Storage Concepts Student Guide

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Storage Concepts

Welcome and Introductions
 Student Introductions
• Name
• Position
• Experience
• Your expectations

Course Description

This 2 day instructor-led course provides a comprehensive introduction
to storage technology concepts, terminology and technologies of
today’s storage industry. The course examines the need for storage
solutions to manage and optimize an IT infrastructure to meet business
The course also examines the major components of a storage system,
common storage architectures and the various means of connecting
storage elements. It compares network attached storage (NAS) and
storage area network (SAN) implementations and data protection
issues. It provides detail on industry-defined tiered storage,
virtualization, and storage management strategies.

 Understanding of basic computer concepts

 Experience working with PCs or servers (Windows or UNIX)

Course Objectives
 By completing the course, you will gain an understanding of:
• Storage industry concepts and technologies
• Industry-defined tiered storage, virtualization, and storage management

Course Topics

1. Introduction to Data Management
and Storage Systems
1a.Overview of Storage Concepts
2. Storage Components and
3. Business Continuity and

4. Virtualization of Storage Systems
5. Archiving and File and Content
6. Storage System Administration

7. Business Challenges
8. Storage Networking and Security

Learning activities appear throughout
the course.

Storage Concepts
Introduction to Data Management and
Storage Systems

Module Objectives

 Upon completion of this module, you should be able to:
• Explain the different types of data
• Explain what Cloud Computing is
• Explain a storage systems’ view of data
• Distinguish between the physical and logical levels of data processing

• Understand and explain the basic concepts of data consistency and data

Module Topics
 Introduction to Data Management – Data Types

 Structured and Unstructured Data
 Data versus Information
 Data Processing Levels

 A Storage Systems View of Data
 Data Consistency and Data Integrity Concepts and Principles

Introduction to Data

Common Users: Data Examples
 Photos

 Movies
 Documents
 Email

 Personal web pages
 Data backed up to online
storage such as Microsoft Sky

 Increasingly popular cloud
systems and on-line


Business Sector Data
 Accounting, invoices, and financial records

 Databases that contain data about clients
 Email communication
 Digitalization of printed documents

 Archiving

State Institutions Data
 Databases

 Audio and video records
 Hospital records
 Confidential and classified data

 Archiving and digitalization


Data Lifecycle
 Data Lifecycle applies to all data that comes into existence
• Data Retention Period applies to certain types of data and is governed by


Structured and Unstructured Data
 Structured Data
• Databases

 Unstructured Data
• Medical Images – MRI scans

• Photographs
• Digital documents – check images
• Satellite images
• Biotechnology

• Digital video
• Email

The Changing Forms of Data
 New data types and business models compound the problem of exploding
storage. Consider the demands brought on by these new business models as
a result of the ubiquity of the Internet.

Total Digital Archive Capacity, by Content Type – Worldwide (TB)



ESG Research Report: Digital Archiving: EndUser Survey & Market Forecast 2006-2010



Unstructured Data



Question: What’s The Difference Between Data and
 Data

 Information

Data Versus Information
 Data

 Information

• A physical and written
representation of information
and knowledge
• Succession of written
characters, which can be
represented by numbers,
letters, or symbols

• Meaningful interpretation of
• Does not have to be written in

Data in binary code…

Data is stored to preserve and

pass information on

New Trends in Data
Management –
Cloud Computing

Video – What Is Cloud Computing?
YouTube video


Three Key Cloud Characteristics

“Cloud is a way of using technology, not a technology in
itself – it's a self-service, on-demand pay-per-use model.
Consolidation, virtualization and automation strategies
will be the catalysts behind cloud adoption.”
– The 451 Group

The 3 key characteristics of a cloud are:
 Self-service

 Pay-per-use
 Dynamic scale up and down

Levels of Data
Processing – Logical
And Physical

Hard Drive Partitioning (Physical Level)
 For example, a laptop running Microsoft Windows
• Installed Hard Drives — CD / DVD / memory card drives
• Each drive assigned a letter = valid address within the Operating System
 For example, hard drives have C: & D: addresses, DVD drive has
E: address

Exercise: Can You Think of Some Reasons for
Partitioning a Hard Drive?
 A user may want to encrypt a partition that will contain critical data
 Other reasons:

You can also send your answers using the CHAT

Logical Level – Volumes / File Systems
 Volume – logical interface
used by an operating system
to access data stored on a
particular media while using a
single instance of a file

 File System – the way in
which files are named,
organized, and stored on the
hard drive

Summary – File System
Stores information about where data is
physically located
Stores metadata, containing additional
Maintains data integrity and allows users to
set access restrictions and permissions
Installed on a homogenous storage area
called a volume
Applications access a file system using an
application programming interface (API)
Sets up the way files are named and

How the NTFS Works

Logical Units on a Storage System
 A storage system is partitions of logical units striped across a large
number of hard drives



Logical Devices

Logical Unit Number (LUN) Concept
 A LUN is a logical device mapped to a storage port
Logical Devices



LUNS are mapped
to servers

Some Definitions

Microcode and Firmware
 Microcode: built-in software that works on the lowest layer of
instructions, directly controlling hardware equipment
• Most basic software – no graphical user interface (GUI)
• Types:
 Microcode stored on individual hard drives

 Microcode on a storage system also containing an integrated interface,
either a command line interface (CLI) or a GUI – firmware

 Firmware: contains microcode and some kind of user interface
(menus, Icons)

Data Consistency
 Data Consistency: means you have valid, usable and readable data
• Point-in-time consistency: data is consistently as it was at any single
instant in time
 For example, synchronous (continuous) data replication
• Transaction consistency: preventing “lost” transactions

• Application consistency

Data Integrity
 Data Integrity: describes accuracy, reliability and correctness in
terms of security and authorized access to a file
• Policies: containing rules that govern access, preventing possible data
• Permissions and restrictions of access tools

Module Summary

 Upon completion of this module, you should have learned to:
• Explain the different types of data
• Explain what Cloud Computing is
• Explain a storage systems’ view of data
• Distinguish between the physical and logical levels of data processing

• Understand and explain the basic concepts of data consistency and data

Storage Concepts
Differentiate between common basic
storage architectures

Module Objectives

 Upon completion of this module, you should be able to:
• Differentiate between common basic storage architectures

Storage Architecture Connectivity



File System

Parallel SCSI
Serial SCSI (FC)

File System




File System




Direct Attach

Network Attach

Storage Area

Direct Attached Storage
 Storage is directly attached to the server
 No other device on the network can access
the stored data
 Example of DAS – A PC with an attached
external disk drive, another; A Mainframe
direct connect to SAN storage array

File System

 Best used for accessing personal data or
high speed non-shared access


Direct Attach

Network Attached Storage
 File oriented data access


 Optimized for file serving

 Easy Installation and Monitoring


 No server intervention (or layer) required for
data access
 Low Total Cost of Ownership
 Use existing Network/cabling
 Multiple protocol support (file sharing) using

 NAS Heads
 NAS Blades (New HDS-G-Series 400-800)
 NAS Filers (HDS-HNAS 3000/4000 Series)


