the longer it will be able to drive I/O at the burst level.

Subject to throughput and throughput-credit caps, the available throughput of an sc1 volume is
expressed by the following formula:
(Volume size) x (Credit accumulation rate per TiB) = Baseline Throughput

For a 1 TiB sc1 volume, burst throughput is limited to 80 MiB/s, the bucket fills with credits at 12 MiB/s,
and it can hold up to 1 TiB-worth of credits.
Larger volumes scale these limits linearly, with throughput capped at a maximum of 250 MiB/s. After
the bucket is depleted, throughput is limited to the baseline rate of 12 MiB/s per TiB.
On volume sizes ranging from 0.5 to 16 TiB, baseline throughput varies from 6 MiB/s to a maximum of
192 MiB/s, which is reached at 16 TiB because
12 MiB/s
16 TiB x ---------- = 192 MiB/s
1 TiB

Burst throughput varies from 40 MiB/s to a cap of 250 MiB/s, which is reached at 3.125 TiB because
250 MiB/s
3.125 TiB x ----------- = 250 MiB/s

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1 TiB

The following table states the full range of base and burst throughput values for sc1:
Volume Size (TiB)

SC1 Base Throughput (MiB/s) SC1 Burst Throughput (MiB/s)

0.5

160

240

3.125

37.5

250

108

250

120

250

132

250

144

250

156

250

168

250

180

250

192

250

The following diagram plots the table values:

Magnetic (standard)
Magnetic volumes are backed by magnetic drives and are suited for workloads where data is accessed
infrequently, and scenarios where low-cost storage for small volume sizes is important. These volumes

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deliver approximately 100 IOPS on average, with burst capability of up to hundreds of IOPS, and they
can range in size from 1 GiB to 1 TiB.

Note
Magnetic is a Previous Generation Volume. For new applications, we recommend using one
of the newer volume types. For more information, see Previous Generation Volumes.

Performance Considerations When Using HDD Volumes
For optimal throughput results using HDD volumes, plan your workloads with the following
considerations in mind.

Throughput Optimized HDD vs. Cold HDD
The st1 and sc1 bucket sizes vary according to volume size, and a full bucket contains enough
tokens for a full volume scan. However, larger st1 and sc1 volumes take longer for the volume scan to
complete due to per-instance and per-volume throughput limits. Volumes attached to smaller instances
are limited to the per-instance throughput rather than the st1 or sc1 throughput limits.
Both st1 and sc1 are designed for performance consistency of 90% of burst throughput 99% of the
time. Non-compliant periods are approximately uniformly distributed, targeting 99% of expected total
throughput each hour.
The following table shows ideal scan times for volumes of various size, assuming full buckets and
sufficient instance throughput.
In general, scan times are expressed by this formula:
Volume size
------------- = Scan time
Throughput

For example, taking the performance consistency guarantees and other optimizations into account, an
st1 customer with a 5 TiB volume can expect to complete a full volume scan in 2.91 to 3.27 hours.
5 TiB
5 TiB
----------- = ------------------- = 10,486 s = 2.91 hours (optimal)
500 MiB/s
0.00047684 TiB/s

2.91 hours
2.91 hours + -------------- = 3.27 hours (minimum expected)
(0.90)(0.99) <-- From expected performance of 90% of burst 99%
of the time

Similarly, an sc1 customer with a 5 TiB volume can expect to complete a full volume scan in 5.83 to
6.54 hours.
5 TiB
------------------- = 20972 s = 5.83 hours (optimal)
0.000238418 TiB/s

5.83 hours
5.83 hours + -------------- = 6.54 hours (minimum expected)
(0.90)(0.99)

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Volume Size (TiB)

ST1 Scan Time with Burst
(Hours)*

SC1 Scan Time with Burst
(Hours)*

1.17

3.64

1.17

3.64

1.75

3.64

2.33

4.66

2.91

5.83

3.50

6.99

4.08

8.16

4.66

9.32

5.24

10.49

5.83

11.65

6.41

12.82

6.99

13.98

7.57

15.15

8.16

16.31

8.74

17.48

9.32

18.64

* These scan times assume an average queue depth (rounded to the nearest whole number) of four or
more when performing 1 MiB of sequential I/O.
Therefore if you have a throughput-oriented workload that needs to complete scans quickly (up to 500
MiB/s), or requires several full volume scans a day, use st1. If you are optimizing for cost, your data
is relatively infrequently accessed, and you don’t need more than 250 MiB/s of scanning performance,
then use sc1.

Inefficiency of Small Read/Writes on HDD
The performance model for st1 and sc1 volumes is optimized for sequential I/Os, favoring highthroughput workloads, offering acceptable performance on workloads with mixed IOPS and throughput,
and discouraging workloads with small, random I/O.
For example, an I/O request of 1 MiB or less counts as a 1 MiB I/O credit. However, if the I/Os are
sequential, they are merged into 1 MiB I/O blocks and count only as a 1 MiB I/O credit.

Limitations on per-Instance Throughput
Throughput for st1 and sc1 volumes will always be the determined by the smaller of the following:
• Throughput limits of the volume
• Throughput limits of the instance

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As for all Amazon EBS volumes, we recommend that you select an appropriate EBS-optimized EC2
instance in order to avoid network bottlenecks. For more information, see Amazon EBS-Optimized
Instances.

Creating an Amazon EBS Volume
You can create an Amazon EBS volume that you can then attach to any EC2 instance within the
same Availability Zone. You can choose to create an encrypted EBS volume, but encrypted volumes
can only be attached to selected instance types. For more information, see Supported Instance
Types (p. 697).
You can also create and attach EBS volumes when you launch instances by specifying a block
device mapping. For more information, see Launching an Instance (p. 279) and Block Device
Mapping (p. 731). You can restore volumes from previously created snapshots. For more information,
see Restoring an Amazon EBS Volume from a Snapshot (p. 652).
If you are creating a volume for a high-performance storage scenario, you should make sure to
use a Provisioned IOPS SSD (io1) volume and attach it to an instance with enough bandwidth to
support your application, such as an EBS-optimized instance or an instance with 10 Gigabit network
connectivity. The same advice holds for Throughput Optimized HDD (st1) and Cold HDD (sc1)
volumes. For more information, see Amazon EC2 Instance Configuration (p. 701).
New EBS volumes receive their maximum performance the moment that they are available and do not
require initialization (formerly known as pre-warming). However, storage blocks on volumes that were
restored from snapshots must be initialized (pulled down from Amazon S3 and written to the volume)
before you can access the block. This preliminary action takes time and can cause a significant
increase in the latency of an I/O operation the first time each block is accessed. For most applications,
amortizing this cost over the lifetime of the volume is acceptable. Performance is restored after the
data is accessed once. For more information, see Initializing Amazon EBS Volumes (p. 706).

To create an EBS volume using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

From the navigation bar, select the region in which you would like to create your volume. This
choice is important because some Amazon EC2 resources can be shared between regions, while
others can't. For more information, see Resource Locations (p. 743).

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In the navigation pane, under ELASTIC BLOCK STORE, choose Volumes.

Above the upper pane, choose Create Volume.

In the Create Volume dialog box, for Volume Type, select General Purpose SSD, Provisioned
IOPS SSD, or Magnetic. For more information, see Amazon EBS Volume Types (p. 638).

Note
Some AWS accounts created before 2012 might have access to Availability Zones in useast-1, us-west-1, or ap-northeast-1 that do not support Provisioned IOPS SSD (io1)
volumes. If you are unable to create an io1 volume (or launch an instance with an io1
volume in its block device mapping) in one of these regions, try a different Availability
Zone in the region. You can verify that an Availability Zone supports io1 volumes by
creating a 4 GiB io1 volume in that zone.
6.

For Size, enter the size of the volume, in GiB.

For io1 volumes, in the IOPS field, enter the maximum number of input/output operations per
second (IOPS) that the volume should support.

For Availability Zone, select the Availability Zone in which to create the volume.

(Optional) To create an encrypted volume, select the Encrypted box and choose the master key
you want to use when encrypting the volume. You can choose the default master key for your
account, or you can choose any Customer Master Key (CMK) that you have previously created
using the AWS Key Management Service. Available keys are visible in the Master Key drop down
menu, or you can paste the full ARN of any key that you have access to. For more information,
see the AWS Key Management Service Developer Guide.

Note
Encrypted volumes can only be attached to selected instance types. For more
information, see Supported Instance Types (p. 697).
10. Choose Yes, Create.

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Important
If you receive one of the following errors, the current volume creation would exceed the
default storage limit for your account:
Maximum number of active volumes bytes, 20, exceeded.
Maximum number of active gp2 volumes bytes, 20, exceeded.
Maximum number of active io1 volumes bytes, 20, exceeded.

To view the default service limits for Amazon EBS, see Amazon Elastic Block Store
(Amazon EBS) Limits in the Amazon Web Services General Reference. To request an
increase in your storage limits, see Request to Increase the Amazon EBS Volume Limit.

To create an EBS volume using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• create-volume (AWS CLI)
• New-EC2Volume (AWS Tools for Windows PowerShell)

Restoring an Amazon EBS Volume from a Snapshot
You can restore an Amazon EBS volume with data from a snapshot stored in Amazon S3. You
need to know the ID of the snapshot you wish to restore your volume from and you need to have
access permissions for the snapshot. For more information on snapshots, see Amazon EBS
Snapshots (p. 685).
New volumes created from existing EBS snapshots load lazily in the background. This means that
after a volume is created from a snapshot, there is no need to wait for all of the data to transfer from
Amazon S3 to your EBS volume before your attached instance can start accessing the volume and all
its data. If your instance accesses data that hasn't yet been loaded, the volume immediately downloads
the requested data from Amazon S3, and continues loading the rest of the data in the background.
EBS volumes that are restored from encrypted snapshots are automatically encrypted. Encrypted
volumes can only be attached to selected instance types. For more information, see Supported
Instance Types (p. 697).
Because of security constraints, you cannot directly restore an EBS volume from a shared encrypted
snapshot that you do not own. You must first create a copy of the snapshot, which you will own. You
can then restore a volume from that copy. For more information, see Amazon EBS Encryption.
New EBS volumes receive their maximum performance the moment that they are available and do not
require initialization (formerly known as pre-warming). However, storage blocks on volumes that were
restored from snapshots must be initialized (pulled down from Amazon S3 and written to the volume)
before you can access the block. This preliminary action takes time and can cause a significant
increase in the latency of an I/O operation the first time each block is accessed. Performance is
restored after the data is accessed once.
For most applications, amortizing the initialization cost over the lifetime of the volume is acceptable.
If you need to ensure that your restored volume always functions at peak capacity in production, you
can force the immediate initialization of the entire volume using dd or fio. For more information, see
Initializing Amazon EBS Volumes (p. 706).

To restore an EBS volume from a snapshot using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

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From the navigation bar, select the region that your snapshot is located in. This choice is important
because some Amazon EC2 resources can be shared between regions, while others can't. For
more information, see Resource Locations (p. 743). If you need to restore the snapshot to a
volume in a different region, you can copy your snapshot to the new region and then restore it to a
volume in that region. For more information, see Copying an Amazon EBS Snapshot (p. 688).

In the navigation pane, choose Volumes, Create Volume.

In the Create Volume dialog box, for Volume Type, choose General Purpose SSD, Provisioned
IOPS SSD, or Magnetic. For more information, see Amazon EBS Volume Types (p. 638).

Note
Some AWS accounts created before 2012 might have access to Availability Zones in useast-1, us-west-1, or ap-northeast-1 that do not support Provisioned IOPS SSD (io1)
volumes. If you are unable to create an io1 volume (or launch an instance with an io1
volume in its block device mapping) in one of these regions, try a different Availability
Zone in the region. You can verify that an Availability Zone supports io1 volumes by
creating a 4 GiB io1 volume in that zone.
5.

For Snapshot, start typing the ID or description of the snapshot from which you are restoring the
volume, and select it from the list of suggested options.

Note
Volumes that are restored from encrypted snapshots can only be attached to instances
that support Amazon EBS encryption. For more information, see Supported Instance
Types (p. 697).
6.

For Size, enter the size of the volume in GiB, or verify that the default size of the snapshot is
adequate.
If you specify both a volume size and a snapshot ID, the size must be equal to or greater than
the snapshot size. When you select a volume type and a snapshot ID, minimum and maximum
sizes for the volume are shown next to the Size list. Any AWS Marketplace product codes from the
snapshot are propagated to the volume.

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For io1 volumes, in the IOPS field, enter the maximum number of input/output operations per
second (IOPS) that the volume can support.

In the Availability Zone list, select the Availability Zone in which to create the volume. EBS
volumes can only be attached to EC2 instances within the same Availability Zone.

Choose Yes, Create.

Important
If you restored a snapshot to a larger volume than the default for that snapshot, you need
to extend the file system on the volume to take advantage of the extra space. For more
information, see Expanding the Storage Space of an EBS Volume on Linux (p. 671).
After you've restored a volume from a snapshot, you can attach it to an instance to begin using it. For
more information, see Attaching an Amazon EBS Volume to an Instance (p. 654).

To restore an EBS volume using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• create-volume (AWS CLI)
• New-EC2Volume (AWS Tools for Windows PowerShell)

Attaching an Amazon EBS Volume to an Instance
You can attach an EBS volumes to one of your instances that is in the same Availability Zone as the
volume.

Prerequisites
• Determine the device names that you'll use. For more information, see Device Naming on Linux
Instances (p. 729).
• Determine how many volumes you can attach to your instance. For more information, see Instance
Volume Limits (p. 728).
• If a volume is encrypted, it can only be attached to an instance that supports Amazon EBS
encryption. For more information, see Supported Instance Types (p. 697).
• If a volume has an AWS Marketplace product code:
• The volume can only be attached to a stopped instance.
• You must be subscribed to the AWS Marketplace code that is on the volume.
• The configuration (instance type, operating system) of the instance must support that specific
AWS Marketplace code. For example, you cannot take a volume from a Windows instance and
attach it to a Linux instance.
• AWS Marketplace product codes are copied from the volume to the instance.

To attach an EBS volume to an instance using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Volumes.

Select a volume and choose Actions, Attach Volume.

In the Attach Volume dialog box, start typing the name or ID of the instance to attach the volume
to for Instance, and select it from the list of suggestion options (only instances that are in the
same Availability Zone as the volume are displayed).

You can keep the suggested device name, or enter a different supported device name.

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Important
The block device driver for the instance assigns the actual volume name when mounting
the volume, and the name assigned can be different from the name that Amazon EC2
recommends.
6.

Choose Attach.

Connect to your instance and make the volume available. For more information, see Making an
Amazon EBS Volume Available for Use (p. 655).

To attach an EBS volume to an instance using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• attach-volume (AWS CLI)
• Add-EC2Volume (AWS Tools for Windows PowerShell)

Making an Amazon EBS Volume Available for Use
After you attach an Amazon EBS volume to your instance, it is exposed as a block device. You can
format the volume with any file system and then mount it. After you make the EBS volume available for
use, you can access it in the same ways that you access any other volume. Any data written to this file
system is written to the EBS volume and is transparent to applications using the device.
Note that you can take snapshots of your EBS volume for backup purposes or to use as a baseline
when you create another volume. For more information, see Amazon EBS Snapshots (p. 685).

Making the Volume Available on Linux
Use the following procedure to make the volume available. Note that you can get directions for
volumes on a Windows instance from Making the Volume Available on Windows in the Amazon EC2
User Guide for Windows Instances.

To make an EBS volume available for use on Linux
1.

Connect to your instance using SSH. For more information, see Step 2: Connect to Your
Instance (p. 28).

Depending on the block device driver of the kernel, the device might be attached with a different
name than what you specify. For example, if you specify a device name of /dev/sdh, your
device might be renamed /dev/xvdh or /dev/hdh by the kernel; in most cases, the trailing
letter remains the same. In some versions of Red Hat Enterprise Linux (and its variants, such
as CentOS), even the trailing letter might also change (where /dev/sda could become /dev/
xvde). In these cases, each device name trailing letter is incremented the same number of times.
For example, /dev/sdb would become /dev/xvdf and /dev/sdc would become /dev/xvdg.
Amazon Linux AMIs create a symbolic link with the name you specify at launch that points to the
renamed device path, but other AMIs might behave differently.
Use the lsblk command to view your available disk devices and their mount points (if applicable)
to help you determine the correct device name to use.
[ec2-user ~]$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvdf 202:80
0 100G 0 disk
xvda1 202:1
0
8G 0 disk /

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The output of lsblk removes the /dev/ prefix from full device paths. In this example, /dev/xvda1
is mounted as the root device (note the MOUNTPOINT is listed as /, the root of the Linux file system
hierarchy), and /dev/xvdf is attached, but it has not been mounted yet.
3.

Determine whether you need to create a file system on the volume. New volumes are raw block
devices, and you need to create a file system on them before you can mount and use them.
Volumes that have been restored from snapshots likely have a file system on them already; if you
create a new file system on top of an existing file system, the operation overwrites your data. Use
the sudo file -s device command to list special information, such as file system type.
[ec2-user ~]$ sudo file -s /dev/xvdf
/dev/xvdf: data

If the output of the previous command shows simply data for the device, then there is no file
system on the device and you need to create one. You can go on to Step 4 (p. 656). If you run
this command on a device that contains a file system, then your output will be different.
[ec2-user ~]$ sudo file -s /dev/xvda1
/dev/xvda1: Linux rev 1.0 ext4 filesystem data, UUID=1701d228-e1bd-4094a14c-8c64d6819362 (needs journal recovery) (extents) (large files) (huge
files)

In the previous example, the device contains Linux rev 1.0 ext4 filesystem data, so this
volume does not need a file system created (you can skip Step 4 (p. 656) if your output shows
file system data).
4.

(Conditional) Use the following command to create an ext4 file system on the volume. Substitute
the device name (such as /dev/xvdf) for device_name. Depending on the requirements of your
application or the limitations of your operating system, you can choose a different file system type,
such as ext3 or XFS.

Caution
This step assumes that you're mounting an empty volume. If you're mounting a volume
that already has data on it (for example, a volume that was restored from a snapshot),
don't use mkfs before mounting the volume (skip to the next step instead). Otherwise,
you'll format the volume and delete the existing data.
[ec2-user ~]$ sudo mkfs -t ext4 device_name

Use the following command to create a mount point directory for the volume. The mount point is
where the volume is located in the file system tree and where you read and write files to after you
mount the volume. Substitute a location for mount_point, such as /data.
[ec2-user ~]$ sudo mkdir mount_point

Use the following command to mount the volume at the location you just created.
[ec2-user ~]$ sudo mount device_name mount_point

(Optional) To mount this EBS volume on every system reboot, add an entry for the device to the /
etc/fstab file.
a.

Create a backup of your /etc/fstab file that you can use if you accidentally destroy or
delete this file while you are editing it.
[ec2-user ~]$ sudo cp /etc/fstab /etc/fstab.orig

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Open the /etc/fstab file using any text editor, such as nano or vim.

Note
You need to open the file as root or by using the sudo command.
c.

Add a new line to the end of the file for your volume using the following format.
device_name
fs_passno

mount_point

file_system_type

fs_mntops

fs_freq

The last three fields on this line are the file system mount options, the dump frequency
of the file system, and the order of file system checks done at boot time. If you don't
know what these values should be, then use the values in the following example for them
(defaults,nofail 0 2). For more information on /etc/fstab entries, see the fstab
manual page (by entering man fstab on the command line). For example, to mount the ext4
file system on the device /dev/xvdf at the mount point /data, add the following entry to /
etc/fstab.

Note
If you ever intend to boot your instance without this volume attached (for example,
so this volume could move back and forth between different instances), you should
add the nofail mount option that allows the instance to boot even if there are errors
in mounting the volume. Debian derivatives, such as Ubuntu, must also add the
nobootwait mount option.
/dev/xvdf

/data

ext4

defaults,nofail

After you've added the new entry to /etc/fstab, you need to check that your entry works.
Run the sudo mount -a command to mount all file systems in /etc/fstab.
[ec2-user ~]$ sudo mount -a

If the previous command does not produce an error, then your /etc/fstab file is OK and
your file system will mount automatically at the next boot. If the command does produce any
errors, examine the errors and try to correct your /etc/fstab.

Warning
Errors in the /etc/fstab file can render a system unbootable. Do not shut down a
system that has errors in the /etc/fstab file.
e.

(Optional) If you are unsure how to correct /etc/fstab errors, you can always restore your
backup /etc/fstab file with the following command.
[ec2-user ~]$ sudo mv /etc/fstab.orig /etc/fstab

Review the file permissions of your new volume mount to make sure that your users and
applications can write to the volume. For more information about file permissions, see File security
at The Linux Documentation Project.

Viewing Volume Information
You can view descriptive information for your Amazon EBS volumes in a selected region at a time
in the AWS Management Console. You can also view detailed information about a single volume,
including the size, volume type, whether or not the volume is encrypted, which master key was used to
encrypt the volume, and the specific instance to which the volume is attached.

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To view information about an EBS volume using the console
1.
2.
3.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the navigation pane, choose Volumes-.
To view more information about a volume, select it.

To view information about an EBS volume using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• describe-volumes (AWS CLI)
• Get-EC2Volume (AWS Tools for Windows PowerShell)

Monitoring the Status of Your Volumes
Amazon Web Services (AWS) automatically provides data, such as Amazon CloudWatch metrics and
volume status checks, that you can use to monitor your Amazon Elastic Block Store (Amazon EBS)
volumes.
Contents
• Monitoring Volumes with CloudWatch (p. 658)
• Monitoring Volumes with Status Checks (p. 661)
• Monitoring Volume Events (p. 663)
• Working with an Impaired Volume (p. 664)
• Working with the AutoEnableIO Volume Attribute (p. 667)

Monitoring Volumes with CloudWatch
CloudWatch metrics are statistical data that you can use to view, analyze, and set alarms on the
operational behavior of your volumes.
The following table describes the types of monitoring data available for your Amazon EBS volumes.
Type

Description

Basic

Data is available automatically in 5-minute periods at no charge. This includes
data for the root device volumes for EBS-backed instances.

Detailed

Provisioned IOPS SSD (io1) volumes automatically send one-minute metrics to
CloudWatch.

When you get data from CloudWatch, you can include a Period request parameter to specify the
granularity of the returned data. This is different than the period that we use when we collect the data
(5-minute periods). We recommend that you specify a period in your request that is equal to or larger
than the collection period to ensure that the returned data is valid.
You can get the data using either the CloudWatch API or the Amazon EC2 console. The console takes
the raw data from the CloudWatch API and displays a series of graphs based on the data. Depending
on your needs, you might prefer to use either the data from the API or the graphs in the console.

Amazon EBS Metrics
Amazon Elastic Block Store (Amazon EBS) sends data points to CloudWatch for several metrics.
Amazon EBS General Purpose SSD (gp2), Throughput Optimized HDD (st1) , Cold HDD (sc1), and

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Magnetic (standard) volumes automatically send five-minute metrics to CloudWatch. Provisioned IOPS
SSD (io1) volumes automatically send one-minute metrics to CloudWatch. For more information about
how to monitor Amazon EBS, see Monitoring the Status of Your Volumes in the Amazon EC2 User
Guide for Linux Instances.
The AWS/EBS namespace includes the following metrics.
Metric

Description

VolumeReadBytes

Provides information on the I/O operations in a specified period of time.
The Sum statistic reports the total number of bytes transferred during
the period. The Average statistic reports the average size of each I/O
operation during the period. The SampleCount statistic reports the total
number of I/O operations during the period. The Minimum and Maximum
statistics are not relevant for this metric. Data is only reported to Amazon
CloudWatch when the volume is active. If the volume is idle, no data is
reported to Amazon CloudWatch.

VolumeWriteBytes

Units: Bytes
VolumeReadOps
VolumeWriteOps

The total number of I/O operations in a specified period of time.

Note
To calculate the average I/O operations per second (IOPS) for the
period, divide the total operations in the period by the number of
seconds in that period.
Units: Count

VolumeTotalReadTime The total number of seconds spent by all operations that completed in a
specified period of time. If multiple requests are submitted at the same
VolumeTotalWriteTimetime, this total could be greater than the length of the period. For example,
for a period of 5 minutes (300 seconds): if 700 operations completed during
that period, and each operation took 1 second, the value would be 700
seconds.

Units: Seconds
VolumeIdleTime

The total number of seconds in a specified period of time when no read or
write operations were submitted.
Units: Seconds

VolumeQueueLength

The number of read and write operation requests waiting to be completed
in a specified period of time.
Units: Count

VolumeThroughputPercentage
Used with Provisioned IOPS SSD volumes only. The percentage of I/O
operations per second (IOPS) delivered of the total IOPS provisioned for
an Amazon EBS volume. Provisioned IOPS SSD volumes deliver within 10
percent of the provisioned IOPS performance 99.9 percent of the time over
a given year.

Note
During a write, if there are no other pending I/O requests in a
minute, the metric value will be 100 percent. Also, a volume's I/O
performance may become degraded temporarily due to an action
you have taken (e.g., creating a snapshot of a volume during peak
usage, running the volume on a non-EBS-optimized instance,
accessing data on the volume for the first time).

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Metric

Description
Units: Percent

VolumeConsumedReadWriteOps
Used with Provisioned IOPS SSD volumes only. The total amount of read
and write operations (normalized to 256K capacity units) consumed in a
specified period of time.

I/O operations that are smaller than 256K each count as 1 consumed
IOPS. I/O operations that are larger than 256K are counted in 256K
capacity units. For example, a 1024K I/O would count as 4 consumed
IOPS.
Units: Count
BurstBalance

Used with Throughput Optimized HDD (st1) and Cold HDD (sc1) volumes
only. Provides information on the balance available in the burst bucket.
Data is only reported to CloudWatch when the volume is active. If the
volume is not attached, no data is reported.
Units: Percent

Dimensions for Amazon EBS Metrics
The only dimension that Amazon EBS sends to CloudWatch is the volume ID. This means that all
available statistics are filtered by volume ID.

Graphs in the Amazon EC2 Console
After you create a volume, you can view the volume's monitoring graphs in the Amazon EC2 console.
Select a volume on the Volumes page in the console and choose Monitoring. The following table lists
the graphs that are displayed. The column on the right describes how the raw data metrics from the
CloudWatch API are used to produce each graph. The period for all the graphs is 5 minutes.
Graph

Description using raw metrics

Read Bandwidth (KiB/s)

Sum(VolumeReadBytes) / Period / 1024

Write Bandwidth (KiB/s)

Sum(VolumeWriteBytes) / Period / 1024

Read Throughput (Ops/s)

Sum(VolumeReadOps) / Period

Write Throughput (Ops/s)

Sum(VolumeWriteOps) / Period

Avg Queue Length (ops)

Avg(VolumeQueueLength)

% Time Spent Idle

Sum(VolumeIdleTime) / Period * 100

Avg Read Size (KiB/op)

Avg(VolumeReadBytes) / 1024

Avg Write Size (KiB/op)

Avg(VolumeWriteBytes) / 1024

Avg Read Latency (ms/op)

Avg(VolumeTotalReadTime) * 1000

Avg Write Latency (ms/op)

Avg(VolumeTotalWriteTime) * 1000

For the average latency graphs and average size graphs, the average is calculated over the total
number of operations (read or write, whichever is applicable to the graph) that completed during the
period.

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Monitoring Volumes with Status Checks
Volume status checks enable you to better understand, track, and manage potential inconsistencies in
the data on an Amazon EBS volume. They are designed to provide you with the information that you
need to determine whether your Amazon EBS volumes are impaired, and to help you control how a
potentially inconsistent volume is handled.
Volume status checks are automated tests that run every 5 minutes and return a pass or fail status. If
all checks pass, the status of the volume is ok. If a check fails, the status of the volume is impaired.
If the status is insufficient-data, the checks may still be in progress on the volume. You can view
the results of volume status checks to identify any impaired volumes and take any necessary actions.
When Amazon EBS determines that a volume's data is potentially inconsistent, the default is that it
disables I/O to the volume from any attached EC2 instances, which helps to prevent data corruption.
After I/O is disabled, the next volume status check fails, and the volume status is impaired. In
addition, you'll see an event that lets you know that I/O is disabled, and that you can resolve the
impaired status of the volume by enabling I/O to the volume. We wait until you enable I/O to give
you the opportunity to decide whether to continue to let your instances use the volume, or to run a
consistency check using a command, such as fsck (Linux) or chkdsk (Windows), before doing so.

Note
Volume status is based on the volume status checks, and does not reflect the volume state.
Therefore, volume status does not indicate volumes in the error state (for example, when a
volume is incapable of accepting I/O.)
If the consistency of a particular volume is not a concern for you, and you'd prefer that the volume be
made available immediately if it's impaired, you can override the default behavior by configuring the
volume to automatically enable I/O. If you enable the AutoEnableIO volume attribute, the volume
status check continues to pass. In addition, you'll see an event that lets you know that the volume was
determined to be potentially inconsistent, but that its I/O was automatically enabled. This enables you
to check the volume's consistency or replace it at a later time.
The I/O performance status check compares actual volume performance to the expected performance
of a volume and alerts you if the volume is performing below expectations. This status check is only
available for io1 volumes that are attached to an instance and is not valid for General Purpose SSD
(gp2), Throughput Optimized HDD (st1), Cold HDD (sc1), or Magnetic (standard) volumes. The I/O
performance status check is performed once every minute and CloudWatch collects this data every 5
minutes, so it may take up to 5 minutes from the moment you attach a io1 volume to an instance for
this check to report the I/O performance status.

Important
While initializing io1 volumes that were restored from snapshots, the performance of the
volume may drop below 50 percent of its expected level, which causes the volume to display
a warning state in the I/O Performance status check. This is expected, and you can ignore
the warning state on io1 volumes while you are initializing them. For more information, see
Initializing Amazon EBS Volumes (p. 706).
The following table lists statuses for Amazon EBS volumes.
Volume status

I/O enabled status

I/O performance status (only
available for Provisioned IOPS
volumes)

Enabled (I/O Enabled or I/O
Auto-Enabled)

Normal (Volume performance is
as expected)

warning

Enabled (I/O Enabled or I/O
Auto-Enabled)

Degraded (Volume performance
is below expectations)

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Volume status

I/O enabled status

I/O performance status (only
available for Provisioned IOPS
volumes)
Severely Degraded (Volume
performance is well below
expectations)

impaired

insufficient-data

Enabled (I/O Enabled or I/O
Auto-Enabled)

Stalled (Volume performance is
severely impacted)

Disabled (Volume is offline and
pending recovery, or is waiting
for the user to enable I/O)

Not Available (Unable to
determine I/O performance
because I/O is disabled)

Enabled (I/O Enabled or I/O
Auto-Enabled)

Insufficient Data

To view and work with status checks, you can use the Amazon EC2 console, the API, or the command
line interface.

To view status checks in the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Volumes.

On the EBS Volumes page, use the Volume Status column lists the operational status of each
volume.

To view an individual volume's status, select the volume, and choose Status Checks.

If you have a volume with a failed status check (status is impaired), see Working with an
Impaired Volume (p. 664).

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Alternatively, you can use the Events pane to view all events for your instances and volumes in a
single pane. For more information, see Monitoring Volume Events (p. 663).

To view volume status information with the command line
You can use one of the following commands to view the status of your Amazon EBS volumes. For
more information about these command line interfaces, see Accessing Amazon EC2 (p. 3).
• describe-volume-status (AWS CLI)
• Get-EC2VolumeStatus (AWS Tools for Windows PowerShell)

Monitoring Volume Events
When Amazon EBS determines that a volume's data is potentially inconsistent, it disables I/O to the
volume from any attached EC2 instances by default. This causes the volume status check to fail, and
creates a volume status event that indicates the cause of the failure.
To automatically enable I/O on a volume with potential data inconsistencies, change the setting of the
AutoEnableIO volume attribute. For more information about changing this attribute, see Working with
an Impaired Volume (p. 664).
Each event includes a start time that indicates the time at which the event occurred, and a duration that
indicates how long I/O for the volume was disabled. The end time is added to the event when I/O for
the volume is enabled.
Volume status events include one of the following descriptions:
Awaiting Action: Enable IO
Volume data is potentially inconsistent. I/O is disabled for the volume until you explicitly enable it.
The event description changes to IO Enabled after you explicitly enable I/O.
IO Enabled
I/O operations were explicitly enabled for this volume.
IO Auto-Enabled
I/O operations were automatically enabled on this volume after an event occurred. We recommend
that you check for data inconsistencies before continuing to use the data.
Normal
For io1 volumes only. Volume performance is as expected.
Degraded
For io1 volumes only. Volume performance is below expectations.
Severely Degraded
For io1 volumes only. Volume performance is well below expectations.
Stalled
For io1 volumes only. Volume performance is severely impacted.
You can view events for your volumes using the Amazon EC2 console, the API, or the command line
interface.

To view events for your volumes in the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Events.

All instances and volumes that have events are listed. You can filter by volume to view only
volume status. You can also filter on specific status types.

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Select a volume to view its specific event.

If you have a volume where I/O is disabled, see Working with an Impaired Volume (p. 664). If you
have a volume where I/O performance is below normal, this might be a temporary condition due to an
action you have taken (e.g., creating a snapshot of a volume during peak usage, running the volume
on an instance that cannot support the I/O bandwidth required, accessing data on the volume for the
first time, etc.).

To view events for your volumes with the command line
You can use one of the following commands to view event information for your Amazon EBS volumes.
For more information about these command line interfaces, see Accessing Amazon EC2 (p. 3).
• describe-volume-status (AWS CLI)
• Get-EC2VolumeStatus (AWS Tools for Windows PowerShell)

Working with an Impaired Volume
This section discusses your options if a volume is impaired because the volume's data is potentially
inconsistent.
Options

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• Option 1: Perform a Consistency Check on the Volume Attached to its Instance (p. 665)
• Option 2: Perform a Consistency Check on the Volume Using Another Instance (p. 666)
• Option 3: Delete the Volume If You No Longer Need It (p. 667)

Option 1: Perform a Consistency Check on the Volume Attached to its Instance
The simplest option is to enable I/O and then perform a data consistency check on the volume while
the volume is still attached to its Amazon EC2 instance.

To perform a consistency check on an attached volume
1.

Stop any applications from using the volume.

Enable I/O on the volume.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Volumes.

Select the volume on which to enable I/O operations.

In the details pane, choose Enable Volume IO.

In Enable Volume IO, choose Yes, Enable.

Check the data on the volume.
a.

Run the fsck (Linux) or chkdsk (Windows) command.

(Optional) Review any available application or system logs for relevant error messages.

If the volume has been impaired for more than 20 minutes you can contact support. Choose
Troubleshoot, and then on the Troubleshoot Status Checks dialog box, choose Contact
Support to submit a support case.

To enable I/O for a volume with the command line
You can use one of the following commands to view event information for your Amazon EBS volumes.
For more information about these command line interfaces, see Accessing Amazon EC2 (p. 3).
• enable-volume-io (AWS CLI)
• Enable-EC2VolumeIO (AWS Tools for Windows PowerShell)
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Option 2: Perform a Consistency Check on the Volume Using Another Instance
Use the following procedure to check the volume outside your production environment.

Important
This procedure may cause the loss of write I/Os that were suspended when volume I/O was
disabled.

To perform a consistency check on a volume in isolation
1.

Stop any applications from using the volume.

Detach the volume from the instance.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Volumes.

Select the volume to detach.

Choose Actions, Force Detach Volume. You'll be prompted for confirmation.

Enable I/O on the volume.
a.

In the navigation pane, choose Volumes.

Select the volume that you detached in the previous step.

In the details pane, choose Enable Volume IO.

In the Enable Volume IO dialog box, choose Yes, Enable.

Attach the volume to another instance. For information, see Launch Your Instance (p. 278) and
Attaching an Amazon EBS Volume to an Instance (p. 654).

Check the data on the volume.
a.

Run the fsck (Linux) or chkdsk (Windows) command.

(Optional) Review any available application or system logs for relevant error messages.

If the volume has been impaired for more than 20 minutes, you can contact support. Choose
Troubleshoot, and then in the troubleshooting dialog box, choose Contact Support to
submit a support case.

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Option 3: Delete the Volume If You No Longer Need It
If you want to remove the volume from your environment, simply delete it. For information about
deleting a volume, see Deleting an Amazon EBS Volume (p. 671).
If you have a recent snapshot that backs up the data on the volume, you can create a new volume from
the snapshot. For information about creating a volume from a snapshot, see Restoring an Amazon
EBS Volume from a Snapshot (p. 652).

Working with the AutoEnableIO Volume Attribute
When Amazon EBS determines that a volume's data is potentially inconsistent, it disables I/O to
the volume from any attached EC2 instances by default. This causes the volume status check to
fail, and creates a volume status event that indicates the cause of the failure. If the consistency of a
particular volume is not a concern, and you prefer that the volume be made available immediately
if it's impaired, you can override the default behavior by configuring the volume to automatically
enable I/O. If you enable the AutoEnableIO volume attribute, I/O between the volume and the
instance is automatically re-enabled and the volume's status check will pass. In addition, you'll see
an event that lets you know that the volume was in a potentially inconsistent state, but that its I/O
was automatically enabled. When this event occurs, you should check the volume's consistency and
replace it if necessary. For more information, see Monitoring Volume Events (p. 663).
This section explains how to view and modify the AutoEnableIO attribute of a volume using the
Amazon EC2 console, the command line interface, or the API.

To view the AutoEnableIO attribute of a volume in the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Volumes.

Select the volume.

In the lower pane, choose Status Checks.

In the Status Checks tab, Auto-Enable IO displays the current setting for your volume, either
Enabled or Disabled.

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To modify the AutoEnableIO attribute of a volume in the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Volumes.

Select the volume.

At the top of the Volumes page, choose Actions.

Choose Change Auto-Enable IO Setting.

In the Change Auto-Enable IO Setting dialog box, select the Auto-Enable Volume IO option to
automatically enable I/O for an impaired volume. To disable the feature, clear the option.

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Choose Save.

Alternatively, instead of completing steps 4-6 in the previous procedure, choose Status Checks, Edit.

To view or modify the AutoEnableIO attribute of a volume with the command line
You can use one of the following commands to view the AutoEnableIO attribute of your Amazon
EBS volumes. For more information about these command line interfaces, see Accessing Amazon
EC2 (p. 3).
• describe-volume-attribute (AWS CLI)
• Get-EC2VolumeAttribute (AWS Tools for Windows PowerShell)
To modify the AutoEnableIO attribute of a volume, you can use one of the commands below.
• modify-volume-attribute (AWS CLI)
• Edit-EC2VolumeAttribute (AWS Tools for Windows PowerShell)

Detaching an Amazon EBS Volume from an Instance
You can detach an Amazon EBS volume from an instance explicitly or by terminating the instance.
However, if the instance is running, you must first unmount the volume from the instance.;
If an EBS volume is the root device of an instance, you must stop the instance before you can detach
the volume.
When a volume with an AWS Marketplace product code is detached from an instance, the product
code is no longer associated with the instance.

Important
After you detach a volume, you are still charged for volume storage as long as the storage
amount exceeds the limit of the AWS Free Tier. You must delete a volume to avoid incurring
further charges. For more information, see Deleting an Amazon EBS Volume (p. 671).
This example unmounts the volume and then explicitly detaches it from the instance. This is useful
when you want to terminate an instance or attach a volume to a different instance. To verify that the
volume is no longer attached to the instance, see Viewing Volume Information (p. 657).
Note that you can reattach a volume that you detached (without unmounting it), but it might not get the
same mount point and the data on the volume might be out of sync if there were writes to the volume in
progress when it was detached.

To detach an EBS volume using the console
1.

Use the following command to unmount the /dev/sdh device.

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[ec2-user ~]$ umount -d /dev/sdh

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Volumes.

Select a volume and choose Actions, Detach Volume.

In the confirmation dialog box, choose Yes, Detach.

To detach an EBS volume from an instance using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• detach-volume (AWS CLI)
• Dismount-EC2Volume (AWS Tools for Windows PowerShell)

Troubleshooting
This section deals with common problems encountered when detaching volumes, and how to resolve
them.

Note
To guard against the possibility of data loss, take a snapshot of your volume before attempting
to unmount it. Forced detachment of a stuck volume can cause damage to the file system or
the data it contains or an inability to attach a new volume using the same device name, unless
you reboot the instance.
• If you encounter problems while detaching a volume through the Amazon EC2 console, it may be
helpful to use the describe-volumes CLI command to diagnose the issue. For more information, see
describe-volumes>.
• If your volume stays in the detachingstate, you can force the detachment by choosing Force
Detach. Use this option only as a last resort to detach a volume from a failed instance, or if you
are detaching a volume with the intention of deleting it. The instance doesn't get an opportunity to
flush file system caches or file system metadata. If you use this option, you must perform file system
check and repair procedures.
• If you've tried to force the volume to detach multiple times over several minutes and it stays in the
detaching state, you can post a request for help to the Amazon EC2 forum. To help expedite a
resolution, include the volume ID and describe the steps that you've already taken.
• When you attempt to detach a volume that is still mounted, the volume can become stuck in the
busy state while it is trying to detach. The following output from describe-volumes shows an
example of this condition:
[ec2-user ~]$ aws ec2 describe-volumes --region us-west-2 --volume-ids
vol-1234abcd
{
"Volumes": [
{
"AvailabilityZone": "us-west-2b",
"Attachments": [
{
"AttachTime": "2016-07-21T23:44:52.000Z",
"InstanceId": "i-fedc9876",
"VolumeId": "vol-1234abcd",
"State": "busy",
"DeleteOnTermination": false,

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"Device": "/dev/sdf"
}
....

