STORAGE VIRTUALIZATIONBy Mohd Nazziman Bin Mohd Mustapha

Storage Requirements

Storage budgets up 1%-5% in 2010

The information explosion meets budget reality

Storage requirements growing 20-40% per year

Information doubling every 18-24 months

2000 2005 2010 2015

Terabytes

Petabytes

Exabytes

Zettabytes

Gigabytes

Storage efficiency strategies and best practices

Storage VirtualizationThin Provisioning

Data CompressionData Deduplication

Automated TieringAutomated Data Migration

Move data to the right place

Store more with what’s on the floor

Stop storing so much

What is Virtualization? Virtualization is a technique of abstracting physical

resources in to logical view

Increases utilization and capability of IT resource

Simplifies resource management by pooling and sharing resources

Significantly reduce downtime– Planned and unplanned

Improved performance of IT resources

Examples of Virtualization

Each application sees its own logical memory, independent of physical memoryVirtual Memory

Each application sees its own logical network, independent of physical networkVirtual

Networks

Each application sees its own logical server, independent of physical serversVirtual Servers

Each application sees its own logical storage, independent of physical storageVirtual Storage

Storage Virtualization Process of presenting a logical view of physical

storage resources to hosts

Logical storage appears and behaves as physical storage directly connected to host

Examples of storage virtualization are:– Host-based volume management– LUN creation– Tape virtualization

Virtualization Layer

Heterogeneous Physical Storage

Servers

Why Storage Virtualization is needed?

SNIA Storage Virtualization Taxonomy

StorageVirtualization

BlockVirtualization

DiskVirtualization

File System,File/record

Virtualization

Other DeviceVirtualization

Tape, Tape Drive,Tape LibraryVirtualization

NetworkBased Virtualization

Storage Device/StorageSubsystem Virtualization

Host Based Virtualization

In-band Virtualization

Out-of-band Virtualization

What is created

Where it is done

How it is implemented

SNIA - Storage networking Industry Association

Where’s it done?

Server

StorageNetwork

Storage

Path management

Volume management

Replication

Volume management - LUNs

Access control

Replication

RAID

Path redirection

Load balancing - ISL trucking

Access control - Zoning

How it is implemented(a) In out-of-band implementation, the

virtualized environment configuration is stored external to the data path. The configuration is stored on the virtualization appliance configured external to the storage network that carries the data.

(b) The in-band implementation places the virtualization function in the data path. General-purpose servers or appliances handle the virtualization and function as a translation engine for the virtual configuration to the physical storage

Servers

StorageArrays

VirtualizationAppliance

Out-of-Band

(a)

StorageNetwork

Servers

StorageArrays

In-Band

(b)

Storage Network

Block-level Virtualization Ties together multiple independent

storage arrays– Presented to host as a single storage device– Mapping used to redirect I/O on this device to

underlying physical arrays

Deployed in a SAN environment

Non-disruptive data mobility and data migration

Enable significant cost and resource optimization

Servers

Heterogeneous Storage Arrays

Virtualization Applied at SAN Level

File-level Virtualization File-level virtualization addresses the NAS challenges by eliminating the

dependencies between the data accessed at the file level and the location where the files are physically stored.

This provides opportunities to optimize storage utilization and server consolidation and to perform non- disruptive file migrations.

File-level Virtualization

Every NAS device is an independent entity, physically and logically

Underutilized storage resources Downtime caused by data migrations

NAS Devices/Platforms

Before File-Level Virtualization

IP

Network

Storage

Array

File

Server

File

Server

Clients Clients

Break dependencies between end-user access and data location

Storage utilization is optimized Nondisruptive migrations

NAS Devices/Platforms

After File-Level Virtualization

IP

Network

Clients Clients

Storage

Array

File

Server

File

Server

Virtualization Appliance

Tape Virtualization

Virtual tape is an archival storage technology that makes it possible to save data as if it were being stored on tape although it may actually be stored on hard disk or on another storage medium. 

Types of Tape Virtualization

The three basic types of tape virtualization today are:- Virtual Tape: disk is used as a cache to concatenate datasets

in a manner that most efficiently uses the capacity of a tape cartridge.

- Virtual Tape Library (VTL) – disk is used to emulate a physical tape library.

- Tape library virtualization – tape drives and tape slots can be allocated dynamically rather than having fixed assignments.

Types of Tape Virtualization

Type What/where? Benefits

Virtual Tape Temporary disk workspace organizes data for writing to tape.

More efficient use of tape cartridges.

Virtual Tape Library (VTL)

Disk storage is used to emulate a tape library.

Increased reliability of restoration, shortened backup times

Tape Library Virtualization

Flexibly allocates the tape drives and tape slots of a physical tape library.

More efficient use of tape library resources.

Benefits of Storage Virtualization Easy Storage Provisioning:– Virtual disks can be created, resized,

and assigned to hosts in a fraction of the time it takes to provision physical storage.

Benefits Non-disruptive Data migration:– The ability to migrate data from

old equipment to new gear, or from one storage tier to another, without bringing systems offline and disrupting applications and users.

Benefits Simpler Storage Management:– Virtualization brings a central

management point and standard set of services to heterogeneous storage devices, simplifying tasks such as mirroring and replication.

Benefits

ChallengesScalability

Ensure storage devices perform appropriate requirementsFunctionality

Virtualized environment must provide same or better functionalityMust continue to leverage existing functionality on arrays

ManageabilityVirtualization device breaks end-to-end view of storage infrastructureMust integrate existing management tools

SupportInteroperability in multivendor environment

END