File System

Network Attach

Network Attached Storage
Targets midsize customers and remote, branch
offices of large organizations
Ideal for customers with a collaborative
environment that requires sharing of files
such as project management teams, law
offices, and design firms

File serving
Software development
Rich media
Publishing and broadcast
Near-line Data Storage to meet regulatory




Introduction to SAN
 Storage Area Network

Is a separate network that includes computer servers, disks, and other storage


Allows networking concepts to be applied to a server/storage model


Has its own connections rather than using a fixed backbone network


Has connections that utilize Fibre Channel equipment


Allows very fast access among servers and storage resources


Enables many servers to share many storage devices


Designed for very high speed shared data storage up to 16 million nodes

Storage Area Network
 Designed to attach computer storage devices
such as disk array controllers and tape libraries
to servers

 Primary purpose is the transfer of data between
computer systems and storage elements
(switches/ directors [large switches])
 Consists of a communication infrastructure and
a management layer so that data transfer is
and robust




 SAN and NAS can co-exist on the same network
 Complicated (relatively) and expensive to


Storage Area Network
 Best suited for complex data centers that
require high availability, scalability, reliability,
and performance
• Storage hosting providers


• International organizations that have multiple
data centers
• Businesses that implement Service Level
Agreements (SLAs)
• Disaster Recovery and, or Business Continuity



 Direct Attached Storage (DAS) – Storage is directly attached to
the application or file server
• Only one computer can access the storage
• A PC with an externally-attached hard disk drive

 Network Attached Storage (NAS) – Multiple computers can
access and share the storage devices
• Accessed over an IP network
• Ideal for collaborative file sharing

 Storage Area Networks (SAN) – Designed to attach computer
storage devices to servers
• Complex communication infrastructure organizes the connections,
storage elements, and computer systems so that data transfer is
secure and robust
• Best suited for:
 Storage hosting providers
 International organizations that have multiple data centers
 Anyone with need for high speed shared data access

Storage Concepts
Storage Components and Technologies

Module Objectives

 Upon completion of this module, you should be able to:
• Identify and describe the major components of a storage system
• Explain the different RAID levels and configurations
• Describe the midrange storage system architecture and its components
• Explain the factors directly influencing the performance of a storage
• Understand and explain the differences between a midrange and an
enterprise storage system

Module Topics
 How a hard drive works

 What means of hardware redundancy we have
 How to describe a midrange storage system architecture and

Module Flow

Hard Drive
and how it

Hard drive



Overview of Disk
Array Components

Disk Drive Components and Connectivity
 A hard disk drive (HDD) is a nonvolatile storage device that stores
data on a magnetic disk.
 Key components of a disk drive:

Disk Drive Components and Connectivity
 Spindle – A spindle holds one or more platters. It is connected to a
motor that spins the platters at constant revolutions per minute
 Platter – A platter is the disk that stores the magnetic patterns. It is
made from a nonmagnetic material, usually glass, aluminum, or
ceramic, and has a thin coating of magnetic material on both sides.

 A platter can spin at a speed of 7,200 to 18,000 RPM. The cost of an
HDD increases for a higher speed.

Disk Drive Components and Connectivity
 Head – The read-write head of an HDD reads data from and writes
data to the platters. It detects (when reading) and modifies (when
writing) the magnetization of the material immediately underneath it.
Information is written to the platter as it rotates at high speed past the
selected head.

 There is one head for each magnetic platter surface on the spindle;
these are mounted on a common actuator arm.
 Actuator – An actuator arm moves the heads in an arc across the
spinning platters, allowing each head to access the entire data area,
similar to the action of the pick-up arm of a record player.

Disk Drive Components and Connectivity
 The performance of an HDD is measured using the following
• Capacity – The number of bytes an HDD can store. The current
maximum capacity of an HDD is 4TB.
• Data transfer rate – The amount of digital data that can be moved to or
from the disk within a given time. It is dependent on the performance of
the HDD assembly and the bandwidth of the data path.
 The average data transfer rate ranges between 50-300 MB per
• Seek time – The time the HDD takes to locate a particular piece of data.
The average seek time ranges from 3 to 9 milliseconds.

Disk Drive Components and Connectivity
 Transfer Rates – Performance


HDD Connectivity

Disk Drive Components and Connectivity
 Bus Cables connect the storage central
processing unit (CPU) to the HDD

 Interface is a device that enables the
connection of electrical circuits together.
 Interfaces use the following standards:
• Parallel advanced technology attachment
• Serial advanced technology attachment
• Small computer systems interface

• Serial attached SCSI (SAS)

Disk Drive Components and Connectivity

PATA is a standard used to connect HDDs to computers, based on
parallel signaling technology. PATA cables are bulky and can be a
maximum of 18 inches long, so they can be used only in internal

Disk Drive Components and Connectivity

SATA evolved from PATA. It uses serial signaling technology. SATA is
a standard used to control and transfer data from a server or storage
appliance to a client application. Compared to PATA, SATA has the
following advantages:
• Greater bandwidth
• Faster data transfer rates – up to 600GB/sec

• Easy to set up and route in smaller computers
• Low power consumption
• Hot-swap support

SATA does not perform as well as SAS

Disk Drive Components and Connectivity
A parallel interface standard used to transfer data between
devices on both internal and external computer buses.

 SCSI advantages over PATA and SATA:
• Faster data speeds
• Multiple devices can connect to a single port
• Device independence; can be used with most SCSI compatible hardware

 SCSI has the following disadvantages:
• SCSI interfaces do not always conform to industry standards.
• SCSI is more expensive than PATA and SATA.

Disk Drive Components and Connectivity
 Serial Attached SCSI (SAS)
Serial Attached SCSI has evolved from the previous SCSI standards
as it uses serial signaling technology. SAS is a standard used to
control and transfer data with SCSI commands from a server or
storage appliance to a client application.
 SAS advantages over SCSI:
• Greater bandwidth

• Faster data transfer rates
• Easy set up and routing in smaller computers
• Low power

 SAS cables are similar to SATA cables.

Redundant Array of
Independent Drives

 Redundant Array of Inexpensive/Independent Drives (RAID) – A
method of storing data on multiple disks by combining various
physical disks into a single logical unit. A logical disk is a
combination of physical disks
 RAID provides the following advantages:
 Data consistency and integrity (security, protection from corruption)
 Fault tolerance
 Capacity
 Reliability

 Better Speed

 Different types of RAID can be implemented, according to application

 The different types of RAID implementation are known as RAID
 Common RAID levels:
• RAID-0

• RAID-1
• RAID-1+ 0
• RAID-5
• RAID-6

RAID-0 (Data Striping)
 RAID-0
• RAID-0 implements striping; data is
spread evenly across two or more

 RAID-0 Benefits:
• Easy to implement
• Increased performance in terms of
data access (more disks equals
more heads, which enables parallel
access to more data records)

 RAID-0 Disadvantage:

This RAID level has no redundancy
and no fault tolerance. If any disk
fails, data on the remaining disks
cannot be retrieved, which is the
major disadvantage.

RAID-0 uses only data striping.