When you encounter this state, detachment can be delayed indefinitely until you unmount the
volume, force detachment, reboot the instance, or all three.

Deleting an Amazon EBS Volume
After you no longer need an Amazon EBS volume, you can delete it. After deletion, its data is gone and
the volume can't be attached to any instance. However, before deletion, you can store a snapshot of
the volume, which you can use to re-create the volume later.
To delete a volume, it must be in the available state (not attached to an instance).

To delete an EBS volume using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Volumes.

Select a volume and choose Actions, Delete Volume.

In the confirmation dialog box, choose Yes, Delete.

To delete an EBS volume using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• delete-volume (AWS CLI)
• Remove-EC2Volume (AWS Tools for Windows PowerShell)

Expanding the Storage Space of an EBS Volume on Linux
You can increase the storage space of an existing EBS volume without losing the data on the volume.
To do this, you migrate your data to a larger volume and then extend the file system on the volume to
recognize the newly-available space. After you verify that your new volume is working properly, you
can delete the old volume.
Tasks
• Migrating Your Data to a Larger Volume (p. 672)
• Extending a Linux File System (p. 673)
• Deleting the Old Volume (p. 675)
If you need to expand the storage space of a volume on a Windows instance, see Expanding the
Storage Space of a Volume in the Amazon EC2 User Guide for Windows Instances.
If you create a larger volume, you will be charged for the additional storage. For more information, see
the Amazon Elastic Block Store section on the Amazon EC2 Pricing page.

Note
If your storage needs demand a larger EBS volume than AWS provides, you may want to
use RAID 0 to "stripe" a single logical volume across multiple physical volumes. For more
information see RAID Configuration on Linux.

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Migrating Your Data to a Larger Volume
You must stop your instance to expand the storage space. When you stop and start an instance, be
aware of the following:
• Any data on any instance store volumes is erased. Therefore, if you have any data on instance store
volumes that you want to keep, back it up to persistent storage.
• If your instance is running in a VPC and has a public IP address, we release the address and give it
a new public IP address. The instance retains its private IP addresses and any Elastic IP addresses.
• If your instance is running in EC2-Classic, we give it new public and private IP addresses, and
disassociate any Elastic IP address that's associated with the instance. You must re-associate any
Elastic IP address after you restart your instance.
• If your instance is in an Auto Scaling group, the Auto Scaling service marks the stopped instance
as unhealthy, and may terminate it and launch a replacement instance. To prevent this, you can
temporarily suspend the Auto Scaling processes for the group. For more information, see Suspend
and Resume Auto Scaling Processes in the Auto Scaling User Guide.

To migrate your data to a larger volume
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances and then locate the instance with the volume that you
want to expand.

Make a note of the instance ID and Availability Zone. You will specify this information when you
attach a new volume to the instance later in this procedure.

Verify that the instance Shutdown Behavior is set to Stop and not Terminate.
a.

Choose the instance.

From the context-menu (right-click) choose Instance Settings, and then choose Change
Shutdown Behavior.

If the Shutdown behavior is set to Terminate, choose Stop, and then choose Apply.
If the Shutdown behavior is already set to Stop, then choose Cancel.

Stop the instance. For more information about how to stop an instance, see Stopping and Starting
Your Instances (p. 300).

Create a snapshot of the volume to expand.
a.

In the navigation pane, choose Volumes, and then locate the volume you want to expand.

From the context-menu (right-click) choose the volume that you want to expand, and then
choose Create Snapshot.

Enter information in the Name and Description fields, and then choose Yes, Create.

Create a new volume from the snapshot.
a.

In the navigation pane, choose Snapshots.

When the status of the snapshot that you just created is set to completed, choose the
snapshot, and then from the context-menu (right-click) choose Create Volume.

In the Create Volume dialog box, choose the desired volume type and enter the new volume
size. You must also set the Availability Zone to match the instance Availability Zone. Choose
Yes, Create.
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Important
If you do not set the Availability Zone to match the instance then you will not be
able to attach the new volume to the instance.
8.

Detach the old volume.
a.

In the navigation pane, choose Volumes, and then choose the old volume from the list.
Make a note of the device name in the Attachment Information field. You will specify
this information when you attach a new volume to the instance later in this procedure. The
information appears in the following format:
i-xxxxxxxxxxxxxxxxx (instance_name):device_name

From the context-menu (right-click) choose the old volume, and then choose Detach Volume.

In the Detach Volume dialog box, choose Yes, Detach. It may take several minutes for the
volume to detach.

Attach the newly expanded volume
a.

In the navigation pane, choose Volumes.

From the context-menu (right-click) choose the new volume, and then choose Attach
Volume.

Start typing the name or ID of the instance in the Instance field, and then choose the
instance.

Enter the same device name retrieved in Step 8.a (p. 673), and then choose Yes, Attach.
It is important to attach the new volume to the exact location you noted above (for example /
dev/sda1).

10. Restart the instance.
a.

In the navigation pane, choose Instances and then choose the instance you want to restart.

From the context-menu (right-click) choose Instance State, and then choose Start.

In the Start Instances dialog box, choose Yes, Start. If the instance fails to start, and the
volume being expanded is a root volume, verify that you attached the expanded volume using
the same device name as the original volume, for example /dev/sda1.

After the instance has started, you can check the file system size to see if your instance recognizes the
larger volume space. On Linux, use the df -h command to check the file system size.
[ec2-user ~]$ df -h
Filesystem
/dev/xvda1
tmpfs

Size
7.9G
1.9G

Used Avail Use% Mounted on
943M 6.9G 12% /
0 1.9G
0% /dev/shm

If the size does not reflect your newly-expanded volume, you must extend the file system of your
device so that your instance can use the new space. For more information, see Extending a Linux File
System (p. 673).

Extending a Linux File System
In Linux, you use a file system-specific command to resize the file system to the larger size of the
new volume. This command works even if the volume you wish to extend is the root volume. For
ext2, ext3, and ext4 file systems, this command is resize2fs. For XFS file systems, this command
is xfs_growfs. For other file systems, refer to the specific documentation for those file systems for
instructions on extending them.

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If you are unsure of which file system you are using, you can use the file -s command to list the file
system data for a device. The following example shows a Linux ext4 file system and an SGI XFS file
system.
[ec2-user ~]$ sudo file -s /dev/xvd*
/dev/xvda1: Linux rev 1.0 ext4 filesystem data ...
/dev/xvdf: SGI XFS filesystem data ...

Note
If the volume you are extending has been partitioned, you need to increase the size of the
partition before you can resize the file system. For more information, see Expanding a Linux
Partition (p. 676).

To check if your volume partition needs resizing
•

Use the lsblk command to list the block devices attached to your instance. The example below
shows three volumes: /dev/xvda, /dev/xvdb, and /dev/xvdf.
[ec2-user ~]$ lsblk
NAME
MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda
202:0
0 30G 0 disk
##xvda1 202:1
0 30G 0 part /
xvdb
202:16
0 30G 0 disk /mnt
xvdf
202:80
0 35G 0 disk
##xvdf1 202:81
0
8G 0 part

The root volume, /dev/xvda1, is a partition on /dev/xvda. Notice that they are both 30 GiB in
size. In this case, the partition occupies all of the room on the device, so it does not need resizing.
The volume /dev/xvdb is not partitioned at all, so it does not need resizing.
However, /dev/xvdf1 is an 8 GiB partition on a 35 GiB device and there are no other partitions
on the volume. In this case, the partition must be resized in order to use the remaining space on
the volume. For more information, see Expanding a Linux Partition (p. 676). After you resize the
partition, you can follow the next procedure to extend the file system to occupy all of the space on
the partition.

To extend a Linux file system
1.

Log in to your Linux instance using an SSH client. For more information about connecting to a
Linux instance, see Connecting to Your Linux Instance Using SSH (p. 289).

Use the df -h command to report the existing file system disk space usage. In this example, the /
dev/xvda1 device has already been expanded to 70 GiB, but the ext4 file system only sees the
original 8 GiB size, and the /dev/xvdf device has been expanded to 100 GiB, but the XFS file
system only sees the original 1 GiB size.
[ec2-user ~]$ df -h
Filesystem
/dev/xvda1
tmpfs
/dev/xvdf

Size
7.9G
1.9G
1014M

Used Avail Use% Mounted on
943M 6.9G 12% /
0 1.9G
0% /dev/shm
33M 982M
4% /mnt

Use the file system-specific command to resize the file system to the new size of the volume. For a
Linux ext2, ext3, or ext4 file system, use the following command, substituting the device name
that you want to extend.
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[ec2-user ~]$ sudo resize2fs /dev/xvda1
resize2fs 1.42.3 (14-May-2012)
Filesystem at /dev/xvda1 is mounted on /; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 5
Performing an on-line resize of /dev/xvda1 to 18350080 (4k) blocks.
The filesystem on /dev/xvda1 is now 18350080 blocks long.

For an XFS file system, first install the XFS userspace tools:
[ec2-user ~]$ sudo yum install xfsprogs

Then use the following command, substituting the mount point of the file system (XFS file systems
must be mounted to resize them).
[ec2-user ~]$ sudo xfs_growfs -d /mnt
meta-data=/dev/xvdf
isize=256
=
sectsz=512
data
=
bsize=4096
=
sunit=0
naming
=version 2
bsize=4096
log
=internal
bsize=4096
=
sectsz=512
realtime =none
extsz=4096
data blocks changed from 262144 to 26214400

agcount=4, agsize=65536 blks
attr=2
blocks=262144, imaxpct=25
swidth=0 blks
ascii-ci=0
blocks=2560, version=2
sunit=0 blks, lazy-count=1
blocks=0, rtextents=0

Note
If you receive an xfsctl failed: Cannot allocate memory error, you may need
to update the Linux kernel on your instance. For more information, refer to your specific
operating system documentation.
If you receive an The filesystem is already nnnnnnn blocks long. Nothing
to do! error, see Expanding a Linux Partition (p. 676).
4.

Use the df -h command to report the existing file system disk space usage, which should now
show the full 70 GiB on the ext4 file system and 100 GiB on the XFS file system.
# df -h
Filesystem
/dev/xvda1
tmpfs
/dev/xvdf

Size
69G
1.9G
100G

Used Avail Use% Mounted on
951M
68G
2% /
0 1.9G
0% /dev/shm
45M 100G
1% /mnt

Deleting the Old Volume
After the new volume has been attached and extended in the instance, you can delete the old volume if
it is no longer needed.

To delete the old volume
1.

In the Amazon EC2 console, choose Volumes in the navigation pane and then choose the volume
you want to delete.

From the context-menu (right-click) choose Delete Volume.

In the Delete Volume dialog box, choose Yes, Delete.

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Expanding a Linux Partition
Some Amazon EC2 root volumes and volumes that are restored from snapshots contain a partition that
actually holds the file system and the data. If you think of a volume as a container, a partition is another
container inside the volume, and the data resides on the partition. Growing the volume size does not
grow the partition; to take advantage of a larger volume, the partition must be expanded to the new
size.

Note
Not all volumes restored from snapshots are partitioned, and this procedure may not apply to
your volume. You may just need to resize the file system on your volume to make all of the
space available. If you are not sure if your volume has a partition that needs resizing, see To
check if your volume partition needs resizing (p. 674) for more information.
If the partition you want to expand is not the root partition, then you can simply unmount it and resize
the partition from the instance itself. If the partition you need to resize is the root partition for an
instance, the process becomes more complicated because you cannot unmount the root partition of a
running instance. You have to perform the following procedures on another instance, which is referred
to as a secondary instance.

Important
The following procedures were written for and tested on Amazon Linux. Other distributions
with different tool sets and tool versions may behave differently.
Topics
• Preparing a Linux Root Partition for Expansion (p. 676)
• Expanding a Linux Partition Using parted (p. 677)
• Expanding a Linux Partition Using gdisk (p. 681)
• Returning an Expanded Partition to its Original Instance (p. 685)

Preparing a Linux Root Partition for Expansion
There are several steps that you need to take to expand the root partition of an instance. If the partition
you need to expand is not the root partition, then this procedure is not necessary.

To prepare a Linux root partition for expansion
1.

If your primary instance is running, stop it. You cannot perform the rest of this procedure on a
running instance. For more information, see Stop and Start Your Instance (p. 299).

Check the integrity of your volume. File-system corruption that is picked up by the snapshot may
render a restored root volume unbootable.

Take a snapshot of your volume. It can be easy to corrupt or lose your data in the following
procedures. If you have a fresh snapshot, you can always start over in case of a mistake and your
data will still be safe. For more information, see Creating an Amazon EBS Snapshot (p. 686).

Record the device name that the volume is attached to. You can find this information on the Root
device field of the instance's details pane. The value is likely /dev/sda1 or /dev/xvda.

Detach the volume from the primary instance. For more information, see Detaching an Amazon
EBS Volume from an Instance (p. 669).

Attach the volume to another (secondary) instance in the same Availability Zone. For more
information, see Attaching an Amazon EBS Volume to an Instance (p. 654). If your EBS
volume is encrypted, you must use a secondary instance that supports Amazon EBS encryption;
otherwise, you can use a t2.micro instance for this procedure. For more information, see
Supported Instance Types (p. 697). If you do not already have a secondary instance, you will
need to launch one. For more information, see Launching an Instance (p. 279).

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Important
The secondary instance must be running when you attach the volume, and you should
not reboot the secondary instance while multiple root volumes are attached; booting an
instance with multiple root volumes attached could cause the instance to boot to the
wrong volume.
7.

Log in to the secondary instance with SSH. For more information, see Connect to Your Linux
Instance (p. 289). Continue with the next procedure.

Expanding a Linux Partition Using parted
The parted utility is a partition editing tool that is available on most Linux distributions. It can create
and edit both MBR partition tables and GPT partition tables. Some versions of parted (newer than
version 2.1) have limited support for GPT partition tables and they may cause boot issues if their
version of parted is used to modify boot volumes. You can check your version of parted with the
parted --version command.
If you are expanding a partition that resides on a GPT partitioned device, you should choose to use the
gdisk utility instead. If you're not sure which disk label type your volume uses, you can check it with the
sudo fdisk -l command. For more information, see To expand a Linux partition using gdisk (p. 681).

To expand a Linux partition using parted
If the partition you need to expand is the root partition, be sure to follow the steps in To prepare a Linux
root partition for expansion (p. 676) first.
1.

Identify the device that contains the partition that you want to expand. Use the lsblk command to
list all devices and partitions attached to the instance.
[ec2-user ~]$ lsblk
NAME
MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvdf
202:80
0 100G 0 disk
##xvdf1 202:81
0
8G 0 part /mnt
xvda1
202:1
0
30G 0 disk /

In this example, the xvdf device has 100 GiB of available storage and it contains an 8 GiB
partition.
2.

Unmount the partition if it is mounted. Run the umount command with the value of MOUNTPOINT
from the lsblk command. In this example, the MOUNTPOINT value for the partition is /mnt.
[ec2-user ~]$ sudo umount /mnt

Take a snapshot of your volume (unless you just took one in the previous procedure). It can be
easy to corrupt or lose your data in the following procedures. If you have a fresh snapshot, you
can always start over in case of a mistake and your data will still be safe. For more information,
see Creating an Amazon EBS Snapshot (p. 686).

Run the parted command on the device (and not the partition on the device). Remember to add
the /dev/ prefix to the name that lsblk outputs.
[ec2-user ~]$ sudo parted /dev/xvdf
GNU Parted 2.1
Using /dev/xvdf
Welcome to GNU Parted! Type 'help' to view a list of commands.

Change the parted units of measure to sectors.

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(parted) unit s

Run the print command to list the partitions on the device. For certain partition table types, you
might be prompted to repair the partition table for the larger volume size. Answer 'Ignore' to any
questions about fixing the existing partition table; you will create a new table later.
(parted) print

If you receive the following message, enter 'Ignore' to prevent the backup GPT location from
changing.
Error: The backup GPT table is not at the end of the disk, as it
should be. This might mean that another operating
system believes the disk is smaller. Fix, by moving the backup to the
end (and removing the old backup)?
Fix/Ignore/Cancel? Ignore

If you receive the following message, enter 'Ignore' again to keep the space on the drive the
same.
Warning: Not all of the space available to /dev/xvdf appears to be
used, you can fix the GPT to use all of the
space (an extra 46137344 blocks) or continue with the current setting?
Fix/Ignore? Ignore

Examine the output for the total size of the disk, the partition table type, the number of the
partition, the start point of the partition, and any flags, such as boot. For gpt partition tables, note
the name of the partition; for msdos partition tables, note the Type field (primary or extended).
These values are used in the upcoming steps.
The following is a gpt partition table example.
Model: Xen Virtual Block Device (xvd)
Disk /dev/xvdf: 209715200s
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start
Flags
128
2048s
bios_grub
1
4096s

End

Size

4095s

2048s

16777182s

16773087s

File system

Name
BIOS Boot Partition

ext4

Linux

The following is an msdos partition table example.
Model: Xen Virtual Block Device (xvd)
Disk /dev/xvdg: 104857600s
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number
1

Start
2048s

End
35649535s

Size
35647488s

Type
primary

File system
ext3

Flags

Delete the partition entry for the partition using the number (1) from the previous step.

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(parted) rm 1

Create a new partition that extends to the end of the volume.
(For the gpt partition table example) Note the start point and name of partition 1 above. For the
gpt example, there is a start point of 4096s, and the name Linux. Run the mkpart command with
the start point of partition 1, the name, and 100% to use all of the available space.
(parted) mkpart Linux 4096s 100%

(For the msdos partition table example) Note the start point and the partition type of partition 1
above. For the msdos example, there is a start point of 2048s and a partition type of primary.
Run the mkpart command with a primary partition type, the start point of partition 1, and 100% to
use all of the available space.
(parted) mkpart primary 2048s 100%

10. Run the print command again to verify your partition.
(For the gpt partition table example)
(parted) print
Model: Xen Virtual Block Device (xvd)
Disk /dev/xvdf: 209715200s
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start
Flags
128
2048s
bios_grub
1
4096s

End

Size

4095s

2048s

209713151s

209709056s

File system

Name
BIOS Boot Partition

ext4

Linux

(For the msdos partition table example)
(parted) print
Model: Xen Virtual Block Device (xvd)
Disk /dev/xvdg: 104857600s
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Number
1

Start
2048s

End
104857599s

Size
104855552s

Type
primary

File system
ext3

Flags

11. Check to see that any flags that were present earlier are still present for the partition that you
expanded. In some cases the boot flag may be lost. If a flag was dropped from the partition when
it was expanded, add the flag with the following command, substituting your partition number and
the flag name. For example, the following command adds the boot flag to partition 1.
(parted) set 1 boot on

You can run the print command again to verify your change.
12. Run the quit command to exit parted.

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(parted) quit

Note
Because you removed a partition and added a partition, parted may warn that you may
need to update /etc/fstab. This is only required if the partition number changes.
13. Check the file system to make sure there are no errors (this is required before you may extend
the file system). Note the file system type from the previous print commands. Choose one of the
commands below based on your file system type; if you are using a different file system, consult
the documentation for that file system to determine the correct check command.
(For ext3 or ext4 file systems)
[ec2-user ~]$ sudo e2fsck -f /dev/xvdf1
e2fsck 1.42.3 (14-May-2012)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/: 31568/524288 files (0.4% non-contiguous), 266685/2096635 blocks

(For xfs file systems)
[ec2-user
Phase 1 Phase 2 Phase 3 Phase 4 Phase 5 Phase 6 Phase 7 done

~]$ sudo xfs_repair /dev/xvdf1
find and verify superblock...
using internal log
zero log...
scan filesystem freespace and inode maps...
found root inode chunk
for each AG...
scan and clear agi unlinked lists...
process known inodes and perform inode discovery...
agno = 0
agno = 1
agno = 2
agno = 3
process newly discovered inodes...
check for duplicate blocks...
setting up duplicate extent list...
check for inodes claiming duplicate blocks...
agno = 0
agno = 1
agno = 2
agno = 3
rebuild AG headers and trees...
reset superblock...
check inode connectivity...
resetting contents of realtime bitmap and summary inodes
traversing filesystem ...
traversal finished ...
moving disconnected inodes to lost+found ...
verify and correct link counts...

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14. The next steps differ depending on whether the expanded partition belongs on the current instance
or if it is the root partition for another instance.
• If this partition belongs on the current instance, remount the partition at the MOUNTPOINT
identified in Step 2 (p. 677).
[ec2-user ~]$ sudo mount /dev/xvdf1 /mnt

After you have mounted the partition, extend the file system to use the newly available space by
following the procedures in Extending a Linux File System (p. 673).
• If this volume is the root partition for another instance, proceed to the procedures in Returning
an Expanded Partition to its Original Instance (p. 685).

Expanding a Linux Partition Using gdisk
The gdisk utility (sometimes called GPT fdisk) is a text-based, menu-driven tool for creating and
editing partition tables, and it has better support for GPT partition tables than parted in some
distributions. Many common Linux distributions (such as Amazon Linux and Ubuntu) provide gdisk
by default. If your distribution does not provide the gdisk command, you can find out how to get it by
visiting Obtaining GPT fdisk; in many cases, it is much easier to launch an Amazon Linux instance to
use as a secondary instance because the gdisk command is already available.

To expand a Linux partition using gdisk
If the partition you need to expand is the root partition, be sure to follow the steps in To prepare a Linux
root partition for expansion (p. 676) first.
1.

Identify the device that contains the partition that you want to expand. Use the lsblk command to
list all devices and partitions attached to the instance.
[ec2-user ~]$ lsblk
NAME
MAJ:MIN RM SIZE RO MOUNTPOINT
xvdf
202:80
0 100G 0
##xvdf1 202:81
0 9.9G 0 /mnt
xvda1
202:1
0
30G 0 /

In this example, the xvdf device has 100 GiB of available storage and it contains an 9.9 GiB
partition.
2.

Run the gdisk command on the device (and not the partition on the device). Remember to add the
/dev/ prefix to the name that lsblk outputs.
[ec2-user ~]$ sudo gdisk /dev/xvdf
gdisk /dev/xvdf
GPT fdisk (gdisk) version 0.8.10

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Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: present
Found valid GPT with protective MBR; using GPT.

Run the p command to print the partition table for the device.

Examine the output for the disk identifier, partition number, starting sector, code for the partition,
and name of the partition. If your volume has multiple partitions, take note of each one.
Command (? for help): p
Disk /dev/xvdf: 209715200 sectors, 100.0 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 947F4655-F3BF-4A1F-8203-A7B30C2A4425
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 20705246
Partitions will be aligned on 2048-sector boundaries
Total free space is 2108 sectors (1.0 MiB)
Number
1

Start (sector)
2048

End (sector) Size
20705152
9.9 GiB

Code
EF00

Name
lxroot

In the above example the disk identifier is 947F4655-F3BF-4A1F-8203-A7B30C2A4425, the
partition number is 1, the starting sector is 2048, the code is EF00, and the name is lxroot.
7.

Because the existing partition table was originally created for a smaller volume, you need to create
a new partition table for the larger volume. Run the o command to create a new, empty partition
table.
Command (? for help): o
This option deletes all partitions and creates a new protective MBR.
Proceed? (Y/N): Y

Use the n command to create a new partition entry for each partition on the device.
•

If your volume has only one partition, at each prompt, enter the values that you recorded
earlier. For the last sector value, use the default value to expand to the entire volume size.
Command (? for help): n
Partition number (1-128, default 1): 1
First sector (34-209715166, default = 2048) or {+-}size{KMGTP}: 2048
Last sector (2048-209715166, default = 209715166) or
{+-}size{KMGTP}: 209715166
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300): EF00
Changed type of partition to 'EFI System'

•

If your volume has more than one partition, there is likely a BIOS boot partition, and a main
data partition. Create a new partition entry for the BIOS boot partition using the values that
you recorded earlier. Create another new partition entry for the main data partition using the
values that you recorded earlier, but for the last sector value, use the default value to expand
to the entire volume size.
Command (? for help): n
Partition number (1-128, default 1): 1
First sector (34-209715166, default = 2048) or {+-}size{KMGTP}:
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Last sector (2048-209715166, default = 209715166) or
{+-}size{KMGTP}: 4095
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300): EF02
Changed type of partition to 'BIOS boot partition'
Command (? for help): n
Partition number (2-128, default 2): 2
First sector (34-209715166, default = 4096) or {+-}size{KMGTP}: 4096
Last sector (4096-209715166, default = 209715166) or
{+-}size{KMGTP}: 209715166
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300): 0700
Changed type of partition to 'Microsoft basic data'

Use the c command to change the name of each partition to the name of the previous partition. If
your partition did not have a name, simply type Enter.
Command (? for help): c
Using 1
Enter name: lxroot

10. Use the x command to enter the expert command menu.
11. Use the g command to change the disk identifier to the original value.
Expert command (? for help): g
Enter the disk's unique GUID ('R' to randomize): 947F4655-F3BF-4A1F-8203A7B30C2A4425
The new disk GUID is 947F4655-F3BF-4A1F-8203-A7B30C2A4425

12. Use the w command to write the changes to the device and exit.
Expert command (? for help): w
Final checks complete. About to write GPT data. THIS WILL OVERWRITE
EXISTING
PARTITIONS!!
Do you want to proceed? (Y/N): Y
OK; writing new GUID partition table (GPT) to /dev/xvdf.
The operation has completed successfully.

13. Check the file system to make sure there are no errors (this is required before you may extend the
file system).
a.

Find the file system type with the following command, substituting the partition you just
expanded (this may be /dev/xvdf2 if your volume had multiple partitions).
[ec2-user ~]$ sudo file -sL /dev/xvdf1

Choose one of the commands below based on your file system type; if you are using a
different file system, consult the documentation for that file system to determine the correct
check command.
(For ext3 or ext4 file systems)
[ec2-user ~]$ sudo e2fsck -f /dev/xvdf1
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Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/: 31568/524288 files (0.4% non-contiguous), 266685/2096635 blocks

(For xfs file systems)

Note
You may need to install the xfsprogs package to work with XFS file systems. Use
the following command to add XFS support to your Amazon Linux instance.
[ec2-user ~]$ sudo yum install -y xfsprogs

[ec2-user
Phase 1 Phase 2 Phase 3 Phase 4 Phase 5 Phase 6 Phase 7 done

After you have mounted the partition, extend the file system to use the newly available space by
following the procedures in Extending a Linux File System (p. 673).
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• If this volume is the root partition for another instance, proceed to the procedures in Returning
an Expanded Partition to its Original Instance (p. 685).

Returning an Expanded Partition to its Original Instance
If you expanded a root partition from another instance, follow this procedure to return the volume to its
original instance.

To return an expanded root partition to its original instance
1.

Detach the expanded partition from its secondary instance. For more information, see Detaching
an Amazon EBS Volume from an Instance (p. 669).

Reattach the volume to the primary instance using the device name that you identified in Step
4 (p. 676) of the preparation procedure (p. 676). For more information, see Attaching an
Amazon EBS Volume to an Instance (p. 654).

Start the primary instance. For more information, see Stop and Start Your Instance (p. 299).

(Optional) If you launched a secondary instance for the sole purpose of expanding the partition,
you can terminate the instance to stop incurring charges. For more information, see Terminate
Your Instance (p. 305).

Connect to your primary instance and extend the file system to use the newly available space by
following the procedures in Extending a Linux File System (p. 673).

After you are finished with this expanding the file system, you can create an AMI from the instance that
you can use to launch new instances with the desired partition size. For more information, see Amazon
Machine Images (AMI) (p. 69).

Amazon EBS Snapshots
You can back up the data on your EBS volumes to Amazon S3 by taking point-in-time snapshots.
Snapshots are incremental backups, which means that only the blocks on the device that have
changed after your most recent snapshot are saved. This minimizes the time required to create the
snapshot and saves on storage costs. When you delete a snapshot, only the data unique to that
snapshot is removed. Active snapshots contain all of the information needed to restore your data (from
the time the snapshot was taken) to a new EBS volume.
Contents
• Snapshot Overview (p. 685)
• Creating an Amazon EBS Snapshot (p. 686)
• Deleting an Amazon EBS Snapshot (p. 687)
• Copying an Amazon EBS Snapshot (p. 688)
• Viewing Amazon EBS Snapshot Information (p. 690)
• Sharing an Amazon EBS Snapshot (p. 691)

Snapshot Overview
When you create an EBS volume, you can create it based on an existing snapshot. The new
volume begins as an exact replica of the original volume that was used to create the snapshot.
When you create a volume from an existing snapshot, it loads lazily in the background so that you
can begin using them right away. If you access a piece of data that hasn't been loaded yet, the
volume immediately downloads the requested data from Amazon S3, and then continues loading the
rest of the volume's data in the background. For more information, see Creating an Amazon EBS
Snapshot (p. 686).

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By modifying their access permissions, snapshots can be shared across AWS accounts. You can
makes copies of your own snapshots as well as snapshots that have been shared with you. For more
information, see Sharing an Amazon EBS Snapshot (p. 691).
EBS snapshots broadly support EBS encryption:
• Snapshots of encrypted volumes are automatically encrypted.
• Volumes that are created from encrypted snapshots are automatically encrypted.
• When you copy an unencrypted snapshot that you own, you can encrypt it during the copy process.
• When you copy an encrypted snapshot that you own, you can reencrypt it with a different key during
the copy process.
For more information, see Amazon EBS Encryption.
Snapshots are constrained to the region in which they are created. After you have created a snapshot
of an EBS volume, you can use it to create new volumes in the same region. For more information,
see Restoring an Amazon EBS Volume from a Snapshot (p. 652). You can also copy snapshots
across regions, making it easier to leverage multiple regions for geographical expansion, data center
migration, and disaster recovery. You can copy any accessible snapshots that have a completed
status. For more information, see Copying an Amazon EBS Snapshot (p. 688).

Creating an Amazon EBS Snapshot
After writing data to an EBS volume, you can periodically create a snapshot of the volume to use
as a baseline for new volumes or for data backup. If you make periodic snapshots of a volume,
the snapshots are incremental so that only the blocks on the device that have changed after your
last snapshot are saved in the new snapshot. Even though snapshots are saved incrementally, the
snapshot deletion process is designed so that you need to retain only the most recent snapshot in
order to restore the volume.
Snapshots occur asynchronously; the point-in-time snapshot is created immediately, but the status of
the snapshot is pending until the snapshot is complete (when all of the modified blocks have been
transferred to Amazon S3), which can take several hours for large initial snapshots or subsequent
snapshots where many blocks have changed. While it is completing, an in-progress snapshot is not
affected by ongoing reads and writes to the volume.

Important
Although you can take a snapshot of a volume while a previous snapshot of that volume is in
the pending status, having multiple pending snapshots of a volume may result in reduced
volume performance until the snapshots complete.
There is a limit of 5 pending snapshots for a single volume. If you receive a
ConcurrentSnapshotLimitExceeded error while trying to create multiple concurrent
snapshots of the same volume, wait for one or more of the pending snapshots to complete
before creating another snapshot of that volume.
Snapshots that are taken from encrypted volumes are automatically encrypted. Volumes that are
created from encrypted snapshots are also automatically encrypted. The data in your encrypted
volumes and any associated snapshots is protected both at rest and in motion. For more information,
see Amazon EBS Encryption.
By default, only you can create volumes from snapshots that you own. However, you can share
your unencrypted snapshots with specific AWS accounts, or you can share them with the entire
AWS community by making them public. For more information, see Sharing an Amazon EBS
Snapshot (p. 691).
You can share an encrypted snapshot only with specific AWS accounts. For others to use your shared,
encrypted snapshot, you must also share the CMK key that was used to encrypt it. Users with access
to your encrypted snapshot must create their own personal copy of it and then use that copy to restore

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the volume. Your copy of a shared, encrypted snapshot can also be re-encrypted with a different key.
For more information, see Sharing an Amazon EBS Snapshot (p. 691).
When a snapshot is created from a volume with an AWS Marketplace product code, the product code
is propagated to the snapshot.
You can take a snapshot of an attached volume that is in use. However, snapshots only capture data
that has been written to your Amazon EBS volume at the time the snapshot command is issued. This
might exclude any data that has been cached by any applications or the operating system. If you can
pause any file writes to the volume long enough to take a snapshot, your snapshot should be complete.
However, if you can't pause all file writes to the volume, you should unmount the volume from within
the instance, issue the snapshot command, and then remount the volume to ensure a consistent and
complete snapshot. You can remount and use your volume while the snapshot status is pending.
To create a snapshot for Amazon EBS volumes that serve as root devices, you should stop the
instance before taking the snapshot.
To unmount the volume in Linux, use the following command:
umount -d device_name

Where device_name is the device name (for example, /dev/sdh).
After you've created a snapshot, you can tag it to help you manage it later. For example, you can add
tags describing the original volume from which the snapshot was created, or the device name that was
used to attach the original volume to an instance. For more information, see Tagging Your Amazon
EC2 Resources (p. 751).

To create a snapshot using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.
4.

Choose Snapshots in the navigation pane.
Choose Create Snapshot.
In the Create Snapshot dialog box, select the volume to create a snapshot for, and then choose
Create.

To create a snapshot using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• create-snapshot (AWS CLI)
• New-EC2Snapshot (AWS Tools for Windows PowerShell)

Deleting an Amazon EBS Snapshot
When you delete a snapshot, only the data exclusive to that snapshot is removed. Deleting previous
snapshots of a volume does not affect your ability to restore volumes from later snapshots of that
volume.
If you make periodic snapshots of a volume, the snapshots are incremental so that only the blocks on
the device that have changed since your last snapshot are saved in the new snapshot. Even though
snapshots are saved incrementally, the snapshot deletion process is designed so that you need to
retain only the most recent snapshot in order to restore the volume.
Note that you can't delete a snapshot of the root device of an EBS volume used by a registered AMI.
You must first deregister the AMI before you can delete the snapshot. For more information, see
Deregistering Your AMI (p. 140).

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To delete a snapshot using the console
1.
2.
3.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
Choose Snapshots in the navigation pane.
Select a snapshot and then choose Delete from the Actions list.

Choose Yes, Delete.

To delete a snapshot using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• delete-snapshot (AWS CLI)
• Remove-EC2Snapshot (AWS Tools for Windows PowerShell)

Copying an Amazon EBS Snapshot
With Amazon EBS, you can create point-in-time snapshots of volumes which we store for you in
Amazon Simple Storage Service (Amazon S3). After you've created a snapshot and it has finished
copying to Amazon S3 (when the snapshot status is completed), you can copy it from one AWS
region to another, or within the same region. Amazon S3 server-side encryption (256-bit AES) protects
a snapshot's data-in-transit during copying. The snapshot copy receives a snapshot ID different from
the original snapshot's ID.

Note
To copy an Amazon Relational Database Service (Amazon RDS) snapshot, see Copying a DB
Snapshot in the Amazon Relational Database Service User Guide.
You can use a copy of a snapshot in the following ways:
• Geographic expansion: Launch your applications in a new region.
• Migration: Move an application to a new region, to enable better availability and minimize cost.
• Disaster recovery: Back up your data and logs across different geographical locations at regular
intervals. In case of disaster, you can restore your applications using point-in-time backups stored in
the secondary region. This minimizes data loss and recovery time.
• Encryption: Encrypt a previously unencrypted snapshot, change the key with which the snapshot is
encrypted, or, for encrypted snapshots that have been shared with you, create a copy that you own
in order to restore the volume from it.
• Data retention and auditing requirements: Copy your encrypted EBS snapshots from one AWS
account to another to preserve data logs or other files for auditing or data retention. Using a different
account helps prevent accidental snapshot deletions, and protects you if your main AWS account is
compromised.

Note
Snapshots created by the CopySnapshot action have an arbitrary volume ID that should not
be used for any purpose.
User-defined tags are not copied from the source snapshot to the new snapshot. After the copy
operation is complete, you can apply user-defined tags to the new snapshot. For more information, see
Tagging Your Amazon EC2 Resources (p. 751).
You can have up to five snapshot copy requests in progress to a single destination per account. You
can copy any accessible snapshots that have a completed status, including shared snapshots and
snapshots that you've created. You can also copy AWS Marketplace, VM Import/Export, and AWS
Storage Gateway snapshots, but you must verify that the snapshot is supported in the destination
region.

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When you copy a snapshot, you are only charged for the data transfer and storage used to copy the
snapshot data across regions and to store the copied snapshot in the destination region. You are not
charged if the snapshot copy fails. However, if you cancel a snapshot copy that is not yet complete, or
delete the source snapshot while the copy is in progress, you are charged for the bandwidth of the data
transferred.
The first snapshot copy to another region is always a full copy. Each subsequent snapshot copy is
incremental (which makes the copy process faster), meaning that only the blocks in the snapshot
that have changed after your last snapshot copy to the same destination are transferred. Support
for incremental snapshots is specific to a region pair where a previous complete snapshot copy of
the source volume is already available in the destination region, and it is limited to the default EBS
CMK for encrypted snapshots. For example, if you copy an unencrypted snapshot from the US East
(N. Virginia) region to the US West (Oregon) region, the first snapshot copy of the volume is a full
copy and subsequent snapshot copies of the same volume transferred between the same regions are
incremental.

Note
Snapshot copies within a single region do not copy any data at all as long as the following
conditions apply:
• The encryption status of the snapshot copy does not change during the copy operation
• For encrypted snapshots, both the source snapshot and the copy are encrypted with the
default EBS CMK
If you would like another account to be able to copy your snapshot, you must either modify the
snapshot permissions to allow access to that account or make the snapshot public so that all AWS
accounts may copy it. For more information, see Sharing an Amazon EBS Snapshot (p. 691).
Encrypted Snapshots
When you copy a snapshot, you can choose to encrypt the copy (if the original snapshot was not
encrypted) or you can specify a CMK different from the original one, and the resulting copied snapshot
will use the new CMK. However, changing the encryption status of a snapshot or using a non-default
EBS CMK during a copy operation always results in a full copy (not incremental), which may incur
greater data transfer and storage charges.
To copy an encrypted snapshot from another account, you must have permissions to use the snapshot
and you must have permissions to use the customer master key (CMK) that was used to encrypt the
original snapshot. For more information, see Sharing an Amazon EBS Snapshot (p. 691).

Note
When copying an encrypted snapshot that was shared with you, you should consider reencrypting the snapshot during the copy process with a different key that you control. This
protects you if the original key is compromised, or if the owner revokes the key for any reason,
which could cause you to lose access to the volume you created.

To copy a snapshot using the Amazon EC2 console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Snapshots.

Select the snapshot to copy, and then choose Copy from the Actions list.

In the Copy Snapshot dialog box, update the following as necessary:
• Destination region: Select the region where you want to write the copy of the snapshot.
• Description: By default, the description includes information about the source snapshot so that
you can identify a copy from the original. You can change this description as necessary.
• Encryption: If the source snapshot is not encrypted, you can choose to encrypt the copy. You
cannot decrypt an encrypted snapshot.

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• Master Key: The customer master key (CMK) that will be used to encrypt this snapshot. You
can select from master keys in your account or type/paste the ARN of a key from a different
account. You can create a new master encryption key in the IAM console.
5.

Choose Copy.

In the Copy Snapshot confirmation dialog box, choose Snapshots to go to the Snapshots page
in the region specified, or choose Close.
To view the progress of the copy process later, switch to the destination region, and then refresh
the Snapshots page. Copies in progress are listed at the top of the page.

To check for failure
If you attempt to copy an encrypted snapshot without having permissions to use the encryption key, the
operation will fail silently. The error state will not be displayed in the console until you refresh the page.
You can also check the state of the snapshot from the command line. For example:
$

aws ec2 describe-snapshots --snapshot-id snap-0123abcd

If the copy failed because of insufficient key permissions, you will see the following message:
"StateMessage": "Given key ID is not accessible"

Note
When copying an encrypted snapshot, you must have describe permissions on the default
CMK. Explicitly denying these permissions will result in copy failure.

To copy a snapshot using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• copy-snapshot (AWS CLI)
• Copy-EC2Snapshot (AWS Tools for Windows PowerShell)

Viewing Amazon EBS Snapshot Information
You can view detailed information about your snapshots.

To view snapshot information using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

Choose Snapshots in the navigation pane.

To reduce the list, choose an option from the Filter list. For example, to view only your snapshots,
choose Owned By Me. You can filter your snapshots further by using the advanced search
options. Choose the search bar to view the filters available.

To view more information about a snapshot, choose it.

