Storage area Network(SANs)

Topics of presentation

What is Storage Area Network Benefits of SAN EnvironmentSAN ComponentsPotential Storage Services LocationsChallenges of SAN ManagementWays to Manage a Storage SubsystemWORLD WIDE NAMESSimple Architecture of SAN Redundant Architecture of SANFibre channel vs. IP based technologySummary of RAID levelsStorage services requirement

STORAGE AREA NETWORKA dedicated network that interconnects hosts and storage devices, usually via fibre channel (FC) switches and optical fiber media. A storage device is a disk sub system array with a set of disk drives.

Fibre Channel Servers

Local Area Network

Fibre Channel Storage Area Network

Benefits of SAN Environment

Storage ConsolidationConcurrent Access by Multiple HostsUse in Disaster Recovery ApplicationsReduced Total Cost of OwnershipReduction of management complexity/overheadImproved availabilityScalabilityImproved data protectionIncreased capacity usage

SAN ComponentsFC cable It is a high-speed data transmission technology used to connect multiple hosts and storage devices over fiber-optic or copper cables.SFP ModuleSmall Form-Factor Pluggable (SFP) modules are transceivers that interface a motherboard with a FC cable and are used to covert electrical signals to optical signals required for fibre channel transmission to and from devices such as RAID controllers, switches and other fibre channel devices Host bus adapters (HBAs)It is also referred to as FC interface cards are installed into hosts. OS-specific device drivers are usually installed for these adapters. Storage devicesRAID architecture where all disks are independently addressed.Interconnect devices such as fibre channel hubs or switches. Other special-purpose devices are SAN gateways, bridges, routers, and extenders

Subsystem

Fabric

Host

• Disks/RAIDs/Controllers• Filers• Tape Libraries

• Appliances• Switches• Directors

• Servers• Mainframes

Area of Intelligence Hardware Platform

Potential Storage Services Locations

Challenges of SAN Management

A SAN must be managed at multiple pointsServer OSHBASwitch Storage Array

DependenciesThe biggest challenge is understanding the dependencies of the various elements upon each other.Device drivers compatibility issues.

ProblemsThe new HBA has a different WWN than the old one and so zoning information in the SAN.

Ways to Manage a Storage Subsystem

Out-of-Band Storage Subsystems The controllers in the storage subsystem are managed directly over the network through the Ethernet connection on each controller in the storage subsystem.

In-Band Storage Subsystems The controllers in the storage subsystem are managed through an Ethernet connection on a host instead of using the Ethernet connections on each controller

WORLD WIDE NAMESIt guarantees uniqueness within a large SAN fabric. There are two type of WWNs:Node WWNs—These are allocated to the entire adapter.Port WWNs—These are assigned to each port within an adapter. These are used for SAN zoning

LAN

Tape Library

Switch

HBAHBA

Storage Array

Controller

Backup Server

ServerServer The Fibre Channel switch is an intelligent device that collects information about the SAN network topology and attached devices.

Switches Enable simultaneous communication between multiple endpoints (such as a server and storage disk)

Provide capabilities for managing those connections between devices so that access is controlled (through zoning)

Provide physical connectivity for failover and load balancing

Simple Architecture

Public LAN

switch

Production servers

Backup server

HB

A

HB

A

HB

A

HB

A

HB

A

HB

A

switch

Controller Controller

Tape Library

ports

1 2 3

Redundant Architecture

redundant components—controllers, switches, ports, HBAs

Cabling to ensure that there is no single point of failure.

No cable connection between the two switches.

Switches remain independent.

Redundancy in various component

Redundancy can be on host level Multiple HBA’s.

Redundancy can be on switch level two or more switches.

Redundancy can be on storage level ,connecting storage controller with Expansion units.

Fibre Channel

Cost and complexityFibre Channel networking requires specialized expertise.

Fibre Channel networking components are considerably more expensive than IP.

Performance4 GB Fibre Channel networking components available today

Deterministic performance

IP

Cost and complexity Ethernet and TC/IP

networking technologies are familiar.

Ethernet networking components are less expensive.

One networking technology to network clients, servers, and storage.

Performance 1 GB Ethernet networking

components available today Not ideal for SAN solution

Fabric devices

Storage arrays

Servers

Fibre channel vs. IP based technology

RAID levelsRAID 0 is the fastest and most efficient array type but offers no data redundancy or fault-tolerance.

RAID 1 is the array technique of choice for performance-critical, fault-tolerant environments and is the only choice for fault-tolerance if no more than two drives are available.

RAID 3 is a popular choice for data-intensive or single-user applications that access long sequential records. However, it does not typically allow multiple I/O operations to be overlapped.

RAID 5 is generally the best choice for multi-user environments that are not particularly sensitive to write performance. At least three, and typically five or more drives are required to build a RAID 5 array.

Storage services requirement

Manageability

Performance

Capacity

Security

Recoverability

Availability

SizeSpeed

Distancenumber of nodesthroughput

Storage services require scalability in

Reach

SAN Environment in NUST DATACENTER

Hosts IBM Xseries 346 2 Switch Brocade ibm 2005-H16 1Storage controller

Ibm Ds 4300 2

HBA Qlogic 2340 2

XSeries 346 Qlogic 2340

Brocade ibm 2005-H16

Enterprise Management Window The Enterprise Management Window (EMW) provides high-level management of storage system