RAID-1 (Data Mirroring)
 RAID-1
• Implements mirroring to create exact
copies of the data on two or more

 RAID-1 Advantages:
• Reduces the overhead of managing
multiple disks and tracking the data.
• Read time is fast because the system
can read from either disk.
• If a disk fails, RAID-1 ensures there is
an exact copy of the data on the
second disk.

 RAID-1 Disadvantages:
• The storage capacity is only half of
the actual capacity as data is written
• RAID-1 is expensive; doubles the

 RAID-1+
• RAID-1+0 is an example of multiple or nested RAID levels.
• A nested RAID level combines the features of multiple RAID levels. The
sequence in which they are implemented determines the naming of the
nested RAID level.
• For example, if RAID-0 is implemented before RAID-1, the RAID level is
called RAID-0+1. RAID-1+0 combines the features of RAID-0 and RAID-1
by mirroring a striped array.

 RAID-1+ has the following advantages:
• Easy to implement
• Fast read/write speed
• Data protection

 RAID-1+ has the disadvantage of high cost to implement.


 RAID-5
• RAID-5 consists of a minimum of three disks (two data and one parity)
• RAID-5 distributes parity information across all disks to minimize potential
bottlenecks if one disk fails, in which case parity data from the other disks
is used to recreate the missing information.

 RAID-5 has the following advantages:
• The most common and secure RAID level
• Fast read speed

• Ensures data recovery if a disk failure occurs

 RAID-5 has the following disadvantages:
• Extra overhead required to calculate and track parity data

• Slower writes because it has to calculate parity before writing data


 RAID-6
• RAID-6 is similar to RAID-5 with an additional parity disk
• In RAID-5, if a second disk fails before the first failed disk has been
rebuilt, data can be irretrievably lost. The additional parity drive in RAID-6
provides a solution to this problem.

 RAID-6 is designed for large environments and offers the following
• Provides protection against double-disk failure

• Has a fast read speed

 RAID-6 has the following disadvantages:
• Similar to RAID-5 plus the cost of the extra parity disk

• Slight performance overhead


RAID Type Configuration and Usage

Spare Disks — Sparing
 Correction Copy – Occurs when a drive in a RAID group fails and a
compatible spare drive exists. Data is then reconstructed on the
spare drive.

Spare Disks — Sparing
 Dynamic Sparing – occurs if the online verification process (built-in
diagnostic) determines that the number of errors has exceeded the
specified threshold of a disk in a RAID group. Data is then moved to
the spare disk, which is a much faster process than data

Correction Copy Parameters
 Copy Back

 No Copy Back

Exercise: RAID Configuration Options
 Considering the following data storage needs, which RAID options would
provide the best performance?

Online transactional database (banking, stock market)
where performance and reliability is key


Search engine, or catalog system for a library


Overnight billing and inventory system

If vILT class, write your answers on blank lines

Building a Midrange
Storage System –

Expansion Unit / Disk Enclosure

A typical expansion unit or disk enclosure (based on SAS architecture),
consists of following components:
• Individual hard drives (SSD, SAS, SATA)
• Expander (buses and wires for connecting drives together)
• Power supplies

• Cooling systems (fans)
• Chassis

Expansion Unit Connectivity
Each expansion unit is connected to both controllers

Back-End Architecture – Midrange Storage System

A midrange storage system contains main controller boards that are
equipped with components that can be put into three categories:
• Front end (connection to hosts or other storage systems)
• Cache (works as a buffer, has major influence on performance)
• Back end (connections to hard drive enclosures, RAID operations)

Back-End SAS Architecture Example


Cache is a temporary storage area for frequently used data. A
system can access the cached copy instead of the data in the
original location. This reduces the time taken to access data.

Cache Operations
The storage system’s microcode contains
algorithms that should anticipate what data is
advantageous to keep (for faster read access)
and what data should be erased. There are two
basic algorithms that affect the way cache is
freed up:



Least Recently Used (LRU) — Data that is
stored in cache and has not been accessed for
a given period of time (i.e., data that is not
accessed frequently enough) is erased.
Most Recently Used (MRU) — Data accessed
most recently is erased. This is based on the
assumption that recently used data may not be
requested for a while.


Cache Data Protection
 Cache Mirroring

Controller 0

Controller 1

x GB Cache

x GB Cache

x GB
Controller 0

x GB
Controller 0

Read/Write Cache

Mirrored Write Cache

x GB
Controller 1
Mirrored Write Cache

x GB
Controller 1
Read/Write Cache

Front-End Architecture
 Interface Board – Ports connecting storage system to servers

 Protocols
• Fibre Channel (FC) – Defines a multi-layered architecture for moving
data; allows data transmission over twisted pair and over fiber optic

• Fibre Channel over Ethernet (FCoE) – Encapsulation of Fibre Channel
frames over Ethernet networks
• iSCSI – Interface connecting storage system to the LAN; allows
organizations to utilize their existing TCP/IP network infrastructure without
investing in expensive Fibre Channel switches

Front-End Architecture – Other Components

In the frontend, we have QE8 FC port controllers that are part of the interface board.
These controllers are mainly responsible for conversion of FC transfer protocol into
PCIe bus used for internal interconnection of all components.. Notice the CPU and
local RAM memory (not cache).

Active-Passive Architecture

In the event of a path failure, LUN ownership does not change. Data is
transferred via the backup path to CTL1 and then internally to CTL0,
bypassing CTL0 front end ports. This diminishes performance because
of internal communication.

Symmetric Active-Active Controllers

Multiple paths to a single LUN
are possible. LUN ownership
automatically changes in the
event of path failure.
Unlike active-passive
architecture, active-active
architecture offers equal
access to the particular LUN
via both paths. This means the
performance is not influenced
by what path is currently used.

Controller Load Balancing – Active-active Architecture

No need to configure LUN ownership manually. Communication goes
either via CTL0 or CTL1. In the event of path failure, no bypassing is
necessary; therefore there is no communication overhead.

Fibre Channel Ports and their Configuration
Host connected to a Target port

Storage connected to an
External port for virtualization

Storage systems
connected via an
Initiator port for

iSCSI Interface



Mixed SAN showing Fibre
Channel SAN connection for
production servers and an
iSCSI LAN for the
Test/Development servers

Module Summary

 Upon completion of this module, you should have learned to:
• Identify and describe the major components of a storage system
• Explain the different RAID levels and configurations
• Describe the midrange storage system architecture and its components
• Explain the factors directly influencing the performance of a storage
• Understand and explain the differences between a midrange and an
enterprise storage system

Storage Concepts
Business Continuity and Replication

Module Objectives

 Upon completion of this module, you should be able to:
• Describe basic concepts of business continuity and replication
• Understand business impact analysis and risk assessment
• Describe basic concepts of disaster recovery

Module Topics
 Business Continuity concepts

 Business Impact Analysis and Risk Assessment
 Back-up strategies and their implementation
 How Business Continuity and Disaster Recovery connect to IT

 Replication options
 Concepts of clusters and geoclusters

Business Continuity

Exercise: Data Center Disaster
 Tornado destroys ABC
Corporation’s data center
• What needs to be prepared
ahead of time?
Set up a Business Continuity team

• Impacts on the business?