To view snapshot information using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• describe-snapshots (AWS CLI)
• Get-EC2Snapshot (AWS Tools for Windows PowerShell)

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Sharing an Amazon EBS Snapshot
You can share your unencrypted snapshots with your co-workers or others in the AWS community
by modifying the permissions of the snapshot. Users that you have authorized can quickly use your
unencrypted shared snapshots as the basis for creating their own EBS volumes. If you choose, you
can also make your unencrypted snapshots available publicly to all AWS users.
You can share an encrypted snapshot with specific AWS accounts, though you cannot make it public.
For others to use the snapshot, you must also share the custom CMK key used to encrypt it. Crossaccount permissions may be applied to a custom key either when it is created or at a later time. Users
with access can copy your snapshot and create their own EBS volumes based on your snapshot while
your original snapshot remains unaffected.

Important
When you share a snapshot (whether by sharing it with another AWS account or making it
public to all), you are giving others access to all the data on your snapshot. Share snapshots
only with people with whom you want to share all your snapshot data.
Several technical and policy restrictions apply to sharing snapshots:
• Snapshots are constrained to the region in which they were created. If you would like to share a
snapshot with another region, you need to copy the snapshot to that region. For more information
about copying snapshots, see Copying an Amazon EBS Snapshot (p. 688).
• If your snapshot uses the longer resource ID format, you can only share it with another account that
also supports longer IDs. For more information, see Resource IDs.
• AWS prevents you from sharing snapshots that were encrypted with your default CMK. Snapshots
that you intend to share must instead be encrypted with a custom CMK. For information about
creating keys, see Creating Keys.
• Users of your shared CMK who will be accessing encrypted snapshots must be granted
DescribeKey and ReEncrypt permissions. For information about managing and sharing CMK
keys, see Controlling Access to Customer Master Keys.
• If you have access to a shared encrypted snapshot and you wish to restore a volume from it, you
must create a personal copy of the snapshot and then use that copy to restore the volume. We
recommend that you re-encrypt the snapshot during the copy process with a different key that you
control. This protects your access to the volume if the original key is compromised, or if the owner
revokes the key for any reason.

To modify snapshot permissions using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

Choose Snapshots in the navigation pane.

Select a snapshot and then choose Modify Permissions from the Actions list.

Choose whether to make the snapshot public or to share it with specific AWS accounts:
•

To make the snapshot public, choose Public.
This is not a valid option for encrypted snapshots or snapshots with AWS Marketplace product
codes.

•

To expose the snapshot to only specific AWS accounts, choose Private, enter the ID of
the AWS account (without hyphens) in the AWS Account Number field, and choose Add
Permission. Repeat until you've added all the required AWS accounts.

Important
If your snapshot is encrypted, you must ensure that the following are true:
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• The snapshot is encrypted with a custom CMK, not your default CMK. If you
attempt to change the permissions of a snapshot encrypted with your default CMK,
the console will display an error message.
• You are sharing the custom CMK with the accounts that have access to your
snapshot.
Choose Save.

To view and modify snapshot permissions using the command line
To view the createVolumePermission attribute of a snapshot, you can use one of the following
commands. For more information about these command line interfaces, see Accessing Amazon
EC2 (p. 3).
• describe-snapshot-attribute (AWS CLI)
• Get-EC2SnapshotAttribute (AWS Tools for Windows PowerShell)
To modify the createVolumePermission attribute of a snapshot, you can use one of the following
commands.
• modify-snapshot-attribute (AWS CLI)
• Edit-EC2SnapshotAttribute (AWS Tools for Windows PowerShell)

Amazon EBS–Optimized Instances
An Amazon EBS–optimized instance uses an optimized configuration stack and provides additional,
dedicated capacity for Amazon EBS I/O. This optimization provides the best performance for your EBS
volumes by minimizing contention between Amazon EBS I/O and other traffic from your instance.
EBS–optimized instances deliver dedicated bandwidth to Amazon EBS, with options between 500
Mbps and 10,000 Mbps, depending on the instance type you use. When attached to an EBS–optimized
instance, General Purpose SSD (gp2) volumes are designed to deliver within 10% of their baseline
and burst performance 99% of the time in a given year, and Provisioned IOPS SSD (io1) volumes are
designed to deliver within 10% of their provisioned performance 99.9% of the time in a given year. Both
Throughput Optimized HDD (st1) and Cold HDD (sc1) guarantee performance consistency of 90% of
burst throughput 99% of the time in a given year. Non-compliant periods are approximately uniformly
distributed, targeting 99% of expected total throughput each hour. For more information, see Amazon
EBS Volume Types (p. 638).
When you enable EBS optimization for an instance that is not EBS–optimized by default, you pay
an additional low, hourly fee for the dedicated capacity. For pricing information, see EBS-optimized
Instances on the Amazon EC2 Pricing page.
Contents
• Instance Types that Support EBS Optimization (p. 692)
• Enabling EBS Optimization at Launch (p. 694)
• Modifying EBS Optimization for a Running Instance (p. 695)

Instance Types that Support EBS Optimization
The following table shows which instance types support EBS optimization, the dedicated bandwidth
to Amazon EBS, the maximum number of IOPS the instance can support if you are using a 16 KiB
I/O size, and the typical maximum aggregate throughput that can be achieved on that connection
in MiB/s with a streaming read workload and128 KiB I/O size . Choose an EBS–optimized instance

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that provides more dedicated EBS throughput than your application needs; otherwise, the connection
between Amazon EBS and Amazon EC2 can become a performance bottleneck.
Note that some instance types are EBS–optimized by default. For instances that are EBS–optimized
by default, there is no need to enable EBS optimization and there is no effect if you disable EBS
optimization using the CLI or API. You can enable EBS optimization for the other instance types
that support EBS optimization when you launch the instances, or enable EBS optimization after the
instances are running.
Instance type

EBS-optimized
by default

Max. bandwidth
(Mbps)*

Expected
throughput (MB/
s)**

Max. IOPS (16
KB I/O size)**

c1.xlarge

1,000

125

8,000

c3.xlarge

500

62.5

4,000

c3.2xlarge

1,000

125

8,000

c3.4xlarge

2,000

250

16,000

c4.large

Yes

500

62.5

4,000

c4.xlarge

Yes

750

93.75

6,000

c4.2xlarge

Yes

1,000

125

8,000

c4.4xlarge

Yes

2,000

250

16,000

c4.8xlarge

Yes

4,000

500

32,000

d2.xlarge

Yes

750

93.75

6,000

d2.2xlarge

Yes

1,000

125

8,000

d2.4xlarge

Yes

2,000

250

16,000

d2.8xlarge

Yes

4,000

500

32,000

g2.2xlarge

1,000

125

8,000

i2.xlarge

500

62.5

4,000

i2.2xlarge

1,000

125

8,000

i2.4xlarge

2,000

250

16,000

m1.large

500

62.5

4,000

m1.xlarge

1,000

125

8,000

m2.2xlarge

500

62.5

4,000

m2.4xlarge

1,000

125

8,000

m3.xlarge

500

62.5

4,000

m3.2xlarge

1,000

125

8,000

m4.large

Yes

450

56.25

3,600

m4.xlarge

Yes

750

93.75

6,000

m4.2xlarge

Yes

1,000

125

8,000

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Instance type

EBS-optimized
by default

Max. bandwidth
(Mbps)*

Expected
throughput (MB/
s)**

Max. IOPS (16
KB I/O size)**

m4.4xlarge

Yes

2,000

250

16,000

m4.10xlarge

Yes

4,000

500

32,000

r3.xlarge

500

62.5

4,000

r3.2xlarge

1,000

125

8,000

r3.4xlarge

2,000

250

16,000

10,000

1,250

65,000

x1.32xlarge

Yes

* These instance types must be launched as EBS-optimized to consistently achieve this level of
performance.
** This value is a rounded approximation based on a 100% read-only workload and it is provided as a
baseline configuration aid. EBS-optimized connections are full-duplex, and can drive more throughput
and IOPS in a 50/50 read/write workload where both communication lanes are used. In some cases,
network, file system, and Amazon EBS encryption overhead can reduce the maximum throughput and
IOPS available.
Note that some instances with 10-gigabit network interfaces, such as i2.8xlarge and r3.8xlarge
do not offer EBS-optimization, and therefore do not have dedicated EBS bandwidth available and
are not listed here. On these instances, network traffic and Amazon EBS traffic is shared on the
same 10-gigabit network interface. Some other 10-gigabit network instances, such as c4.8xlarge
and d2.8xlarge offer dedicated EBS bandwidth in addition to a 10-gigabit interface which is used
exclusively for network traffic.

Enabling EBS Optimization at Launch
You can enable EBS optimization for an instance by setting its EBS–optimized attribute.

To enable EBS optimization when launching an instance using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

Click Launch Instance. In Step 1: Choose an Amazon Machine Image (AMI), select an AMI.

In Step 2: Choose an Instance Type, select an instance type that is listed as supporting EBS
optimization.

In Step 3: Configure Instance Details, complete the fields that you need and select Launch
as EBS-optimized instance. If the instance type that you selected in the previous step doesn't
support EBS optimization, this option is not present. If the instance type that you selected is EBS–
optimized by default, this option is selected and you can't deselect it.

Follow the directions to complete the wizard and launch your instance.

To enable EBS optimization when launching an instance using the command line
You can use one of the following options with the corresponding command. For more information about
these command line interfaces, see Accessing Amazon EC2 (p. 3).
• --ebs-optimized with run-instances (AWS CLI)
• -EbsOptimized with New-EC2Instance (AWS Tools for Windows PowerShell)

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Modifying EBS Optimization for a Running Instance
You can enable or disable EBS optimization for a running instance by modifying its EBS–optimized
instance attribute.

To enable EBS optimization for a running instance using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.

In the navigation pane, click Instances, and select the instance.
Click Actions, select Instance State, and then click Stop.

In the confirmation dialog box, click Yes, Stop. It can take a few minutes for the instance to stop.

With the instance still selected, click Actions, select Instance Settings, and then click Change
Instance Type.

In the Change Instance Type dialog box, do one of the following:

• If the instance type of your instance is EBS–optimized by default, EBS-optimized is selected
and you can't deselect it. You can click Cancel, because EBS optimization is already enabled
for the instance.
• If the instance type of your instance supports EBS optimization, select EBS-optimized, and
then click Apply.
• If the instance type of your instance does not support EBS optimization, EBS-optimized is
deselected and you can't select it. You can select an instance type from Instance Type that
supports EBS optimization, select EBS-optimized, and then click Apply.
Click Actions, select Instance State, and then click Start.

To enable EBS optimization for a running instance using the command line
You can use one of the following options with the corresponding command. For more information about
these command line interfaces, see Accessing Amazon EC2 (p. 3).
• --ebs-optimized with modify-instance-attribute (AWS CLI)
• -EbsOptimized with Edit-EC2InstanceAttribute (AWS Tools for Windows PowerShell)

Amazon EBS Encryption
Amazon EBS encryption offers you a simple encryption solution for your EBS volumes without the
need for you to build, maintain, and secure your own key management infrastructure. When you create
an encrypted EBS volume and attach it to a supported instance type, the following types of data are
encrypted:
• Data at rest inside the volume
• All data moving between the volume and the instance
• All snapshots created from the volume
The encryption occurs on the servers that host EC2 instances, providing encryption of data-in-transit
from EC2 instances to EBS storage.
Amazon EBS encryption uses AWS Key Management Service (AWS KMS) customer master keys
(CMK) when creating encrypted volumes and any snapshots created from them. The first time you

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create an encrypted volume in a region, a default CMK is created for you automatically. This key is
used for Amazon EBS encryption unless you select a CMK that you created separately using AWS
KMS. Creating your own CMK gives you more flexibility, including the ability to create, rotate, and
disable keys to define access controls, and to audit the encryption keys used to protect your data. For
more information, see the AWS Key Management Service Developer Guide.
This feature is supported with all EBS volume types (General Purpose SSD [gp2], Provisioned IOPS
SSD [io1], Throughput Optimized HDD [st1], Cold HDD [sc1], and Magnetic [standard]), and
you can expect the same IOPS performance on encrypted volumes as you would with unencrypted
volumes, with a minimal effect on latency. You can access encrypted volumes the same way that you
access unencrypted volumes; encryption and decryption are handled transparently and they require no
additional action from you, your EC2 instance, or your application.
Snapshots that are taken from encrypted volumes are automatically encrypted. Volumes that are
created from encrypted snapshots are also automatically encrypted. Public snapshots of encrypted
volumes are not supported, but you can share an encrypted snapshot with specific accounts if you take
the following steps:
1. Use a custom CMK, not your default CMK, to encrypt your volume.
2. Give the specific accounts access to the custom CMK.
3. Create the snapshot.
4. Give the specific accounts access to the snapshot.
For more information, see Sharing an Amazon EBS Snapshot.
Amazon EBS encryption is only available on certain instance types. You can attach both encrypted
and unencrypted volumes to a supported instance type. For more information, see Supported Instance
Types (p. 697).
Contents
• Encryption Key Management (p. 696)
• Supported Instance Types (p. 697)
• Changing the Encryption State of Your Data (p. 697)

Encryption Key Management
Amazon EBS encryption handles key management for you. Each newly-created volume is encrypted
with a unique 256-bit key; any snapshots of this volume and any subsequent volumes created
from those snapshots also share that key. These keys are protected by our own key management
infrastructure, which implements strong logical and physical security controls to prevent unauthorized
access. Your data and associated keys are encrypted using the industry-standard AES-256 algorithm.
You cannot change the CMK that is associated with an existing snapshot or encrypted volume.
However, you can associate a different CMK during a snapshot copy operation (including encrypting a
copy of an unencrypted snapshot) and the resulting copied snapshot will use the new CMK.
Amazon’s overall key management infrastructure uses Federal Information Processing Standards
(FIPS) 140-2 approved cryptographic algorithms and is consistent with National Institute of Standards
and Technology (NIST) 800-57 recommendations.
Each AWS account has a unique master key that is stored completely separate from your data,
on a system that is surrounded with strong physical and logical security controls. Each encrypted
volume (and its subsequent snapshots) is encrypted with a unique volume encryption key that is then
encrypted with a region-specific secure master key. The volume encryption keys are used in memory
on the server that hosts your EC2 instance; they are never stored on disk in plain text.

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Supported Instance Types
Amazon EBS encryption is available on the instance types listed in the table below. These instance
types leverage the Intel AES New Instructions (AES-NI) instruction set to provide faster and simpler
data protection. You can attach both encrypted and unencrypted volumes to these instance types
simultaneously.
Instance family

Instance types that support Amazon EBS encryption

General purpose

Compute optimized

Memory optimized

Storage optimized

GPU instances

g2.2xlarge | g2.8xlarge

For more information about these instance types, see Instance Type Details.

Changing the Encryption State of Your Data
There is no direct way to encrypt an existing unencrypted volume, or to remove encryption from an
encrypted volume. However, you can migrate data between encrypted and unencrypted volumes. You
can also apply a new encryption status while copying a snapshot:
• While copying an unencrypted snapshot of an unencrypted volume, you can encrypt the copy.
Volumes restored from this encrypted copy will also be encrypted.
• While copying an encrypted snapshot of an encrypted volume, you can re-encrypt the copy using
a different CMK. Volumes restored from the encrypted copy will only be accessible using the newly
applied CMK.

Migrate Data between Encrypted and Unencrypted Volumes
When you have access to both an encrypted and unencrypted volume, you can freely transfer data
between them. EC2 carries out the encryption or decryption operations transparently.

To migrate data between encrypted and unencrypted volumes
1.

Create your destination volume (encrypted or unencrypted, depending on your need) by following
the procedures in Creating an Amazon EBS Volume (p. 650).

Attach the destination volume to the instance that hosts the data to migrate. For more information,
see Attaching an Amazon EBS Volume to an Instance (p. 654).

Make the destination volume available by following the procedures in Making an Amazon EBS
Volume Available for Use (p. 655). For Linux instances, you can create a mount point at /mnt/
destination and mount the destination volume there.

Copy the data from your source directory to the destination volume. It may be most convenient to
use a bulk-copy utility for this.

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Linux
Use the rsync command as follows to copy the data from your source to the destination volume.
In this example, the source data is located in /mnt/source and the destination volume is
mounted at /mnt/destination.
[ec2-user ~]$ sudo rsync -avh --progress /mnt/source/ /mnt/destination/

Windows
At a command prompt, use the robocopy command to copy the data from your source to the
destination volume. In this example, the source data is located in D:\ and the destination volume
is mounted at E:\.
PS C:\Users\Administrator> robocopy D:\ E:\ /e /copyall /eta

Apply Encryption While Copying a Snapshot
Because you can apply encryption to a snapshot while copying it, another path to encrypting your data
is the following procedure.

To encrypt a volume's data by means of snapshot copying
1.

Create a snapshot of your unencrypted EBS volume. This snapshot is also unencrypted.

Copy the snapshot while applying encryption parameters. The resulting target snapshot is
encrypted.

Restore the encrypted snapshot to a new volume, which is also encrypted.

For more information, see Copying an Amazon EBS Snapshot.

Re-Encrypt a Snapshot with a New CMK
The ability to encrypt a snapshot during copying also allows you to re-encrypt an already-encrypted
snapshot that you own. In this operation, the plaintext of your snapshot will be encrypted using a new
CMK that you provide. Volumes restored from the resulting copy will only be accessible using the new
CMK.
In a related scenario, you may choose to re-encrypt a snapshot that has been shared with you. Before
you can restore a volume from a shared encrypted snapshot, you must create your own copy of it.
By default, the copy will be encrypted with the key shared by the snapshot's owner. However, we
recommend that you re-encrypt the snapshot during the copy process with a different key that you
control. This protects your access to the volume if the original key is compromised, or if the owner
revokes the key for any reason.
The following procedure demonstrates how to re-encrypt a snapshot that you own.

To re-encrypt a snapshot using the console
1.
2.
3.
4.

Create a custom CMK. For more information, see AWS Key Management Service Developer
Guide.
Create an EBS volume encrypted with (for this example) your default CMK.
Create a snapshot of your encrypted EBS volume. This snapshot is also encrypted with your
default CMK.
On the Snapshots page, choose Actions, then choose Copy.

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In the Copy Snapshot window, supply the complete ARN for your custom CMK (in the form
arn:aws:kms:us-east-1:012345678910:key/abcd1234-a123-456a-a12b-a123b4cd56ef) in
the Master Key field, or choose it from the menu. Click Copy.

The resulting copy of the snapshot—and all volumes restored from it—will be encrypted with your
custom CMK.
The following procedure demonstrates how to re-encrypt a shared encrypted snapshot as you copy it.
For this to work, you need access permissions to both the shared encrypted snapshot and to the CMK
that encrypted it.

To copy and re-encrypt a shared snapshot using the console
1.

Choose the shared encrypted snapshot on the Snapshots page, choose Actions, then choose
Copy.

In the Copy Snapshot window, supply the complete ARN for a CMK that you own (in the form
arn:aws:kms:us-east-1:012345678910:key/abcd1234-a123-456a-a12b-a123b4cd56ef) in
the Master Key field, or choose it from the menu. Click Copy.

The resulting copy of the snapshot—and all volumes restored from it—will be encrypted with the CMK
that you supplied. Changes to the original shared snapshot, its encryption status, or the shared CMK
will have no effect on your copy.
For more information, see Copying an Amazon EBS Snapshot.

Amazon EBS Volume Performance on Linux
Instances
Several factors, including I/O characteristics and the configuration of your instances and volumes, can
affect the performance of Amazon EBS. Customers who follow the guidance on our Amazon EBS and
Amazon EC2 product detail pages typically achieve good performance out of the box. However, there
are some cases where you may need to do some tuning in order achieve peak performance on the
platform. This topic discusses general best practices as well as performance tuning that is specific
to certain use cases. We recommend that you tune performance with information from your actual
workload, in addition to benchmarking, to determine your optimal configuration. After you learn the
basics of working with EBS volumes, it's a good idea to look at the I/O performance you require and at
your options for increasing Amazon EBS performance to meet those requirements.
For more information, see Amazon EBS Volume Performance on Linux Instances in the Amazon EC2
User Guide for Linux Instances.
Contents
• Amazon EBS Performance Tips (p. 699)
• Amazon EC2 Instance Configuration (p. 701)
• I/O Characteristics (p. 704)
• Initializing Amazon EBS Volumes (p. 706)
• RAID Configuration on Linux (p. 707)
• Benchmark EBS Volumes (p. 711)

Amazon EBS Performance Tips
These tips represent best practices for getting optimal performance from your EBS volumes in a variety
of user scenarios.

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Use EBS-Optimized Instances
On instances without support for EBS-optimized throughput, network traffic can contend with traffic
between your instance and your EBS volumes; on EBS-optimized instances, the two types of traffic
are kept separate. Some EBS-optimized instance configurations incur an extra cost (such as C3, R3,
and M3), while others are always EBS-optimized at no extra cost (such as M4, C4, and D2). For more
information, see Amazon EC2 Instance Configuration (p. 701).

Understand How Performance is Calculated
When you measure the performance of your EBS volumes, it is important to understand the
units of measure involved and how performance is calculated. For more information, see I/O
Characteristics (p. 704).

Understand Your Workload
There is a relationship between the maximum performance of your EBS volumes, the size and number
of I/O operations, and the time it takes for each action to complete. Each of these factors (performance,
I/O, and latency) affects the others, and different applications are more sensitive to one factor or
another. For more information, see Benchmark EBS Volumes (p. 711).

Be Aware of the Performance Penalty When Initializing Volumes from
Snapshots
There is a significant increase in latency when you first access each block of data on a new EBS
volume that was restored from a snapshot. You can avoid this performance hit by accessing each
block prior to putting the volume into production. This process is called initialization (formerly known as
pre-warming). For more information, see Initializing Amazon EBS Volumes (p. 706).

Factors That Can Degrade HDD Performance
When you create a snapshot of a Throughput Optimized HDD (st1) or Cold HDD (sc1) volume,
performance may drop as far as the volume's baseline value while the snapshot is in progress. This
behavior is specific to these volume types. Other factors that can limit performance include driving
more throughput than the instance can support, the performance penalty encountered while initializing
volumes restored from a snapshot, and excessive amounts of small, random I/O on the volume. For
more information about calculating throughput for HDD volumes, see Amazon EBS Volume Types .
Your performance can also be impacted if your application isn’t sending enough I/O requests. This can
be monitored by looking at your volume’s queue length and I/O size. The queue length is the number
of pending I/O requests from your application to your volume. For maximum consistency, HDD-backed
volumes must maintain a queue length (rounded to the nearest whole number) of 4 or more when
performing 1 MiB sequential I/O. For more information about ensuring consistent performance of your
volumes, see I/O Characteristics (p. 704)

Increase Read-Ahead for High-Throughput, Read-Heavy Workloads on
st1 and sc1
Some workloads are read-heavy and access the block device through the operating system page
cache (for example, from a file system). In this case, to achieve the maximum throughput, we
recommend that you configure the read-ahead setting to 1 MiB. This is a per-block-device setting that
should only be applied to your HDD volumes. The following examples assume that you are on an
Amazon Linux instance.
To examine the current value of read-ahead for your block devices, use the following command:
[ec2-user ~]$ sudo blockdev --report /dev/

Block device information is returned in the following format:

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RO
rw

RA
256

SSZ
512

BSZ
4096

StartSec
4096

Size
8587820544

Device
/dev/

The device shown reports a read-ahead value of 256 bytes (the default). Multiply this number by the
sector size (512 bytes) to obtain the size of the read-ahead buffer, which in this case is 128 KiB. To set
the buffer value to 1 MiB, use the following command:
[ec2-user ~]$ sudo blockdev --setra 2048 /dev/

Verify that the read-ahead setting now displays 2,048 by running the first command again.
Only use this setting when your workload consists of large, sequential I/Os. If it consists mostly of
small, random I/Os, this setting will actually degrade your performance. In general, if your workload
consists mostly of small or random I/Os, you should consider using a General Purpose SSD (gp2)
volume rather than st1 or sc1.

Use a Modern Linux Kernel
Use a modern Linux kernel with support for indirect descriptors. Any Linux kernel 3.8 and above
has this support, as well as any current-generation EC2 instance. If your average I/O size is at
or near 44 KiB, you may be using an instance or kernel without support for indirect descriptors.
For information about deriving the average I/O size from Amazon CloudWatch metrics, see I/O
Characteristics (p. 704).
To achieve maximum throughput on st1 or sc1 volumes for any Linux kernel 4.2 and above, we
recommend setting the xen_blkfront.max parameter to 256. This parameter can be set in your OS
boot command line. For example, in an Amazon Linux AMI, you can add it to the end of the kernel line
in the GRUB configuration found in /boot/grub/menu.lst:
kernel /boot/vmlinuz-4.4.5-15.26.amzn1.x86_64 root=LABEL=/ console=ttyS0
xen_blkfront.max=256

Reboot your instance for this setting to take effect.
For more information, see Configuring GRUB. Other Linux distributions, especially those that do not
use the GRUB bootloader, may require a different approach to adjusting the kernel parameters.
For more information about EBS I/O characteristics, see the Amazon EBS: Designing for Performance
re:Invent presentation on this topic.

Use RAID 0 to Maximize Utilization of Instance Resources
Some instance types can drive more I/O throughput than what you can provision for a single EBS
volume. You can join multiple gp2, io1, st1, or sc1 volumes together in a RAID 0 configuration to
use the available bandwidth for these instances. For more information, see RAID Configuration on
Linux (p. 707).

Track Performance with Amazon CloudWatch
Amazon Web Services provides performance metrics for Amazon EBS that you can analyze and view
with Amazon CloudWatch and status checks that you can use to monitor the health of your volumes.
For more information, see Monitoring the Status of Your Volumes (p. 658).

Amazon EC2 Instance Configuration
When you plan and configure EBS volumes for your application, it is important to consider the
configuration of the instances that you will attach the volumes to. In order to get the most performance

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out of your EBS volumes, you should attach them to an instance with enough bandwidth to support
your volumes, such as an EBS-optimized instance or an instance with 10 Gigabit network connectivity.
This is especially important when you stripe multiple volumes together in a RAID configuration.
Use EBS-Optimized or 10 Gigabit Network Instances
Any performance-sensitive workloads that require minimal variability and dedicated Amazon EC2 to
Amazon EBS traffic, such as production databases or business applications, should use volumes
that are attached to an EBS-optimized instance or an instance with 10 Gigabit network connectivity.
EC2 instances that do not meet this criteria offer no guarantee of network resources. The only way
to ensure sustained reliable network bandwidth between your EC2 instance and your EBS volumes
is to launch the EC2 instance as EBS-optimized or choose an instance type with 10 Gigabit network
connectivity. To see which instance types include 10 Gigabit network connectivity, see Instance Type
Details. For information about configuring EBS-optimized instances, see Amazon EBS–Optimized
Instances.
Choose an EC2 Instance with Enough Bandwidth
Launching an instance that is EBS-optimized provides you with a dedicated connection between your
EC2 instance and your EBS volume. However, it is still possible to provision EBS volumes that exceed
the available bandwidth for certain instance types, especially when multiple volumes are striped in
a RAID configuration. The following table shows which instance types are available to be launched
as EBS-optimized, the dedicated throughput to instance types are available to be launched as EBSoptimized, the dedicated bandwidth to Amazon EBS, the maximum amount of IOPS the instance
can support if you are using a 16 KB I/O size, and the approximate I/O bandwidth available on that
connection in MB/s. Be sure to choose an EBS-optimized instance that provides more dedicated EBS
throughput than your application needs; otherwise, the Amazon EBS to Amazon EC2 connection will
become a performance bottleneck.

Note
The table below and the following examples use 16 KB as an I/O size for explanatory
purposes only; your application I/O size may vary (Amazon EBS measures each I/O operation
per second that is 256 KiB or smaller as one IOPS). For more information about IOPS and the
relationship between I/O size and volume throughput limits, see I/O Characteristics (p. 704).
Instance type

EBS-optimized
by default

Max. bandwidth
(Mbps)*

Expected
throughput (MB/
s)**

Max. IOPS (16
KB I/O size)**

c1.xlarge

1,000

125

8,000

c3.xlarge

500

62.5

4,000

c3.2xlarge

1,000

125

8,000

c3.4xlarge

2,000

250

16,000

c4.large

Yes

500

62.5

4,000

c4.xlarge

Yes

750

93.75

6,000

c4.2xlarge

Yes

1,000

125

8,000

c4.4xlarge

Yes

2,000

250

16,000

c4.8xlarge

Yes

4,000

500

32,000

d2.xlarge

Yes

750

93.75

6,000

d2.2xlarge

Yes

1,000

125

8,000

d2.4xlarge

Yes

2,000

250

16,000

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Instance type

EBS-optimized
by default

Max. bandwidth
(Mbps)*

Expected
throughput (MB/
s)**

Max. IOPS (16
KB I/O size)**

d2.8xlarge

Yes

4,000

500

32,000

g2.2xlarge

1,000

125

8,000

i2.xlarge

500

62.5

4,000

i2.2xlarge

1,000

125

8,000

i2.4xlarge

2,000

250

16,000

m1.large

500

62.5

4,000

m1.xlarge

1,000

125

8,000

m2.2xlarge

500

62.5

4,000

m2.4xlarge

1,000

125

8,000

m3.xlarge

500

62.5

4,000

m3.2xlarge

1,000

125

8,000

m4.large

Yes

450

56.25

3,600

m4.xlarge

Yes

750

93.75

6,000

m4.2xlarge

Yes

1,000

125

8,000

m4.4xlarge

Yes

2,000

250

16,000

m4.10xlarge

Yes

4,000

500

32,000

r3.xlarge

500

62.5

4,000

r3.2xlarge

1,000

125

8,000

r3.4xlarge

2,000

250

16,000

10,000

1,250

65,000

x1.32xlarge

Yes

* These instance types must be launched as EBS-optimized to consistently achieve this level of
performance.
** This value is a rounded approximation based on a 100% read-only workload and it is provided as a
baseline configuration aid. EBS-optimized connections are full-duplex, and can drive more throughput
and IOPS in a 50/50 read/write workload where both communication lanes are used. In some cases,
network, file system, and Amazon EBS encryption overhead can reduce the maximum throughput and
IOPS available.
Note that some instances with 10-gigabit network interfaces, such as i2.8xlarge, c3.8xlarge,
and r3.8xlarge, do not offer EBS-optimization, and therefore do not have dedicated EBS bandwidth
available and are not listed here. However, you can use all of that bandwidth for traffic to Amazon
EBS if your application isn’t pushing other network traffic that contends with Amazon EBS. Some other
10-gigabit network instances, such as c4.8xlarge and d2.8xlarge offer dedicated Amazon EBS
bandwidth in addition to a 10-gigabit interface which is used exclusively for network traffic.
The m1.large instance has a maximum 16 KB IOPS value of 4,000, but unless this instance type is
launched as EBS-optimized, that value is an absolute best-case scenario and is not guaranteed; to

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consistently achieve 4,000 16 KB IOPS, you must launch this instance as EBS-optimized. However, if
a 4,000 IOPS io1 volume is attached to an EBS-optimized m1.large instance, the Amazon EC2 to
Amazon EBS connection bandwidth limit prevents this volume from providing the 320 MB/s maximum
aggregate throughput available to it. In this case, we must use an EBS-optimized EC2 instance that
supports at least 320 MB/s of throughput, such as the c4.8xlarge instance type.
Volumes of type General Purpose SSD (gp2) have a throughput limit between 128 MB/s and 160
MB/s per volume (depending on volume size), which pairs well with a 1,000 Mbps EBS-optimized
connection. Instance types that offer more than 1,000 Mbps of throughput to Amazon EBS can
use more than one gp2 volume to take advantage of the available throughput. Volumes of type
Provisioned IOPS SSD (io1) have a throughput limit range of 256 KiB for each IOPS provisioned,
up to a maximum of 320 MiB/s (at 1,280 IOPS). For more information, see Amazon EBS Volume
Types (p. 638).
Instance types with 10 Gigabit network connectivity support up to 800 MB/s of throughput and 48,000
16K IOPS for unencrypted Amazon EBS volumes and up to 25,000 16K IOPS for encrypted Amazon
EBS volumes. Because the maximum io1 value for EBS volumes is 20,000 for io1 volumes and
10,000 for gp2 volumes, you can use several EBS volumes simultaneously to reach the level of I/
O performance available to these instance types. For more information about which instance types
include 10 Gigabit network connectivity, see Instance Type Details.
You should use EBS-optimized instances when available to get the full performance benefits
of Amazon EBS gp2 and io1 volumes. For more information, see Amazon EBS–Optimized
Instances (p. 692).

I/O Characteristics
On a given volume configuration, certain I/O characteristics drive the performance behavior for your
EBS volumes. SSD-backed volumes—General Purpose SSD (gp2) and Provisioned IOPS SSD (io1)
—deliver consistent performance whether an I/O operation is random or sequential. HDD-backed
volumes—Throughput Optimized HDD (st1) and Cold HDD (sc1)—deliver optimal performance only
when I/O operations are large and sequential. To understand how SSD and HDD volumes will perform
in your application, it is important to know the connection between demand on the volume, the quantity
of IOPS available to it, the time it takes for an I/O operation to complete, and the volume's throughput
limits.
IOPS
IOPS are a unit of measure representing input/output operations per second. The operations are
measured in KiB, and the underlying drive technology determines the maximum amount of data that
a volume type counts as a single I/O. I/O size is capped at 256 KiB for SSD volumes and 1,024 KiB
for HDD volumes because SSD volumes handle small or random I/O much more efficiently than HDD
volumes.
When small I/O operations are physically contiguous, Amazon EBS attempts to merge them into a
single I/O up to the maximum size. For example, for SSD volumes, a single 1,024 KiB I/O operation
would count as 4 operations, while 256 I/O operations at 4 KiB each would count as 64 operations.
However, 256 random I/O operations at 4 KiB each would count as 256 operations.
Similarly, for HDD-backed volumes, both a single 1,024 KiB I/O operation and 8 sequential 128 KiB
operations would count as one operation. However, 8 random 128 KiB I/O operations would count as 8
operations.
Consequently, when you create an SSD-backed volume supporting 3,000 IOPS (either by provisioning
an io1 volume at 3,000 IOPS or by sizing a gp2 volume at 1000 GiB), and you attach it to an EBSoptimized instance that can provide sufficient bandwidth, you can transfer up to 3,000 I/Os of data per
second, with throughput determined by I/O size.
Volume Queue Length and Latency

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The volume queue length is the number of pending I/O requests for a device. Latency is the true endto-end client time of an I/O operation, in other words, the time elapsed between sending an I/O to EBS
and receiving an acknowledgement from EBS that the I/O read or write is complete. Queue length
must be correctly calibrated with I/O size and latency to avoid creating bottlenecks either on the guest
operating system or on the network link to EBS.
Optimal queue length varies for each workload, depending on your particular application's sensitivity to
IOPS and latency. If your workload is not delivering enough I/O requests to fully use the performance
available to your EBS volume, then your volume might not deliver the IOPS or throughput that you
have provisioned.
Transaction-intensive applications are sensitive to increased I/O latency and are well-suited for SSDbacked io1 and gp2 volumes. You can maintain high IOPS while keeping latency down by maintaining
a low queue length and a high number of IOPS available to the volume. Consistently driving more
IOPS to a volume than it has available can cause increased I/O latency.
Throughput-intensive applications are less sensitive to increased I/O latency, and are well-suited for
HDD-backed st1 and sc1 volumes. You can maintain high throughput to HDD-backed volumes by
maintaining a high queue length when performing large, sequential I/O.
I/O size and volume throughput limits
For SSD-backed volumes, if your I/O size is very large, you may experience a smaller number of
IOPS than you provisioned because you are hitting the throughput limit of the volume. For example,
a gp2 volume under 1000 GiB with burst credits available has an IOPS limit of 3,000 and a volume
throughput limit of 160 MiB/s. If you are using a 256 KiB I/O size, your volume reaches its throughput
limit at 640 IOPS (640 x 256 KiB = 160 MiB). For smaller I/O sizes (such as 16 KiB), this same volume
can sustain 3,000 IOPS because the throughput is well below 160 MiB/s. (These examples assume
that your volume's I/O is not hitting the throughput limits of the instance.) For more information about
the throughput limits for each EBS volume type, see Amazon EBS Volume Types (p. 638).
For smaller I/O operations, you may see a higher-than-provisioned IOPS value as measured from
inside your instance. This happens when the instance operating system merges small I/O operations
into a larger operation before passing them to Amazon EBS.
If your workload uses sequential I/Os on HDD-backed st1 and sc1 volumes, you may experience a
higher than expected number of IOPS as measured from inside your instance. This happens when the
instance operating system merges sequential I/Os and counts them in 1,024 KiB-sized units. If your
workload uses small or random I/Os, you may experience a lower throughput than you expect. This is
because we count each random, non-sequential I/O toward the total IOPS count, which can cause you
to hit the volume's IOPS limit sooner than expected.
Whatever your EBS volume type, if you are not experiencing the IOPS or throughput you expect
in your configuration, ensure that your EC2 instance bandwidth is not the limiting factor. You
should always use a current-generation, EBS-optimized instance (or one that includes 10 Gb/s
network connectivity) for optimal performance. For more information, see Amazon EC2 Instance
Configuration (p. 701). Another possible cause for not experiencing the expected IOPS is that you
are not driving enough I/O to the EBS volumes.
Monitor I/O Characteristics with CloudWatch
You can monitor these I/O characteristics with each volume's CloudWatch metrics. Important metrics to
consider include:
• BurstBalance
• VolumeReadBytes
• VolumeWriteBytes
• VolumeReadOps
• VolumeWriteOps
• VolumeQueueLength

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BurstBalance displays the burst bucket balance for HDD-backed volumes as a percentage.
When your burst bucket is depleted, volume throughput is throttled to the baseline. Check the
BurstBalance value to determine whether your volume is being throttled for this reason.

HDD-backed st1 and sc1 volumes are designed to perform best with workloads that take
advantage of the 1,024 KiB maximum I/O size. To determine your volume's average I/O size, divide
VolumeWriteBytes by VolumeWriteOps. The same calculation applies to read operations. If
average I/O size is below 64 KiB, increasing the size of the I/O operations sent to an st1 or sc1
volume should improve performance.

Note
If average I/O size is at or near 44 KiB, you may be using an instance or kernel without
support for indirect descriptors. Any Linux kernel 3.8 and above has this support, as well as
any current-generation instance.
If your I/O latency is higher than you require, check VolumeQueueLength to make sure your
application is not trying to drive more IOPS than you have provisioned. If your application requires a
greater number of IOPS than your volume can provide, you should consider using a larger gp2 volume
with a higher base performance level or an io1 volume with more provisioned IOPS to achieve faster
latencies.
For more information about Amazon EBS I/O characteristics, see the Amazon EBS: Designing for
Performance re:Invent presentation on this topic.

Initializing Amazon EBS Volumes
New EBS volumes receive their maximum performance the moment that they are available and do not
require initialization (formerly known as pre-warming). However, storage blocks on volumes that were
restored from snapshots must be initialized (pulled down from Amazon S3 and written to the volume)
before you can access the block. This preliminary action takes time and can cause a significant
increase in the latency of an I/O operation the first time each block is accessed. For most applications,
amortizing this cost over the lifetime of the volume is acceptable. Performance is restored after the
data is accessed once.
You can avoid this performance hit in a production environment by reading from all of the blocks on
your volume before you use it; this process is called initialization. For a new volume created from a
snapshot, you should read all the blocks that have data before using the volume.

Initializing Amazon EBS Volumes on Linux
New EBS volumes receive their maximum performance the moment that they are available and do
not require initialization (formerly known as pre-warming). For volumes that have been restored from
snapshots, use the dd or fio utilities to read from all of the blocks on a volume. All existing data on the
volume will be preserved.

To initialize a volume restored from a snapshot on Linux
1.
2.

Attach the newly-restored volume to your Linux instance.
Use the lsblk command to list the block devices on your instance.
[ec2-user ~]$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvdf 202:80
0 30G 0 disk

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xvda1 202:1

0 disk /

Here you can see that the new volume, /dev/xvdf, is attached, but not mounted (because there
is no path listed under the MOUNTPOINT column).
3.

Use the dd or fio utilities to read all of the blocks on the device. The dd command is installed by
default on Linux systems, but fio is considerably faster because it allows multi-threaded reads.

Note
This step may take several minutes up to several hours, depending on your EC2 instance
bandwidth, the IOPS provisioned for the volume, and the size of the volume.
•

Using dd: The if (input file) parameter should be set to the drive you wish to initialize. The
of (output file) parameter should be set to the Linux null virtual device, /dev/null. The bs
parameter sets the block size of the read operation; for optimal performance, this should be
set to 1 MB.
[ec2-user ~]$ sudo dd if=/dev/xvdf of=/dev/null bs=1M

•

Using fio: If you have fio installed on your system, you can copy and paste the command
below to initialize your volume. The --filename (input file) parameter should be set to the
drive you wish to initialize.

