INTRODUCTION OF

STORAGE AREA NETWORK

SUMMARY

1)What is SAN

2)Basics of SAN

3)Architecture of SAN

4)Basic mechanism of SAN

WHAT IS SAN

Storage area network is a design to transfer data, from server

to clients. It is alternative to the directly attached targets. It

is primarily used as the storage device server can access this.

It is also highly performance storage device enabling to

communicate with one another.

TECHNOLOGIES

Different of technologies are used for SAN. Most popular is the Fiber

channel. But IP based solutions are also used. Concepts of SAN also

implemented on the devices those are attached to like disk, tapes, RAID, file

server etc. We frequently used NAS and SAN collaterally. Difference between

them are SAN is network storage sub system NAS is storage subsystem. SAN

extension of disk channel not connected to server but NAS connected to server via

IP network.

BASICS OF SAN

Different technologies can be used to interconnect different network nodes.

Fiber channel is dedicated high performance channel. It is used fiber channel

protocol. SCSI protocol carry IP packet over the network. SCSI is the extension

of the SCSI bus.

INITIATOR AND TARGET

Fiber channel can be source or the destination of the

information. If the node is initiator then it is connected to the

network through HBA (Host Bus Adapter) it is a physical layer

connection. It may be electrical or fiber optical. If the node is

target then it is connected through RAID (Redundant Array of

Independent Disk) or storage drives.

HARD DRIVES

Basic storage is the hard drives. It is composed of different

disks, platters, cylinders, track and sectors. It is metallic disk

used for storage of data. Logical block address within the disk

is 512 byte. Files can be stored in the sectors so they can be

stored and retrieved. File system deals with clusters of blocks

and it uses FAT (File Allocation Table) to map the file sectors.

JBOD AND RAID

Jbods are group of disks packaged in a connected via FC loop.

RAID is more sophisticated device it improves the storage disk

performance. It improves the performance the reading and writing from

disk at the same time or it mirroring the information on the multiple disk

array.

ARCHITECTURE OF SAN

RAID array containing the disk array and RAID controller . It

providing hardware and feature of RAID 0- 5. Direct attached storage

is an architecture is used to storage privately attached servers. It is

expensive and complex to manage. Storage is accessed from block level not

file level. It is high performance. It uses good management tool and storage

is shared. It uses interoperability.

NAS

Network attached storage is an architecture which attached

to the server with a multiprocess network. This network is a IP

process network. Transmission Control Protocol can be tuned

to optimized storage transport.

MECHANISM OF SAN

Fiber channel act as a transport layer of SCSI. Fiber channel

is used instead of TCP/IP network to connect server to the

storage. In the long graphical distance IP can be used. It can be

used in the IP traffic. FC offers layer 2 transport service and

used layer 3 to map upper layer protocols like SCSI, HIPPI and

IP.

SWITCHING FABRIC

SERVICE

FC switching fabric relies upon number of software

applications and to deliver transport service.

Most relevant ones are Zoning, Alias service, domain

controller.

Those service allow fabric to function without disruption.

It consist of a set of information distributed across the fabric

nodes.

STANDARDIZATION BODY

Fiber channel standardized by ANSI T11 committee.

SCSI standardized by T10 committee. URL = www.T10.org

FCIA is the fiber channel industry association it is not

involved in the standardization process. University of New

Hampshire also involved here.

THANK YOU