Write your answers on blank lines or send your answers via the CHAT

Exercise: Data Center Disaster
 Tornado destroys ABC
Corporation’s data center
• What needs to be prepared
ahead of time?
Set up a Business Continuity team
A Disaster Recovery Plan
Another data center location
Suppliers ready to replace damaged equipment

Employees trained in responding to these situations
Staff in place at the alternate site to take over
Failback to main data center

• Impacts on the business?
Financial loss

Damaged reputation and company image

Business Continuity Management: Regulatory
 Identifies critical business processes and establishes rules and
• Implementation governed by regulations and standards
Sarbanes Oxley –
Corporate reporting
and financial results;
tells CEO and CFO
that they must be able
to defend accuracy of
their books

Basel II –
International banking
regulation that deals
with amortizing cost of
risk into financial

British Standard For
Business Continuity
(BS25999) – guidance
for determining
business processes
and their importance

North American
Standard –

Business Continuity Planning
 The implementation of business continuity concepts with respect to
the particular organization. The planning normally includes:
• Business Impact Analysis: Identifies which business processes, users
and applications are critical to the survival of the business
• Risk Assessment : Determines probability of threats to an organization
• Policies: Aligns BC policies with the company’s business strategy
• Business Recovery Plan: Defines procedures to be taken when a
particular situation occurs
• Disaster Recovery Plan: Describes how to get the critical applications
working again after an incident takes place

• Testing and Training Schedules: Provides a timeline for business
continuity plan testing

Business Impact Analysis – RPO and RTO
 Recovery Point Objective (RPO) – Worst case time between last
backup and interruption time
• Represents how much data must be recovered
• How much can you afford to lose?

 Recovery Time Objective (RTO) – How long is the customer willing
to live with downed systems?
• Represents outage duration

Business Continuity versus Disaster Recovery
Disaster Recovery – Part of business continuity that focuses only on IT
Disaster Recovery Plan contains:
 Basic information – purpose, area of application, requirements, log of
DR plan modifications, members of DR team, their roles and
 Notification/activation phase – notification procedure, call tree,
damage assessment, activation criteria, plan activation

 Recovery procedures – succession of recovery procedures according
to their importance, logging, escalation
 Standard operation resumption – checking whether all systems work
properly, termination of DR plan
 Amendments – call book, vendor SLA, RTO of processes

Data Backup and
Data Replication

Exercise: Data Backup and Data Replication
 Is data backup different from data replication?
Backup =

Replication =

Write your answers on blank lines or send your answers via the CHAT

Example: Data Backup Configuration

Back-up over
LAN is the
simplest solution.
The back-up
server pulls data
from production
servers and then
it sends data to a
tape library or
NAS device.

Data Backup Models
 Full Backup: Data is stored in
exact copies
 Incremental Backup: Only the
data that was changed or added
since last time backup is
 Differential Backup: Only the
data that differs from the initial
full backup is recorded
 Reverse Delta Backup: At
every scheduled backup, the
initial full backup image is
synchronized so that it mirrors
the current state of data on

Backup Requirements
To back-up the data from production servers you need:
 A back-up device – in enterprise environment it will most probably be a
tape library, but it can also be a storage system with a LUN dedicated for
 A back-up server – in most cases you need a back-up server that is
communicating directly with the back-up device and that controls back-up
from all the servers
 Back-up software – software that runs on a back-up server and that
allows to make configuration according to your needs
 Back-up agents – these agents are small applications installed on all
your production servers. They are part of back-up software and they
allow communication between a back-up server and production servers.

Backup Optimization
Techniques used to achieve better backup utilization:
 Compression – the output archive file is smaller than total of the
original files
 Deduplication – the technique that eliminates duplicities in data
 Multiplexing – the ability of software and equipment to back-up data
from several sources simultaneously
 Staging – back up to a disk first and then transfer the data from this
disk to tape – known as Disk-to-disk-to-tape (D2D2T)

Data Replication Overview
 A volume with source data is called a Primary Volume (P-VOL), and
a volume to which the data is copied is a Secondary Volume (S-VOL).
 In-system – all operations with logical units (LUs) within the same
storage system
 Remote – all operations with LUs across different storage systems



Data Replication Overview

Data Replication
Within and between array heterogeneous replication

 Data replication (or protection) provides operational and disaster recovery
• Replicates data within or between storage systems without disruption
• Creates multiple protected copies from each source volume
• Can run independent of host OS, database, file system
• Mirrors image of data
• Offers quick restart and recovery in disaster situations

 Once created, copies can be used for:
• Data warehousing or data mining applications
• Backup and recovery

• Application development

Exercise: Data Backup Or Data Replication?
 In the event of a major disaster, would you use your backup solution
or data replication solution to recover your business critical online
• Break up into teams, discuss, and present your reasons for choosing one
of the solutions over the other.

If a vILT class, present your answers over the phone

Data Replication – Copy Operations

 Data copy operations:
• Initial Copy
 All data is copied from
 Copies everything
including empty blocks
• Update Copy
 Only differentials are

Requirements for All Replication Products
 Any volumes involved in replication operations (source and
destination) should be:
• Same size (in blocks)
• Must be mapped to a port
 Source can be online and in use.

 Destination must not be in use/mounted.

 Intermix of RAID levels and drive type is supported.
 Licensing
• License is capacity independent.

Data Replication Operations – Establish Pairs

Primary Server

Backup Server

Create Pair
Status change: SIMPLEX to COPY to PAIR


S-VOLs are inaccessible
after the paircreate
command is issued.


Data Replication Operations – Split Pairs

Primary Server

Backup Server

Status change: PAIR to PSUS
Updates are
marked in

Backup S-VOL
backup data
to tape


S-VOL now accessible.
Updates are marked in
S-VOL differential bitmaps

Data Replication Operations – Resynchronizing Pairs

Primary Server

Backup Server




Caution: Any changes applied
to S-VOL while the pair is split
are discarded during NORMAL

Normal Resync
Reverse Resync
Status: PSUS to PAIR

Data Replication Operations – Quick Restore

Primary Server

Backup Server

Quick Restore Pair
Swaps LDEV Mapping
Status: Split to PAIR with copy direction reversed




Quick Restore


In-System Replication
 In-system hardware-based copy facility that
• Full volume point-in-time copies
• Host Independent

Storage System

• Nondisruptive replication
• Clone images are RAID protected copies

Production Data

LU # 1


Clone Image

LU # 2

In-System Replication: Copy-On-Write Snapshots
 Snapshots
• Create a point-in-time
(PiT) copy or “snapshot”
of the data
• Uses less space than full
copies or clones
Frequent, cost effective,
point-in-time copies
• Multiple copies of a
primary volume
• Immediate read/write
access to virtual copy

• Fast restore from any
virtual copy

Copy on write snapshot. Notice that both P-VOL and V-VOL are
accessible for I/O operations. Snapshots can be created instantly

In-System Replication: Copy-On-Write Snapshots

 Copy-on Write virtual volume (V-VOL) maintains a view of the primary volume
(P-VOL) at a particular point in time

 V-VOL is a composite of original data in the P-VOL and change data in the pool
 V-VOL presents as a full volume copy to any secondary host
 Since V-VOL does not copy all data, it can be created or deleted almost instantly

Remote Replication

Remote Replication Scheme

Remote replication scheme; DWDM, ATM or IP
connections to remote site are possible.
Primary Host

Any Distance





Synchronous Remote Replication

 The remote I/O is not posted “complete” to the
application until it is written to a remote
 The remote copy is always a “mirror” image
 Provides fast recovery with no data loss
 Limited distance – response-time impact




Synchronous Replication

Provides a remote “mirror” of any customer data

• The remote copy is always identical to the local copy
• Allows very fast restart/recovery with no data loss
• No dependence on host operating system, database,
or file system
• Distance limit is variable, but typically less than 100

• Impacts application response time
• Distance depends on application read/write activity,
network bandwidth, response-time tolerance and
other factors

Asynchronous Remote Replication
• The local I/O is disconnected from the
remote I/O

• Very little impact to response time over
any distance

• Data integrity and update sequence
maintained over any distance

• Fast restart/recovery








Dynamic Replication

Dynamic Replication Appliance
A possible implementation of a Replication Appliance. Data is collected
from servers over LAN and then it is send to a storage system. Each
server is running an agent that splits the data.