Note
To install fio on Amazon Linux, use the following command: sudo yum install -y fio
To install fio on Ubuntu, use the following command: sudo apt-get install -y fio
[ec2-user ~]$ sudo fio --filename=/dev/xvdf --rw=randread --bs=128k -iodepth=32 --ioengine=libaio --direct=1 --name=volume-initialize

When the operation is finished, you will see a report of the read operation. Your volume is
now ready for use. For more information, see Making an Amazon EBS Volume Available for
Use (p. 655).

RAID Configuration on Linux
With Amazon EBS, you can use any of the standard RAID configurations that you can use with
a traditional bare metal server, as long as that particular RAID configuration is supported by the
operating system for your instance. This is because all RAID is accomplished at the software level.
For greater I/O performance than you can achieve with a single volume, RAID 0 can stripe multiple
volumes together; for on-instance redundancy, RAID 1 can mirror two volumes together.
Amazon EBS volume data is replicated across multiple servers in an Availability Zone to prevent the
loss of data from the failure of any single component. This replication makes Amazon EBS volumes
ten times more reliable than typical commodity disk drives. For more information, see Amazon EBS
Availability and Durability in the Amazon EBS product detail pages.

Note
You should avoid booting from a RAID volume. Grub is typically installed on only one device in
a RAID array, and if one of the mirrored devices fails, you may be unable to boot the operating
system.
If you need to create a RAID array on a Windows instance, see RAID Configuration on Windows in the
Amazon EC2 User Guide for Windows Instances.
Contents
• RAID Configuration Options (p. 708)
• Creating a RAID Array on Linux (p. 708)

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RAID Configuration Options
The following table compares the common RAID 0 and RAID 1 options.
ConfigurationUse

Advantages

Disadvantages

RAID 0

When I/O performance is
more important than fault
tolerance; for example, as
in a heavily used database
(where data replication is
already set up separately).

I/O is distributed across
the volumes in a stripe.
If you add a volume, you
get the straight addition of
throughput.

Performance of the stripe
is limited to the worst
performing volume in
the set. Loss of a single
volume results in a
complete data loss for the
array.

RAID 1

When fault tolerance is
more important than I/O
performance; for example,
as in a critical application.

Safer from the standpoint
of data durability.

Does not provide a write
performance improvement;
requires more Amazon
EC2 to Amazon EBS
bandwidth than non-RAID
configurations because the
data is written to multiple
volumes simultaneously.

Important
RAID 5 and RAID 6 are not recommended for Amazon EBS because the parity write
operations of these RAID modes consume some of the IOPS available to your volumes.
Depending on the configuration of your RAID array, these RAID modes provide 20-30%
fewer usable IOPS than a RAID 0 configuration. Increased cost is a factor with these RAID
modes as well; when using identical volume sizes and speeds, a 2-volume RAID 0 array can
outperform a 4-volume RAID 6 array that costs twice as much.
Creating a RAID 0 array allows you to achieve a higher level of performance for a file system than you
can provision on a single Amazon EBS volume. A RAID 1 array offers a "mirror" of your data for extra
redundancy. Before you perform this procedure, you need to decide how large your RAID array should
be and how many IOPS you want to provision.
The resulting size of a RAID 0 array is the sum of the sizes of the volumes within it, and the bandwidth
is the sum of the available bandwidth of the volumes within it. The resulting size and bandwidth of a
RAID 1 array is equal to the size and bandwidth of the volumes in the array. For example, two 500 GiB
Amazon EBS volumes with 4,000 provisioned IOPS each will create a 1000 GiB RAID 0 array with
an available bandwidth of 8,000 IOPS and 640 MB/s of throughput or a 500 GiB RAID 1 array with an
available bandwidth of 4,000 IOPS and 320 MB/s of throughput.
This documentation provides basic RAID setup examples. For more information about RAID
configuration, performance, and recovery, see the Linux RAID Wiki at https://raid.wiki.kernel.org/
index.php/Linux_Raid.

Creating a RAID Array on Linux
Use the following procedure to create the RAID array. Note that you can get directions for Windows
instances from Creating a RAID Array on Windows in the Amazon EC2 User Guide for Windows
Instances.

To create a RAID array on Linux
1.

Create the Amazon EBS volumes for your array. For more information, see Creating an Amazon
EBS Volume (p. 650).

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Important
Create volumes with identical size and IOPS performance values for your array. Make
sure you do not create an array that exceeds the available bandwidth of your EC2
instance. For more information, see Amazon EC2 Instance Configuration (p. 701).
2.

Attach the Amazon EBS volumes to the instance that you want to host the array. For more
information, see Attaching an Amazon EBS Volume to an Instance (p. 654).

Use the mdadm command to create a logical RAID device from the newly attached Amazon
EBS volumes. Substitute the number of volumes in your array for number_of_volumes and the
device names for each volume in the array (such as /dev/xvdf) for device_name. You can also
substitute MY_RAID with your own unique name for the array.

Note
You can list the devices on your instance with the lsblk command to find the device
names.
(RAID 0 only) To create a RAID 0 array, execute the following command (note the --level=0
option to stripe the array):
[ec2-user ~]$ sudo mdadm --create --verbose /dev/md0 --level=0 -name=MY_RAID --raid-devices=number_of_volumes device_name1 device_name2

(RAID 1 only) To create a RAID 1 array, execute the following command (note the --level=1
option to mirror the array):
[ec2-user ~]$ sudo mdadm --create --verbose /dev/md0 --level=1 -name=MY_RAID --raid-devices=number_of_volumes device_name1 device_name2

Allow time for the RAID array to initialize and synchronize. You can track the progress of these
operations with the following command:
[ec2-user ~]$ sudo cat /proc/mdstat

This yields output such as the following:
Personalities : [raid1]
md0 : active raid1 xvdg[1] xvdf[0]
20955008 blocks super 1.2 [2/2] [UU]
[=========>...........] resync = 46.8% (9826112/20955008)
finish=2.9min speed=63016K/sec

In general, you can display detailed information about your RAID array with the following
command:
[ec2-user ~]$ sudo mdadm --detail /dev/md0

This yields information such as the following:
/dev/md0:
Version
Creation Time
Raid Level
Array Size
Used Dev Size
Raid Devices

:
:
:
:
:
:

1.2
Mon Jun 27 11:31:28 2016
raid1
20955008 (19.98 GiB 21.46 GB)
20955008 (19.98 GiB 21.46 GB)
2
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Total Devices : 2
Persistence : Superblock is persistent
Update Time : Mon Jun 27 11:37:02 2016
State : clean
...
...
...
Number
0
1

Major
202
202

Minor
80
96

RaidDevice State
0
active sync
1
active sync

/dev/sdf
/dev/sdg

Create a file system on your RAID array, and give that file system a label to use when you mount
it later. For example, to create an ext4 file system with the label MY_RAID, execute the following
command:
[ec2-user ~]$ sudo mkfs.ext4 -L MY_RAID /dev/md0

Depending on the requirements of your application or the limitations of your operating system, you
can use a different file system type, such as ext3 or XFS (consult your file system documentation
for the corresponding file system creation command).
6.

Create a mount point for your RAID array.
[ec2-user ~]$ sudo mkdir -p /mnt/raid

Finally, mount the RAID device on the mount point that you created:
[ec2-user ~]$ sudo mount LABEL=MY_RAID /mnt/raid

Your RAID device is now ready for use.
8.

(Optional) To mount this Amazon EBS volume on every system reboot, add an entry for the device
to the /etc/fstab file.
a.

Create a backup of your /etc/fstab file that you can use if you accidentally destroy or
delete this file while you are editing it.
[ec2-user ~]$ sudo cp /etc/fstab /etc/fstab.orig

Open the /etc/fstab file using your favorite text editor, such as nano or vim.

Add a new line to the end of the file for your volume using the following format.
device_label
fs_passno

mount_point

file_system_type

fs_mntops

fs_freq

The last three fields on this line are the file system mount options, the dump frequency
of the file system, and the order of file system checks done at boot time. If you don't
know what these values should be, then use the values in the example below for them
(defaults,nofail 0 2). For more information about /etc/fstab entries, see the fstab
manual page (by entering man fstab on the command line). For example, to mount the ext4
file system on the device with the label MY_RAID at the mount point /mnt/raid, add the
following entry to /etc/fstab.

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/mnt/raid

ext4

defaults,nofail

After you've added the new entry to /etc/fstab, you need to check that your entry works.
Run the sudo mount -a command to mount all file systems in /etc/fstab.
[ec2-user ~]$ sudo mount -a

Warning
Errors in the /etc/fstab file can render a system unbootable. Do not shut down a
system that has errors in the /etc/fstab file.
e.

(Optional) If you are unsure how to correct /etc/fstab errors, you can always restore your
backup /etc/fstab file with the following command.
[ec2-user ~]$ sudo mv /etc/fstab.orig /etc/fstab

Benchmark EBS Volumes
This section demonstrates how you can test the performance of Amazon EBS volumes by simulating I/
O workloads. The process is as follows:
1. Launch an EBS-optimized instance.
2. Create new EBS volumes.
3. Attach the volumes to your EBS-optimized instance.
4. Configure and mount the block device.
5. Install a tool to benchmark I/O performance.
6. Benchmark the I/O performance of your volumes.
7. Delete your volumes and terminate your instance so that you don't continue to incur charges.

Important
Some of the procedures described in this topic will result in the destruction of existing data
on the EBS volumes you benchmark. The benchmarking procedures are intended for use on
volumes specially created for testing purposes, not production volumes.

Set Up Your Instance
To get optimal performance from EBS volumes, we recommend that you use an EBS-optimized
instance. EBS-optimized instances deliver dedicated throughput between Amazon EC2 and Amazon
EBS, with instance. EBS-optimized instances deliver dedicated bandwidth between Amazon EC2 and
Amazon EBS, with options between 500 and 10,000 Mbps, depending on the instance type.
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To create an EBS-optimized instance, choose Launch as an EBS-Optimized instance when
launching the instance using the Amazon EC2 console, or specify --ebs-optimized when using the
command line. Be sure that you launch a current-generation instance that supports this option. For
the example tests in this topic, we recommend that you launch a c3.4xlarge instance. For more
information, see Amazon EBS–Optimized Instances (p. 692).

Setting up Provisioned IOPS SSD (io1) volumes
To create an io1 volume, choose Provisioned IOPS SSD when creating the volume using the
Amazon EC2 console, or, at the command line, specify --type io1 --iops n where n is an integer
between 100 and 20000. For information about creating EBS volumes, see Creating an Amazon EBS
Volume (p. 650). For information about attaching these volumes to your instance, see Attaching an
Amazon EBS Volume to an Instance (p. 654).
For the example tests, we recommend that you create a RAID array with 6 volumes, which offers
a high level of performance. Because you are charged by gigabytes provisioned (and the number
of provisioned IOPS for io1 volumes), not the number of volumes, there is no additional cost for
creating multiple, smaller volumes and using them to create a stripe set. If you're using Oracle Orion
to benchmark your volumes, it can simulate striping the same way that Oracle ASM does, so we
recommend that you let Orion do the striping. If you are using a different benchmarking tool, you need
to stripe the volumes yourself.
To create a six-volume stripe set on Amazon Linux, use a command such as the following:
[ec2-user ~]$ sudo mdadm --create /dev/md0 --level=0 --chunk=64 --raiddevices=6 /dev/sdf /dev/sdg /dev/sdh /dev/sdi /dev/sdj /dev/sdk

For this example, the file system is XFS. Use the file system that meets your requirements. Use the
following command to install XFS file system support:
[ec2-user ~]$ sudo yum install -y xfsprogs

Then, use these commands to create, mount, and assign ownership to the XFS file system:
[ec2-user ~]$ sudo mkdir -p /mnt/p_iops_vol0 && sudo mkfs.xfs /dev/md0
[ec2-user ~]$ sudo mount -t xfs /dev/md0 /mnt/p_iops_vol0
[ec2-user ~]$ sudo chown ec2-user:ec2-user /mnt/p_iops_vol0/

Setting up Throughput Optimized HDD (st1) or Cold HDD (sc1) volumes
To create an st1 volume, choose Throughput Optimized HDD when creating the volume using the
Amazon EC2 console, or specify --type st1 when using the command line. To create an sc1 volume,
choose Cold HDD when creating the volume using the Amazon EC2 console, or specify --type sc1
when using the command line. For information about creating EBS volumes, see Creating an Amazon
EBS Volume (p. 650). For information about attaching these volumes to your instance, see Attaching
an Amazon EBS Volume to an Instance (p. 654).
AWS provides a JSON template for use with AWS CloudFormation that simplifies this setup procedure.
Access the template and save it as a JSON file. AWS CloudFormation allows you to configure your
own SSH keys and offers an easy way to set up a performance test environment to evaluate st1
volumes. The template creates a current-generation instance and a 2 TiB st1 volume, and attaches
the volume to the instance at /dev/xvdf.

To create an HDD volume with the template
1.

Open the AWS CloudFormation console at https://console.aws.amazon.com/cloudformation/.

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Choose Create Stack.

Choose Upload a Template to Amazon S3 and select the JSON template you previously
obtained.

Give your stack a name like “ebs-perf-testing”, and select an instance type (the default is
r3.8xlarge) and SSH key.

Choose Next twice, and then choose Create Stack.

After the status for your new stack moves from CREATE_IN_PROGRESS to COMPLETE, choose
Outputs to get the public DNS entry for your new instance, which will have a 2 TiB st1 volume
attached to it.

Connect using SSH to your new stack as user ec2-user, with the hostname obtained from the
DNS entry in the previous step.

Proceed to Install Benchmark Tools (p. 713).

Install Benchmark Tools
The following table lists some of the possible tools you can use to benchmark the performance of EBS
volumes.
Tool

Description

fio

For benchmarking I/O performance. (Note that fio has a dependency on
libaio-devel.)
To install fio on Amazon Linux, run the following command:
[ec2-user ~]$ sudo yum install -y fio

To install fio on Ubuntu, run the following command:
$ sudo apt-get install -y fio

Oracle Orion
Calibration Tool

For calibrating the I/O performance of storage systems to be used with Oracle
databases.

These benchmarking tools support a wide variety of test parameters. You should use commands that
approximate the workloads your volumes will support. These commands provided below are intended
as examples to help you get started.

Choosing the Volume Queue Length
Choosing the best volume queue length based on your workload and volume type.

Queue Length on SSD-backed Volumes
To determine the optimal queue length for your workload on SSD-backed volumes, we recommend
that you target a queue length of 1 for every 500 IOPS available (baseline for gp2 volumes and the
provisioned amount for io1 volumes). Then you can monitor your application performance and tune
that value based on your application requirements.
Increasing the queue length is beneficial until you achieve the provisioned IOPS, throughput or optimal
system queue length value, which is currently set to 32. For example, a volume with 1,000 provisioned
IOPS should target a queue length of 2. You should experiment with tuning these values up or down to
see what performs best for your application.

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Queue Length on HDD-backed Volumes
To determine the optimal queue length for your workload on HDD-backed volumes, we recommend
that you target a queue length of at least 4 while performing 1MiB sequential I/Os. Then you can
monitor your application performance and tune that value based on your application requirements.
For example, a 2 TiB st1 volume with burst throughput of 500 MiB/s and IOPS of 500 should
target a queue length of 4, 8, or 16 while performing 1,024 KiB, 512 KiB, or 256 KiB sequential I/Os
respectively. You should experiment with tuning these values value up or down to see what performs
best for your application.

Perform Benchmarking
The following procedures describe benchmarking commands for various EBS volume types.
Run the following commands on an EBS-optimized instance with attached EBS volumes. If the EBS
volumes were restored from snapshots, be sure to initialize them before benchmarking. For more
information, see Initializing Amazon EBS Volumes (p. 706).
When you are finished testing your volumes, see the following topics for help cleaning up: Deleting an
Amazon EBS Volume (p. 671) and Terminate Your Instance (p. 305).

Benchmarking io1 Volumes
Run fio on the stripe set that you created.
The following command performs 16 KB random write operations.
[ec2-user ~]$ sudo fio --directory=/mnt/p_iops_vol0 \
--name fio_test_file --direct=1 --rw=randwrite --bs=16k --size=1G \
--numjobs=16 --time_based --runtime=180 --group_reporting --norandommap

The following command performs 16 KB random read operations.
[ec2-user ~]$ sudo fio --directory=/mnt/p_iops_vol0 \
--name fio_test_file --direct=1 --rw=randread --bs=16k --size=1G \
--numjobs=16 --time_based --runtime=180 --group_reporting --norandommap

For more information about interpreting the results, see this tutorial: Inspecting disk IO performance
with fio.

Benchmarking st1 and sc1 Volumes
Run fio on your st1 or sc1 volume.

Note
Prior to running these tests, set buffered I/O on your instance as described in Increase ReadAhead for High-Throughput, Read-Heavy Workloads on st1 and sc1 (p. 700).
The following command performs 1 MiB sequential read operations against an attached st1 block
device (e.g., /dev/xvdf):
[ec2-user ~]$ sudo fio --filename=/dev/ --direct=1 --rw=read
--randrepeat=0 --ioengine=libaio --bs=1024k --iodepth=8 --time_based=1 -runtime=180
--name=fio_direct_read_test

The following command performs 1 MiB sequential write operations against an attached st1 block
device:
[ec2-user ~]$ sudo fio --filename=/dev/ --direct=1 --rw=write

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--randrepeat=0 --ioengine=libaio --bs=1024k --iodepth=8 --time_based=1 -runtime=180
--name=fio_direct_write_test

Some workloads perform a mix of sequential reads and sequential writes to different parts of the block
device. To benchmark such a workload, we recommend that you use separate, simultaneous fio
jobs for reads and writes, and use the fio offset_increment option to target different block device
locations for each job.
Running this workload is a bit more complicated than a sequential-write or sequential-read workload.
Use a text editor to create a fio job file, called fio_rw_mix.cfg in this example, that contains the
following:
[global]
clocksource=clock_gettime
randrepeat=0
runtime=180
offset_increment=100g
[sequential-write]
bs=1M
ioengine=libaio
direct=1
iodepth=8
filename=/dev/
do_verify=0
rw=write
rwmixread=0
rwmixwrite=100
[sequential-read]
bs=1M
ioengine=libaio
direct=1
iodepth=8
filename=/dev/
do_verify=0
rw=read
rwmixread=100
rwmixwrite=0

Then run the following command:
[ec2-user ~]$ sudo fio fio_rw_mix.cfg

For more information about interpreting the results, see the Inspecting disk I/O performance with fio
tutorial.
Multiple fio jobs for direct I/O, even though using sequential read or write operations, can result in
lower than expected throughput for st1 and sc1 volumes. We recommend that you use one direct I/O
job and use the iodepth parameter to control the number of concurrent I/O operations.

Amazon EC2 Instance Store
An instance store provides temporary block-level storage for your instance. This storage is located on
disks that are physically attached to the host computer. Instance store is ideal for temporary storage

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of information that changes frequently, such as buffers, caches, scratch data, and other temporary
content, or for data that is replicated across a fleet of instances, such as a load-balanced pool of web
servers.
An instance store consists of one or more instance store volumes exposed as block devices. The
size of an instance store varies by instance type. The virtual devices for instance store volumes are
ephemeral[0-23]. Instance types that support one instance store volume have ephemeral0.
Instance types that support two instance store volumes have ephemeral0 and ephemeral1, and so
on. While an instance store is dedicated to a particular instance, the disk subsystem is shared among
instances on a host computer.

Contents
• Instance Store Lifetime (p. 716)
• Instance Store Volumes (p. 717)
• Add Instance Store Volumes to Your EC2 Instance (p. 719)
• SSD Instance Store Volumes (p. 722)
• Instance Store Swap Volumes (p. 723)
• Optimizing Disk Performance for Instance Store Volumes (p. 726)

Instance Store Lifetime
You can specify instance store volumes for an instance only when you launch it. The data in an
instance store persists only during the lifetime of its associated instance. If an instance reboots
(intentionally or unintentionally), data in the instance store persists. However, data in the instance store
is lost under the following circumstances:
• The underlying disk drive fails
• The instance stops
• The instance terminates
Therefore, do not rely on instance store for valuable, long-term data. Instead, you can build a degree
of redundancy (for example, RAID 1/5/6), or use a file system (for example, HDFS and MapR-FS) that
supports redundancy and fault tolerance. You can also back up data periodically to more durable data
storage solutions such as Amazon S3 or Amazon EBS.

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You can't detach an instance store volume from one instance and attach it to a different instance. If you
create an AMI from an instance, the data on its instance store volumes isn't preserved and isn't present
on the instance store volumes of the instances that you launch from the AMI.

Instance Store Volumes
The instance type determines the size of the instance store available and the type of hardware used for
the instance store volumes. Instance store volumes are included as part of the instance's hourly cost.
You must specify the instance store volumes that you'd like to use when you launch the instance, and
then format and mount them before using them. You can't make an instance store volume available
after you launch the instance. For more information, see Add Instance Store Volumes to Your EC2
Instance (p. 719).
Some instance types use solid state drives (SSD) to deliver very high random I/O performance. This
is a good option when you need storage with very low latency, but you don't need the data to persist
when the instance terminates or you can take advantage of fault-tolerant architectures. For more
information, see SSD Instance Store Volumes (p. 722).
The following table provides the quantity, size, type, and performance optimizations of instance store
volumes available on each instance type.
Instance Type

Instance Store
Volumes

Type

Needs
Initialization*

c1.medium

1 x 350 GB†

HDD

✔

c1.xlarge

4 x 420 GB (1,680
GB)

HDD

✔

c3.large

2 x 16 GB (32
GB)

SSD

✔

c3.xlarge

2 x 40 GB (80
GB)

SSD

✔

c3.2xlarge

2 x 80 GB (160
GB)

SSD

✔

c3.4xlarge

2 x 160 GB (320
GB)

SSD

✔

c3.8xlarge

2 x 320 GB (640
GB)

SSD

✔

cc2.8xlarge

4 x 840 GB (3,360
GB)

HDD

✔

cg1.4xlarge

2 x 840 GB (1,680
GB)

HDD

✔

cr1.8xlarge

2 x 120 GB (240
GB)

SSD

✔

d2.xlarge

3 x 2,000 GB (6
TB)

HDD

d2.2xlarge

6 x 2,000 GB (12
TB)

HDD

d2.4xlarge

12 x 2,000 GB (24
TB)

HDD

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Instance Type

Instance Store
Volumes

Type

d2.8xlarge

24 x 2,000 GB (48
TB)

HDD

g2.2xlarge

1 x 60 GB

SSD

✔

g2.8xlarge

2 x 120 GB (240
GB)

SSD

✔

hi1.4xlarge

2 x 1,024 GB
(2,048 GB)

SSD

hs1.8xlarge

24 x 2,000 GB (48
TB)

HDD

i2.xlarge

1 x 800 GB

SSD

✔

i2.2xlarge

2 x 800 GB (1,600
GB)

SSD

✔

i2.4xlarge

4 x 800 GB (3,200
GB)

SSD

✔

i2.8xlarge

8 x 800 GB (6,400
GB)

SSD

✔

m1.small

1 x 160 GB†

HDD

✔

m1.medium

1 x 410 GB

HDD

✔

m1.large

2 x 420 GB (840
GB)

HDD

✔

m1.xlarge

4 x 420 GB (1,680
GB)

HDD

✔

m2.xlarge

1 x 420 GB

HDD

✔

m2.2xlarge

1 x 850 GB

HDD

✔

m2.4xlarge

2 x 840 GB (1,680
GB)

HDD

✔

m3.medium

1 x 4 GB

SSD

✔

m3.large

1 x 32 GB

SSD

✔

m3.xlarge

2 x 40 GB (80
GB)

SSD

✔

m3.2xlarge

2 x 80 GB (160
GB)

SSD

✔

r3.large

1 x 32 GB

SSD

✔

r3.xlarge

1 x 80 GB

SSD

✔

r3.2xlarge

1 x 160 GB

SSD

✔

r3.4xlarge

1 x 320 GB

SSD

✔

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Initialization*

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Instance Type

Instance Store
Volumes

Type

r3.8xlarge

2 x 320 GB (640
GB)

SSD

x1.32xlarge

2 x 1,920 GB
(3,840 GB)

SSD

Needs
Initialization*

TRIM Support**
✔

* Volumes attached to certain instances will suffer a first-write penalty unless initialized. For more
information about initializing instance store volumes, see Optimizing Disk Performance for Instance
Store Volumes.
** SSD-based instance store volumes that support TRIM instructions are not pre-formatted with any
file system. However, you can format volumes with the file system of your choice after you launch your
instance. For more information, see Instance Store Volume TRIM Support (p. 722).
† The c1.medium and m1.small instance types also include a 900 MB instance store swap volume,
which may not be automatically enabled at boot time. For more information, see Instance Store Swap
Volumes (p. 723).

Add Instance Store Volumes to Your EC2
Instance
You specify the EBS volumes and instance store volumes for your instance using a block device
mapping. Each entry in a block device mapping includes a device name and the volume that it maps
to. The default block device mapping is specified by the AMI you use. Alternatively, you can specify
a block device mapping for the instance when you launch it. For more information, see Block Device
Mapping (p. 731).
A block device mapping always specifies the root volume for the instance. The root volume is either
an Amazon EBS volume or an instance store volume. For more information, see Storage for the Root
Device (p. 71). The root volume is mounted automatically. For instances with an instance store volume
for the root volume, the size of this volume varies by AMI, but the maximum size is 10 GB.
You can use a block device mapping to specify additional EBS volumes when you launch your
instance, or you can attach additional EBS volumes after your instance is running. For more
information, see Amazon EBS Volumes (p. 636).
You can specify the instance store volumes for your instance only when you launch an instance. You
can't attach instance store volumes to an instance after you've launched it.
The number and size of available instance store volumes for your instance varies by instance type.
Some instance types do not support instance store volumes. For more information about the instance
store volumes support by each instance type, see Instance Store Volumes (p. 717). If the instance
type you choose for your instance supports instance store volumes, you must add them to the block
device mapping for the instance when you launch it. After you launch the instance, you must ensure
that the instance store volumes for your instance are formatted and mounted before you can use them.
Note that the root volume of an instance store-backed instance is mounted automatically.
Contents
• Adding Instance Store Volumes to an AMI (p. 720)
• Adding Instance Store Volumes to an Instance (p. 720)
• Making Instance Store Volumes Available on Your Instance (p. 721)

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Adding Instance Store Volumes to an AMI
You can create an AMI with a block device mapping that includes instance store volumes. After you
add instance store volumes to an AMI, any instance that you launch from the AMI includes these
instance store volumes. Note that when you launch an instance, you can omit volumes specified in the
AMI block device mapping and add new volumes.

Important
For M3 instances, specify instance store volumes in the block device mapping of the instance,
not the AMI. Amazon EC2 might ignore instance store volumes that are specified only in the
block device mapping of the AMI.

To add instance store volumes to an Amazon EBS-backed AMI using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances.

Select an instance, choose Actions, select Image, and then select Create Image.

In the Create Image dialog, add a meaningful name and description for your image.

For each instance store volume to add, choose Add New Volume, select an instance store
volume from Type, and select a device name from Device. (For more information, see Device
Naming on Linux Instances (p. 729).) The number of available instance store volumes depends
on the instance type.

Click Create Image.

To add instance store volumes to an AMI using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• create-image or register-image (AWS CLI)
• New-EC2Image and Register-EC2Image (AWS Tools for Windows PowerShell)

Adding Instance Store Volumes to an Instance
When you launch an instance, the default block device mapping is provided by the specified AMI. If you
need additional instance store volumes, you must add them to the instance as you launch it. Note that
you can also omit devices specified in the AMI block device mapping.

Important
For M3 instances, you might receive instance store volumes even if you do not specify them in
the block device mapping for the instance.

Important
For HS1 instances, no matter how many instance store volumes you specify in the block
device mapping of an AMI, the block device mapping for an instance launched from the

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AMI automatically includes the maximum number of supported instance store volumes. You
must explicitly remove the instance store volumes that you don't want from the block device
mapping for the instance before you launch it.

To update the block device mapping for an instance using the console
1.

Open the Amazon EC2 console.

From the dashboard, choose Launch Instance.

In Step 1: Choose an Amazon Machine Image (AMI), select the AMI to use and choose Select.

Follow the wizard to complete Step 1: Choose an Amazon Machine Image (AMI), Step 2:
Choose an Instance Type, and Step 3: Configure Instance Details.

In Step 4: Add Storage, modify the existing entries as needed. For each instance store volume
to add, click Add New Volume, select an instance store volume from Type, and select a device
name from Device. The number of available instance store volumes depends on the instance
type.

Complete the wizard to launch the instance.

To update the block device mapping for an instance using the command line
You can use one of the following options commands with the corresponding command. For more
information about these command line interfaces, see Accessing Amazon EC2 (p. 3).
• --block-device-mappings with run-instances (AWS CLI)
• -BlockDeviceMapping with New-EC2Instance (AWS Tools for Windows PowerShell)

Making Instance Store Volumes Available on Your
Instance
After you launch an instance, the instance store volumes are available to the instance, but you can't
access them until they are mounted. For Linux instances, the instance type determines which instance
store volumes are mounted for you and which are available for you to mount yourself. For Windows
instances, the EC2Config service mounts the instance store volumes for an instance. The block device
driver for the instance assigns the actual volume name when mounting the volume, and the name
assigned can be different than the name that Amazon EC2 recommends.
Many instance store volumes are pre-formatted with the ext3 file system. SSD-based instance store
volumes that support TRIM instruction are not pre-formatted with any file system. However, you
can format volumes with the file system of your choice after you launch your instance. For more
information, see Instance Store Volume TRIM Support (p. 722). For Windows instances, the
EC2Config service reformats the instance store volumes with the NTFS file system.
You can confirm that the instance store devices are available from within the instance itself using
instance metadata. For more information, see Viewing the Instance Block Device Mapping for Instance
Store Volumes (p. 739).

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For Windows instances, you can also view the instance store volumes using Windows Disk
Management. For more information, see Listing the Disks Using Windows Disk Management.
For Linux instances, you can view and mount the instance store volumes as described in the following
procedure.

To make an instance store volume available on Linux
1.

Connect to the instance using an SSH client.

Use the df -h command to view the volumes that are formatted and mounted. Use the lsblk to
view any volumes that were mapped at launch but not formatted and mounted.

To format and mount an instance store volume that was mapped only, do the following:
a.

Create a file system on the device using the mkfs command.

Create a directory on which to mount the device using the mkdir command.

Mount the device on the newly created directory using the mount command.

SSD Instance Store Volumes
The following instances support instance store volumes that use solid state drives (SSD) to deliver
very high random I/O performance: C3, G2, HI1, I2, M3, R3, and X1. For more information about the
instance store volumes support by each instance type, see Instance Store Volumes (p. 717).
To ensure the best IOPS performance from your SSD instance store volumes on Linux, we
recommend that you use the most recent version of the Amazon Linux AMI, or another Linux AMI with
a kernel version of 3.8 or later. If you do not use a Linux AMI with a kernel version of 3.8 or later, your
instance will not achieve the maximum IOPS performance available for these instance types.
Like other instance store volumes, you must map the SSD instance store volumes for your instance
when you launch it, and the data on an SSD instance volume persists only for the life of its associated
instance. For more information, see Add Instance Store Volumes to Your EC2 Instance (p. 719).

Instance Store Volume TRIM Support
The following instances support SSD volumes with TRIM: I2, R3.
With instance store volumes that support TRIM, you can use the TRIM command to notify the SSD
controller when you no longer need data that you've written. This provides the controller with more free
space, which can reduce write amplification and increase performance. For more information about
using TRIM commands, see the documentation for the operating system for your instance.
Instance store volumes that support TRIM are fully trimmed before they are allocated to your instance.
These volumes are not formatted with a file system when an instance launches, so you must format
them before they can be mounted and used. For faster access to these volumes, you should specify
the file system-specific option that skips the TRIM operation when you format them. On Linux, you
should also add the discard option to your mount command or /etc/fstab file entries for the
devices that support TRIM so that they use this feature effectively. On Windows, use the following
command: fsutil behavior set DisableDeleteNotify 1.

To make an instance store volume with TRIM support available for use on Linux
1.

Map the instance store volume when you launch the instance. For more information, see Add
Instance Store Volumes to Your EC2 Instance (p. 719).

From the instance, list the available devices using the lsblk command or view the instance store
volumes using instance metadata (p. 739).

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Verify that your operating system and device support TRIM using the following command
(replacing xvdb with the name of your device):
[ec2-user ~]$ sudo cat /sys/block/xvdb/queue/discard_max_bytes
322122547200

If this command returns a value other than 0, then your operating system and device support
TRIM.
4.

Format the volume with the file system of your choice.
•

(EXT4) To format the volume with the ext4 file system, use the following command (replacing
xvdc with the name of your device):
[ec2-user ~]$ sudo mkfs.ext4 -E nodiscard /dev/xvdc

•

(XFS) To format the volume with the xfs file system, use the following command (replacing
xvdb with the name of your device):
[ec2-user ~]$ sudo mkfs.xfs -K /dev/xvdb

Note
You might need to install XFS file system support on your operating system for
this command to work. For Amazon Linux, use the sudo yum install -y xfsprogs
command.
5.

Mount the device using the discard option. Be sure to specify the device name of the volume.
You can select an existing directory or create a new one using the mkdir command.
[ec2-user ~]$ sudo mount -o discard /dev/xvdb /mnt/my-data

(Optional) If you want the device to mount at boot time, you can add or modify an entry in the /
etc/fstab file with the discard option.
/dev/xvdb
/dev/xvdc

/mnt/xvdb
/mnt/xvdc

xfs
ext4

defaults,nofail,discard
defaults,nofail,discard

0
0

2
2

Important
After you edit the /etc/fstab file, verify that there are no errors running the sudo
mount -a command. If there are any errors in this file, the system may not boot properly
or at all.

Instance Store Swap Volumes
Swap space in Linux can be used when a system requires more memory than it has been physically
allocated. When swap space is enabled, Linux systems can swap infrequently used memory pages
from physical memory to swap space (either a dedicated partition or a swap file in an existing file
system) and free up that space for memory pages that require high speed access.

Note
Using swap space for memory paging is not as fast or efficient as using RAM. If your workload
is regularly paging memory into swap space, you should consider migrating to a larger
instance type with more RAM. For more information, see Resizing Your Instance (p. 189).
The c1.medium and m1.small instance types have a limited amount of physical memory to work
with, and they are given a 900 MiB swap volume at launch time to act as virtual memory for Linux
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AMIs. Although the Linux kernel sees this swap space as a partition on the root device, it is actually a
separate instance store volume, regardless of your root device type.
Amazon Linux AMIs automatically enable and use this swap space, but your AMI may require some
additional steps to recognize and use this swap space. To see if your instance is using swap space,
you can use the swapon -s command.
[ec2-user@ip-12-34-56-78 ~]$ swapon -s
Filename
Priority
/dev/xvda3

Type

Size

Used

partition

917500

-1

The above instance has a 900 MiB swap volume attached and enabled. If you don't see a swap
volume listed with this command, you may need to enable swap space for the device. Check your
available disks using the lsblk command.
[ec2-user@ip-12-34-56-78 ~]$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda1 202:1
0
8G 0 disk /
xvda3 202:3
0 896M 0 disk

Here, the swap volume xvda3 is available to the instance, but it is not enabled (notice that the
MOUNTPOINT field is empty). You can enable the swap volume with the swapon command.

Note
You need to prepend /dev/ to the device name listed by lsblk. Your device may be named
differently, such as sda3, sde3, or xvde3. Use the device name for your system in the
command below.
[ec2-user@ip-12-34-56-78 ~]$ sudo swapon /dev/xvda3

Now the swap space should show up in lsblk and swapon -s output.
[ec2-user@ip-12-34-56-78 ~]$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
xvda1 202:1
0
8G 0 disk /
xvda3 202:3
0 896M 0 disk [SWAP]
[ec2-user@ip-12-34-56-78 ~]$ swapon -s
Filename
Type
Priority
/dev/xvda3
partition

Size

Used

917500

-1

You will also need to edit your /etc/fstab file so that this swap space is automatically enabled at
every system boot.
[ec2-user@ip-12-34-56-78 ~]$ sudo vim /etc/fstab

Append the following line to your /etc/fstab file (using the swap device name for your system):
/dev/xvda3

none

swap

To use an instance store volume as swap space
Any instance store volume can be used as swap space. For example, the m3.medium instance type
includes a 4 GB SSD instance store volume that is appropriate for swap space. If your instance store

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volume is much larger (for example, 350 GB), you may consider partitioning the volume with a smaller
swap partition of 4-8 GB and the rest for a data volume.

Note
This procedure applies only to instance types that suppport instance storage. For a list of
supported instance types, see Instance Store Volumes (p. 717).
1.

List the block devices attached to your instance to get the device name for your instance store
volume.
[ec2-user ~]$ lsblk -p
NAME
MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
/dev/xvdb 202:16
0
4G 0 disk /media/ephemeral0
/dev/xvda1 202:1
0
8G 0 disk /

In this example, the instance store volume is /dev/xdvb. Because this is an Amazon Linux
instance, the instance store volume is formatted and mounted at /media/ephemeral0; not all
Linux operating systems do this automatically.
2.

(Optional) If your instance store volume is mounted (it will list a MOUNTPOINT in the lsblk
command output), you need to unmount it with the following command.
[ec2-user ~]$ sudo umount /dev/xvdb

Set up a Linux swap area on the device with the mkswap command.
[ec2-user ~]$ sudo mkswap /dev/xvdb
mkswap: /dev/xvdb: warning: wiping old ext3 signature.
Setting up swapspace version 1, size = 4188668 KiB
no label, UUID=b4f63d28-67ed-46f0-b5e5-6928319e620b

Enable the new swap space.
[ec2-user ~]$ sudo swapon /dev/xvdb

Verify that the new swap space is being used.
[ec2-user ~]$ swapon -s
Filename
Type Size Used Priority
/dev/xvdb

partition 4188668 0 -1

Edit your /etc/fstab file so that this swap space is automatically enabled at every system boot.
[ec2-user ~]$ sudo vim /etc/fstab

If your /etc/fstab file has an entry for /dev/xvdb (or /dev/sdb) change it to match the line
below; if it does not have an entry for this device, append the following line to your /etc/fstab
file (using the swap device name for your system):
/dev/xvdb

none

swap

Important
Instance store volume data is lost when an instance is stopped; this includes the instance
store swap space formatting created in Step 3 (p. 725). If you stop and restart an
instance that has been configured to use instance store swap space, you must repeat
Step 1 (p. 725) through Step 5 (p. 725) on the new instance store volume.

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Optimizing Disk Performance for Instance Store
Volumes
Because of the way that Amazon EC2 virtualizes disks, the first write to any location on most instance
store volumes performs more slowly than subsequent writes. For most applications, amortizing this
cost over the lifetime of the instance is acceptable. However, if you require high disk performance, we
recommend that you initialize your drives by writing once to every drive location before production use.

Note
Some instance types with direct-attached solid state drives (SSD) and TRIM support provide
maximum performance at launch time, without initialization. For information about the instance
store for each instance type, see Instance Store Volumes (p. 717).
If you require greater flexibility in latency or throughput, we recommend using Amazon EBS.
To initialize the instance store volumes, use the following dd commands, depending on which store you
want to initialize (for example, /dev/sdb).

Note
Make sure to unmount the drive before performing this command.
Initialization can take a long time (about 8 hours for an extra large instance).
To initialize the instance store volumes, use the following commands on the m1.large, m1.xlarge,
c1.xlarge, m2.xlarge, m2.2xlarge, and m2.4xlarge instance types:
dd
dd
dd
dd

if=/dev/zero
if=/dev/zero
if=/dev/zero
if=/dev/zero

of=/dev/sdb
of=/dev/sdc
of=/dev/sdd
of=/dev/sde

bs=1M
bs=1M
bs=1M
bs=1M

To perform initialization on all instance store volumes at the same time, use the following command:
dd if=/dev/zero bs=1M|tee /dev/sdb|tee /dev/sdc|tee /dev/sde > /dev/sdd

Configuring drives for RAID initializes them by writing to every drive location. When configuring
software-based RAID, make sure to change the minimum reconstruction speed:
echo $((30*1024)) > /proc/sys/dev/raid/speed_limit_min

Amazon Simple Storage Service (Amazon S3)
Amazon S3 is a repository for Internet data. Amazon S3 provides access to reliable, fast, and
inexpensive data storage infrastructure. It is designed to make web-scale computing easy by enabling
you to store and retrieve any amount of data, at any time, from within Amazon EC2 or anywhere on
the web. Amazon S3 stores data objects redundantly on multiple devices across multiple facilities and
allows concurrent read or write access to these data objects by many separate clients or application
threads. You can use the redundant data stored in Amazon S3 to recover quickly and reliably from
instance or application failures.
Amazon EC2 uses Amazon S3 for storing Amazon Machine Images (AMIs). You use AMIs for
launching EC2 instances. In case of instance failure, you can use the stored AMI to immediately launch
another instance, thereby allowing for fast recovery and business continuity.
Amazon EC2 also uses Amazon S3 to store snapshots (backup copies) of the data volumes. You
can use snapshots for recovering data quickly and reliably in case of application or system failures.