Remote Replication and Geoclusters
interconnection scheme.
Both sites (local and
remote) are equipped
with the same nodes.
Data from the Disk Array
A are synchronously
replicated to Disk Array B
over iFCP, FCIP or Dark
Fiber technology, both
SANs are interconnected.
Servers in both locations
are also interconnected,
usually using TCP/IP

Three Data Center Multi-target Replication

Three data center multi-target replication. The maximum possible data
protection is ensured by using two remote sites for data replication.

Diversity in Data Protection Requirements

Solution Area of Cost, Performance and Distance

Exercise: Replication Scenario
 Scenario:
• Financial services business with two data centers 300 miles apart

 Your task:
• Describe a disaster recovery strategy for this business using data replication.

If a vILT class, use your drawing tools to show your configuration on the slide

Module Summary

 Upon completion of this module, you should have learned to:
• Describe basic concepts of business continuity and replication
• Understand business impact analysis and risk assessment
• Describe basic concepts of disaster recovery

Storage Concepts
Virtualization of Storage Systems

Module Objectives

 Upon completion of this module, you should be able to:
• Understand and explain virtualization concepts and its benefits
• Explain the difference between fat and thin provisioning
• Describe SAN virtualization concepts

Module Topics
 Virtualization concepts, features, and benefits

 Different types of virtualization
 “Fat” and “Thin” provisioning concepts and features


What Is Virtualization?
 Definition (source:
• Virtualization is the abstraction of computer resources.
• Hides the physical characteristics of computing resources from the way in
which other systems, applications, or end users interact with those
• Single physical resources appear to function as multiple logical
resources, or multiple physical resources appear as a single logical

 Virtualization has moved “out of the box” and into the infrastructure,
or cloud, and virtualization solutions are available at these layers:
• Virtualization of applications
• Virtualization of computers
• Virtualization of networks
• Virtualization of storage

Server Virtualization

The traditional architecture model requires one physical server
per operating system and application. A virtualized server is
able to run several virtual machines that all share the physical


Elements of Virtualization
 Virtualization Areas

Server Virtualization
 Server virtualization is increasingly used; it provides better utilization
of server resources
 One-to-many virtualization – Makes one physical server look like
many servers; allows multiple operating systems on one physical

Layers of Virtualization

 Users can access the application
from s a virtual desktop.
 Applications can run on several
virtual machines
 The server can be virtualized
 The host can access a virtualized

VMware® Based Server Virtualization

Hyper-V™ Based Server Virtualization
The hypervisor virtualization layer is thin and optimized for direct access to
hardware resources. Virtual machines in child partitions access the virtualization
layer through the VMBus interface. Device drivers for virtual machines are loaded
from the parent partition with the original instance of Windows 2008 Server.
Virtual machine configuration and management are also done in the parent
partition operating system.

Virtualization with Blade Servers

Blade servers are
installed in a blade
server chassis. The
chassis is then placed in
a standard rack. These
blade servers offer
logical partitioning,
which is a highly
sophisticated form of
server virtualization.

Storage System Virtualization

Every storage system offers RAID functionality but additionally
may offer other virtualization capabilities such as:
 Cache Partitions
 Virtual Ports
 Storage virtualization (of other storage systems)
 Thin provisioning and automatic tiering

Virtualization Benefits
Migration – VMs and LUNs
can be easily transferred from
one physical device to another.
Backup – encapsulation
simplifies backup of the VM
Hardware platform
independence – physical
servers can be of different
Enhanced utilization – allows
effective use of resources
Lower power consumption
Lower RPO and RTO

Physical resources can be
added without disruption


Virtualized Server Cluster


Virtualization – Thin
Provisioning and
Automated Tiering

Comparison of Fat and Thin Provisioning
 To avoid future service interruptions, today it is common to overallocate storage by approximately 50% - 75%.


Actual DATA

Thin Provisioning

Parity groups are
added to a thin
provisioning pool.
Virtual volumes
are mapped to
servers. Virtual
volumes do not
contain any actual
data. Data is stored
in the storage pool.
Virtual volumes
contain pointers that
point to the location
of data in the pool.

Thin Provisioning Benefits

• Increased physical disk striping for better performance
• Reduces the need for performance expertise

• Simplifies storage capacity planning and administration
• Increases storage utilization
• Eliminates downtime for application storage capacity
• Improves application uptime and SLAs

Zero Page Reclaim

The storage system scans the storage pool for used data
blocks that contain only zeros. These blocks are then erased
and freed automatically.

Thin Provisioning

An example of how thin provisioning can help you save the
cost of buying all the capacity in advance.

Exercise: Virtualization
1. Definition of Virtualization
• Virtualization is the ____________ of computer resources.
• Hides the __________________ of computing resources from the way in
which other systems, applications, or end users interact with those resources.
• Single physical resources appear to function as ____________________ .
• Or multiple physical resources appear as _____________________.

2. Identify some of the common objects that can be virtualized:
• ___________________________
• ___________________________

If a vILT class, write your answers on blank lines

Virtualization in
Storage System

Virtualization in Storage System Controller

Controller based virtualization of external storage. Hitachi
Virtual Storage Platform (VSP) is an example of an
enterprise-level storage system that supports virtualization
of external storage.

virtualization the
data center
consists of
storage systems
in a SAN.

Virtualization in Storage System Controller

After virtualization the VSP storage system provides access to
virtualized volumes from the other storage systems

Virtualization –
Logical Partitioning

Storage Virtualization – Logical Partitioning

In this figure we see one
storage system (VSP) with
three external storage
systems that create a
virtualized storage pool. The
VSP is then virtualized to
Partition 1
provide two logical partitions
— private virtual storage
machines. Hosts are then
able to access and use only
the resources (cache, ports
and disks) assigned to the
respective partition.


Exercise: Benefits
 From your point of view, what do you think are the benefits of partitioning

If a vILT class, send your answers via the CHAT
or over the phone

Dynamic (Automated) Tiering

All the benefits of
Dynamic Provisioning
Dynamic Tiering





Further simplified
Further reduced
Better Performance

Dynamic Tiering in Hitachi Virtual Storage Platform

The Future of Virtualization

Storage systems are heading towards fully virtualized

Market Adoption Cycles

Direct Attached


Cloud or Virtualized

Cloud Storage

“Cloud is a way of using technology, not a technology in

itself – it is a self-service, on-demand pay-per-use
model. Consolidation, virtualization and automation
strategies will be the catalysts behind cloud adoption.”
– The 451 Group

Key characteristics of the cloud are:
The ability to scale and provision dynamically in a cost
efficient way
The ability to make the most of new and existing
infrastructure without having to manage the complexity of
the underlying technology
Cloud architecture can be:

• Private: Hosted within an organization’s firewall
• Public: Hosted on the internet
• Hybrid: A combination of private and public

Module Summary

 Upon completion of this module, you should have learned to :
• Understand and explain virtualization concepts and its benefits
• Explain the difference between fat and thin provisioning
• Describe SAN virtualization concepts

Storage Concepts
Archiving and File and Content

Module Objectives

 Upon completion of this module, you should be able to:
• Explain the basic concepts and features of archiving
• Describe what is meant by Fixed Content
• Understand the differences between archiving and backup

Module Topics
 Fixed Content and its characteristics

 Components of a digital archive
 Content management

Introduction to

Fixed Content

What is Fixed Content?
• Data objects that have a long-term value, do not change over
time, and are easily accessible and secure

Legal Records
Satellite Images

Digital Video
Medical Records

Motivation for Data Archiving

There are several reasons for implementing data archiving
policies and technical solutions. Some of the most
prominent reasons are:

Effective utilization of high performance tiers
Cheaper storage for fixed content
Data retention regulation
Simplified content management
Indexing and searching capabilities of a digital archive

Archive Solutions?

Seeking an archiving solution. The storage systems we have discussed
up until now are not very suitable for fixed content storage and archiving.

Legal Requirements of Data Retention Periods
Many organizations have increasing regulations, especially in the
pharmaceutical industry, the food processing industry, healthcare, financial
services and auditing. The Sarbanes-Oxley Act very strictly regulates the
length of retention of financial records and accounting in companies.

The Need for a Better Archiving Solution
An example of a decentralized and fragmented archiving solution.
Disparate storage systems do not provide a common search engine,
and they are not very scalable. A digital archive can solve this problem.

A Digital Archive

A digital archive works on the object level. Each object
contains fixed content data, metadata and description of

Block Level Storage Compared to Object Level Storage

A traditional block level storage system compared to an
object level storage system. The object level storage system
consists of powerful proprietary servers and management
software. These servers are connected to a RAID array.

Internal Object Representation

A data object and its components in detail. This example
illustrates how objects are handled by a object storage’s
digital archive.

Digital Archive Features

Active functions of a digital archive are:

• Content verification – Ensures authenticity and integrity of
each data object
• Protection service – Ensures stability of the digital archive
• Compression service – Achieves better utilization of
storage space assigned to the digital archive
• Deduplication service – Detects and removes duplicities
• Replication service – Ensures redundancy of archived
• Search capabilities – Allows users to search documents

Digital Archive Accessibility

In this example, a digital archive can be accessed using
multiple independent standard protocols. WebDAV is an
extension to HTTP protocol that allows remote management
of files stored on web server

Digital Archive Compliance Features

The most important compliance features of a digital archive
 Write once read many (WORM)
 Retention period definition

 Data shredding
 Data encryption

Exercise: Fixed Content

Which 2 statements are true about the definition of fixed content?
(Choose 2)
Fixed content is …
a. Content that cannot be archived and restored
b. Content that can only be changed by the system administrator

c. Static data that is in a final state
d. Content that will not / cannot change


If vILT class, write your answers on blank lines,

Exercise: Backup versus Archive

Explain the differences between what is meant by Backup and Archive.

If vILT class, Send your answers to the instructor
via the WebEx CHAT tool or phone.

Exercise: Object Representation
Fixed-content data (Data)

1. Describe what each is.

System metadata

2. What does an object contain?

Send your answers using CHAT
Custom metadata

If vILT class, write your answers on blank lines

Module Summary

 Upon completion of this module, you should have learned to:
• Explain the basic concepts and features of archiving
• Describe what is meant by Fixed Content
• Understand the differences between archiving and backup

Storage Concepts
Storage System Administration

Module Objectives

 Upon completion of this module, you should be able to:
• Describe everyday storage administrator tasks
• Explain how to configure and monitor storage systems
• Describe tools used by the storage administrator in managing storage

Module Topics
 Storage system administrator tasks and common functions

 Storage system management software
 Storage system implementer tasks


Who is a Storage System Administrator?
 In charge of maintaining a storage system infrastructure
• Tasks based on Service-level Agreements (SLAs)

Storage Administrator Tasks
 Capacity Management
Amount of data to be stored; size
and performance of LUNs; hard drive
performance; I/O performance and
R/W operations

 Availability Management
Replication, backup, and archive
strategies; protection against
component failures

 Continuity Management
Part of business continuity planning
and disaster recovery procedures

 Financial Management
Budget preparation; cost calculation
and invoicing and TCO

Storage Administrator Tasks – Other Common

 Configuration of RAID
groups and volumes
 Implementation of
changes in volume
 Data replication
 Configuration of cache
 Cache partitioning
 Backup of storage system

Integration of a New Storage System
When purchasing a new storage
system, the storage administrator
must think through the whole
implementation process, including
the following items:
 Storage system model
 Switch model
 Cabling
 Rack usage and floor space
 Power requirements
 Air conditioning
 LAN infrastructure

Tasks of a Storage System Implementer
 Installation and initial configuration of the storage system

 Basic training to familiarize the customer with the new
 Conduct all hardware replacement and upgrade
 Monitor the storage system remotely
 Help with performance tuning
 Microcode updates

Module Summary

 Upon completion of this module, you should have learned to:
• Describe everyday storage administrator tasks
• Explain how to configure and monitor storage systems
• Describe tools used by the storage administrator in managing storage

Storage Concepts
Business Challenges

Module Objectives

 Upon completion of this module, you should be able to:
• Identify business challenges driving the need for storage
• Understand why storage systems are important for business
• Explain the energy and green issues faced by today’s businesses

Module Topics
 Business challenges companies face

 Advanced data classification and tiered storage
 Data center operations environmental concerns


Business Challenges
Business challenges can be classified as follows:
 Accelerating storage growth — need more and more capacity
 Increasing requirements on high availability — cannot afford any
disruptions because our data has become too important for our business
 Fast and effective response to business growth — need to be able to
react quickly to new conditions
 Heterogeneous infrastructure — result of fast infrastructure growth,
which was not properly planned, causing TCO to increase rapidly
 Compliance and security challenges — need to process, protect and
retain data according to legal requirements and regulations
 Power and cooling challenges — pay too much for electricity and
cooling and may be running out of space in the server room
 Data center challenges — specific needs for those whose business is
focused primarily on cloud type provision of storage and computing

Data Growth Forecast

An overview of the storage requirements in the past years
provide you with the necessary information to forecast
data growth.