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You can also use snapshots as a baseline to create multiple new data volumes, expand the size of
an existing data volume, or move data volumes across multiple Availability Zones, thereby making
your data usage highly scalable. For more information about using data volumes and snapshots, see
Amazon Elastic Block Store (p. 634).
Objects are the fundamental entities stored in Amazon S3. Every object stored in Amazon S3 is
contained in a bucket. Buckets organize the Amazon S3 namespace at the highest level and identify
the account responsible for that storage. Amazon S3 buckets are similar to Internet domain names.
Objects stored in the buckets have a unique key value and are retrieved using a HTTP URL address.
For example, if an object with a key value /photos/mygarden.jpg is stored in the myawsbucket
bucket, then it is addressable using the URL http://myawsbucket.s3.amazonaws.com/photos/
mygarden.jpg.
For more information about the features of Amazon S3, see the Amazon S3 product page.

Amazon S3 and Amazon EC2
Given the benefits of Amazon S3 for storage, you may decide to use this service to store files and data
sets for use with EC2 instances. There are several ways to move data to and from Amazon S3 to your
instances. In addition to the examples discussed below, there are a variety of tools that people have
written that you can use to access your data in Amazon S3 from your computer or your instance. Some
of the common ones are discussed in the AWS forums.
If you have permission, you can copy a file to or from Amazon S3 and your instance using one of the
following methods.
GET or wget
The wget utility is an HTTP and FTP client that allows you to download public objects from Amazon
S3. It is installed by default in Amazon Linux and most other distributions, and available for download
on Windows. To download an Amazon S3 object, use the following command, substituting the URL of
the object to download.
wget http://s3.amazonaws.com/my_bucket/my_folder/my_file.ext

This method requires that the object you request is public; if the object is not public, you receive an
ERROR 403: Forbidden message. If you receive this error, open the Amazon S3 console and
change the permissions of the object to public. For more information, see the Amazon Simple Storage
Service Developer Guide.
AWS Command Line Interface
The AWS Command Line Interface (AWS CLI) is a unified tool to manage your AWS services. With just
one tool to download and configure, you can control multiple AWS services from the command line and
automate them through scripts. The AWS CLI allows users to authenticate themselves and download
restricted items from Amazon S3 and also to upload items. For more information, such as how to install
and configure the tools, see the AWS Command Line Interface detail page.
The aws s3 cp command is similar to the Unix cp command (the syntax is: aws s3 cp source
destination). You can copy files from Amazon S3 to your instance, you can copy files from your
instance to Amazon S3, and you can even copy files from one Amazon S3 location to another.
Use the following command to copy an object from Amazon S3 to your instance.
$ aws s3 cp s3://my_bucket/my_folder/my_file.ext my_copied_file.ext

Use the following command to copy an object from your instance back into Amazon S3.

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$ aws s3 cp my_copied_file.ext s3://my_bucket/my_folder/my_file.ext

Use the following command to copy an object from one Amazon S3 location to another.
$ aws s3 cp s3://my_bucket/my_folder/my_file.ext
s3://my_bucket/my_folder/my_file2.ext

The aws s3 sync command can synchronize an entire Amazon S3 bucket to a local directory location.
This can be helpful for downloading a data set and keeping the local copy up-to-date with the remote
set. The command syntax is: aws s3 sync source destination. If you have the proper permissions
on the Amazon S3 bucket, you can push your local directory back up to the cloud when you are
finished by reversing the source and destination locations in the command.
Use the following command to download an entire Amazon S3 bucket to a local directory on your
instance.
$ aws s3 sync s3://remote_S3_bucket local_directory

AWS Tools for Windows PowerShell
Windows instances have the benefit of a graphical browser that you can use to access the Amazon
S3 console directly; however, for scripting purposes, Windows users can also use the AWS Tools for
Windows PowerShell to move objects to and from Amazon S3.
Use the following command to copy an Amazon S3 object to your Windows instance.
PS C:\> Copy-S3Object -BucketName my_bucket -Key my_folder/my_file.ext LocalFile my_copied_file.ext

Amazon S3 API
If you are a developer, you can use an API to access data in Amazon S3. For more information, see
the Amazon Simple Storage Service Developer Guide. You can use this API and its examples to help
develop your application and integrate it with other APIs and SDKs, such as the boto Python interface.

Instance Volume Limits
The maximum number of volumes that your instance can have depends on the operating system.
When considering how many volumes to add to your instance, you should consider whether you need
increased I/O bandwidth or increased storage capacity.
Contents
• Linux-Specific Volume Limits (p. 728)
• Windows-Specific Volume Limits (p. 729)
• Bandwidth vs Capacity (p. 729)

Linux-Specific Volume Limits
Attaching more than 40 volumes can cause boot failures. Note that this number includes the root
volume, plus any attached instance store volumes and EBS volumes. If you experience boot problems

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on an instance with a large number of volumes, stop the instance, detach any volumes that are not
essential to the boot process, and then reattach the volumes after the instance is running.

Important
Attaching more than 40 volumes to a Linux instance is supported on a best effort basis only
and is not guaranteed.

Windows-Specific Volume Limits
The following table shows the volume limits for Windows instances based on the driver used. Note that
these numbers include the root volume, plus any attached instance store volumes and EBS volumes.

Important
Attaching more than the following volumes to a Windows instance is supported on a best effort
basis only and is not guaranteed.
Driver

Volume Limit

AWS PV

Citrix PV

Red Hat PV

We do not recommend that you give a Windows instance more than 26 volumes with AWS PV or Citrix
PV drivers, as it is likely to cause performance issues.
To determine which PV drivers your instance is using, or to upgrade your Windows instance from Red
Hat to Citrix PV drivers, see Upgrading PV Drivers on Your Windows Instance.
For more information about how device names related to volumes, see Mapping Disks to Volumes on
Your Windows EC2 Instance in the Amazon EC2 User Guide for Windows Instances.

Bandwidth vs Capacity
For consistent and predictable bandwidth use cases, use EBS-optimized or 10 Gigabit network
connectivity instances and General Purpose SSD or Provisioned IOPS SSD volumes. Follow the
guidance in Amazon EC2 Instance Configuration (p. 701) to match the IOPS you have provisioned
for your volumes to the bandwidth available from your instances for maximum performance. For
RAID configurations, many administrators find that arrays larger than 8 volumes have diminished
performance returns due to increased I/O overhead. Test your individual application performance and
tune it as required.

Device Naming on Linux Instances
When you attach a volume to your instance, you include a device name for the volume. This device
name is used by Amazon EC2. The block device driver for the instance assigns the actual volume
name when mounting the volume, and the name assigned can be different from the name that Amazon
EC2 uses.
Contents
• Available Device Names (p. 730)
• Device Name Considerations (p. 730)

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For information about device names on Windows instances, see Device Naming on Windows
Instances in the Amazon EC2 User Guide for Windows Instances.

Available Device Names
The following table lists the available device names for Linux instances. The number of volumes that
you can attach to your instance is determined by the operating system. For more information, see
Instance Volume Limits (p. 728).
Virtualization
Type

Available

Reserved for
Root

Used for
Instance Store
Volumes

Recommended
for EBS Volumes

Paravirtual

/dev/sd[a-z]

/dev/sda1

/dev/sd[b-e]

/dev/sd[f-p]

/dev/sd[b-y]
(hs1.8xlarge)

/dev/sd[f-p][1-6]

/dev/sd[f-p]

/dev/sd[a-z][1-15]
/dev/hd[a-z]
/dev/hd[a-z][1-15]
HVM

/dev/sd[a-z]

Differs by AMI*

/dev/sd[b-e]

/dev/xvd[b-c][a-z]

/dev/sda1 or /dev/
xvda

/dev/sd[b-y]
(hs1.8xlarge)
/dev/sd[b-i]
(i2.8xlarge)

Note that you can determine the root device name for your particular AMI with the following AWS CLI
command:
aws ec2 describe-images --image-ids image_id --query Images[].RootDeviceName

For more information about instance store volumes, see Amazon EC2 Instance Store (p. 715). For
information about the root device storage, see Amazon EC2 Root Device Volume (p. 14).

Device Name Considerations
Keep the following in mind when selecting a device name:
• Although you can attach your EBS volumes using the device names used to attach instance store
volumes, we strongly recommend that you don't because the behavior can be unpredictable.
• Depending on the block device driver of the kernel, the device might be attached with a different
name than what you specify. For example, if you specify a device name of /dev/sdh, your device
might be renamed /dev/xvdh or /dev/hdh by the kernel; in most cases, the trailing letter remains
the same. In some versions of Red Hat Enterprise Linux (and its variants, such as CentOS), even
the trailing letter might also change (where /dev/sda could become /dev/xvde). In these cases,
each device name trailing letter is incremented the same number of times. For example, /dev/sdb
would become /dev/xvdf and /dev/sdc would become /dev/xvdg. Amazon Linux AMIs create
a symbolic link with the name you specify at launch that points to the renamed device path, but other
AMIs might behave differently.
• There are two types of virtualization available for Linux instances: paravirtual (PV) and hardware
virtual machine (HVM). The virtualization type of an instance is determined by the AMI used to
launch the instance. Some instance types support both PV and HVM, some support HVM only,

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and others support PV only. Be sure to note the virtualization type of your AMI, because the
recommended and available device names that you can use depend on the virtualization type of your
instance. For more information, see Linux AMI Virtualization Types (p. 74).
• You cannot attach volumes that share the same device letters both with and without trailing digits.
For example, if you attach a volume as /dev/sdc and another volume as /dev/sdc1, only /dev/
sdc is visible to the instance. To use trailing digits in device names, you must use trailing digits on all
device names that share the same base letters (such as /dev/sdc1, /dev/sdc2, /dev/sdc3).
• Hardware virtual machine (HVM) AMIs don't support the use of trailing numbers on device names.
• Some custom kernels might have restrictions that limit use to /dev/sd[f-p] or /dev/sd[f-p]
[1-6]. If you're having trouble using /dev/sd[q-z] or /dev/sd[q-z][1-6], try switching to /
dev/sd[f-p] or /dev/sd[f-p][1-6].

Block Device Mapping
Each instance that you launch has an associated root device volume, either an Amazon EBS volume
or an instance store volume. You can use block device mapping to specify additional EBS volumes
or instance store volumes to attach to an instance when it's launched. You can also attach additional
EBS volumes to a running instance; see Attaching an Amazon EBS Volume to an Instance (p. 654).
However, the only way to attach instance store volumes to an instance is to use block device mapping
to attach them as the instance is launched.
For more information about root device volumes, see Changing the Root Device Volume to
Persist (p. 17).
Contents
• Block Device Mapping Concepts (p. 731)
• AMI Block Device Mapping (p. 734)
• Instance Block Device Mapping (p. 736)

Block Device Mapping Concepts
A block device is a storage device that moves data in sequences of bytes or bits (blocks). These
devices support random access and generally use buffered I/O. Examples include hard disks, CDROM drives, and flash drives. A block device can be physically attached to a computer or accessed
remotely as if it were physically attached to the computer. Amazon EC2 supports two types of block
devices:
• Instance store volumes (virtual devices whose underlying hardware is physically attached to the host
computer for the instance)
• EBS volumes (remote storage devices)
A block device mapping defines the block devices (instance store volumes and EBS volumes) to attach
to an instance. You can specify a block device mapping as part of creating an AMI so that the mapping
is used by all instances launched from the AMI. Alternatively, you can specify a block device mapping
when you launch an instance, so this mapping overrides the one specified in the AMI from which you
launched the instance.
Contents
• Block Device Mapping Entries (p. 732)
• Block Device Mapping Instance Store Caveats (p. 732)
• Example Block Device Mapping (p. 733)

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• How Devices Are Made Available in the Operating System (p. 733)

Block Device Mapping Entries
When you create a block device mapping, you specify the following information for each block device
that you need to attach to the instance:
• The device name used within Amazon EC2. For more information, see Device Naming on Linux
Instances (p. 729).

Important
The block device driver for the instance assigns the actual volume name when mounting
the volume, and the name assigned can be different from the name that Amazon EC2
recommends.
• [Instance store volumes] The virtual device: ephemeral[0-23]. Note that the number and size of
available instance store volumes for your instance varies by instance type.
• [EBS volumes] The ID of the snapshot to use to create the block device (snap-xxxxxxxx). This value
is optional as long as you specify a volume size.
• [EBS volumes] The size of the volume, in GiB. The specified size must be greater than or equal to
the size of the specified snapshot.
• [EBS volumes] Whether to delete the volume on instance termination (true or false). The default
value is true for the root device volume and false for attached volumes. When you create an AMI,
its block device mapping inherits this setting from the instance. When you launch an instance, it
inherits this setting from the AMI.
• [EBS volumes] The volume type, which can be gp2 for General Purpose SSD, io1 for Provisioned
IOPS SSD, st1 for Throughput Optimized HDD, sc1 for Cold HDD, or standard for Magnetic. The
default value is gp2 in the Amazon EC2 console, and standard in the AWS SDKs and the AWS
CLI.
• [EBS volumes] The number of input/output operations per second (IOPS) that the volume supports.
(Not used with gp2, st1, sc1, or standard volumes.)

Block Device Mapping Instance Store Caveats
There are several caveats to consider when launching instances with AMIs that have instance store
volumes in their block device mappings.
• Some instance types include more instance store volumes than others, and some instance types
contain no instance store volumes at all. If your instance type supports one instance store volume,
and your AMI has mappings for two instance store volumes, then the instance launches with one
instance store volume.
• Instance store volumes can only be mapped at launch time. You cannot stop an instance without
instance store volumes (such as the t2.micro), change the instance to a type that supports
instance store volumes, and then restart the instance with instance store volumes. However, you
can create an AMI from the instance and launch it on an instance type that supports instance store
volumes, and map those instance store volumes to the instance.
• If you launch an instance with instance store volumes mapped, and then stop the instance and
change it to an instance type with fewer instance store volumes and restart it, the instance store
volume mappings from the initial launch still show up in the instance metadata. However, only the
maximum number of supported instance store volumes for that instance type are available to the
instance.

Note
When an instance is stopped, all data on the instance store volumes is lost.
• Depending on instance store capacity at launch time, M3 instances may ignore AMI instance store
block device mappings at launch unless they are specified at launch. You should specify instance

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store block device mappings at launch time, even if the AMI you are launching has the instance
store volumes mapped in the AMI, to ensure that the instance store volumes are available when the
instance launches.

Example Block Device Mapping
This figure shows an example block device mapping for an EBS-backed instance. It maps /dev/sdb
to ephemeral0 and maps two EBS volumes, one to /dev/sdh and the other to /dev/sdj. It also
shows the EBS volume that is the root device volume, /dev/sda1.

Note that this example block device mapping is used in the example commands and APIs in this topic.
You can find example commands and APIs that create block device mappings in Specifying a Block
Device Mapping for an AMI (p. 734) and Updating the Block Device Mapping when Launching an
Instance (p. 736).

How Devices Are Made Available in the Operating System
Device names like /dev/sdh and xvdh are used by Amazon EC2 to describe block devices. The
block device mapping is used by Amazon EC2 to specify the block devices to attach to an EC2
instance. After a block device is attached to an instance, it must be mounted by the operating system
before you can access the storage device. When a block device is detached from an instance, it is
unmounted by the operating system and you can no longer access the storage device.
With a Linux instance, the device names specified in the block device mapping are mapped to their
corresponding block devices when the instance first boots. The instance type determines which
instance store volumes are formatted and mounted by default. You can mount additional instance
store volumes at launch, as long as you don't exceed the number of instance store volumes available
for your instance type. For more information, see Amazon EC2 Instance Store (p. 715). The block
device driver for the instance determines which devices are used when the volumes are formatted and
mounted. For more information, see Attaching an Amazon EBS Volume to an Instance (p. 654).

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AMI Block Device Mapping
Each AMI has a block device mapping that specifies the block devices to attach to an instance when
it is launched from the AMI. An AMI that Amazon provides includes a root device only. To add more
block devices to an AMI, you must create your own AMI.
Contents
• Specifying a Block Device Mapping for an AMI (p. 734)
• Viewing the EBS Volumes in an AMI Block Device Mapping (p. 735)

Specifying a Block Device Mapping for an AMI
There are two ways to specify volumes in addition to the root volume when you create an AMI. If you've
already attached volumes to a running instance before you create an AMI from the instance, the block
device mapping for the AMI includes those same volumes. For EBS volumes, the existing data is
saved to a new snapshot, and it's this new snapshot that's specified in the block device mapping. For
instance store volumes, the data is not preserved.
For an EBS-backed AMI, you can add EBS volumes and instance store volumes using a block device
mapping. For an instance store-backed AMI, you can add instance store volumes only by modifying the
block device mapping entries in the image manifest file when registering the image.

Note
For M3 instances, you must specify instance store volumes in the block device mapping for
the instance when you launch it. When you launch an M3 instance, instance store volumes
specified in the block device mapping for the AMI may be ignored if they are not specified as
part of the instance block device mapping.

To add volumes to an AMI using the console
1.

Open the Amazon EC2 console.

In the navigation pane, choose Instances.

Select an instance and choose Actions, Image, Create Image.

In the Create Image dialog box, choose Add New Volume.

Select a volume type from the Type list and a device name from the Device list. For an EBS
volume, you can optionally specify a snapshot, volume size, and volume type.

Choose Create Image.

To add volumes to an AMI using the command line
Use the create-image AWS CLI command to specify a block device mapping for an EBS-backed AMI.
Use the register-image AWS CLI command to specify a block device mapping for an instance storebacked AMI.
Specify the block device mapping using the following parameter:
--block-device-mappings [mapping, ...]

To add an instance store volume, use the following mapping:
{
"DeviceName": "/dev/sdf",
"VirtualName": "ephemeral0"

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}

To add an empty 100 GiB Magnetic volume, use the following mapping:
{
"DeviceName": "/dev/sdg",
"Ebs": {
"VolumeSize": 100
}
}

To add an EBS volume based on a snapshot, use the following mapping:
{
"DeviceName": "/dev/sdh",
"Ebs": {
"SnapshotId": "snap-xxxxxxxx"
}
}

To omit a mapping for a device, use the following mapping:
{
"DeviceName": "/dev/sdj",
"NoDevice": ""
}

Alternatively, you can use the -BlockDeviceMapping parameter with the following commands (AWS
Tools for Windows PowerShell):
• New-EC2Image
• Register-EC2Image

Viewing the EBS Volumes in an AMI Block Device Mapping
You can easily enumerate the EBS volumes in the block device mapping for an AMI.

To view the EBS volumes for an AMI using the console
1.

Open the Amazon EC2 console.

In the navigation pane, choose AMIs.

Choose EBS images from the Filter list to get a list of EBS-backed AMIs.

Select the desired AMI, and look at the Details tab. At a minimum, the following information is
available for the root device:
• Root Device Type (ebs)
• Root Device Name (for example, /dev/sda1)
• Block Devices (for example, /dev/sda1=snap-1234567890abcdef0:8:true)
If the AMI was created with additional EBS volumes using a block device mapping, the Block
Devices field displays the mapping for those additional volumes as well. (Recall that this screen
doesn't display instance store volumes.)

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To view the EBS volumes for an AMI using the command line
Use the describe-images (AWS CLI) command or Get-EC2Image (AWS Tools for Windows
PowerShell) command to enumerate the EBS volumes in the block device mapping for an AMI.

Instance Block Device Mapping
By default, an instance that you launch includes any storage devices specified in the block device
mapping of the AMI from which you launched the instance. You can specify changes to the block
device mapping for an instance when you launch it, and these updates overwrite or merge with the
block device mapping of the AMI. However,

Limits
• For the root volume, you can only modify the following: volume size, volume type, and the Delete on
Termination flag.
• When you modify an EBS volume, you can't decrease its size. Therefore, you must specify a
snapshot whose size is equal to or greater than the size of the snapshot specified in the block device
mapping of the AMI.
Contents
• Updating the Block Device Mapping when Launching an Instance (p. 736)
• Updating the Block Device Mapping of a Running Instance (p. 737)
• Viewing the EBS Volumes in an Instance Block Device Mapping (p. 738)
• Viewing the Instance Block Device Mapping for Instance Store Volumes (p. 739)

Updating the Block Device Mapping when Launching an
Instance
You can add EBS volumes and instance store volumes to an instance when you launch it. Note that
updating the block device mapping for an instance doesn't make a permanent change to the block
device mapping of the AMI from which it was launched.

To add volumes to an instance using the console
1.

Open the Amazon EC2 console.

From the dashboard, choose Launch Instance.

On the Choose an Amazon Machine Image (AMI) page, select the AMI to use and choose
Select.

Follow the wizard to complete the Choose an Instance Type and Configure Instance Details
pages.

On the Add Storage page, you can modify the root volume, EBS volumes, and instance store
volumes as follows:
• To change the size of the root volume, locate the Root volume under the Type column, and
change its Size field.
• To suppress an EBS volume specified by the block device mapping of the AMI used to launch
the instance, locate the volume and click its Delete icon.
• To add an EBS volume, choose Add New Volume, choose EBS from the Type list, and fill in
the fields (Device, Snapshot, and so on).
• To suppress an instance store volume specified by the block device mapping of the AMI used to
launch the instance, locate the volume, and choose its Delete icon.

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• To add an instance store volume, choose Add New Volume, select Instance Store from the
Type list, and select a device name from Device.
Complete the remaining wizard pages, and choose Launch.

To add volumes to an instance using the comamnd line
Use the run-instances AWS CLI command to specify a block device mapping for an instance.
Specify the block device mapping using the following parameter:
--block-device-mappings [mapping, ...]

For example, suppose that an EBS-backed AMI specifies the following block device mapping:
• /dev/sdb=ephemeral0
• /dev/sdh=snap-1234567890abcdef0
• /dev/sdj=:100
To prevent /dev/sdj from attaching to an instance launched from this AMI, use the following
mapping:
{
"DeviceName": "/dev/sdj",
"NoDevice": ""
}

To increase the size of /dev/sdh to 300 GiB, specify the following mapping. Notice that you don't
need to specify the snapshot ID for /dev/sdh, because specifying the device name is enough to
identify the volume.
{
"DeviceName": "/dev/sdh",
"Ebs": {
"VolumeSize": 300
}
}

To attach an additional instance store volume, /dev/sdc, specify the following mapping. If the
instance type doesn't support multiple instance store volumes, this mapping has no effect.
{
"DeviceName": "/dev/sdc",
"VirtualName": "ephemeral1"
}

Alternatively, you can use the -BlockDeviceMapping parameter with the New-EC2Instance
command (AWS Tools for Windows PowerShell).

Updating the Block Device Mapping of a Running Instance
You can use the following modify-instance-attribute AWS CLI command to update the block device
mapping of a running instance. Note that you do not need to stop the instance before changing this
attribute.

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$ aws ec2 modify-instance-attribute --instance-id i-1a2b3c4d --block-devicemappings file://mapping.json

For example, to preserve the root volume at instance termination, specify the following in
mapping.json:
[
{
"DeviceName": "/dev/sda1",
"Ebs": {
"DeleteOnTermination": false
}
}
]

Alternatively, you can use the -BlockDeviceMapping parameter with the Edit-EC2InstanceAttribute
command (AWS Tools for Windows PowerShell).

Viewing the EBS Volumes in an Instance Block Device
Mapping
You can easily enumerate the EBS volumes mapped to an instance.

Note
For instances launched before the release of the 2009-10-31 API, AWS can't display the block
device mapping. You must detach and reattach the volumes so that AWS can display the
block device mapping.

To view the EBS volumes for an instance using the console
1.

Open the Amazon EC2 console.

2.
3.

In the navigation pane, choose Instances.
In the search bar, type Root Device Type, and then choose EBS. This displays a list of EBSbacked instances.
Select the desired instance and look at the details displayed in the Description tab. At a minimum,
the following information is available for the root device:

• Root device type (ebs)
• Root device (for example, /dev/sda1)
• Block devices (for example, /dev/sda1, /dev/sdh, and /dev/sdj)
If the instance was launched with additional EBS volumes using a block device mapping, the
Block devices field displays those additional volumes as well as the root device. (Recall that this
dialog box doesn't display instance store volumes.)

To display additional information about a block device, select its entry next to Block devices. This
displays the following information for the block device:
• EBS ID (vol-xxxxxxxx)

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• Root device type (ebs)
• Attachment time (yyyy-mmThh:mm:ss.ssTZD)
• Block device status (attaching, attached, detaching, detached)
• Delete on termination (Yes, No)
To view the EBS volumes for an instance using the command line
Use the describe-instances (AWS CLI) command or Get-EC2Instance (AWS Tools for Windows
PowerShell) command to enumerate the EBS volumes in the block device mapping for an instance.

Viewing the Instance Block Device Mapping for Instance
Store Volumes
When you view the block device mapping for your instance, you can see only the EBS volumes, not the
instance store volumes. You can use instance metadata to query the complete block device mapping.
The base URI for all requests for instance metadata is http://169.254.169.254/latest/.
First, connect to your running instance.
Use this query on a running instance to get its block device mapping.
$ curl http://169.254.169.254/latest/meta-data/block-device-mapping/

The response includes the names of the block devices for the instance. For example, the output for an
instance store–backed m1.small instance looks like this.
ami
ephemeral0
root
swap

The ami device is the root device as seen by the instance. The instance store volumes are named
ephemeral[0-23]. The swap device is for the page file. If you've also mapped EBS volumes, they
appear as ebs1, ebs2, and so on.
To get details about an individual block device in the block device mapping, append its name to the
previous query, as shown here.
$ curl http://169.254.169.254/latest/meta-data/block-device-mapping/
ephemeral0

For more information, see Instance Metadata and User Data (p. 337).

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Using Public Data Sets

Using Public Data Sets
Amazon Web Services provides a repository of public data sets that can be seamlessly integrated into
AWS cloud-based applications. Amazon stores the data sets at no charge to the community and, as
with all AWS services, you pay only for the compute and storage you use for your own applications.
Contents
• Public Data Set Concepts (p. 740)
• Finding Public Data Sets (p. 740)
• Creating a Public Data Set Volume from a Snapshot (p. 741)
• Attaching and Mounting the Public Data Set Volume (p. 742)

Public Data Set Concepts
Previously, large data sets such as the mapping of the Human Genome and the US Census data
required hours or days to locate, download, customize, and analyze. Now, anyone can access these
data sets from an EC2 instance and start computing on the data within minutes. You can also leverage
the entire AWS ecosystem and easily collaborate with other AWS users. For example, you can
produce or use prebuilt server images with tools and applications to analyze the data sets. By hosting
this important and useful data with cost-efficient services such as Amazon EC2, AWS hopes to provide
researchers across a variety of disciplines and industries with tools to enable more innovation, more
quickly.
For more information, go to the Public Data Sets on AWS Page.

Available Public Data Sets
Public data sets are currently available in the following categories:
• Biology—Includes Human Genome Project, GenBank, and other content.
• Chemistry—Includes multiple versions of PubChem and other content.
• Economics—Includes census data, labor statistics, transportation statistics, and other content.
• Encyclopedic—Includes Wikipedia content from multiple sources and other content.

Finding Public Data Sets
Before you can use a public data set, you must locate the data set and determine which format the
data set is hosted in. The data sets are available in two possible formats: Amazon EBS snapshots or
Amazon S3 buckets.

To find a public data set and determine its format
1.

Go to the Public Data Sets Page to see a listing of all available public data sets. You can also
enter a search phrase on this page to query the available public data set listings.

Click the name of a data set to see its detail page.

On the data set detail page, look for a snapshot ID listing to identify an Amazon EBS formatted
data set or an Amazon S3 URL.

Data sets that are in snapshot format are used to create new EBS volumes that you attach to an EC2
instance. For more information, see Creating a Public Data Set Volume from a Snapshot (p. 741).

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For data sets that are in Amazon S3 format, you can use the AWS SDKs or the HTTP query API to
access the information, or you can use the AWS CLI to copy or synchronize the data to and from your
instance. For more information, see Amazon S3 and Amazon EC2 (p. 727).
You can also use Amazon EMR to analyze and work with public data sets. For more information, see
What is Amazon EMR?.

Creating a Public Data Set Volume from a
Snapshot
To use a public data set that is in snapshot format, you create a new volume, specifying the snapshot
ID of the public data set. You can create your new volume using the AWS Management Console as
follows. If you prefer, you can use the create-volume AWS CLI command instead.

To create a public data set volume from a snapshot
1.

Open the Amazon EC2 console.

From the navigation bar, select the region that your data set snapshot is located in.

Important
Snapshot IDs are constrained to a single region, and you cannot create a volume from
a snapshot that is located in another region. In addition, you can only attach an EBS
volume to an instance in the same Availability Zone. For more information, see Resource
Locations (p. 743).
If you need to create this volume in a different region, you can copy the snapshot to your required
region and then restore it to a volume in that region. For more information, see Copying an
Amazon EBS Snapshot (p. 688).
3.
4.
5.

In the navigation pane, click Volumes.
Above the upper pane, click Create Volume.
In the Create Volume dialog box, in the Type list, select General Purpose SSD, Provisioned
IOPS SSD, or Magnetic. For more information, see Amazon EBS Volume Types (p. 638).

In the Snapshot field, start typing the ID or description of the snapshot for your data set. Select
the snapshot from the list of suggested options.

Note

If the snapshot ID you are expecting to see does not appear, you may have a different
region selected in the Amazon EC2 console. If the data set you identified in Finding
Public Data Sets (p. 740) does not specify a region on its detail page, it is likely
contained in the us-east-1 US East (N. Virginia) region.
In the Size field, enter the size of the volume (in GiB or TiB), or verify the that the default size of
the snapshot is adequate.

Note

8.
9.

If you specify both a volume size and a snapshot ID, the size must be equal to or greater
than the snapshot size. When you select a volume type and a snapshot ID, minimum and
maximum sizes for the volume are shown next to the Size list.
For Provisioned IOPS SSD volumes, in the IOPS field, enter the maximum number of input/output
operations per second (IOPS) that the volume can support.
In the Availability Zone list, select the Availability Zone in which to launch the instance.

Important
EBS volumes can only be attached to instances in the same Availability Zone.
10. Click Yes, Create.

Important
If you created a larger volume than the default size for that snapshot (by specifying a size
in Step 7 (p. 741)), you need to extend the file system on the volume to take advantage

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Attaching and Mounting the Public Data Set Volume

of the extra space. For more information, see Expanding the Storage Space of an EBS
Volume on Linux (p. 671).

Attaching and Mounting the Public Data Set
Volume
After you have created your new data set volume, you need to attach it to an EC2 instance to access
the data (this instance must also be in the same Availability Zone as the new volume). For more
information, see Attaching an Amazon EBS Volume to an Instance (p. 654).
After you have attached the volume to an instance, you need to mount the volume on the instance. For
more information, see Making an Amazon EBS Volume Available for Use (p. 655).

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Resource Locations

Resources and Tags

Amazon EC2 provides different resources that you can create and use. Some of these resources
include images, instances, volumes, and snapshots. When you create a resource, we assign the
resource a unique resource ID.
Some resources can be tagged with values that you define, to help you organize and identify them.
The following topics describe resources and tags, and how you can work with them.
Topics
• Resource Locations (p. 743)
• Resource IDs (p. 744)
• Listing and Filtering Your Resources (p. 748)
• Tagging Your Amazon EC2 Resources (p. 751)
• Amazon EC2 Service Limits (p. 760)
• Amazon EC2 Usage Reports (p. 762)

Resource Locations
The following table describes which Amazon EC2 resources are global, regional, or based on
Availability Zone.
Resource

Type

Description

AWS account

Global

You can use the same AWS account in all regions.

Key pairs

Global or
Regional

You can use the key pairs that you create using
Amazon EC2 only in the region where you created
them. You can create and upload an RSA key pair that
you can use in all regions.
For more information, see Amazon EC2 Key
Pairs (p. 481).

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Resource IDs

Resource

Type

Description

Amazon EC2 resource
identifiers

Regional

Each resource identifier, such as an AMI ID, instance
ID, EBS volume ID, or EBS snapshot ID, is tied to its
region and can be used only in the region where you
created the resource.

User-supplied resource
names

Regional

Each resource name, such as a security group name
or key pair name, is tied to its region and can be used
only in the region where you created the resource.
Although you can create resources with the same
name in multiple regions, they aren't related to each
other.

AMIs

Regional

An AMI is tied to the region where its files are located
within Amazon S3. You can copy an AMI from one
region to another. For more information, see Copying
an AMI (p. 135).

Elastic IP addresses

Regional

An Elastic IP address is tied to a region and can be
associated only with an instance in the same region.

Security groups

Regional

A security group is tied to a region and can be
assigned only to instances in the same region. You
can't enable an instance to communicate with an
instance outside its region using security group rules.
Traffic from an instance in another region is seen as
WAN bandwidth.

EBS snapshots

Regional

An EBS snapshot is tied to its region and can only
be used to create volumes in the same region. You
can copy a snapshot from one region to another.
For more information, see Copying an Amazon EBS
Snapshot (p. 688).

EBS volumes

Availability Zone An Amazon EBS volume is tied to its Availability Zone
and can be attached only to instances in the same
Availability Zone.

Instances

Availability Zone An instance is tied to the Availability Zones in which
you launched it. However, note that its instance ID is
tied to the region.

Resource IDs
When resources are created, we assign each resource a unique resource ID. You can use resource
IDs to find your resources in the Amazon EC2 console. If you are using a command line tool or the
Amazon EC2 API to work with Amazon EC2, resource IDs are required for certain commands. For
example, if you are using the stop-instances AWS CLI command to stop an instance, you must specify
the instance ID in the command.
Resource ID Length
A resource ID takes the form of a resource identifier (such as snap for a snapshot) followed by a
hyphen and a unique combination of letters and numbers. Starting in January 2016, we're gradually
introducing longer length IDs for some Amazon EC2 and Amazon EBS resource types. The length
of the alphanumeric character combination was in an 8-character format; the new IDs are in a 17character format, for example, i-1234567890abcdef0 for an instance ID.

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Supported resource types will have an opt-in period, during which you can enable the longer ID format.
After you've enabled longer IDs for a resource type, any new resources that you create are created
with a longer ID unless you explicitly disable the longer ID format. A resource ID does not change after
it's created; therefore, your existing resources with shorter IDs are not affected. Similarly, if you disable
longer IDs for a resource type, any resources that you created with the longer IDs are not affected.
All supported resource types will have a deadline date, after which all new resources of this type
default to the longer ID format, and you can no longer disable the longer ID format. You can enable
or disable longer IDs per IAM user and IAM role. By default, an IAM user or role defaults to the same
settings as the root user.
Depending on when you created your account, supported resource types may default to using longer
IDs. However, you can opt out of using longer IDs until the deadline date for that resource type. For
more information, see Longer EC2 and EBS Resource IDs in the Amazon EC2 FAQs.
Resources created with longer IDs are visible to all IAM users and IAM roles, regardless of individual
settings and provided that they have permissions to view the relevant resource types.
Topics
• Working with Longer IDs (p. 745)
• Controlling Access to Longer ID Settings (p. 748)

Working with Longer IDs
You can view and modify the longer ID settings for yourself, or for a different IAM user, IAM role, or the
root user of the account.
Topics
• Viewing and Modifying Your Longer ID Settings (p. 745)
• Viewing and Modifying Longer ID Settings for Users or Roles (p. 747)

Viewing and Modifying Your Longer ID Settings
You can use the Amazon EC2 console or the AWS CLI to view the resource types that support long
IDs, and enable or disable the longer ID format for yourself. The procedures in this section apply to the
IAM user or IAM role that's logged into the console or that makes the request; they do not apply to the
entire AWS account.

To view and modify the longer ID settings using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation bar at the top of the screen, the current region is displayed. Select the region for
which you want to view or change the longer ID settings. Settings are not shared between regions.

From the dashboard, under Account Attributes, choose Resource ID length management. The
resource types that support longer IDs are listed. The date at which you're automatically switched
over to using longer IDs for each resource type is displayed in the Deadline column.

To enable the longer ID format for a supported resource type, choose the check box for the Use
Longer IDs column. To disable the longer ID format, clear the check box.

Important
If you’re logged in as the root user, these settings apply to the entire account, unless an
IAM user or role logs in and explicitly overrides these settings for themselves. Resources
created with longer IDs are visible to all IAM users, regardless of individual settings and
provided that they have permissions to view the relevant resource types.

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To view and modify longer ID settings using the AWS CLI
To view the longer ID settings of all supported resources, use the describe-id-format AWS CLI
command:
aws ec2 describe-id-format
{
"Statuses": [
{
"Deadline": "2016-11-01T13:00:00.000Z",
"UseLongIds": false,
"Resource": "instance"
},
{
"Deadline": "2016-11-01T13:00:00.000Z",
"UseLongIds": true,
"Resource": "reservation"
},
{
"Deadline": "2016-11-01T13:00:00.000Z",
"UseLongIds": false,
"Resource": "volume"
},
{
"Deadline": "2016-11-01T13:00:00.000Z",
"UseLongIds": false,
"Resource": "snapshot"
}
]
}

The results apply to the IAM user, IAM role, or root user that makes the request; they do not apply to
the entire AWS account. The results above indicate that the instance, reservation, volume, and
snapshot resource types can be enabled or disabled for longer IDs; the reservation resource is
already enabled. The Deadline field indicates the date (in UTC) at which you will be automatically
switched over to using longer IDs for that resource. If a deadline date is not yet available, this value is
not returned.
To enable longer IDs for a specified resource, use the modify-id-format AWS CLI command:
aws ec2 modify-id-format --resource resource-type --use-long-ids

To disable longer IDs for a specified resource, use the modify-id-format AWS CLI command:
aws ec2 modify-id-format --resource resource-type --no-use-long-ids

If you’re using these actions as the root user, then these settings apply to the entire account, unless
an IAM user or role explicitly overrides these settings for themselves. These commands are per-region
only. To modify the settings for other regions, use the --region parameter in the command.

Note
In the 2015-10-01 version of the Amazon EC2 API, if you call describe-id-format or
modify-id-format using IAM role credentials, the results apply to the entire AWS account,
and not the specific IAM role. In the current version of the Amazon EC2 API, the results apply
to the IAM role only.

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Alternatively, you can use the following commands:

To describe the ID format
• DescribeIdFormat (Amazon EC2 API)
• Get-EC2IdFormat (AWS Tools for Windows PowerShell)

To modify the ID format
• ModifyIdFormat (Amazon EC2 API)
• Edit-EC2IdFormat (AWS Tools for Windows PowerShell)

Viewing and Modifying Longer ID Settings for Users or
Roles
You can view supported resource types and enable the longer ID settings for a specific IAM user, IAM
role, or the root user of your account by using the describe-identity-id-format and modify-identity-idformat AWS CLI commands. To use these commands, you must specify the ARN of an IAM user,
IAM role, or root account user in the request. For example, the ARN of the role 'EC2Role' in account
123456789012 is arn:aws:iam::123456789012:role/EC2Role. For more information, see
Principal in the IAM User Guide.
To view the longer ID settings of all supported resources for a specific IAM user or IAM role, use the
following AWS CLI command:
aws ec2 describe-identity-id-format --principal-arn arn-of-iam-principal

To enable the longer ID settings for a resource type for a specific IAM user or IAM role, use the
following AWS CLI command:
aws ec2 modify-identity-id-format --principal-arn arn-of-iam-principal -resource resource-type --use-long-ids

These commands apply to the ARN specified in the request, they do not apply to the IAM user, IAM
role, or root user that made the request.
You can enable the longer ID settings for all IAM users, IAM roles, and the root user of your account by
using the following AWS CLI command:
aws ec2 modify-identity-id-format --principal-arn all --resource resourcetype --use-long-ids

Alternatively, you can use the following commands:

To describe the ID format
• DescribeIdentityIdFormat (Amazon EC2 API)
• Get-EC2IdentityIdFormat (AWS Tools for Windows PowerShell)

To modify the ID format
• ModifyIdentityIdFormat (Amazon EC2 API)

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• Edit-EC2IdentityIdFormat (AWS Tools for Windows PowerShell)

Controlling Access to Longer ID Settings
By default, IAM users and roles do not have permission to use the ec2:DescribeIdFormat,
ec2:DescribeIdentityIdFormat, ec2:ModifyIdFormat, and ec2:ModifyIdentityIdFormat
actions unless they're explicitly granted permission through their associated IAM policies. For example,
an IAM role may have permission to use all Amazon EC2 actions through an "Action": "ec2:*"
element in the policy statement.
To prevent IAM users and roles from viewing or modifying the longer resource ID settings for
themselves or other users and roles in your account, ensure that the IAM policy contains the following
statement:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Deny",
"Action": [
"ec2:ModifyIdFormat",
"ec2:DescribeIdFormat",
"ec2:ModifyIdentityIdFormat",
"ec2:DescribeIdentityIdFormat"
],
"Resource": "*"
}
]
}

We do not support resource-level permissions for the ec2:DescribeIdFormat,
ec2:DescribeIdentityIdFormat, ec2:ModifyIdFormat, and ec2:ModifyIdentityIdFormat
actions.