Data Growth Forecast – Tier View

Data growth forecast in relation to performance tiers

Structured, Unstructured and Replicated Data Growth

Advanced Data Classification and Tiering

Tiered storage infrastructure

Power Requirements and Cooling

Greatest issues organizations and companies face

What is the greatest facility problem
with your primary data center?

Power and cooling exceeds server




Installed base
(M units)

New server spending
Power and cooling








Raised Floor

None of
the above


N = 112

Gartner, Best Practices in Data Center Facilities

Facility Cost








1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Power Challenges Facing Data Centers

Some of the challenges facing data centers with respect to
electricity, cooling and environmental requirements include:
 Running out of power, cooling and space
 Growing energy costs
 Increasing regulatory compliance issues
 Data center expansion without consideration for future power and cooling

 Data storage configured without adequate consideration to heat
distribution (equipment racks should be installed with cold rows and hot
 Difficulty relieving data center hot spots without disrupting applications

Other Challenges Facing Data Centers

In addition to power consumption metrics in kW, there are
other metrics that should be considered:
 Total five-year power and space costs
 Heat loading (kW/sq ft)

 Space requirements (sq ft)
 Floor loading (lbs/sq ft)

Controller-based virtualization and thin provisioning can
also yield substantial environmental advantages because
they reduce the need for storage capacity.

HDD and Fan Power Savings

Features that work on the HDD and fan level and lead to
significant power savings:
 Spin down drives in selected RAID groups
 SATA drives will park heads when idle for more than
2 hours
 Adjust fan speeds to maintain correct temperatures
 Keep data in cache as long as possible

Green Data Center

Hot and Cold Rows

Arrange racks in alternating rows with cold air intakes
facing one way and hot air exhausts facing the other

Module Summary

 Upon completion of this module, you should have learned to:
• Identify business challenges driving the need for storage
• Understand why storage systems are important for business
• Explain the energy and green issues faced by today’s businesses

Storage Concepts
Storage Networking and Security

Module Objectives

 Upon completion of this module, you should be able to:
• Describe basic networking concepts
• Explain how common network devices operate
• Explain how devices communicate in a network
• Explain storage area network security

Module Topics

• Basic networking concepts
• Operations of common network devices
• Possibilities we have in storage system
• How devices communicate with each other
through the network
• How to secure Storage Area Networks

Introduction to
Networks –

Twisted Pair Cable

Twisted Pair Cable structure, RJ45 connectors

Fiber Optic Cable
Fiber Optic Cables – Fiber optics is a technology that uses glass or
plastic fibers to transmit data as light impulses. A fiber optic cable
consists of a bundle of fibers and each fiber can transmit millions of
messages modulated onto light waves.

Fiber Optic Connectors
Fiber Optic Cable LC connector and SFP transceiver

Storage Network Components – Nodes

Network nodes are all the devices connected in the network. We
distinguish between endpoint communication nodes and data
redistribution nodes.

Storage Network Components – Ports
 Ports

On a storage network, a port enables a node to communicate with
another node over a Fibre Channel connection.
• A node can contain multiple ports.

On a storage network, a port enables
the following connections:
• Server to switch
• Switch to switch
• Switch to storage

Storage Network Components – HBAs
 Host Bus Adapter (HBA) – In a storage system, an HBA is a Fibre
Channel interface card installed in a server. It connects a computer
and storage devices on a network.
Each HBA has a unique WWN. The two types of WWNs on an HBA
are these:
• Node WWN: Shared by all ports on an HBA
• Port WWN: Unique to each port on the HBA

Storage Network Components – WWNs

WWN address, World Wide Name, is a unique label, which identifies a
particular device in Fiber Channel network

WWN example - 5 0 0 6 0 E 8 0 1 0 4 5 3 0 3 0 1 6

The Open Systems Interconnection (OSI) Model

The Open Systems
Interconnection (OSI)
model is a conceptual
model that
characterizes and
standardizes the
internal functions of a
communications system
by partitioning it into
abstraction layers.

Storage Network Components – HUB
 Hub – a simple device that allows interconnection and
communication among nodes.

Storage Network Components – Fibre Channel
 Switch – also allows interconnection and communication among
nodes within one network

Storage Network Components – Routers
 Router – provides an interface between two different networks

Storage Network Components – Directors
 Directors

A director is a large and complex switch. It is:
• Highly available, reliable, scalable, and manageable
• Fault tolerant with the ability to recover from a non-fatal error
• Designed with redundant hardware components

• Capable of supporting Fibre Channel and fiber
connectivity (FICON)
• Potentially expensive and complex
• Designed for enterprises with large data centers

 Large networks often use Fibre Channel switches
and directors in the same implementation.

Exercise: Storage Network Components
Match the storage network component with the appropriate description:
1. Connects and transmits signals between nodes
a. Node
2. Transmits or receives data over a network
b. Port
3. Fibre Channel interface card
c. WWN

d. HBA
e. Cable

4. Enables a node to communicate with another
5. Unique number used to identify elements on a FC
storage network

If vILT class, write your answers on blank lines

Storage Networking

SAN Topologies
 Point-to-Point (FC-P2P) – A point-to-point (P-P) topology is considered
the simplest topology, in which two devices are directly connected using
Fibre Channel.
• It has fixed bandwidth; data is transmitted serially over a single cable.
• It can be used with DAS.

SAN Topologies
 Arbitrated Loop (AL) – An FC topology where all devices are part of
a loop and only one device can communicate with another device at
a time

 In AL, devices use an access request mechanism called arbitrate
(ARB), which circles the loop.
• A device can use ARB depending on its priority and access rights.

• The device with the highest priority gets first access.

SAN Topologies
 Switched Fabric (FC-SW) – A Fibre Channel topology that connects
multiple devices by using Fibre Channel switches

 In a switched fabric topology, bandwidth is not shared between
devices, enabling devices to transmit and receive data at full speed
at all times.

Direct Attached Storage

 Direct attached storage infrastructure. Server is directly connected to
a storage system. Storage system can be accessed only through the
server. Server can be accessed from Local Area Network (LAN).

Storage Area
Network (SAN)

Storage Area Network
 Storage Area Network (SAN) is a high-speed network of shared
storage devices. Servers attached to a SAN can access any SAN
attached storage devices.

 The only components in a SAN are storage devices and switches.
SAN is designed to connect computer storage devices, such as disk
array controllers and tape libraries, to multiple servers, or hosts.

SAN Components

Storage Area Networks are using Fiber Channel
infrastructure, which includes Host Bus Adaptors installed
in servers, Fiber Channel cables and switches, Fiber
Channel ports installed in the storage system front end and
proprietary network protocols.

Host Bus Adaptor (HBA) and an example of WWN number.

SAN over iSCSI Interface
 Internet Small Computer Systems Interface (iSCSI) – SAN can be
implemented by using a network protocol standard called iSCSI
which uses the SCSI protocol to transmit data over TCP/IP networks.
 iSCSI allows organizations to use their existing TCP/IP network
infrastructure without investing in expensive Fibre Channel switches.


Network Attached

Network Attached Storage
Network Attached Storage (NAS) is represented by the server that
functions as the NAS Head and common storage system. There are
solutions that integrate both these functionalities in one package (NAS
Appliances). NAS devices work relatively independently; they do not
require servers with applications. All clients, application and other servers
can access files stored in a NAS device.