Listing and Filtering Your Resources
You can get a list of some types of resource using the Amazon EC2 console. You can get a list of each
type of resource using its corresponding command or API action. If you have many resources, you can
filter the results to include only the resources that match certain criteria.
Topics
• Advanced Search (p. 748)
• Listing Resources Using the Console (p. 749)
• Filtering Resources Using the Console (p. 750)
• Listing and Filtering Using the CLI and API (p. 751)

Advanced Search
Advanced search allows you to search using a combination of filters to achieve precise results. You
can filter by keywords, user-defined tag keys, and predefined resource attributes.
The specific search types available are:

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• Search by keyword
To search by keyword, type or paste what you’re looking for in the search box, and then choose
Enter. For example, to search for a specific instance, you can type the instance ID.
• Search by fields
You can also search by fields, tags, and attributes associated with a resource. For example, to find
all instances in the stopped state:
1. In the search box, start typing Instance State. As you type, you'll see a list of suggested fields.
2. Select Instance State from the list.
3. Select Stopped from the list of suggested values.
4. To further refine your list, select the search box for more search options.
• Advanced search
You can create advanced queries by adding multiple filters. For example, you can search by tags
and see instances for the Flying Mountain project running in the Production stack, and then search
by attributes to see all t2.micro instances, or all instances in us-west-2a, or both.
• Inverse search
You can search for resources that do not match a specified value. For example, to list all instances
that are not terminated, search by the Instance State field, and prefix the Terminated value with an
exclamation mark (!).
• Partial search
When searching by field, you can also enter a partial string to find all resources that contain the
string in that field. For example, search by Instance Type, and then type t2 to find all t2.micro,
t2.small or t2.medium instances.
• Regular expression
Regular expressions are useful when you need to match the values in a field with a specific pattern.
For example, search by the Name tag, and then type ^s.* to see all instances with a Name tag that
starts with an 's'. Regular expression search is not case-sensitive.
After you have the precise results of your search, you can bookmark the URL for easy reference. In
situations where you have thousands of instances, filters and bookmarks can save you a great deal of
time; you don’t have to run searches repeatedly.
Combining search filters
In general, multiple filters with the same key field (e.g., tag:Name, search, Instance State) are
automatically joined with OR. This is intentional, as the vast majority of filters would not be logical
if they were joined with AND. For example, you would get zero results for a search on Instance
State=running AND Instance State=stopped. In many cases, you can granulate the results by using
complementary search terms on different key fields, where the AND rule is automatically applied
instead. If you search for tag: Name:=All values and tag:Instance State=running, you get search results
that contain both those criteria. To fine-tune your results, simply remove one filter in the string until the
results fit your requirements.

Listing Resources Using the Console
You can view the most common Amazon EC2 resource types using the console. To view additional
resources, use the command line interface or the API actions.

To list EC2 resources using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

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In the navigation pane, choose the option that corresponds to the resource, such as AMIs or
Instances.

The page displays all the available resources.

Filtering Resources Using the Console
You can perform filtering and sorting of the most common resource types using the Amazon EC2
console. For example, you can use the search bar on the instances page to sort instances by tags,
attributes, or keywords.
You can also use the search field on each page to find resources with specific attributes or values. You
can use regular expressions to search on partial or multiple strings. For example, to find all instances
that are using the MySG security group, enter MySG in the search field. The results will include any
values that contain MySG as a part of the string, such as MySG2 and MySG3. To limit your results to
MySG only, enter \bMySG\b in the search field. To list all the instances whose type is either m1.small
or m1.large, enter m1.small|m1.large in the search field.

To list volumes in the us-east-1b Availability Zone with a status of available
1.

In the navigation pane, choose Volumes.

Click on the search box, select Attachment Status from the menu, and then select Detached. (A
detached volume is available to be attached to an instance in the same Availability Zone.)

Click on the search box again, select State, and then select Available.

Click on the search box again, select Availability Zone, and then select us-east-1b.

Any volumes that meet this criteria are displayed.

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To list public 64-bit Linux AMIs backed by Amazon EBS
1.

In the navigation pane, choose AMIs.

In the Filter pane, select Public images, EBS images, and then your Linux distribution from the
Filter lists.

Enter x86_64 in the search field.

Any AMIs that meet this criteria are displayed.

Listing and Filtering Using the CLI and API
Each resource type has a corresponding CLI command or API request that you use to list resources of
that type. For example, you can list Amazon Machine Images (AMI) using ec2-describe-images or
DescribeImages. The response contains information for all your resources.
The resulting lists of resources can be long, so you might want to filter the results to include only
the resources that match certain criteria. You can specify multiple filter values, and you can also
specify multiple filters. For example, you can list all the instances whose type is either m1.small or
m1.large, and that have an attached EBS volume that is set to delete when the instance terminates.
The instance must match all your filters to be included in the results.

Note
If you use a tag filter, the response includes the tags for your resources; otherwise, tags may
be omitted in the response.
You can also use wildcards with the filter values. An asterisk (*) matches zero or more characters,
and a question mark (?) matches exactly one character. For example, you can use *database*
as a filter value to get all EBS snapshots that include database in the description. If you were to
specify database as the filter value, then only snapshots whose description equals database would
be returned. Filter values are case sensitive. We support only exact string matching, or substring
matching (with wildcards). If a resulting list of resources is long, using an exact string filter may return
the response faster.

Tip
Your search can include the literal values of the wildcard characters; you just need to escape
them with a backslash before the character. For example, a value of \*amazon\?\\ searches
for the literal string *amazon?\.
For a list of supported filters per Amazon EC2 resource, see the relevant documentation:
• For the AWS CLI, see the relevant describe command in the AWS Command Line Interface
Reference.
• For Windows PowerShell, see the relevant Get command in the AWS Tools for Windows
PowerShell Reference.
• For the Query API, see the relevant Describe API action in the Amazon EC2 API Reference.

Tagging Your Amazon EC2 Resources
To help you manage your instances, images, and other Amazon EC2 resources, you can optionally
assign your own metadata to each resource in the form of tags. This topic describes tags and shows
you how to create them.
Contents
• Tag Basics (p. 752)
• Tag Restrictions (p. 753)

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• Tagging Your Resources for Billing (p. 754)
• Working with Tags Using the Console (p. 755)
• Working with Tags Using the CLI or API (p. 760)

Tag Basics
Tags enable you to categorize your AWS resources in different ways, for example, by purpose, owner,
or environment. This is useful when you have many resources of the same type — you can quickly
identify a specific resource based on the tags you've assigned to it. Each tag consists of a key and an
optional value, both of which you define. For example, you could define a set of tags for your account's
Amazon EC2 instances that helps you track each instance's owner and stack level. We recommend
that you devise a set of tag keys that meets your needs for each resource type. Using a consistent set
of tag keys makes it easier for you to manage your resources. You can search and filter the resources
based on the tags you add.
The following diagram illustrates how tagging works. In this example, you've assigned two tags to
each of your instances, one called Owner and another called Stack. Each of the tags also has an
associated value.

Tags don't have any semantic meaning to Amazon EC2 and are interpreted strictly as a string of
characters. Also, tags are not automatically assigned to your resources.
You can work with tags using the AWS Management Console, the Amazon EC2 command line
interface (CLI), the AWS CLI, and the Amazon EC2 API.
You can assign tags only to resources that already exist. You cannot assign tags when you create a
resource; for example, when you use the run-instances AWS CLI command. When you use the
Amazon EC2 console, some resource creation screens enable you to specify tags which are applied
immediately after the resource is created. If you add a tag that has the same key as an existing tag on

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that resource, the new value overwrites the old value. You can edit tag keys and values, and you can
remove tags from a resource at any time. You can set a tag's value to the empty string, but you can't
set a tag's value to null.
If you're using AWS Identity and Access Management (IAM), you can control which users in your
AWS account have permission to create, edit, or delete tags. For more information about IAM, see
Controlling Access to Amazon EC2 Resources (p. 498).

Tag Restrictions
The following basic restrictions apply to tags:
• Maximum number of tags per resource—50
• Maximum key length—127 Unicode characters in UTF-8
• Maximum value length—255 Unicode characters in UTF-8
• Tag keys and values are case sensitive.
• Do not use the aws: prefix in your tag names or values because it is reserved for AWS use. You
can't edit or delete tag names or values with this prefix. Tags with this prefix do not count against
your tags per resource limit.
• If your tagging schema will be used across multiple services and resources, remember that other
services may have restrictions on allowed characters. Generally allowed characters are: letters,
spaces, and numbers representable in UTF-8, plus the following special characters: + - = . _ : / @.
You can't terminate, stop, or delete a resource based solely on its tags; you must specify the resource
identifier. For example, to delete snapshots that you tagged with a tag key called DeleteMe, you
must use the DeleteSnapshots action with the resource identifiers of the snapshots, such as
snap-1234567890abcdef0. To identify resources by their tags, you can use the DescribeTags
action to list all of your tags and their associated resources. You can also filter by resource type
or tag keys and values. You can't call DeleteSnapshots with a filter that specified the tag. For
more information about using filters when listing your resources, see Listing and Filtering Your
Resources (p. 748).
You can tag public or shared resources, but the tags you assign are available only to your AWS
account and not to the other accounts sharing the resource.
You can't tag all resources, and some you can only tag using API actions or the command line. The
following table lists all Amazon EC2 resources and the tagging restrictions that apply to them, if any.
Resources with tagging restrictions of None can be tagged with API actions, the CLI, and the console.
Resource

Tagging support

Tagging restrictions

AMI

Yes

None

Bundle task

Customer gateway

Yes

Dedicated Host

DHCP option

Yes

None

EBS volume

Yes

None

Instance store volume

Elastic IP

Instance

Yes

None

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Resource

Tagging support

Tagging restrictions

Internet gateway

Yes

None

Key pair

NAT gateway

Network ACL

Yes

None

Network interface

Yes

None

Placement group

Reserved Instance

Yes

Reserved Instance listing

Route table

Yes

None

Spot instance request

Yes

None

Security group - EC2-Classic

Yes

None

Security group - VPC

Yes

None

Snapshot

Yes

None

Subnet

Yes

None

Virtual private gateway

Yes

None

VPC

Yes

None

VPC endpoint

VPC flow log

VPC peering connection

Yes

None

VPN connection

Yes

None

For more information about tagging using the AWS Management Console, see Working with Tags
Using the Console (p. 755). For more information about tagging using the API or command line, see
Working with Tags Using the CLI or API (p. 760).

Tagging Your Resources for Billing
You can use tags to organize your AWS bill to reflect your own cost structure. To do this, sign up to
get your AWS account bill with tag key values included. For more information about setting up a cost
allocation report with tags, see Setting Up Your Monthly Cost Allocation Report in About AWS Account
Billing. To see the cost of your combined resources, you can organize your billing information based
on resources that have the same tag key values. For example, you can tag several resources with
a specific application name, and then organize your billing information to see the total cost of that
application across several services. For more information, see Cost Allocation and Tagging in About
AWS Account Billing.

Note
If you've just enabled reporting, the current month's data will be available for viewing in about
24 hours.

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Working with Tags Using the Console
Using the Amazon EC2 console, you can see which tags are in use across all of your Amazon EC2
resources in the same region. You can view tags by resource and by resource type, and you can also
view how many items of each resource type are associated with a specified tag. You can also use the
Amazon EC2 console to apply or remove tags from one or more resources at a time.
For ease of use and best results, use Tag Editor in the AWS Management Console, which provides
a central, unified way to create and manage your tags. For more information, see Working with Tag
Editor in Getting Started with the AWS Management Console.
Contents
• Displaying Tags (p. 755)
• Adding and Deleting Tags on an Individual Resource (p. 756)
• Adding and Deleting Tags to a Group of Resources (p. 757)
• Adding a Tag When You Launch an Instance (p. 758)
• Filtering a List of Resources by Tag (p. 759)

Displaying Tags
You can display tags in two different ways in the Amazon EC2 console. You can display the tags for an
individual resource or for all resources.
To display tags for individual resources
When you select a resource-specific page in the Amazon EC2 console, it displays a list of those
resources. For example, if you select Instances from the navigation pane, the console displays a list
of Amazon EC2 instances. When you select a resource from one of these lists (e.g., an instance), if the
resource supports tags, you can view and manage its tags. On most resource pages, you can view the
tags in the Tags tab on the details pane.
You can add a column to the resource list that displays all values for tags with the same key. This
column enables you to sort and filter the resource list by the tag. There are two ways to add a new
column to the resource list to display your tags.
• On the Tags tab, select Show Column. A new column will be added to the console.
• Choose the Show/Hide Columns gear-shaped icon, and in the Show/Hide Columns dialog box,
select the tag key under Your Tag Keys.
To display tags for all resources
You can display tags across all resources by selecting Tags from the navigation pane in the Amazon
EC2 console. The following image shows the Tags pane, which lists all tags in use by resource type.

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Adding and Deleting Tags on an Individual Resource
You can manage tags for an individual resource directly from the resource's page.

To add a tag to an individual resource
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

From the navigation bar, select the region that meets your needs. This choice is important
because some Amazon EC2 resources can be shared between regions, while others can't. For
more information, see Resource Locations (p. 743).

In the navigation pane, select a resource type (for example, Instances).

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Select the resource from the resource list.

Select the Tags tab in the details pane.

Choose the Add/Edit Tags button.

In the Add/Edit Tags dialog box, specify the key and value for each tag, and then choose Save.

To delete a tag from an individual resource
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose a resource type (for example, Instances).

Select the resource from the resource list.

Select the Tags tab in the details pane.

Choose Add/Edit Tags, select the Delete icon for the tag, and choose Save.

Adding and Deleting Tags to a Group of Resources
To add a tag to a group of resources
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Tags.

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At the top of the content pane, choose Manage Tags.

From the Filter drop-down list, select the type of resource (for example, instances) that you want
to add tags to.

In the resources list, select the check box next to each resource that you want to add tags to.

In the Key and Value boxes under Add Tag, type the tag key and values you want, and then
choose Add Tag.

Note
If you add a new tag with the same tag key as an existing tag, the new tag overwrites the
existing tag.

To remove a tag from a group of resources
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Tags.

At the top of the content pane, choose Manage Tags.

To view the tags in use, select the Show/Hide Columns gear-shaped icon, and in the Show/Hide
Columns dialog box, select the tag keys you want to view, and then choose Close.

From the Filter drop-down list, select the type of resource (for example, instances) that you want
to remove tags from.

In the resource list, select the check box next to each resource that you want to remove tags from.

Under Remove Tag, type the tag's name in the Key box, and then choose Remove Tag.

Adding a Tag When You Launch an Instance
To add a tag using the Launch Wizard
1.

From the navigation bar, select the region for the instance. This choice is important because some
Amazon EC2 resources can be shared between regions, while others can't. Select the region that
meets your needs. For more information, see Resource Locations (p. 743).

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Choose Launch Instance.

The Choose an Amazon Machine Image (AMI) page displays a list of basic configurations called
Amazon Machine Images (AMIs). Choose the AMI that you want to use and choose Select. For
more information about selecting an AMI, see Finding a Linux AMI (p. 75).

On the Configure Instance Details page, configure the instance settings as necessary, and then
choose Next: Add Storage.

On the Add Storage page, you can specify additional storage volumes for your instance. Choose
Next: Tag Instance when done.

On the Tag Instance page, specify tags for the instance by providing key and value combinations.
Choose Create Tag to add more than one tag to your instance. Choose Next: Configure
Security Group when you are done.

On the Configure Security Group page, you can choose from an existing security group that you
own, or let the wizard create a new security group for you. Choose Review and Launch when you
are done.

Review your settings. When you're satisfied with your selections, choose Launch. Select an
existing key pair or create a new one, select the acknowledgment check box, and then choose
Launch Instances.

Filtering a List of Resources by Tag
You can filter your list of resources based on one or more tag keys and tag values.

To filter a list of resources by tag
1.

Display a column for the tag as follows:
a.

Select one of the resources.

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2.
3.

Select the Tags tab in the details pane.

Locate the tag in the list and choose Show Column.

Choose the filter icon in the top right corner of the column for the tag to display the filter list.
Select the tag values, and then choose Apply Filter to filter the results list.

Note
For more information about filters see Listing and Filtering Your Resources (p. 748).

Working with Tags Using the CLI or API
Use the following to add, update, list, and delete the tags for your resources. The corresponding
documentation provides examples.
Task

AWS CLI

AWS Tools for
Windows PowerShell

API Action

Add or overwrite one or more tags.

create-tags

New-EC2Tag

CreateTags

Delete one or more tags.

delete-tags

Remove-EC2Tag

DeleteTags

Describe one or more tags.

describe-tags

Get-EC2Tag

DescribeTags

You can also filter a list of resources according to their tags. The following examples demonstrate how
to filter your instances using tags with the describe-instances command.
Example 1: Describe instances with the specified tag key
The following command describes the instances with a Stack tag, regardless of the value of the tag.
aws ec2 describe-instances --filters Name=tag-key,Values=Stack

Example 2: Describe instances with the specified tag
The following command describes the instances with the tag Stack=production.
aws ec2 describe-instances --filters Name=tag:Stack,Values=production

Example 3: Describe instances with the specified tag value
The following command describes the instances with a tag with the value production, regardless of the
tag key.
aws ec2 describe-instances --filters Name=tag-value,Values=production

Important
If you describe resources without using a tag filter, the results may not return the tags for your
resources. To ensure that tags are returned in results, we recommend that you either describe
tags (and use a resource filter if necessary), or describe your resources and use one or more
tag filters.

Amazon EC2 Service Limits
Amazon EC2 provides different resources that you can use. These resources include images,
instances, volumes, and snapshots. When you create your AWS account, we set default limits on these

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resources on a per-region basis. For example, there is a limit on the number of instances that you
can launch in a region. Therefore, when you launch an instance in the US West (Oregon) Region, the
request must not cause your usage to exceed your current instance limit in that region.
The Amazon EC2 console provides limit information for the resources managed by the Amazon
EC2 and Amazon VPC consoles. You can request an increase for many of these limits. Use the limit
information that we provide to manage your AWS infrastructure. Plan to request any limit increases in
advance of the time that you'll need them.
For more information about the limits for other services, see AWS Service Limits in the Amazon Web
Services General Reference.

Viewing Your Current Limits
Use the EC2 Service Limits page in the Amazon EC2 console to view the current limits for resources
provided by Amazon EC2 and Amazon VPC, on a per-region basis.

To view your current limits
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

From the navigation bar, select a region.

From the navigation pane, choose Limits.

Locate the resource in the list. The Current Limit column displays the current maximum for that
resource for your account.

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Requesting a Limit Increase
Use the Limits page in the Amazon EC2 console to request an increase in the limits for resources
provided by Amazon EC2 or Amazon VPC, on a per-region basis.

To request a limit increase
1.
2.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
From the navigation bar, select a region.

From the navigation pane, choose Limits.

Locate the resource in the list. Choose Request limit increase.

Complete the required fields on the limit increase form. We'll respond to you using the contact
method that you specified.

Amazon EC2 Usage Reports
The usage reports provided by Amazon EC2 enable you to analyze the usage of your instances in
depth. The data in the usage reports is updated multiple times each day. You can filter the reports by
AWS account, region, Availability Zone, operating system, instance type, purchasing option, tenancy,
and tags.
To get usage and cost data for an account, you must have its account credentials and enable detailed
billing reports with resources and tags for the account. If you're using consolidated billing and are
logged into the payer account, you can view data for the payer account and all its linked accounts. If
you're using consolidated billing and are logged into one of the linked accounts, you can only view data
for that linked account. For information about consolidated billing, see Pay Bills for Multiple Accounts
with Consolidated Billing.
Topics
• Available Reports (p. 762)
• Getting Set Up for Usage Reports (p. 762)
• Granting IAM Users Access to the Amazon EC2 Usage Reports (p. 764)
• Instance Usage Report (p. 764)
• Reserved Instance Utilization Reports (p. 767)

Available Reports
You can generate the following reports:
• Instance usage report (p. 764). This report covers your usage of On-Demand instances, Spot
instances, and Reserved Instances.
• Reserved Instances utilization report (p. 767). This report covers the usage of your capacity
reservation.
To access the reports, open the AWS Management Console. In the navigation pane, choose Reports
then choose the report you'd like to view.

Getting Set Up for Usage Reports
Before you begin, enable detailed billing reports with resources and tags as shown in the following
procedure. After you complete this procedure, we'll start collecting usage data for your instances.

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If you've already enabled detailed billing reports, you can access the usage data that we've been
collecting since you enabled them.

Important
To complete these procedures, you must log in using your AWS account credentials. You
can't complete these procedures if you log in using IAM user credentials.

To enable detailed billing reports
1.

Select an existing Amazon S3 bucket to receive your usage data. Be sure to manage access to
this bucket as it contains your billing data. (We don't require that you keep these files; in fact, you
can delete them immediately if you don't need them.) If you don't have a bucket, create one as
follows:
a.

Open the Amazon S3 console.

Select Create Bucket.

In the Create a Bucket dialog box, enter a name for your bucket (for example, usernameec2-usage-data), select a region, and then choose Create. For more information about the
requirements for bucket names, see Creating a Bucket in the Amazon Simple Storage Service
Console User Guide.

Open the Billing and Cost Management console at https://console.aws.amazon.com/billing/home?
#.

Choose Preferences in the navigation pane.

Select Receive Billing Reports.

Specify the name of your Amazon S3 bucket in Save to S3 Bucket, and then select Verify.

Grant AWS permission to publish usage data to your Amazon S3 bucket.
a.

Under Receive Billing Reports, choose sample policy. Copy the sample policy. Notice that
the sample policy uses the bucket name you specified.

Open the Amazon S3 console in another browser tab. Select your bucket, choose Properties,
and then expand Permissions. In the Permissions section, choose Add bucket policy.
Paste the sample policy into the text area and choose Save. In the Permissions section,
choose Save.

Return to the browser tab with the sample policy and choose Done.

Under Report, select Detailed billing report with resources and tags.

Choose Save preferences.

Note
It can take up to a day before you can see your data in the reports.
You can categorize your instances using tags. After you tag your instances, you must enable reporting
on these tags.

To enable usage reporting by tag
1.

Tag your instances. For best results, ensure that you add each tag you plan to use for reporting
to each of your instances. For more information about how to tag an instance, see Tagging Your
Amazon EC2 Resources (p. 751).

Open the Billing and Cost Management console at https://console.aws.amazon.com/billing/home?
#.

Select Preferences in the navigation pane.

Under Report, choose Manage report tags.

The page displays the list of tags that you've created. Select the tags that you'd like to use to filter
or group your instance usage data, and then click Save. We automatically exclude any tags that
you don't select from your instance usage report.

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Granting IAM Users Access to
the Amazon EC2 Usage Reports

Note
We apply these changes only to the data for the current month. It can take up to a day for
these changes to take effect.

Granting IAM Users Access to the Amazon EC2
Usage Reports
By default, IAM users can't access the Amazon EC2 usage reports. You must create an IAM policy that
grants IAM users permission to access these reports.
The following policy allows users to view both Amazon EC2 usage reports.
{
"Version": "2012-10-17",
"Statement":[{
"Effect": "Allow",
"Action": "ec2-reports:*",
"Resource": "*"
}
]
}

The following policy allows users to view the instance usage report.
{
"Version": "2012-10-17",
"Statement":[{
"Effect": "Allow",
"Action": "ec2-reports:ViewInstanceUsageReport",
"Resource": "*"
}
]
}

The following policy allows users to view the Reserved Instances utilization report.
{
"Version": "2012-10-17",
"Statement":[{
"Effect": "Allow",
"Action": "ec2-reports:ViewReservedInstanceUtilizationReport",
"Resource": "*"
}
]
}

For more information, see Permissions and Policies in the IAM User Guide.

Instance Usage Report
You can use the instance usage report to view your instance usage and cost trends. You can see
your usage data in either instance hours or cost. You can choose to see hourly, daily and monthly

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aggregates of your usage data. You can filter or group the report by region, Availability Zone, instance
type, AWS account, platform, tenancy, purchase option, or tag. After you configure a report, you can
bookmark it so that it's easy to get back to later.
Here's an example of some of the questions that you can answer by creating an instance usage report:
• How much am I spending on instances of each instance type?
• How many instance hours are being used by a particular department?
• How is my instance usage distributed across Availability Zones?
• How is my instance usage distributed across AWS accounts?
Topics
• Report Formats (p. 765)
• Viewing Your Instance Usage (p. 766)
• Bookmarking a Customized Report (p. 767)
• Exporting Your Usage Data (p. 767)

Report Formats
We display the usage data that you request as both a graph and a table.
For example, the following graph displays cost by instance type. The key for the graph indicates which
color represents which instance type. To get detailed information about a segment of a bar, hover over
it.

The corresponding table displays one column for each instance type. Notice that we include a color
band in the column head that is the same color as the instance type in the graph.

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Viewing Your Instance Usage
The following procedures demonstrate how to generate usage reports using some of the capabilities
we provide.
Before you begin, you must get set up. For more information, see Getting Set Up for Usage
Reports (p. 762).

To filter and group your instance usage by instance type
1.

Open the Amazon EC2 console.

In the navigation pane, choose Reports and then select EC2 Instance Usage Report.

Select an option for Unit. To view the time that your instances have been running, in hours, select
Instance Hours. To view the cost of your instance usage, select Cost.

Select options for Granularity and Time range.
• To view the data summarized for each hour in the time range, select Hourly granularity. You
can select a time range of up to 2 days when viewing hourly data.
• To view the data summarized for each day in the time range, select Daily granularity. You can
select a time range of up to 2 months when viewing daily data.
• To view the data summarized for each month in the time range, select Monthly granularity.

In the Filter list, select Instance Type. In the Group by list, select Instance Type.

In the filter area, select one or more instance types and then select Update Report. The filters you
specify appear under Applied Filters.

Notice that you can return to the Amazon EC2 console by choosing either Reports or EC2
Management Console at the top of the page.
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To group your instance usage based on tags
1.

Open the Instance Usage Reports page.

Select an option for Unit. To view the time that your instances have been running, in hours, select
Instance Hours. To view the cost of your instance usage, select Cost.

In the Group by list, select Tag.

Choose the Key Name box, select a name from the list, and then choose Update Report. If there
are no items in this list, you must enable usage reporting by tag. For more information, see To
enable usage reporting by tag (p. 763).

Bookmarking a Customized Report
You might want to generate a customized report again. Do this by bookmarking the report.

To bookmark a custom report
1.

Select the options and filters for your report. Each selection you make adds a parameter to the
console URL. For example, granularity=Hourly and Filters=filter_list.

Using your browser, add the console URL as a bookmark.

To generate the same report in the future, use the bookmark that you created.

Exporting Your Usage Data
You might want to include your report graph or table in other reports. Do this by exporting the data.

To export usage data
1.

Select the options and filters for your report.

To export the usage data from the table as a .csv file, click Download and select CSV Only.

To export the graphical usage data as a .png file, click Download and select Graph Only.

Reserved Instance Utilization Reports
The Reserved Instance utilization report describes the utilization over time of each group (or bucket)
of Amazon EC2 Reserved Instances that you own. Each bucket has a unique combination of region,
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Availability Zone, instance type, tenancy, offering type, and platform. You can specify the time range
that the report covers, from a custom range to weeks, months, a year, or three years. The available
data depends on when you enable detailed billing reports for the account (see Getting Set Up for
Usage Reports (p. 762)). The Reserved Instance utilization report compares the Reserved Instance
prices paid for instance usage in the bucket with On-Demand prices and shows your savings for the
time range covered by the report.
To get usage and cost data for an account, you must have its account credentials and enable detailed
billing reports with resources and tags for the account. If you're using consolidated billing and are
logged into the payer account, you can view data for the payer account and all its linked accounts. If
you're using consolidated billing and are logged into one of the linked accounts, you can only view data
for that linked account. For information about consolidated billing, see Pay Bills for Multiple Accounts
with Consolidated Billing.

Note
The Reserved Instance buckets aggregate Reserved Instances across EC2-VPC and EC2Classic network platform types in the same way that your bill is calculated. Additionally,
Reserved Instances in a bucket may have different upfront and hourly prices.
Here are examples of some of the questions that you can answer using the Reserved Instance
utilization report:
• How well am I utilizing my Reserved Instances?
• Are my Reserved Instances helping me save money?
For information about Reserved Instances, see Reserved Instances (p. 194).
Before you begin, you must get set up. For more information, see Getting Set Up for Usage
Reports (p. 762).
Topics
• Getting to Know the Report (p. 768)
• Viewing Your Reserved Instance Utilization (p. 770)
• Bookmarking a Customized Report (p. 770)
• Exporting Your Usage Data (p. 771)
• Options Reference (p. 771)

Getting to Know the Report
The Reserved Instance utilization report displays your requested utilization data in graph and table
formats.
To access the report, open the AWS Management Console. In the navigation pane, choose Reports
and then select EC2 Reserved Instance Usage Report.
The report aggregates Reserved Instance usage data for a given period by bucket. In the report, each
row in the table represents a bucket and provides the following metrics:
• Count—The highest number of Reserved Instances owned at the same time during the period of the
report.
• Usage Cost—The total Reserved Instance usage fees applied to instance usage covered by the
Reserved Instance bucket.
• Total Cost—The usage cost plus the amortized upfront fee for the usage period associated with the
Reserved Instance bucket.

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Note
If the bucket contains a Reserved Instance that you sold in the Reserved Instance
Marketplace and that Reserved Instance was active at any point during the period
of the report, the total cost of the bucket might be inflated and your savings might be
underestimated.
• Savings—The difference between what your usage for the period would have cost at On-Demand
prices and what it actually cost using Reserved Instances (Total Cost).
• Average Utilization—The average hourly utilization rate for the Reserved Instance bucket over the
period.
• Maximum Utilization—The highest utilization rate of any hour during the period covered by the
report.
For each row—or Reserved Instance bucket—in the table, the graph represents data based on your
selected Show metric over the selected Time range for the report. Each point in the graph represents
a metric at a point in time. For information about report options, see Options Reference (p. 771).
A color band at the edge of each selected row in the table corresponds to a report line in the graph.
You can show a row in the graph by selecting the checkbox at the beginning of the row.
By default, the Reserved Instance utilization report returns data over the last 14 days for all Reserved
Instance buckets. The graph shows the average utilization for the first five buckets in the table. You
can customize the report graph to show different utilization (average utilization, maximum utilization) or
cost (total cost, usage cost) data over a period ranging from 7 days to weeks, months, or years.

Customizing the Report
You can customize the Reserved Instance utilization report with Time range and Filter options.
Time range provides a list of common relative time ranges, ranging from Last 7 Days to Last 3 Years.
Select the time range that works best for your needs, and then click Update Report to apply the
change. To apply a time range that is not on the list, select Custom and enter the start date and end
date for which you want to run the report.
Filter lets you scope your Reserved Instance utilization report by one or more of the following
Reserved Instance qualities: region, instance type, accounts, platforms, tenancy, and offering types.
For example, you can filter by region or by specific Availability Zones in a region, or both. To filter by
region, select Regions, then select the regions and Availability Zones you want to include in the report,
and choose Update Report.

The report will return all results if no filter is applied.

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For information about report options, see Options Reference (p. 771).

Viewing Your Reserved Instance Utilization
In this section, we will highlight aspects of your Reserved Instance utilization that the graph and table
capture. For the purposes of this discussion, we'll use the following report, which is based on test data.

This Reserved Instance utilization report displays the average utilization of Reserved Instances in the
last two months. This report reveals the following information about the account's Reserved Instances
and how they have been utilized.
• Average Utilization
Most of the Reserved Instances in the table were utilized well. Standouts were the two m1.medium
medium utilization Reserved Instances (row 2), which were utilized all the time at 100% average
utilization, and the m1.xlarge (row 3) and m1.small (row 4) heavy utilization Reserved Instances,
which also were utilized all the time. In contrast, the high-count heavy utilization Reserved Instances
(row 5) had lower average utilization rates.
It is also worth noting that the 12 m1.large medium utilization Reserved Instances (row 1) were
utilized on average only 27 percent of the time.
• Maximum Utilization
At some point during the two-month period, all of the Reserved Instances were used 100 percent.
• Savings
All across the board, the report shows that for this test account, using Reserved Instances instead of
On-Demand instances results in savings for the account owner.
• Question
Does the account have too many m1.large medium utilization Reserved Instances (row 1)?

Bookmarking a Customized Report
You might want to generate a customized report again. Do this by bookmarking the report.
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To bookmark a custom report
1.

Select the options and filters for your report. Each selection you make adds a parameter to the
console URL. For example, granularity=Hourly and Filters=filter_list.

Using your browser, add the console URL as a bookmark.

To generate the same report in the future, use the bookmark that you created.

Exporting Your Usage Data
You might want to include your report graph or table in other reports. Do this by exporting the data.

To export usage data
1.

Select the options and filters for your report.

To export the usage data from the table as a .csv file, click Download and select CSV Only.

To export the graphical usage data as a .png file, click Download and select Graph Only.

Options Reference
Use the Show options to specify the metric to be displayed by the report graph.
• Average Utilization
Shows the average of the utilization rates for each hour over the selected time range, where the
utilization rate of a bucket for an hour is the number of instance hours used for that hour divided by
the total number of Reserved Instances owned in that hour.
• Maximum Utilization
Shows the highest of the utilization rates of any hour over the selected time range, where the
utilization rate of a bucket for an hour is the number of instance hours used for that hour divided by
the total number of Reserved Instances owned in that hour.
• Total Cost
Shows the usage cost plus the amortized portion of the upfront cost of the Reserved Instances in the
bucket over the period for which the report is generated.
• Usage Cost
Shows the total cost based on hourly fees for a selected bucket of Reserved Instances.
Use Time range to specify the period on which the report will be based.

Note
All times are specified in UTC time.
• Last 7 Days
Shows data for usage that took place during the current and previous six calendar days. Can be
used with daily or monthly granularities.
• Last 14 Days
Shows data for usage that took place during the current and previous 13 calendar days. Can be
used with daily or monthly granularities.
• This Month
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Shows data for usage that took place during the current calendar month. Can be used with daily or
monthly granularities.
• Last 3 Months
Shows data for usage that took place during the current and previous two calendar months. Can be
used with daily or monthly granularities.
• Last 6 Months
Shows data for usage that took place during the current and previous five calendar months. Can be
used with monthly granularities.
• Last 12 Months
Shows data for usage that took place during the current and previous 11 calendar months. Can be
used with monthly granularity.
• This Year
Shows data for usage that took place during the current calendar year. Can be used with monthly
granularity.
• Last 3 Years
Shows data for usage that took place during the current and previous two calendar years. Can be
used with monthly granularity.
• Custom
Shows data for the time range for the entered Start and End dates specified in the following format:
mm/dd/yyyy. Can be used with hourly, daily, or monthly granularities, but you can only specify a
maximum time range of two days for hourly data, two months for daily data, and three years for
monthly data.
Use Filter to scope the data displayed in the report.
• Regions
• Instance Type
• Accounts
• Platforms
• Tenancy
• Offering Types

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Troubleshooting Instances

The following documentation can help you troubleshoot problems that you might have with your
instance.
Contents
• What To Do If An Instance Immediately Terminates (p. 773)
• Troubleshooting Connecting to Your Instance (p. 774)
• Troubleshooting Stopping Your Instance (p. 779)
• Troubleshooting Terminating (Shutting Down) Your Instance (p. 781)
• Troubleshooting Instance Recovery Failures (p. 781)
• Troubleshooting Instances with Failed Status Checks (p. 782)
• Troubleshooting Instance Capacity (p. 805)
• Getting Console Output and Rebooting Instances (p. 805)
• My Instance is Booting from the Wrong Volume (p. 807)
For additional help with Windows instances, see Troubleshooting Windows Instances in the Amazon
EC2 User Guide for Windows Instances.
You can also search for answers and post questions on the Amazon EC2 forum.

What To Do If An Instance Immediately
Terminates
After you launch an instance, we recommend that you check its status to confirm that it goes from the
pending state to the running state, not the terminated state.
The following are a few reasons why an instance might immediately terminate:
• You've reached your EBS volume limit. For information about the volume limit, and to submit a
request to increase your volume limit, see Request to Increase the Amazon EBS Volume Limit.

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• An EBS snapshot is corrupt.
• The instance store-backed AMI you used to launch the instance is missing a required part (an
image.part.xx file).

Getting the Reason for Instance Termination
You can use the Amazon EC2 console, CLI, or API to get information about the reason that the
instance terminated.

To get the reason that an instance terminated using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances, and select your instance.

In the Description tab, locate the reason next to the label State transition reason. If the instance
is still running, there's typically no reason listed. If you've explicitly stopped or terminated the
instance, the reason is User initiated shutdown.

To get the reason that an instance terminated using the command line
1.

Use the describe-instances command:
$ aws ec2 describe-instances --instance-id instance_id

In the JSON response that's displayed, locate the StateReason element. It looks similar to the
following example.
"StateReason": {
"Message": "Client.UserInitiatedShutdown: User initiated shutdown",
"Code": "Client.UserInitiatedShutdown"
},

This example response shows the reason code that you'll see after you stop or terminate a
running instance. If the instance terminated immediately, you'll see code and message elements
that describe the reason that the instance terminated (for example, VolumeLimitExceeded).

Troubleshooting Connecting to Your Instance
The following are possible problems you may have and error messages you may see while trying to
connect to your instance.
Contents
• Error connecting to your instance: Connection timed out (p. 775)
• Error: User key not recognized by server (p. 776)
• Error: Host key not found, Permission denied (publickey), or Authentication failed, permission
denied (p. 777)
• Error: Unprotected Private Key File (p. 778)
• Error: Server refused our key or No supported authentication methods available (p. 778)
• Error using MindTerm on Safari Browser (p. 779)
• Error Using Mac OS X RDP Client (p. 779)
• Cannot Ping Instance (p. 779)

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Error connecting to your
instance: Connection timed out
For additional help with Windows instances, see Troubleshooting Windows Instances in the Amazon
EC2 User Guide for Windows Instances.

You can also search for answers and post questions on the Amazon EC2 forum.

Error connecting to your instance: Connection
timed out
If you try to connect to your instance and get an error message Network error: Connection
timed out or Error connecting to [instance], reason: -> Connection timed out:
connect, try the following:
• Check your security group rules. You need a security group rule that allows inbound traffic from your
public IP address on the proper port.
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances, and then select your instance.

In the Description tab, next to Security groups, choose view rules to display the list of rules
that are in effect.

For Linux instances: Verify that there is a rule that allows traffic from your computer to port 22
(SSH).
For Windows instances: Verify that there is a rule that allows traffic from your computer to port
3389 (RDP).
If your security group has a rule that allows inbound traffic from a single IP address, this address
may not be static if your computer is on a corporate network or if you are connecting through
an Internet service provider (ISP). Instead, specify the range of IP addresses used by client
computers. If your security group does not have a rule that allows inbound traffic as described
in the previous step, add a rule to your security group. For more information, see Authorizing
Network Access to Your Instances (p. 541).

• [EC2-VPC] Check the route table for the subnet. You need a route that sends all traffic destined
outside the VPC (0.0.0.0/0) to the Internet gateway for the VPC.
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the Description tab, write down the values of VPC ID and Subnet ID.

Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

In the navigation pane, choose Internet Gateways. Verify that there is an Internet gateway
attached to your VPC. Otherwise, choose Create Internet Gateway and follow the directions to
create an Internet gateway, select the Internet gateway, and then choose Attach to VPC and
follow the directions to attach it to your VPC.

In the navigation pane, choose Subnets, and then select your subnet.

On the Route Table tab, verify that there is a route with 0.0.0.0/0 as the destination and
the Internet gateway for your VPC as the target. Otherwise, choose the ID of the route table
(rtb-xxxxxxxx) to navigate to the Routes tab for the route table, choose Edit, Add another
route, enter 0.0.0.0/0 in Destination, select your Internet gateway from Target, and then
choose Save.

• [EC2-VPC] Check the network access control list (ACL) for the subnet. The network ACLs must
allow inbound and outbound traffic from your public IP address on the proper port. The default
network ACL allows all inbound and outbound traffic.
1.

Open the Amazon VPC console at https://console.aws.amazon.com/vpc/.

In the navigation pane, choose Your VPCs.

On the Summary tab, find Network ACL, choose the ID (acl-xxxxxxxx), and select the ACL.
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Error: User key not recognized by server

On the Inbound Rules tab, verify that the rules allow traffic from your computer. Otherwise,
delete or modify the rule that is blocking traffic from your computer.

On the Outbound Rules tab, verify that the rules allow traffic to your computer. Otherwise,
delete or modify the rule that is blocking traffic to your computer.