File Access Protocols
supported include:
• NFS,

Network Attached Storage
 In NAS, the storage device is directly connected to the LAN and
there is no server between the data and other network devices.
 Data is presented to the server at file level.


Network Attached Storage
 Advantages of NAS

• Offers storage to different open-systems operating systems over
• Data is presented to servers at file level, reducing server overhead
• Dedicated file server, optimized for sharing files between many
• Minimizes overhead by centrally managing storage
• Facilitates easy and inexpensive implementation
 Disadvantages of NAS
• Relies on the client-server model for communication and data
transport which creates network overhead

• Lower performance than a SAN

NAS Implementations
 Methods of NAS Implementation – An organization can implement
NAS architecture by following methods:

• NAS appliance or filer
• NAS blade

• NAS gateway

NAS Appliance
 NAS Appliance – Combines a front-end file server and back-end
storage system in a single unit. This approach is called a closed-box
 NAS appliance has the following advantages:
• Combines a file server with the storage array
• Provides efficient performance
• Has high reliability
• Enables easy installation, management, and use

• Provides the least expensive NAS implementation

 NAS appliance has the following disadvantages:
• Is not scalable
• No pool storage, which makes it hard to achieve high utilization.

NAS Blade
 NAS Blade – Allows multi-protocol data storage in a large disk array
 NAS blade has following advantages in addition to a NAS appliance:
• Is scalable
• Provides backup of storage data
• Supports multiple NAS blades

NAS Gateway
 NAS Gateway – All devices communicate directly with the file
A NAS gateway overcomes the limitations of a NAS appliance.
 It has the following advantages:
• Separates file server from storage device
• Is less expensive than a NAS appliance
• Supports multiple NAS gateways
• Has better utilization rates
• Combines NAS with SAN capacity to meet growing storage requirements
• Provides NAS functionalities to SAN storage

 NAS gateway controller uses FC protocol to connect to external

Converged Solution – SAN and NAS Together
 Converged solution – SAN and NAS together
• NAS head with storage over the SAN
• NAS scales to the limits of the SAN
 Limited by NAS file system’s capacity

 Co-exists with application servers


 Centrally managed

NAS Gateway


Raid Storage

Storage Networking Architectures…Side by Side






IP Network


File System


File System

Exercise: Storage Networking Concepts
1. A DAS device is not shared, so no other network device can access the
data without first accessing the server. True or False?

2. Select the best description for the Fibre Channel topology known as

Two devices, data transmitted serially over a single cable


Multiple devices connected in a loop, highest priority device gets first


Multiple devices connected using Fibre Channel switch, devices transmit
and receive data at full speed at all times

Network Protocols

 Protocol – A set of rules that govern communication between
computers on a network. It regulates the following characteristics of
a network:


Access method
Physical topologies allowed in the network
Types of cable that can be used in the network
Speed of data transfer


The different types of protocols that can be used in a network are:

• Ethernet
• Fibre Channel protocol (FCP)
• Fiber connectivity (FICON)

• Internet protocol (IP)
• Internet small computer system interface (iSCSI)
• Fibre Channel over IP (FCIP)
• Internet Fibre Channel protocol (iFCP)
• Fibre Channel over Ethernet (FCoE)

Uses an access method called carrier sense multiple access/collision
detection (CSM/CD). Before transmitting, a node checks whether any other
node is using the network. If clear, the node begins to transmit. Ethernet
allows data transmission over twisted pair or fiber optic cables and is mainly
used in LANs. There are various versions of Ethernet with various speed
Defines a multi-layered architecture for moving data. FCP packages SCSI
commands into Fibre Channel frames ready for transmission. FCP also
allows data transmission over twisted pair and over fiber optic cables. It is
mainly used in large data centers for applications requiring high availability,
such as transaction processing and databases.

Connects a mainframe to its peripheral devices and disk array. Ficon is
based on FCP and has evolved from the older ESCON protocol.

IP is used to transfer data across a network. Each device on the network
has a unique IP address that identifies it. IP works in conjunction with the
TCP, iSCSI and FCIP protocols. When you transfer messages over a
network by using IP, IP breaks the message into smaller units called
packets (third layer in OSI model). Each packet is treated as an individual
unit. IP delivers the packets to the destination. TCP Is the protocol that
combines the packets into the correct order to reform the message that
was sent from the source.

Establishes and manages connection between IP-based storage devices,
and it hosts and enables deployment of IP-based storage area networks. It
facilitates data transfers over intranets, manages storage over long
distances and is cost-effective, robust and reliable. iSCSI is best-suited
for web server, email and departmental business applications in small to
medium sized businesses.


Fibre Channel over IP is a TCP/IP based tunnelling protocol that
connects geographically distributed Fibre Channel SANs. FCIP
encapsulates Fibre Channel frames into frames that comply with TCP/IP
standards. It can be useful when connecting two SAN networks over the
Internet tunnel, in a similar fashion to virtual private networks (VPNs)
allowing connection to a distant LAN over the Internet.
iFCP is again TCP/IP based. It is basically an adaptation of FCIP using
routing instead of tunneling. It interconnects Fibre Channel storage
devices or SANs by using an IP infrastructure. iFCP moves Fibre
Channel data over IP networks by using iSCSI protocols.
Both FCIP and iFCP provide means to extend Fibre Channel networks
over distance. Both these protocols are highly reliable and scalable. They
are best suited for connecting two data centers for centralized data
management or disaster recovery.

Fibre Channel over Ethernet is an encapsulation of Fibre Channel frames
over Ethernet networks. This allows Fibre Channel to use 10Gb Ethernet
networks while preserving the Fibre Channel protocol. FCoE provides
these advantages:
 Network (IP) and storage (SAN) data traffic can be consolidated using a
single network switch.

 It reduces the number of network interface cards required to connect
disparate storage and IP networks.
 Reduces the number of cables and switches.
 Reduces power and cooling costs.
Thus, you can build your SAN using Ethernet cables (mostly twisted pair).
You can use one switch for your IP-based network traffic (LAN) and for
creating SAN infrastructure. Even though the switch and cabling are the
same, LAN will run on TCP/IP while SAN runs on FCP.

Exercise: Storage Networking
Match the following list of components with the appropriate definition:
a. Client-server

1. Network connecting devices in a small
geographic area

b. Protocol

2. Relationship between two computers – one
sends requests; one responds with data

c. LAN
d. WAN

3. Set of rules governing communication
among computers on a network
4. Network connecting devices across larger
geographical areas

If vILT class, write your answers on blank lines

Storage Area
Network Security

LUN Mapping
 A LUN is a logical device mapped to a storage port.
Logical Devices



LUNS are mapped
To servers

 Zones – Defined to establish rules governing communication of
network devices
• WWN Zoning (Soft Zoning)
• Port Based Zoning (Hard Zoning)
• Mixed Zoning

An example of WWN based zoning

Module Summary

 Upon completion of this module, you should have learned to:
• Describe basic networking concepts
• Explain how common network devices operate
• Explain how devices communicate in a network
• Explain storage area network security


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Title                           : Storage Concepts
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