• If your computer is on a corporate network, ask your network administrator whether the internal
firewall allows inbound and outbound traffic from your computer on port 22 (for Linux instances) or
port 3389 (for Windows instances).
If you have a firewall on your computer, verify that it allows inbound and outbound traffic from your
computer on port 22 (for Linux instances) or port 3389 (for Windows instances).
• Check that your instance has a public IP address. If not, you can associate an Elastic IP address
with your instance. For more information, see Elastic IP Addresses (p. 581).
• Check the CPU load on your instance; the server may be overloaded. AWS automatically provides
data such as Amazon CloudWatch metrics and instance status, which you can use to see how
much CPU load is on your instance and, if necessary, adjust how your loads are handled. For more
information, see Monitoring Your Instances Using CloudWatch (p. 419).
• If your load is variable, you can automatically scale your instances up or down using Auto Scaling
and Elastic Load Balancing.
• If your load is steadily growing, you can move to a larger instance type. For more information, see
Resizing Your Instance (p. 189).

Error: User key not recognized by server
If you use SSH to connect to your instance
• Use ssh -vvv to get triple verbose debugging information while connecting:
#ssh -vvv -i [your key name].pem ec2-user@[public DNS address of your
instance].compute-1.amazonaws.com

The following sample output demonstrates what you might see if you were trying to connect to your
instance with a key that was not recognized by the server:
open/ANT/myusername/.ssh/known_hosts).
debug2: bits set: 504/1024
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: boguspem.pem ((nil))
debug1: Authentications that can continue: publickey
debug3: start over, passed a different list publickey
debug3: preferred gssapi-keyex,gssapi-with-mic,publickey,keyboardinteractive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey

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Error: Host key not found,
Permission denied (publickey), or
debug1: Next authentication
publickey
Authenticationmethod:
failed, permission
denied
debug1: Trying private key: boguspem.pem
debug1: read PEM private key done: type RSA
debug3: sign_and_send_pubkey: RSA
9c:4c:bc:0c:d0:5c:c7:92:6c:8e:9b:16:e4:43:d8:b2
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
Permission denied (publickey).

If you use SSH (MindTerm) to connect to your instance
• If Java is not enabled, the server does not recognize the user key. To enable Java, go to How do I
enable Java in my web browser? in the Java documentation.

If you use PuTTY to connect to your instance
• Verify that your private key (.pem) file has been converted to the format recognized by PuTTY (.ppk).
For more information about converting your private key, see Connecting to Your Linux Instance from
Windows Using PuTTY (p. 293).

Note
In PuTTYgen, load your private key file and select Save Private Key rather than Generate.
• Verify that you are connecting with the appropriate user name for your AMI. Enter the user name in
the Host name box in the PuTTY Configuration window.
• For an Amazon Linux AMI, the user name is ec2-user.
• For a RHEL5 AMI, the user name is either root or ec2-user.
• For an Ubuntu AMI, the user name is ubuntu.
• For a Fedora AMI, the user name is either fedora or ec2-user.
• For SUSE Linux, the user name is either root or ec2-user.
• Otherwise, if ec2-user and root don't work, check with the AMI provider.
• Verify that you have an inbound security group rule to allow inbound traffic to the appropriate port.
For more information, see Authorizing Network Access to Your Instances (p. 541).

Error: Host key not found, Permission denied
(publickey), or Authentication failed, permission
denied
If you connect to your instance using SSH and get any of the following errors, Host key not
found in [directory], Permission denied (publickey), or Authentication failed,
permission denied, verify that you are connecting with the appropriate user name for your AMI
and that you have specified the proper private key (.pem) file for your instance. For MindTerm clients,
enter the user name in the User name box in the Connect To Your Instance window.
The appropriate user names are as follows:
• For an Amazon Linux AMI, the user name is ec2-user.
• For a RHEL5 AMI, the user name is either root or ec2-user.
• For an Ubuntu AMI, the user name is ubuntu.
• For a Fedora AMI, the user name is either fedora or ec2-user.

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Error: Unprotected Private Key File

• For SUSE Linux, the user name is either root or ec2-user.
• Otherwise, if ec2-user and root don't work, check with the AMI provider.
Confirm that you are using the private key file that corresponds to the key pair that you selected when
you launched the instance.
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

Select your instance. In the Description tab, verify the value of Key pair name.

If you did not specify a key pair when you launched the instance, you can terminate the instance
and launch a new instance, ensuring that you specify a key pair. If this is an instance that you
have been using but you no longer have the .pem file for your key pair, you can replace the key
pair with a new one. For more information, see Connecting to Your Linux Instance if You Lose
Your Private Key (p. 486).

Error: Unprotected Private Key File
Your private key file must be protected from read and write operations from any other users. If your
private key can be read or written to by anyone but you, then SSH ignores your key and you see the
following warning message below.
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@
WARNING: UNPROTECTED PRIVATE KEY FILE!
@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Permissions 0777 for '.ssh/my_private_key.pem' are too open.
It is required that your private key files are NOT accessible by others.
This private key will be ignored.
bad permissions: ignore key: .ssh/my_private_key.pem
Permission denied (publickey).

If you see a similar message when you try to log in to your instance, examine the first line of the error
message to verify that you are using the correct public key for your instance. The above example uses
the private key .ssh/my_private_key.pem with file permissions of 0777, which allow anyone to
read or write to this file. This permission level is very insecure, and so SSH ignores this key. To fix the
error, execute the following command, substituting the path for your private key file.
$ chmod 0400 .ssh/my_private_key.pem

Error: Server refused our key or No supported
authentication methods available
If you use PuTTY to connect to your instance and get either of the following errors, Error: Server
refused our key or Error: No supported authentication methods available, verify
that you are connecting with the appropriate user name for your AMI. Enter the user name in the User
name box in the PuTTY Configuration window.
The appropriate user names are as follows:
• For an Amazon Linux AMI, the user name is ec2-user.
• For a RHEL5 AMI, the user name is either root or ec2-user.
• For an Ubuntu AMI, the user name is ubuntu.
• For a Fedora AMI, the user name is either fedora or ec2-user.

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Error using MindTerm on Safari Browser

• For SUSE Linux, the user name is either root or ec2-user.
• Otherwise, if ec2-user and root don't work, check with the AMI provider.
You should also verify that your private key (.pem) file has been correctly converted to the format
recognized by PuTTY (.ppk). For more information about converting your private key, see Connecting
to Your Linux Instance from Windows Using PuTTY (p. 293).

Error using MindTerm on Safari Browser
If you use MindTerm to connect to your instance, and are using the Safari web browser, you may get
the following error:
Error connecting to your_instance_ip, reason:
—> Key exchange failed: Host authentication failed

You need to update the browser's security settings to allow the AWS Management Console to run the
Java plugin in unsafe mode.

To enable the Java plugin to run in unsafe mode
1.

In Safari, keep the Amazon EC2 console open, and choose Safari, Preferences, Security.

Choose Plug-in Settings (or Manage Website Settings on older versions of Safari).

Choose the Java plugin on the left, then locate the AWS Management Console URL in the
Currently Open Websites list. Select Run in Unsafe Mode from its associated list.

When prompted, choose Trust in the warning dialog. Choose Done to return the browser.

Error Using Mac OS X RDP Client
If you are connecting to a Windows Server 2012 R2 instance using the Remote Desktop Connection
client from the Microsoft website, you may get the following error:
Remote Desktop Connection cannot verify the identity of the computer that you
want to connect to.

Download the Microsoft Remote Desktop app from the Apple iTunes store, and use the app to connect
to your instance.

Cannot Ping Instance
The ping command is a type of ICMP traffic — if you are unable to ping your instance, ensure that
your inbound security group rules allow ICMP traffic for the Echo Request message from all sources,
or from the computer or instance from which you are issuing the command. If you are unable to issue a
ping command from your instance, ensure that your outbound security group rules allow ICMP traffic
for the Echo Request message to all destinations, or to the host that you are attempting to ping.

Troubleshooting Stopping Your Instance
If you have stopped your Amazon EBS-backed instance and it appears "stuck" in the stopping state,
there may be an issue with the underlying host computer.

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First, try stopping the instance again. If you are using the stop-instances (AWS CLI) command be sure
to use the --force option.
If you can't force the instance to stop, you can create an AMI from the instance and launch a
replacement instance.
You are not billed for any instance hours while an instance is not in the running state.

To create a replacement instance
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances and select the instance.

Choose Actions, Image, Create Image.

In the Create Image dialog box, fill in the following fields and then choose Create Image:
a.

Specify a name and description for the AMI.

Choose No reboot.

Launch an instance from the AMI and verify that the instance is working.

Select the stuck instance, choose Actions, Instance State, Terminate. If the instance also gets
stuck terminating, Amazon EC2 automatically forces it to terminate within a few hours.

If you are unable to create an AMI from the instance as described in the previous procedure, you can
set up a replacement instance as follows:

To create a replacement instance (if the previous procedure fails)
1.

Select the instance, open the Description tab, and view the Block devices list. Select each
volume and write down its volume ID. Be sure to note which volume is the root volume.

In the navigation pane, choose Volumes. Select each volume for the instance, and choose
Actions, Create Snapshot.

In the navigation pane, choose Snapshots. Select the snapshot that you just created, and choose
Actions, Create Volume.

Launch an instance of the same type as the stuck instance (Amazon Linux, Windows, and so on).
Note the volume ID and device name of its root volume.

In the navigation pane, choose Instances, select the instance that you just launched, choose
Actions, Instance State, and then choose Stop.

In the navigation pane, choose Volumes, select the root volume of the stopped instance, and
choose Actions, Detach Volume.

Select the root volume that you created from the stuck instance, choose Actions, Attach Volume,
and attach it to the new instance as its root volume (using the device name that you wrote down).
Attach any additional non-root volumes to the instance.

In the navigation pane, choose Instances and select the replacement instance. Choose Actions,
Instance State, Start. Verify that the instance is working.

Select the stuck instance, choose Actions,Instance State, Terminate. If the instance also gets
stuck terminating, Amazon EC2 automatically forces it to terminate within a few hours.

If you're unable to complete these procedures, you can post a request for help to the Amazon EC2
forum. To help expedite a resolution, include the instance ID and describe the steps that you've already
taken.

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Terminating Your Instance

Troubleshooting Terminating (Shutting Down)
Your Instance
You are not billed for any instance hours while an instance is not in the running state. In other words,
when you terminate an instance, you stop incurring charges for that instance as soon as its state
changes to shutting-down.

Delayed Instance Termination
If your instance remains in the shutting-down state longer than a few minutes, it might be delayed
due to shutdown scripts being run by the instance.
Another possible cause is a problem with the underlying host computer. If your instance remains in
the shutting-down state for several hours, Amazon EC2 treats it as a stuck instance and forcibly
terminates it.
If it appears that your instance is stuck terminating and it has been longer than several hours, post a
request for help to the Amazon EC2 forum. To help expedite a resolution, include the instance ID and
describe the steps that you've already taken.

Terminated Instance Still Displayed
After you terminate an instance, it remains visible for a short while before being deleted. The status
shows as terminated. If the entry is not deleted after several hours, contact Support.

Automatically Launch or Terminate Instances
If you terminate all your instances, you may see that we launch a new instance for you. If you launch
an instance, you may see that we terminate one of your instances. If you stop an instance, you may
see that we terminate the instance and launch a new instance. Generally, these behaviors mean that
you've used Auto Scaling or Elastic Beanstalk to scale your computing resources automatically based
on criteria that you've defined.
For more information, see the Auto Scaling User Guide or the AWS Elastic Beanstalk Developer
Guide.

Troubleshooting Instance Recovery Failures
The following issues can cause automatic recovery of your instance to fail:
• Temporary, insufficient capacity of replacement hardware.
• The instance has an attached instance store storage, which is an unsupported configuration for
automatic instance recovery.
• There is an ongoing Service Health Dashboard event that prevented the recovery process from
successfully executing. Refer to http://status.aws.amazon.com for the latest service availability
information.
• The instance has reached the maximum daily allowance of three recovery attempts.
The automatic recovery process will attempt to recover your instance for up to three separate failures
per day. If the instance system status check failure persists, we recommend that you manually start
and stop the instance. For more information, see Stop and Start Your Instance (p. 299).

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Failed Status Checks

Your instance may subsequently be retired if automatic recovery fails and a hardware degradation is
determined to be the root cause for the original system status check failure.

Troubleshooting Instances with Failed Status
Checks
Topics
• Initial Steps (p. 782)
• Retrieving System Logs (p. 783)
• Troubleshooting System Log Errors for Linux-Based Instances (p. 783)
• Out of memory: kill process (p. 784)
• ERROR: mmu_update failed (Memory management update failed) (p. 785)
• I/O error (Block device failure) (p. 786)
• IO ERROR: neither local nor remote disk (Broken distributed block device) (p. 787)
• request_module: runaway loop modprobe (Looping legacy kernel modprobe on older Linux
versions) (p. 788)
• "FATAL: kernel too old" and "fsck: No such file or directory while trying to open /dev" (Kernel and
AMI mismatch) (p. 789)
• "FATAL: Could not load /lib/modules" or "BusyBox" (Missing kernel modules) (p. 789)
• ERROR Invalid kernel (EC2 incompatible kernel) (p. 791)
• request_module: runaway loop modprobe (Looping legacy kernel modprobe on older Linux
versions) (p. 792)
• fsck: No such file or directory while trying to open... (File system not found) (p. 793)
• General error mounting filesystems (Failed mount) (p. 794)
• VFS: Unable to mount root fs on unknown-block (Root filesystem mismatch) (p. 796)
• Error: Unable to determine major/minor number of root device... (Root file system/device
mismatch) (p. 797)
• XENBUS: Device with no driver... (p. 798)
• ... days without being checked, check forced (File system check required) (p. 798)
• fsck died with exit status... (Missing device) (p. 799)
• GRUB prompt (grubdom>) (p. 800)
• Bringing up interface eth0: Device eth0 has different MAC address than expected, ignoring. (Hardcoded MAC address) (p. 802)
• Unable to load SELinux Policy. Machine is in enforcing mode. Halting now. (SELinux
misconfiguration) (p. 803)
• XENBUS: Timeout connecting to devices (Xenbus timeout) (p. 804)

Initial Steps
If your instance fails a status check, first determine whether your applications are exhibiting any
problems. If you verify that the instance is not running your applications as expected, follow these
steps:

To investigate impaired instances using the Amazon EC2 console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

In the navigation pane, choose Instances, and then select your instance.

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Retrieving System Logs

In the details pane, choose Status Checks to see the individual results for all System Status
Checks and Instance Status Checks.

If a system status check has failed, you can try one of the following options:
• Create an instance recovery alarm. For more information, see Create Alarms That Stop, Terminate,
or Recover an Instance in the Amazon CloudWatch Developer Guide.
• For an instance using an Amazon EBS-backed AMI, stop and restart the instance.
• For an instance using an instance-store backed AMI, terminate the instance and launch a
replacement.
• Wait for Amazon EC2 to resolve the issue.
• Post your issue to the Amazon EC2 forum.
• Retrieve the system log and look for errors.

Retrieving System Logs
If an instance status check fails, you can reboot the instance and retrieve the system logs. The
logs may reveal an error that can help you troubleshoot the issue. Rebooting clears unnecessary
information from the logs.

To reboot an instance and retrieve the system log
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.
3.

In the navigation pane, choose Instances, and select your instance.
Choose Actions, Instance State, Reboot. It may take a few minutes for your instance to reboot.

4.
5.

Verify that the problem still exists; in some cases, rebooting may resolve the problem.
When the instance is in the running state, choose Actions, Instance Settings, Get System
Log.
Review the log that appears on the screen, and use the list of known system log error statements
below to troubleshoot your issue.
If your experience differs from our check results, or if you are having an issue with your instance
that our checks did not detect, choose Submit feedback on the Status Checks tab to help us
improve our detection tests.
If your issue is not resolved, you can post your issue to the Amazon EC2 forum.

6.
7.

Troubleshooting System Log Errors for LinuxBased Instances
For Linux-based instances that have failed an instance status check, such as the instance reachability
check, verify that you followed the steps above to retrieve the system log. The following list contains
some common system log errors and suggested actions you can take to resolve the issue for each
error .
Memory Errors
• Out of memory: kill process (p. 784)
• ERROR: mmu_update failed (Memory management update failed) (p. 785)
Device Errors
• I/O error (Block device failure) (p. 786)

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Out of memory: kill process

• IO ERROR: neither local nor remote disk (Broken distributed block device) (p. 787)
Kernel Errors
• request_module: runaway loop modprobe (Looping legacy kernel modprobe on older Linux
versions) (p. 788)
• "FATAL: kernel too old" and "fsck: No such file or directory while trying to open /dev" (Kernel and
AMI mismatch) (p. 789)
• "FATAL: Could not load /lib/modules" or "BusyBox" (Missing kernel modules) (p. 789)
• ERROR Invalid kernel (EC2 incompatible kernel) (p. 791)
File System Errors
• request_module: runaway loop modprobe (Looping legacy kernel modprobe on older Linux
versions) (p. 792)
• fsck: No such file or directory while trying to open... (File system not found) (p. 793)
• General error mounting filesystems (Failed mount) (p. 794)
• VFS: Unable to mount root fs on unknown-block (Root filesystem mismatch) (p. 796)
• Error: Unable to determine major/minor number of root device... (Root file system/device mismatch)
(p. 797)
• XENBUS: Device with no driver... (p. 798)
• ... days without being checked, check forced (File system check required) (p. 798)
• fsck died with exit status... (Missing device) (p. 799)
Operating System Errors
• GRUB prompt (grubdom>) (p. 800)
• Bringing up interface eth0: Device eth0 has different MAC address than expected, ignoring. (Hardcoded MAC address) (p. 802)
• Unable to load SELinux Policy. Machine is in enforcing mode. Halting now. (SELinux
misconfiguration) (p. 803)
• XENBUS: Timeout connecting to devices (Xenbus timeout) (p. 804)

Out of memory: kill process
An out of memory error is indicated by a system log entry similar to the one shown below.
[115879.769795] Out of memory: kill process 20273 (httpd) score 1285879
or a child
[115879.769795] Killed process 1917 (php-cgi) vsz:467184kB, anonrss:101196kB, file-rss:204kB

Potential Cause
Exhausted memory

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Do one of the following:

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ERROR: mmu_update failed
(Memory management update failed)

For this instance type

Do this
• Stop the instance, and modify the instance
to use a different instance type, and start the
instance again. For example, a larger or a
memory-optimized instance type.
• Reboot the instance to return it to a nonimpaired status. The problem will probably
occur again unless you change the instance
type.

Instance store-backed

Do one of the following:
• Terminate the instance and launch a new
instance, specifying a different instance type.
For example, a larger or a memory-optimized
instance type.
• Reboot the instance to return it to an
unimpaired status. The problem will probably
occur again unless you change the instance
type.

ERROR: mmu_update failed (Memory
management update failed)
Memory management update failures are indicated by a system log entry similar to the following:
...
Press `ESC' to enter the menu... 0
(2.6.35.14-95.38.amzn1.i686)'

[H[J

Booting 'Amazon Linux 2011.09

root (hd0)
Filesystem type is ext2fs, using whole disk
kernel /boot/vmlinuz-2.6.35.14-95.38.amzn1.i686 root=LABEL=/ console=hvc0
LANG=
en_US.UTF-8 KEYTABLE=us
initrd /boot/initramfs-2.6.35.14-95.38.amzn1.i686.img
ERROR: mmu_update failed with rc=-22

Potential Cause
Issue with Amazon Linux

Suggested Action
Post your issue to the Developer Forums or contact AWS Support.

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I/O error (Block device failure)

I/O error (Block device failure)
An input/output error is indicated by a system log entry similar to the following example:
[9943662.053217]
[9943664.191262]
[9943664.191285]
[9943664.191297]
[9943664.191304]
[9943664.191310]
[9943664.191317]
[9943664.191324]
[9943664.191332]
[9943664.191339]
[9943664.191581]
[9943664.191590]
[9943664.191597]
[9943664.191767]
[9943664.191970]
[9943664.192143]
[9943664.192949]
[9943664.193112]
[9943664.193266]
...

end_request: I/O
end_request: I/O
Buffer I/O error
Buffer I/O error
Buffer I/O error
Buffer I/O error
Buffer I/O error
Buffer I/O error
Buffer I/O error
Buffer I/O error
end_request: I/O
Buffer I/O error
Buffer I/O error
end_request: I/O
end_request: I/O
end_request: I/O
end_request: I/O
end_request: I/O
end_request: I/O

error, dev sde, sector
error, dev sde, sector
on device md0, logical
on device md0, logical
on device md0, logical
on device md0, logical
on device md0, logical
on device md0, logical
on device md0, logical
on device md0, logical
error, dev sde, sector
on device md0, logical
on device md0, logical
error, dev sde, sector
error, dev sde, sector
error, dev sde, sector
error, dev sde, sector
error, dev sde, sector
error, dev sde, sector

52428288
52428168
block 209713024
block 209713025
block 209713026
block 209713027
block 209713028
block 209713029
block 209713030
block 209713031
52428280
block 209713136
block 209713137
52428288
52428288
52428288
52428288
52428288
52428288

Potential Causes
Instance type

Potential cause

Amazon EBS-backed

A failed Amazon EBS volume

Instance store-backed

A failed physical drive

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Use the following procedure:
1. Stop the instance.
2. Detach the volume.
3. Attempt to recover the volume.

Note
It's good practice to snapshot your
Amazon EBS volumes often. This
dramatically decreases the risk of
data loss as a result of failure.
4. Re-attach the volume to the instance.
5. Detach the volume.
Instance store-backed

Terminate the instance and launch a new
instance.

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IO ERROR: neither local nor remote
disk (Broken distributed block device)

For this instance type

Do this

Note
Data cannot be recovered. Recover
from backups.

Note
It's a good practice to use either
Amazon S3 or Amazon EBS for
backups. Instance store volumes are
directly tied to single host and single
disk failures.

IO ERROR: neither local nor remote disk (Broken
distributed block device)
An input/output error on the device is indicated by a system log entry similar to the following example:
...
block drbd1: Local IO failed in request_timer_fn. Detaching...
Aborting journal on device drbd1-8.
block drbd1: IO ERROR: neither local nor remote disk
Buffer I/O error on device drbd1, logical block 557056
lost page write due to I/O error on drbd1
JBD2: I/O error detected when updating journal superblock for drbd1-8.

Potential Causes
Instance type

Potential cause

Amazon EBS-backed

A failed Amazon EBS volume

Instance store-backed

A failed physical drive

Suggested Action
Terminate the instance and launch a new instance.
For an Amazon EBS-backed instance you can recover data from a recent snapshot by creating an
image from it. Any data added after the snapshot cannot be recovered.

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request_module: runaway loop modprobe (Looping
legacy kernel modprobe on older Linux versions)

request_module: runaway loop modprobe
(Looping legacy kernel modprobe on older Linux
versions)
This condition is indicated by a system log similar to the one shown below. Using an unstable or old
Linux kernel (for example, 2.6.16-xenU) can cause an interminable loop condition at startup.
Linux version 2.6.16-xenU (builder@xenbat.amazonsa) (gcc version 4.0.1
20050727 (Red Hat 4.0.1-5)) #1 SMP Mon May 28 03:41:49 SAST 2007
BIOS-provided physical RAM map:
Xen: 0000000000000000 - 0000000026700000 (usable)
0MB HIGHMEM available.
...
request_module: runaway loop modprobe binfmt-464c
request_module: runaway loop modprobe binfmt-464c
request_module: runaway loop modprobe binfmt-464c
request_module: runaway loop modprobe binfmt-464c
request_module: runaway loop modprobe binfmt-464c

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Use a newer kernel, either GRUB-based or
static, using one of the following options:
Option 1: Terminate the instance and launch a
new instance, specifying the –kernel and –
ramdisk parameters.
Option 2:
1. Stop the instance.
2. Modify the kernel and ramdisk attributes to
use a newer kernel.
3. Start the instance.

Instance store-backed

Terminate the instance and launch a new
instance, specifying the –kernel and –ramdisk
parameters.

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"FATAL: kernel too old" and "fsck: No
such file or directory while trying to
open /dev" (Kernel and AMI mismatch)

"FATAL: kernel too old" and "fsck: No such file
or directory while trying to open /dev" (Kernel
and AMI mismatch)
This condition is indicated by a system log similar to the one shown below.
Linux version 2.6.16.33-xenU (root@dom0-0-50-45-1-a4-ee.z-2.aes0.internal)
(gcc version 4.1.1 20070105 (Red Hat 4.1.1-52)) #2 SMP Wed Aug 15 17:27:36
SAST 2007
...
FATAL: kernel too old
Kernel panic - not syncing: Attempted to kill init!

Potential Causes
Incompatible kernel and userland

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Use the following procedure:
1. Stop the instance.
2. Modify the configuration to use a newer
kernel.
3. Start the instance.

Instance store-backed

Use the following procedure:
1. Create an AMI that uses a newer kernel.
2. Terminate the instance.
3. Start a new instance from the AMI you
created.

"FATAL: Could not load /lib/modules" or
"BusyBox" (Missing kernel modules)
This condition is indicated by a system log similar to the one shown below.
[
0.370415] Freeing unused kernel memory: 1716k freed
Loading, please wait...
WARNING: Couldn't open directory /lib/modules/2.6.34-4-virtual: No such file
or directory
FATAL: Could not open /lib/modules/2.6.34-4-virtual/modules.dep.temp for
writing: No such file or directory
FATAL: Could not load /lib/modules/2.6.34-4-virtual/modules.dep: No such file
or directory
Couldn't get a file descriptor referring to the console
Begin: Loading essential drivers... ...

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Amazon Elastic Compute Cloud
User Guide for Linux Instances
"FATAL: Could not load /lib/modules"
or "BusyBox" (Missing kernel modules)
FATAL: Could not load /lib/modules/2.6.34-4-virtual/modules.dep: No
or directory
FATAL: Could not load /lib/modules/2.6.34-4-virtual/modules.dep: No
or directory
Done.
Begin: Running /scripts/init-premount ...
Done.
Begin: Mounting root file system... ...
Begin: Running /scripts/local-top ...
Done.
Begin: Waiting for root file system... ...
Done.
Gave up waiting for root device. Common problems:
- Boot args (cat /proc/cmdline)
- Check rootdelay= (did the system wait long enough?)
- Check root= (did the system wait for the right device?)
- Missing modules (cat /proc/modules; ls /dev)
FATAL: Could not load /lib/modules/2.6.34-4-virtual/modules.dep: No
or directory
FATAL: Could not load /lib/modules/2.6.34-4-virtual/modules.dep: No
or directory
ALERT! /dev/sda1 does not exist. Dropping to a shell!

such file
such file

BusyBox v1.13.3 (Ubuntu 1:1.13.3-1ubuntu5) built-in shell (ash)
Enter 'help' for a list of built-in commands.
(initramfs)

Potential Causes
One or more of the following conditions can cause this problem:
• Missing ramdisk
• Missing correct modules from ramdisk
• Amazon EBS root volume not correctly attached as /dev/sda1

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Use the following procedure:
1. Select corrected ramdisk for the Amazon EBS
volume.
2. Stop the instance.
3. Detach the volume and repair it.
4. Attach the volume to the instance.
5. Start the instance.
6. Modify the AMI to use the corrected ramdisk.

Instance store-backed

Use the following procedure:
1. Terminate the instance and launch a new
instance with the correct ramdisk.

790

Amazon Elastic Compute Cloud
User Guide for Linux Instances
ERROR Invalid kernel (EC2 incompatible kernel)

For this instance type

Do this
2. Create a new AMI with the correct ramdisk.

ERROR Invalid kernel (EC2 incompatible kernel)
This condition is indicated by a system log similar to the one shown below.
...
root (hd0)
Filesystem type is ext2fs, using whole disk
kernel /vmlinuz root=/dev/sda1 ro
initrd /initrd.img
ERROR Invalid kernel: elf_xen_note_check: ERROR: Will only load images
built for the generic loader or Linux images
xc_dom_parse_image returned -1
Error 9: Unknown boot failure
Booting 'Fallback'
root (hd0)
Filesystem type is ext2fs, using whole disk
kernel /vmlinuz.old root=/dev/sda1 ro
Error 15: File not found

Potential Causes
One or both of the following conditions can cause this problem:
• Supplied kernel is not supported by GRUB
• Fallback kernel does not exist

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Use the following procedure:
1. Stop the instance.
2. Replace with working kernel.
3. Install a fallback kernel.
4. Modify the AMI by correcting the kernel.

Instance store-backed

Use the following procedure:
1. Terminate the instance and launch a new
instance with the correct kernel.

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Amazon Elastic Compute Cloud
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request_module: runaway loop modprobe (Looping
legacy kernel modprobe on older Linux versions)

For this instance type

Do this
2. Create an AMI with the correct kernel.
3. (Optional) Seek technical assistance for data
recovery using AWS Support.

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

792

Amazon Elastic Compute Cloud
User Guide for Linux Instances
fsck: No such file or directory while
trying to open... (File system not found)

For this instance type

Do this

Instance store-backed

Terminate the instance and launch a new
instance, specifying the –kernel and –ramdisk
parameters.

fsck: No such file or directory while trying to
open... (File system not found)
This condition is indicated by a system log similar to the one shown below.
Welcome to Fedora
Press 'I' to enter interactive startup.
Setting clock : Wed Oct 26 05:52:05 EDT 2011 [
Starting udev: [

]

Setting hostname localhost:

[

]

No devices found
Setting up Logical Volume Management: File descriptor 7 left open
No volume groups found
[ OK ]
Checking filesystems
Checking all file systems.
[/sbin/fsck.ext3 (1) -- /] fsck.ext3 -a /dev/sda1
/dev/sda1: clean, 82081/1310720 files, 2141116/2621440 blocks
[/sbin/fsck.ext3 (1) -- /mnt/dbbackups] fsck.ext3 -a /dev/sdh
fsck.ext3: No such file or directory while trying to open /dev/sdh
/dev/sdh:
The superblock could not be read or does not describe a correct ext2
filesystem. If the device is valid and it really contains an ext2
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternate superblock:
e2fsck -b 8193
[FAILED]

*** An error occurred during the file system check.
*** Dropping you to a shell; the system will reboot
*** when you leave the shell.
Give root password for maintenance
(or type Control-D to continue):

Potential Causes
• A bug exists in ramdisk filesystem definitions /etc/fstab
• Misconfigured filesystem definitions in /etc/fstab
• Missing/failed drive

793

Amazon Elastic Compute Cloud
User Guide for Linux Instances
General error mounting filesystems (Failed mount)

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Use the following procedure:
1. Stop the instance, detach the root volume,
repair/modify /etc/fstab the volume, attach the
volume to the instance, and start the instance.
2. Fix ramdisk to include modified /etc/fstab (if
applicable).
3. Modify the AMI to use a newer ramdisk.

Tip
The sixth field in the fstab defines
availability requirements of the mount
– a nonzero value implies that an
fsck will be done on that volume and
must succeed. Using this field can be
problematic in Amazon EC2 because a
failure typically results in an interactive
console prompt which is not currently
available in Amazon EC2. Use care with
this feature and read the Linux man
page for fstab.
Instance store-backed

Use the following procedure:
1. Terminate the instance and launch a new
instance.
2. Detach any errant Amazon EBS volumes and
the reboot instance.
3. (Optional) Seek technical assistance for data
recovery using AWS Support.

General error mounting filesystems (Failed
mount)
This condition is indicated by a system log similar to the one shown below.
Loading xenblk.ko module
xen-vbd: registered block device major 8
Loading ehci-hcd.ko module
Loading ohci-hcd.ko module
Loading uhci-hcd.ko module
USB Universal Host Controller Interface driver v3.0
Loading mbcache.ko module
Loading jbd.ko module
Loading ext3.ko module
Creating root device.
Mounting root filesystem.
kjournald starting. Commit interval 5 seconds

794

Amazon Elastic Compute Cloud
User Guide for Linux Instances
General error mounting filesystems (Failed mount)

EXT3-fs: mounted filesystem with ordered data mode.
Setting up other filesystems.
Setting up new root fs
no fstab.sys, mounting internal defaults
Switching to new root and running init.
unmounting old /dev
unmounting old /proc
unmounting old /sys
mountall:/proc: unable to mount: Device or resource busy
mountall:/proc/self/mountinfo: No such file or directory
mountall: root filesystem isn't mounted
init: mountall main process (221) terminated with status 1
General error mounting filesystems.
A maintenance shell will now be started.
CONTROL-D will terminate this shell and re-try.
Press enter for maintenance
(or type Control-D to continue):

Potential Causes
Instance type

Potential cause

Amazon EBS-backed

• Detached or failed Amazon EBS volume.
• Corrupted filesystem.
• Mismatched ramdisk and AMI combination
(e.g., Debian ramdisk with a SUSE AMI).

Instance store-backed

• A failed drive.
• A corrupted file system.
• A mismatched ramdisk and combination (for
example, a Debian ramdisk with a SUSE AMI).

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Use the following procedure:
1. Stop the instance.
2. Detach the root volume.
3. Attach the root volume to a known working
instance.
4. Run filesystem check (fsck –a /dev/...).
5. Fix any errors.
6. Detach the volume from the known working
instance.
7. Attach the volume to the stopped instance.
8. Start the instance.
9. Recheck the instance status.

795

Amazon Elastic Compute Cloud
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VFS: Unable to mount root fs on unknownblock (Root filesystem mismatch)

For this instance type

Do this

Instance store-backed

Try one of the following:
• Start a new instance.
• (Optional) Seek technical assistance for data
recovery using AWS Support.

VFS: Unable to mount root fs on unknown-block
(Root filesystem mismatch)
This condition is indicated by a system log similar to the one shown below.
Linux version 2.6.16-xenU (builder@xenbat.amazonsa) (gcc version 4.0.1
20050727 (Red Hat 4.0.1-5)) #1 SMP Mon May 28 03:41:49 SAST 2007
...
Kernel command line: root=/dev/sda1 ro 4
...
Registering block device major 8
...
Kernel panic - not syncing: VFS: Unable to mount root fs on unknownblock(8,1)

Potential Causes
Instance type

Potential cause

Amazon EBS-backed

• Device not attached correctly.
• Root device not attached at correct device
point.
• Filesystem not in expected format.
• Use of legacy kernel (e.g., 2.6.16-XenU).

Instance store-backed

Hardware device failure.

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Do one of the following:
• Stop and then restart the instance.
• Modify root volume to attach at the correct
device point, possible /dev/sda1 instead of /
dev/sda.
• Stop and modify to use modern kernel.

Instance store-backed

Terminate the instance and launch a new
instance using a modern kernel.

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Amazon Elastic Compute Cloud
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Error: Unable to determine major/minor number of
root device... (Root file system/device mismatch)

Error: Unable to determine major/minor number
of root device... (Root file system/device
mismatch)
This condition is indicated by a system log similar to the one shown below.
...
XENBUS: Device with no driver: device/vif/0
XENBUS: Device with no driver: device/vbd/2048
drivers/rtc/hctosys.c: unable to open rtc device (rtc0)
Initializing network drop monitor service
Freeing unused kernel memory: 508k freed
:: Starting udevd...
done.
:: Running Hook [udev]
:: Triggering uevents...<30>udevd[65]: starting version 173
done.
Waiting 10 seconds for device /dev/xvda1 ...
Root device '/dev/xvda1' doesn't exist. Attempting to create it.
ERROR: Unable to determine major/minor number of root device '/dev/xvda1'.
You are being dropped to a recovery shell
Type 'exit' to try and continue booting
sh: can't access tty; job control turned off
[ramfs /]#

Potential Causes
• Missing or incorrectly configured virtual block device driver
• Device enumeration clash (sda versus xvda or sda instead of sda1)
• Incorrect choice of DomU kernel

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Use the following procedure:
1. Stop the instance.
2. Detach the volume.
3. Fix the device mapping problem.
4. Start the instance.
5. Modify the AMI to address device mapping
issues.

Instance store-backed

Use the following procedure:
1. Create a new AMI with the appropriate fix
(map block device correctly).
2. Terminate the instance and launch a new
instance from the AMI you created.

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XENBUS: Device with no driver...

XENBUS: Device with no driver...
This condition is indicated by a system log similar to the one shown below.
XENBUS: Device with no driver: device/vbd/2048
drivers/rtc/hctosys.c: unable to open rtc device (rtc0)
Initalizing network drop monitor service
Freeing unused kernel memory: 508k freed
:: Starting udevd...
done.
:: Running Hook [udev]
:: Triggering uevents...<30>udevd[65]: starting version 173
done.
Waiting 10 seconds for device /dev/xvda1 ...
Root device '/dev/xvda1' doesn't exist. Attempting to create it.
ERROR: Unable to determine major/minor number of root device '/dev/xvda1'.
You are being dropped to a recovery shell
Type 'exit' to try and continue booting
sh: can't access tty; job control turned off
[ramfs /]#

Potential Causes
• Missing or incorrectly configured virtual block device driver
• Device enumeration clash (sda versus xvda)
• Incorrect choice of DomU kernel

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Use the following procedure:
1. Stop the instance.
2. Detach the volume.
3. Fix the device mapping problem.
4. Start the instance.
5. Modify the AMI to address device mapping
issues.

Instance store-backed

Use the following procedure:
1. Create an AMI with the appropriate fix (map
block device correctly).
2. Terminate the instance and launch a new
instance using the AMI you created.

... days without being checked, check forced
(File system check required)
This condition is indicated by a system log similar to the one shown below.

798

Amazon Elastic Compute Cloud
User Guide for Linux Instances
fsck died with exit status... (Missing device)
...
Checking filesystems
Checking all file systems.
[/sbin/fsck.ext3 (1) -- /] fsck.ext3 -a /dev/sda1
/dev/sda1 has gone 361 days without being checked, check forced

Potential Causes
Filesystem check time passed; a filesystem check is being forced

Suggested Actions
• Wait until the filesystem check completes. Note that a filesystem check can take a long time
depending on the size of the root filesystem.
• Modify your filesystems to remove the filesystem check (fsck) enforcement using tune2fs or tools
appropriate for your filesystem.

fsck died with exit status... (Missing device)
This condition is indicated by a system log similar to the one shown below.
Cleaning up ifupdown....
Loading kernel modules...done.
...
Activating lvm and md swap...done.
Checking file systems...fsck from util-linux-ng 2.16.2
/sbin/fsck.xfs: /dev/sdh does not exist
fsck died with exit status 8
[31mfailed (code 8).[39;49m

Potential Causes
• Ramdisk looking for missing drive
• Filesystem consistency check forced
• Drive failed or detached

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Try one or more of the following to resolve the
issue:
• Stop the instance, attach the volume to an
existing running instance.
• Manually run consistency checks.
• Fix ramdisk to include relevant utilities.
• Modify filesystem tuning parameters to remove
consistency requirements (not recommended).

Instance store-backed

Try one or more of the following to resolve the
issue:

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Amazon Elastic Compute Cloud
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GRUB prompt (grubdom>)

For this instance type

Do this
• Rebundle ramdisk with correct tooling.
• Modify file system tuning parameters to
remove consistency requirements (not
recommended).
• Terminate the instance and launch a new
instance.
• (Optional) Seek technical assistance for data
recovery using AWS Support.

GRUB prompt (grubdom>)
This condition is indicated by a system log similar to the one shown below.
GNU GRUB

version 0.97

(629760K lower / 0K upper memory)

[ Minimal BASH-like line editing is supported.
the

first

completions.

word,

TAB

lists

possible

For

command

Anywhere else TAB lists the possible

completions of a device/filename. ]
grubdom>

Potential Causes
Instance type

Potential causes

Amazon EBS-backed

• Missing GRUB configuration file.
• Incorrect GRUB image used, expecting GRUB
configuration file at a different location.
• Unsupported filesystem used to store your
GRUB configuration file (for example,
converting your root file system to a type that is
not supported by an earlier version of GRUB).

Instance store-backed

800

Amazon Elastic Compute Cloud
User Guide for Linux Instances
GRUB prompt (grubdom>)

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Option 1: Modify the AMI and relaunch the
instance:
1. Modify the source AMI to create a GRUB
configuration file at the standard location (/
boot/grub/menu.lst).
2. Verify that your version of GRUB supports
the underlying file system type and upgrade
GRUB if necessary.
3. Pick the appropriate GRUB image, (hd0-1st
drive or hd00 – 1st drive, 1st partition).
4. Terminate the instance and launch a new one
using the AMI the you created.
Option 2: Fix the existing instance:
1. Stop the instance.
2. Detach the root filesystem.
3. Attach the root filesystem to a known working
instance.
4. Mount filesystem.
5. Create a GRUB configuration file.
6. Verify that your version of GRUB supports
the underlying file system type and upgrade
GRUB if necessary.
7. Detach filesystem.
8. Attach to the original instance.
9. Modify kernel attribute to use the appropriate
GRUB image (1st disk or 1st partition on 1st
disk).
10.Start the instance.

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Amazon Elastic Compute Cloud
User Guide for Linux Instances
Bringing up interface eth0: Device eth0
has different MAC address than expected,
For this instance type ignoring. (Hard-coded MAC
Doaddress)
this

Instance store-backed

Option 1: Modify the AMI and relaunch the
instance:
1. Create the new AMI with a GRUB
configuration file at the standard location (/
boot/grub/menu.lst).
2. Pick the appropriate GRUB image, (hd0-1st
drive or hd00 – 1st drive, 1st partition).
3. Verify that your version of GRUB supports
the underlying file system type and upgrade
GRUB if necessary.
4. Terminate the instance and launch a new
instance using the AMI you created.
Option 2: Terminate the instance and launch a
new instance, specifying the correct kernel.

Note
To recover data from the existing
instance, contact AWS Support.

Bringing up interface eth0: Device eth0 has
different MAC address than expected, ignoring.
(Hard-coded MAC address)
This condition is indicated by a system log similar to the one shown below.
...
Bringing up loopback interface:
Bringing up interface eth0:
expected, ignoring.
[FAILED]
Starting auditd: [

[

]

Device eth0 has different MAC address than

]

Potential Causes
There is a hard-coded interface MAC in the AMI configuration

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Do one of the following:
• Modify the AMI to remove the hard coding and
relaunch the instance.
• Modify the instance to remove the hard-coded
MAC address.

802

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Unable to load SELinux Policy.
Machine is in enforcing mode. Halting
now. (SELinux misconfiguration)
For this instance type
Do this

OR
Use the following procedure:
1. Stop the instance.
2. Detach the root volume.
3. Attach the volume to another instance and
modify the volume to remove the hard-coded
MAC address.
4. Attach the volume to the original instance.
5. Start the instance.
Instance store-backed

Do one of the following:
• Modify the instance to remove the hard-coded
MAC address.
• Terminate the instance and launch a new
instance.

Unable to load SELinux Policy. Machine is
in enforcing mode. Halting now. (SELinux
misconfiguration)
This condition is indicated by a system log similar to the one shown below.
audit(1313445102.626:2): enforcing=1 old_enforcing=0 auid=4294967295
Unable to load SELinux Policy. Machine is in enforcing mode. Halting now.
Kernel panic - not syncing: Attempted to kill init!

Potential Causes
SELinux has been enabled in error:
• Supplied kernel is not supported by GRUB
• Fallback kernel does not exist

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Use the following procedure:
1. Stop the failed instance.
2. Detach the failed instance's root volume.
3. Attach the root volume to another running
Linux instance (later referred to as a recovery
instance).
4. Connect to the recovery instance and mount
the failed instance's root volume.

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Amazon Elastic Compute Cloud
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XENBUS: Timeout connecting
to devices (Xenbus timeout)

For this instance type

Do this
5. Disable SELinux on the mounted root volume.
This process varies across Linux distributions;
for more information, consult your OS-specific
documentation.

Note
On some systems, you
disable SELinux by setting
SELINUX=disabled in the
/mount_point/etc/sysconfig/
selinux file, where mount_point
is the location that you mounted the
volume on your recovery instance.
6. Unmount and detach the root volume from
the recovery instance and reattach it to the
original instance.
7. Start the instance.
Instance store-backed

Use the following procedure:
1. Terminate the instance and launch a new
instance.
2. (Optional) Seek technical assistance for data
recovery using AWS Support.

XENBUS: Timeout connecting to devices
(Xenbus timeout)
This condition is indicated by a system log similar to the one shown below.
Linux version 2.6.16-xenU (builder@xenbat.amazonsa) (gcc version 4.0.1
20050727 (Red Hat 4.0.1-5)) #1 SMP Mon May 28 03:41:49 SAST 2007
...
XENBUS: Timeout connecting to devices!
...
Kernel panic - not syncing: No init found. Try passing init= option to
kernel.

Potential Causes
• The block device not is connected to the instance
• This instance is using a very old DomU kernel

Suggested Actions
For this instance type

Do this

Amazon EBS-backed

Do one of the following:
• Modify the AMI and instance to use a modern
kernel and relaunch the instance.

804

Amazon Elastic Compute Cloud
User Guide for Linux Instances
Instance Capacity

For this instance type

Do this
• Reboot the instance.

Instance store-backed

Do one of the following:
• Terminate the instance.
• Modify the AMI to use a modern kernel, and
launch a new instance using this AMI.

Troubleshooting Instance Capacity
The following errors are related to instance capacity.

Error: InsufficientInstanceCapacity
If you get an InsufficientInstanceCapacity error when you try to launch an instance, AWS does
not currently have enough available capacity to service your request. Try the following:
• Wait a few minutes and then submit your request again; capacity can shift frequently.
• Submit a new request with a reduced number of instances. For example, if you're making a single
request to launch 15 instances, try making 3 requests for 5 instances, or 15 requests for 1 instance
instead.
• Submit a new request without specifying an Availability Zone.
• Submit a new request using a different instance type (which you can resize at a later stage). For
more information, see Resizing Your Instance (p. 189).
• Try purchasing Reserved Instances. Reserved Instances are a long-term capacity reservation. For
more information, see: Amazon EC2 Reserved Instances.

Error: InstanceLimitExceeded
If you get an InstanceLimitExceeded error when you try to launch an instance, you have reached
your concurrent running instance limit. For new AWS accounts, the default limit is 20. If you need
additional running instances, complete the form at Request to Increase Amazon EC2 Instance Limit.

Getting Console Output and Rebooting
Instances
Console output is a valuable tool for problem diagnosis. It is especially useful for troubleshooting
kernel problems and service configuration issues that could cause an instance to terminate or become
unreachable before its SSH daemon can be started.
Similarly, the ability to reboot instances that are otherwise unreachable is valuable for both
troubleshooting and general instance management.
EC2 instances do not have a physical monitor through which you can view their console output. They
also lack physical controls that allow you to power up, reboot, or shut them down. Instead, you perform
these tasks through the Amazon EC2 API and the command line interface (CLI).

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Instance Reboot

Instance Reboot
Just as you can reset a computer by pressing the reset button, you can reset EC2 instances using the
Amazon EC2 console, CLI, or API. For more information, see Reboot Your Instance (p. 302).

Caution
For Windows instances, this operation performs a hard reboot that might result in data
corruption.

Instance Console Output
For Linux/Unix instances, the instance console output displays the exact console output that would
normally be displayed on a physical monitor attached to a computer. This output is buffered because
the instance produces it and then posts it to a store where the instance's owner can retrieve it.
For Windows instances, the instance console output displays the last three system event log errors.
The posted output is not continuously updated; only when it is likely to be of the most value. This
includes shortly after instance boot, after reboot, and when the instance terminates.

Note
Only the most recent 64 KB of posted output is stored, which is available for at least 1 hour
after the last posting.
Only the instance owner can access the console output. You can retrieve the console output for your
instances using the console or the command line.

To get console output using the console
1.
2.
3.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
In the left navigation pane, choose Instances, and select the instance.
Choose Actions, Instance Settings, Get System Log.

To get console output using the command line
You can use one of the following commands. For more information about these command line
interfaces, see Accessing Amazon EC2 (p. 3).
• get-console-output (AWS CLI)
• Get-EC2ConsoleOutput (AWS Tools for Windows PowerShell)
For more information about common system log errors, see Troubleshooting System Log Errors for
Linux-Based Instances (p. 783).

Capture a Screenshot of an Unreachable
Instance
If you are unable to reach your instance via SSH or RDP, you can capture a screenshot of your
instance and view it as an image. This provides visibility as to the status of the instance, and allows for
quicker troubleshooting.
There is no data transfer cost for this screenshot. The image is generated in JPG format, no larger than
100kb.

To access the instance console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

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Instance Recovery When a Host Computer Fails

In the left navigation pane, choose Instances.

Select the instance to capture.

4.
5.

Choose Actions, Instance Settings.
Choose Get Instance Screenshot.

Right-click on the image to download and save it.

To capture a screenshot using the command line
You can use one of the following commands. The returned content is base64-encoded. For more
information about these command line interfaces, see Accessing Amazon EC2 (p. 3).
• get-console-screenshot (AWS CLI)
• GetConsoleScreenshot (Amazon EC2 Query API)

Instance Recovery When a Host Computer Fails
If there is an unrecoverable issue with the hardware of an underlying host computer, AWS may
schedule an instance stop event. You'll be notified of such an event ahead of time by email.

To recover an Amazon EBS-backed instance running on a host computer that failed
1.
2.

Back up any important data on your instance store volumes to Amazon EBS or Amazon S3.
Stop the instance.

3.
4.

Start the instance.
Restore any important data.

[EC2-Classic] If the instance had an associated Elastic IP address, you must reassociate it with
the instance.

For more information, see Stop and Start Your Instance (p. 299).

To recover an instance store-backed instance running on a host computer that failed
1.
2.
3.

Create an AMI from the instance.
Upload the image to Amazon S3.
Back up important data to Amazon EBS or Amazon S3.

4.
5.

Terminate the instance.
Launch a new instance from the AMI.

6.
7.

Restore any important data to the new instance.
[EC2-Classic] If the original instance had an associated Elastic IP address, you must associate it
with the new instance.

For more information, see Creating an Instance Store-Backed Linux AMI (p. 92).

My Instance is Booting from the Wrong
Volume
In some situations, you may find that a volume other than the volume attached to /dev/xvda or /
dev/sda has become the root volume of your instance. This can happen when you have attached

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the root volume of another instance, or a volume created from the snapshot of a root volume, to an
instance with an existing root volume.
This is due to how the initial ramdisk in Linux works. It will choose the volume defined as / in the
/etc/fstab, and in some distributions, including Amazon Linux, this is determined by the label
attached to the volume partition. Specifically, you will find that your /etc/fstab looks something like
the following:
LABEL=/ / ext4 defaults,noatime 1 1
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0

And if you were to check the label of both volumes, you would see that they both contain the / label:
[ec2-user ~]$ sudo e2label /dev/xvda1
/
[ec2-user ~]$ sudo e2label /dev/xvdf1
/

In this example, you could end up having /dev/xvdf1 become the root device that your instance
boots to after the initial ramdisk runs, instead of the /dev/xvda1 volume you had intended to boot
from. Solving this is fairly simple; you can use the same e2label command to change the label of the
attached volume that you do not want to boot from.

Note
In some cases, specifying a UUID in /etc/fstab can resolve this, however, if both volumes
come from the same snapshot, or the secondary is created from a snapshot of the primary
volume, they will share a UUID.
[ec2-user ~]$ sudo blkid
/dev/xvda1: LABEL="/" UUID=73947a77-ddbe-4dc7-bd8f-3fe0bc840778
TYPE="ext4" PARTLABEL="Linux" PARTUUID=d55925ee-72c8-41e7b514-7084e28f7334
/dev/xvdf1: LABEL="old/" UUID=73947a77-ddbe-4dc7-bd8f-3fe0bc840778
TYPE="ext4" PARTLABEL="Linux" PARTUUID=d55925ee-72c8-41e7b514-7084e28f7334

To change the label of an attached volume
1.

Use the e2label command to change the label of the volume to something other than /.
[ec2-user ~]$ sudo e2label /dev/xvdf1 old/

Verify that the volume has the new label.
[ec2-user ~]$ sudo e2label /dev/xvdf1
old/

After making this change, you should be able to reboot the instance and have the proper volume
selected by the initial ramdisk when the instance boots.

Important
If you intend to detach the volume with the new label and return it to another instance to use
as the root volume, you must perform the above procedure again and change the volume

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label back to its original value; otherwise, the other instance will not boot because the ramdisk
will be unable to find the volume with the label /.

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Making API Requests
We provide the Query API for Amazon EC2, as well as software development kits (SDK) for Amazon
Web Services (AWS) that enable you to access Amazon EC2 from your preferred programming
language.
For more information about working with the Query API for Amazon EC2, see Making API Requests in
the Amazon EC2 API Reference.

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Document History
The following table describes important additions to the Amazon EC2 documentation. We also update
the documentation frequently to address the feedback that you send us.
Current API version: 2016-04-01.
Feature
Automatic scaling for
Spot fleet

API
Version

Description

Release
Date

You can now set up scaling policies for your
Spot fleet. For more information, see Automatic
Scaling for Spot Fleet (p. 253).

1
September
2016

Run Command support
for managed instances

2016-04-01 Amazon EC2 Run Command now supports
30 June
the management of on-premises servers and
2016
virtual machines (VMs) and VMs from other cloud
providers. For more information, see Setting Up
Run Command On Managed Instances (p. 371)

Elastic Network
Adapter (ENA)

2016-04-01 You can now use ENA for enhanced networking.
For more information, see Enhanced Networking
Types (p. 608).

28 June
2016

Enhanced support for
viewing and modifying
longer IDs

2016-04-01 You can now view and modify longer ID settings
for other IAM users, IAM roles, or the root user.
For more information, see Resource IDs (p. 744).

23 June
2016

Copy encrypted
Amazon EBS
snapshots between
AWS accounts

2016-04-01 You can now copy encrypted EBS snapshots
between AWS accounts. For more information,
see Copying an Amazon EBS Snapshot (p. 688).

21 June
2016

Capture a screenshot
of an instance console

2015-10-01 You can now obtain additional information when
debugging instances that are unreachable. For
more information, see Capture a Screenshot of
an Unreachable Instance (p. 806).

24 May
2016

X1 instances

2015-10-01 Memory-optimized instances designed for
running in-memory databases, big data
processing engines, and high performance
computing (HPC) applications. For more
information, see X1 Instances (p. 187).

18 May
2016

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Feature

API
Version

Description

Two new EBS volume
types

2015-10-01 You can now create Throughput Optimized
HDD (st1) and Cold HDD (sc1) volumes. For
more information, see Amazon EBS Volume
Types (p. 638).

Release
Date
19 April
2016

Added new
NetworkPacketsIn and
NetworkPacketsOut
metrics for Amazon
EC2

Added new NetworkPacketsIn and
NetworkPacketsOut metrics for Amazon
EC2. For more information, see Instance
Metrics (p. 421).

23 March
2016

CloudWatch metrics for
Spot fleet

You can now get CloudWatch metrics for
your Spot fleet. For more information, see
CloudWatch Metrics for Spot Fleet (p. 251).

21 March
2016

Scheduled Instances

2015-10-01 Scheduled Reserved Instances (Scheduled
Instances) enable you to purchase capacity
reservations that recur on a daily, weekly, or
monthly basis, with a specified start time and
duration. For more information, see Scheduled
Reserved Instances (p. 215).

13 January
2016

Longer resource IDs

2015-10-01 We're gradually introducing longer length IDs for
some Amazon EC2 and Amazon EBS resource
types. During the opt-in period, you can enable
the longer ID format for supported resource
types. For more information, see Resource
IDs (p. 744).

13 January
2016

ClassicLink DNS
support

2015-10-01 You can enable ClassicLink DNS support for
11 January
your VPC so that DNS hostnames that are
2016
addressed between linked EC2-Classic instances
and instances in the VPC resolve to private IP
addresses and not public IP addresses. For
more information, see Enabling ClassicLink DNS
Support (p. 555).

New t2.nano instance
type

2015-10-01 T2 instances are designed to provide moderate
15
base performance and the capability to burst to
December
significantly higher performance as required by
2015
your workload. They are intended for applications
that need responsiveness, high performance for
limited periods of time, and a low cost. For more
information, see T2 Instances (p. 160).

Dedicated hosts

2015-10-01 An Amazon EC2 Dedicated host is a physical
server with instance capacity dedicated for
your use. For more information, see Dedicated
Hosts (p. 264).

23
November
2015

Spot instance duration

2015-10-01 You can now specify a duration for your Spot
instances. For more information, see Specifying
a Duration for Your Spot Instances (p. 231).

6 October
2015

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Feature

API
Version

Description

Release
Date

Spot fleet modify
request

2015-10-01 You can now modify the target capacity of your
Spot fleet request. For more information, see
Modifying a Spot Fleet Request (p. 242).

29
September
2015

Spot fleet diversified
allocation strategy

2015-04-15 You can now allocate Spot instances in multiple
Spot pools using a single Spot fleet request.
For more information, see Spot Fleet Allocation
Strategy (p. 224).

15
September
2015

Spot fleet instance
weighting

2015-04-15 You can now define the capacity units that each
instance type contributes to your application's
performance, and adjust your bid price for each
Spot pool accordingly. For more information, see
Spot Fleet Instance Weighting (p. 225).

31 August
2015

New reboot alarm
action and new IAM
role for use with alarm
actions

Added the reboot alarm action and new IAM role
for use with alarm actions. For more information,
see Create Alarms That Stop, Terminate,
Reboot, or Recover an Instance (p. 450).

23 July
2015

New t2.large
instance type

T2 instances are designed to provide moderate
16 June
base performance and the capability to burst to
2015
significantly higher performance as required by
your workload. They are intended for applications
that need responsiveness, high performance for
limited periods of time, and a low cost. For more
information, see T2 Instances (p. 160).

M4 instances

The next generation of general-purpose
instances that provide a balance of compute,
memory, and network resources. M4 instances
are powered by a custom Intel 2.4 GHz Intel®
Xeon® E5 2676v3 (Haswell) processor with
AVX2.

11 June
2015

Spot fleets

2015-04-15 You can manage a collection, or fleet, of Spot
instances instead of managing separate Spot
instance requests. For more information, see
How Spot Fleet Works (p. 224).

18 May
2015

Migrate Elastic IP
addresses to EC2Classic

2015-04-15 You can migrate an Elastic IP address that
you've allocated for use in the EC2-Classic
platform to the EC2-VPC platform. For more
information, see Migrating an Elastic IP Address
from EC2-Classic to EC2-VPC (p. 583).

15 May
2015

Importing VMs with
multiple disks as AMIs

2015-03-01 The VM Import process now supports importing
VMs with multiple disks as AMIs. For more
information, see Importing a VM as an Image
Using VM Import/Export in the VM Import/Export
User Guide .

23 April
2015

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Feature

API
Version

Description

Release
Date

New g2.8xlarge
instance type

The new g2.8xlarge instance is backed by
four high-performance NVIDIA GPUs, making it
well suited for GPU compute workloads including
large scale rendering, transcoding, machine
learning, and other server-side workloads that
require massive parallel processing power.

7 April
2015

D2 instances

Next generation Amazon EC2 dense-storage
instances that are optimized for applications
requiring sequential access to large amount
of data on direct attached instance storage.
D2 instances are designed to offer best price/
performance in the dense-storage family.
Powered by 2.4 GHz Intel® Xeon® E5 2676v3
(Haswell) processors, D2 instances improve
on HS1 instances by providing additional
compute power, more memory, and Enhanced
Networking. In addition, D2 instances are
available in four instance sizes with 6TB, 12TB,
24TB, and 48TB storage options.

24 March
2015

For more information, see D2 Instances (p. 170).
Automatic recovery for
EC2 instances

You can create an Amazon CloudWatch alarm
that monitors an Amazon EC2 instance and
automatically recovers the instance if it becomes
impaired due to an underlying hardware failure
or a problem that requires AWS involvement to
repair. A recovered instance is identical to the
original instance, including the instance ID, IP
addresses, and all instance metadata.

12 January
2015

For more information, see Recover Your
Instance (p. 310).
C4 instances

Next-generation compute-optimized instances
that provide very high CPU performance at
an economical price. C4 instances are based
on custom 2.9 GHz Intel® Xeon® E5-2666 v3
(Haswell) processors. With additional Turbo
boost, the processor clock speed in C4 instances
can reach as high as 3.5Ghz with 1 or 2 core
turbo. Expanding on the capabilities of C3
compute-optimized instances, C4 instances offer
customers the highest processor performance
among EC2 instances. These instances are
ideally suited for high-traffic web applications,
ad serving, batch processing, video encoding,
distributed analytics, high-energy physics,
genome analysis, and computational fluid
dynamics.
For more information, see C4 Instances (p. 163).

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Feature

API
Version

ClassicLink

2014-10-01 ClassicLink enables you to link your EC2Classic instance to a VPC in your account.
You can associate VPC security groups
with the EC2-Classic instance, enabling
communication between your EC2-Classic
instance and instances in your VPC using
private IP addresses. For more information, see
ClassicLink (p. 550).

Spot instance
termination notices

Description

Release
Date
7 January
2015

The best way to protect against Spot instance
5 January
interruption is to architect your application to be
2015
fault tolerant. In addition, you can take advantage
of Spot instance termination notices, which
provide a two-minute warning before Amazon
EC2 must terminate your Spot instance.
For more information, see Spot Instance
Termination Notices (p. 261).

DescribeVolumes
pagination support

2014-09-01 The DescribeVolumes API call now supports
23 October
the pagination of results with the MaxResults
2014
and NextToken parameters. For more
information, see DescribeVolumes in the Amazon
EC2 API Reference.

T2 instances

2014-06-15 T2 instances are designed to provide moderate
30 June
base performance and the capability to burst to
2014
significantly higher performance as required by
your workload. They are intended for applications
that need responsiveness, high performance for
limited periods of time, and a low cost. For more
information, see T2 Instances (p. 160).

New EC2 Service
Limits page

Amazon EBS General
Purpose SSD Volumes

Use the EC2 Service Limits page in the Amazon 19 June
EC2 console to view the current limits for
2014
resources provided by Amazon EC2 and Amazon
VPC, on a per-region basis.
2014-05-01 General Purpose SSD volumes offer costeffective storage that is ideal for a broad range
of workloads. These volumes deliver single-digit
millisecond latencies, the ability to burst to 3,000
IOPS for extended periods of time, and a base
performance of 3 IOPS/GiB. General Purpose
SSD volumes can range in size from 1 GiB to 1
TiB. For more information, see General Purpose
SSD (gp2) Volumes (p. 640).

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Feature

API
Version

Description

Release
Date

Amazon EBS
encryption

2014-05-01 Amazon EBS encryption offers seamless
encryption of EBS data volumes and snapshots,
eliminating the need to build and maintain a
secure key management infrastructure. EBS
encryption enables data at rest security by
encrypting your data using Amazon-managed
keys. The encryption occurs on the servers that
host EC2 instances, providing encryption of data
as it moves between EC2 instances and EBS
storage. For more information, see Amazon EBS
Encryption (p. 695).

21 May
2014

R3 instances

2014-02-01 Next generation memory-optimized instances
with the best price point per GiB of RAM and
high performance. These instances are ideally
suited for relational and NoSQL databases, inmemory analytics solutions, scientific computing,
and other memory-intensive applications that can
benefit from the high memory per vCPU, high
compute performance, and enhanced networking
capabilities of R3 instances.

9 April
2014

For more information about the hardware
specifications for each Amazon EC2 instance
type, see Amazon EC2 Instances.
New Amazon Linux
AMI release

Amazon Linux AMI 2014.03 is released.

27 March
2014

Amazon EC2 Usage
Reports

Amazon EC2 Usage Reports is a set of reports
that shows cost and usage data of your usage
of EC2. For more information, see Amazon EC2
Usage Reports (p. 762).

28 January
2014

Additional M3
instances

2013-10-15 The M3 instance sizes m3.medium and
m3.large are now supported. For more
information about the hardware specifications for
each Amazon EC2 instance type, see Amazon
EC2 Instances.

20 January
2014

I2 instances

2013-10-15 These instances provide very high IOPS and
support TRIM on Linux instances for better
successive SSD write performance. I2 instances
also support enhanced networking that delivers
improve inter-instance latencies, lower network
jitter, and significantly higher packet per second
(PPS) performance. For more information, see I2
Instances (p. 169).

19
December
2013

Updated M3 instances

2013-10-15 The M3 instance sizes, m3.xlarge and
m3.2xlarge now support instance store with
SSD volumes. For more information about the
hardware specifications for each Amazon EC2
instance type, see Amazon EC2 Instances.

19
December
2013

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Feature

API
Version

Description

Release
Date

Importing Linux virtual
machines

2013-10-15 The VM Import process now supports the
importation of Linux instances. For more
information, see the VM Import/Export User
Guide.

16
December
2013

Resource-level
permissions for
RunInstances

2013-10-15 You can now create policies in AWS Identity and
Access Management to control resource-level
permissions for the Amazon EC2 RunInstances
API action. For more information and example
policies, see Controlling Access to Amazon EC2
Resources (p. 498).

20
November
2013

C3 instances

2013-10-15 Compute-optimized instances that provide very
high CPU performance at an economical price.
C3 instances also support enhanced networking
that delivers improved inter-instance latencies,
lower network jitter, and significantly higher
packet per second (PPS) performance. These
instances are ideally suited for high-traffic web
applications, ad serving, batch processing, video
encoding, distributed analytics, high-energy
physics, genome analysis, and computational
fluid dynamics.

14
November
2013

For more information about the hardware
specifications for each Amazon EC2 instance
type, see Amazon EC2 Instances.
Launching an instance
from the AWS
Marketplace
G2 instances

New launch wizard

Modifying Instance
Types of Amazon EC2
Reserved Instances
New Amazon Linux
AMI release

You can now launch an instance from the AWS
Marketplace using the Amazon EC2 launch
wizard. For more information, see Launching an
AWS Marketplace Instance (p. 287).

11
November
2013

2013-10-01 These instances are ideally suited for video
creation services, 3D visualizations, streaming
graphics-intensive applications, and other
server-side workloads requiring massive parallel
processing power. For more information, see
Linux GPU Instances (p. 166).

4
November
2013

There is a new and redesigned EC2 launch
wizard. For more information, see Launching an
Instance (p. 279).

10 October
2013

2013-10-01 You can now modify the instance type of Linux
09 October
Reserved Instances within the same family (for
2013
example, M1, M2, M3, C1). For more information,
see Modifying Your Reserved Instances (p. 210).
Amazon Linux AMI 2013.09 is released.

Modifying Amazon EC2 2013-08-15 You can now modify Reserved Instances in a
Reserved Instances
region. For more information, see Modifying Your
Reserved Instances (p. 210).

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Feature

API
Version

Description

Release
Date

Assigning a public IP
address

2013-07-15 You can now assign a public IP address
when you launch an instance in a VPC. For
more information, see Assigning a Public IP
Address (p. 575).

20 August
2013

Granting resource-level
permissions

2013-06-15 Amazon EC2 supports new Amazon Resource
Names (ARNs) and condition keys. For more
information, see IAM Policies for Amazon
EC2 (p. 500).

8 July
2013

Incremental Snapshot
Copies

2013-02-01 You can now perform incremental snapshot
copies. For more information, see Copying an
Amazon EBS Snapshot (p. 688).

11 June
2013

New Tags page

There is a new Tags page in the Amazon EC2
console. For more information, see Tagging Your
Amazon EC2 Resources (p. 751).

04 April
2013

New Amazon Linux
AMI release

Amazon Linux AMI 2013.03 is released.

27 March
2013

Additional EBSoptimized instance
types

2013-02-01 The following instance types can now be
launched as EBS-optimized instances:
c1.xlarge, m2.2xlarge, m3.xlarge, and
m3.2xlarge.

19 March
2013

For more information, see Amazon EBS–
Optimized Instances (p. 692).
Copy an AMI from one
region to another

2013-02-01 You can copy an AMI from one region to another, 11 March
enabling you to launch consistent instances in
2013
more than one AWS region quickly and easily.
For more information, see Copying an
AMI (p. 135).

Launch instances into
a default VPC

2013-02-01 Your AWS account is capable of launching
11 March
instances into either the EC2-Classic or EC22013
VPC platform, or only into the EC2-VPC platform,
on a region-by-region basis. If you can launch
instances only into EC2-VPC, we create a default
VPC for you. When you launch an instance, we
launch it into your default VPC, unless you create
a nondefault VPC and specify it when you launch
the instance.
For more information, see Supported
Platforms (p. 549).

High-memory cluster
(cr1.8xlarge) instance
type

2012-12-01 Have large amounts of memory coupled with
high CPU and network performance. These
instances are well suited for in-memory analytics,
graph analysis, and scientific computing
applications.

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Feature

API
Version

High storage
(hs1.8xlarge)
instance type

2012-12-01 High storage instances provide very high storage
density and high sequential read and write
performance per instance. They are well-suited
for data warehousing, Hadoop/MapReduce, and
parallel file systems. For more information, see
HS1 Instances (p. 174).

20
December
2012

EBS snapshot copy

2012-12-01 You can use snapshot copies to create backups
of data, to create new Amazon EBS volumes, or
to create Amazon Machine Images (AMIs). For
more information, see Copying an Amazon EBS
Snapshot (p. 688).

17
December
2012

Updated EBS metrics
and status checks for
Provisioned IOPS SSD
volumes

2012-10-01 Updated the EBS metrics to include two new
metrics for Provisioned IOPS SSD volumes. For
more information, see Monitoring Volumes with
CloudWatch (p. 658). Also added new status
checks for Provisioned IOPS SSD volumes. For
more information, see Monitoring Volumes with
Status Checks (p. 661).

20
November
2012

Linux Kernels

Description

Updated AKI IDs; reorganized distribution
kernels; updated PVOps section.

Release
Date

13
November
2012

M3 instances

2012-10-01 There are new M3 extra-large and M3 doubleextra-large instance types. For more information
about the hardware specifications for each
Amazon EC2 instance type, see Amazon EC2
Instances.

31 October
2012

Spot instance request
status

2012-10-01 Spot instance request status makes it easy to
determine the state of your Spot requests.

14 October
2012

New Amazon Linux
AMI release

Amazon Linux AMI 2012.09 is released.

11 October
2012

Amazon EC2 Reserved 2012-08-15 The Reserved Instance Marketplace matches
11
Instance Marketplace
sellers who have Amazon EC2 Reserved
September
Instances that they no longer need with buyers
2012
who are looking to purchase additional capacity.
Reserved Instances bought and sold through the
Reserved Instance Marketplace work like any
other Reserved Instances, except that they can
have less than a full standard term remaining and
can be sold at different prices.
Provisioned IOPS SSD
for Amazon EBS

2012-07-20 Provisioned IOPS SSD volumes deliver
predictable, high performance for I/O intensive
workloads, such as database applications, that
rely on consistent and fast response times. For
more information, see Amazon EBS Volume
Types (p. 638).

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Feature

API
Version

Description

Release
Date

High I/O instances for
Amazon EC2

2012-06-15 High I/O instances provides very high, low
latency, disk I/O performance using SSD-based
local instance storage. For more information, see
HI1 Instances (p. 173).

18 July
2012

IAM roles on Amazon
EC2 instances

2012-06-01 IAM roles for Amazon EC2 provide:

11 June
2012

• AWS access keys for applications running on
Amazon EC2 instances.
• Automatic rotation of the AWS access keys on
the Amazon EC2 instance.
• Granular permissions for applications running
on Amazon EC2 instances that make requests
to your AWS services.
Spot instance features
that make it easier
to get started and
handle the potential of
interruption.

You can now manage your Spot instances as
follows:

7 June
2012

• Place bids for Spot instances using Auto
Scaling launch configurations, and set up a
schedule for placing bids for Spot instances.
For more information, see Launching Spot
Instances in Your Auto Scaling Group in the
Auto Scaling User Guide.
• Get notifications when instances are launched
or terminated.
• Use AWS CloudFormation templates to launch
Spot instances in a stack with AWS resources.

EC2 instance export
and timestamps for
status checks for
Amazon EC2

2012-05-01 Added support for timestamps on instance status
and system status to indicate the date and time
that a status check failed.

25 May
2012

EC2 instance export,
and timestamps in
instance and system
status checks for
Amazon VPC

2012-05-01 Added support for EC2 instance export to Citrix
Xen, Microsoft Hyper-V, and VMware vSphere.
Added support for timestamps in instance and
system status checks.

25 May
2012

Cluster Compute Eight
Extra Large instances

2012-04-01 Added support for cc2.8xlarge instances in a
VPC.

26 April
2012

AWS Marketplace
AMIs

2012-04-01 Added support for AWS Marketplace AMIs.

19 April
2012

New Linux AMI release

Amazon Linux AMI 2012.03 is released.

28 March
2012

New AKI version

We've released AKI version 1.03 and AKIs for
the AWS GovCloud (US) region.

28 March
2012

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Feature

API
Version

Medium instances,
support for 64-bit on
all AMIs, and a Javabased SSH Client

2011-12-15 Added support for a new instance type and 64bit information. Added procedures for using
the Java-based SSH client to connect to Linux
instances.

7 March
2012

Reserved Instance
pricing tiers

2011-12-15 Added a new section discussing how to take
advantage of the discount pricing that is built into
the Reserved Instance pricing tiers.

5 March
2012

Elastic Network
Interfaces (ENIs) for
EC2 instances in
Amazon Virtual Private
Cloud

2011-12-01 Added new section about elastic network
21
interfaces (ENIs) for EC2 instances in a VPC. For December
more information, see Elastic Network Interfaces 2011
(ENI) (p. 588).

New GRU Region and
AKIs

Description

Release
Date

Added information about the release of new
AKIs for the SA-East-1 Region. This release
deprecates the AKI version 1.01. AKI version
1.02 will continue to be backward compatible.

14
December
2011

New offering types for
2011-11-01 You can choose from a variety of Reserved
Amazon EC2 Reserved
Instance offerings that address your projected
Instances
use of the instance.

01
December
2011

Amazon EC2 instance
status

16
November
2011

2011-11-01 You can view additional details about the status
of your instances, including scheduled events
planned by AWS that might have an impact
on your instances. These operational activities
include instance reboots required to apply
software updates or security patches, or instance
retirements required where there are hardware
issues. For more information, see Monitoring the
Status of Your Instances (p. 411).

Amazon EC2 Cluster
Compute Instance
Type

Added support for Cluster Compute Eight Extra
Large (cc2.8xlarge) to Amazon EC2.

14
November
2011

New PDX Region and
AKIs

Added information about the release of new AKIs
for the new US-West 2 Region.

8
November
2011

Spot instances in
Amazon VPC

New Linux AMI release

2011-07-15 Added information about the support for Spot
instances in Amazon VPC. With this update,
users can launch Spot instances a virtual private
cloud (VPC). By launching Spot instances in
a VPC, users of Spot instances can enjoy the
benefits of Amazon VPC.

11 October
2011

Added information about the release of Amazon
Linux AMI 2011.09. This update removes the
beta tag from the Amazon Linux AMI, supports
the ability to lock the repositories to a specific
version, and provides for notification when
updates are available to installed packages
including security updates.

26
September
2011

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Amazon Elastic Compute Cloud
User Guide for Linux Instances

Feature

API
Version

Description

Simplified VM import
2011-07-15 The VM Import process is simplified with the
process for users of the
enhanced functionality of ImportInstance
CLI tools
and ImportVolume, which now will perform
the upload of the images into Amazon EC2
after creating the import task. In addition, with
the introduction of ResumeImport, users can
restart an incomplete upload at the point the task
stopped.

Release
Date
15
September
2011

Support for importing in
VHD file format

VM Import can now import virtual machine
24 August
image files in VHD format. The VHD file format
2011
is compatible with the Citrix Xen and Microsoft
Hyper-V virtualization platforms. With this
release, VM Import now supports RAW, VHD and
VMDK (VMware ESX-compatible) image formats.
For more information, see the VM Import/Export
User Guide.

Update to the Amazon
EC2 VM Import
Connector for VMware
vCenter

Added information about the 1.1 version of
the Amazon EC2 VM Import Connector for
VMware vCenter virtual appliance (Connector).
This update includes proxy support for Internet
access, better error handling, improved task
progress bar accuracy, and several bug fixes.

27 June
2011

Enabling Linux AMI
to run user-provided
kernels

Added information about the AKI version change
from 1.01 to 1.02. This version updates the
PVGRUB to address launch failures associated
with t1.micro Linux instances. For more
information, see User Provided Kernels (p. 149).

20 June
2011

2011-05-15 Added information about the Spot instances
Availability Zone pricing feature. In this release,
we've added new Availability Zone pricing
options as part of the information returned when
you query for Spot instance requests and Spot
price history. These additions make it easier to
determine the price required to launch a Spot
instance into a particular Availability Zone.

26 May
2011

Spot instances
Availability Zone
pricing changes

AWS Identity and
Access Management

Added information about AWS Identity and
Access Management (IAM), which enables users
to specify which Amazon EC2 actions a user
can use with Amazon EC2 resources in general.
For more information, see Controlling Access to
Amazon EC2 Resources (p. 498).

26 April
2011

Enabling Linux AMI
to run user-provided
kernels

Added information about enabling a Linux AMI
to use PVGRUB Amazon Kernel Image (AKI) to
run a user-provided kernel. For more information,
see User Provided Kernels (p. 149).

26 April
2011

822

Amazon Elastic Compute Cloud
User Guide for Linux Instances

Feature

Description

Release
Date

Dedicated instances

Launched within your Amazon Virtual Private
Cloud (Amazon VPC), Dedicated Instances are
instances that are physically isolated at the host
hardware level. Dedicated Instances let you
take advantage of Amazon VPC and the AWS
cloud, with benefits including on-demand elastic
provisioning and pay only for what you use, while
isolating your Amazon EC2 compute instances
at the hardware level. For more information, see
Using EC2 Dedicated Instances in the Amazon
VPC User Guide.

27 March
2011

Reserved Instances
updates to the AWS
Management Console

Updates to the AWS Management Console
make it easier for users to view their Reserved
Instances and purchase additional Reserved
Instances, including Dedicated Reserved
Instances. For more information, see Reserved
Instances (p. 194).

27 March
2011

New Amazon Linux
reference AMI

The new Amazon Linux reference AMI replaces
15 March
the CentOS reference AMI. Removed information 2011
about the CentOS reference AMI, including
the section named Correcting Clock Drift
for Cluster Instances on CentOS 5.4 AMI.
For more information, see AMIs for GPU
Instances (p. 167).

Metadata information

API
Version

2011-01-01 Added information about metadata to reflect
changes in the 2011-01-01 release. For more
information, see Instance Metadata and
User Data (p. 337) and Instance Metadata
Categories (p. 344).

11 March
2011

Amazon EC2 VM
Import Connector for
VMware vCenter

Added information about the Amazon EC2 VM
Import Connector for VMware vCenter virtual
appliance (Connector). The Connector is a
plug-in for VMware vCenter that integrates with
VMware vSphere Client and provides a graphical
user interface that you can use to import your
VMware virtual machines to Amazon EC2.

3 March
2011

Force volume
detachment

You can now use the AWS Management
Console to force the detachment of an Amazon
EBS volume from an instance. For more
information, see Detaching an Amazon EBS
Volume from an Instance (p. 669).

23
February
2011

Instance termination
protection

You can now use the AWS Management
Console to prevent an instance from being
terminated. For more information, see Enabling
Termination Protection for an Instance (p. 306).

23
February
2011

Correcting Clock Drift
for Cluster Instances
on CentOS 5.4 AMI

Added information about how to correct clock
drift for cluster instances running on Amazon's
CentOS 5.4 AMI.

25 January
2011

823

Amazon Elastic Compute Cloud
User Guide for Linux Instances

Feature

API
Version

VM Import

2010-11-15 Added information about VM Import, which
allows you to import a virtual machine or volume
into Amazon EC2. For more information, see the
VM Import/Export User Guide.

15
December
2010

Basic monitoring for
instances

2010-08-31 Added information about basic monitoring for
EC2 instances.

12
December
2010

Cluster GPU instances

2010-08-31 Amazon EC2 offers cluster GPU instances
(cg1.4xlarge) for high-performance computing
(HPC) applications. For more information about
the hardware specifications for each Amazon
EC2 instance type, see Amazon EC2 Instances.

14
November
2010

Filters and Tags

2010-08-31 Added information about listing, filtering, and
tagging resources. For more information, see
Listing and Filtering Your Resources (p. 748) and
Tagging Your Amazon EC2 Resources (p. 751).

19
September
2010

Idempotent Instance
Launch

2010-08-31 Added information about ensuring idempotency
when running instances. For more information,
see Ensuring Idempotency in the Amazon EC2
API Reference.

19
September
2010

Micro instances

2010-06-15 Amazon EC2 offers the t1.micro instance
type for certain types of applications. For more
information, see T1 Micro Instances (p. 175).

8
September
2010

Amazon EC2 now integrates with AWS Identity
and Access Management (IAM). For more
information, see Controlling Access to Amazon
EC2 Resources (p. 498).

2
September
2010

AWS Identity and
Access Management
for Amazon EC2

Description

Release
Date

Cluster instances

2010-06-15 Amazon EC2 offers cluster compute instances
for high-performance computing (HPC)
applications. For more information about the
hardware specifications for each Amazon EC2
instance type, see Amazon EC2 Instances.

12 July
2010

Amazon VPC IP
Address Designation

2010-06-15 Amazon VPC users can now specify the IP
address to assign an instance launched in a
VPC.

12 July
2010

Amazon CloudWatch
Monitoring for Amazon
EBS Volumes
High-memory extra
large instances

Amazon CloudWatch monitoring is now
automatically available for Amazon EBS
volumes. For more information, see Monitoring
Volumes with CloudWatch (p. 658).
2009-11-30 Amazon EC2 now supports a High-Memory
Extra Large (m2.xlarge) instance type. For more
information about the hardware specifications for
each Amazon EC2 instance type, see Amazon
EC2 Instances.

824

14 June
2010

22
February
2010

Amazon Elastic Compute Cloud
User Guide for Linux Instances

AWS Glossary
For the latest AWS terminology, see the AWS Glossary in the AWS General Reference.

825

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