nixCraft

Hello,

Please tell me the difference between SAN(storage area network) and NAS (network attach storage) in terms of there working and reliability.

Thanks

A SAN commonly used Fibre Channel

Any computer that connects to LAN act as NAS using NFS or CIFS

NAS uses TCP/IP and NFS/CIFS/HTTP protcols

SAN uses Encapsulated SCSI protcol

See Image:
Image:Compingles2.GIF - Wikipedia, the free encyclopedia
Nas-San Comparison

__________________
Rocky Jr.
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Never send a boy to do a mans job.

Hi,
The basic diffence b/w SAN, NAS is
"The kind of I/O Operation ? if it is an Block I/O then it is SAN,
if it is an File I/O then it is an NAS"
For More clarity : Lets say, Server A is an NFS Server and have /data been exported/shared via NFS & Host B mounts the remote /data to its /mnt directory, when Host B wants to write ( create,modify,delete anything) to /mnt it would write in a file i/o based, this file i/o operation traverse via the Lan/TCP and eventually in Server A this file i/o is tranfered into block i/o physically while writing, so in NAS, ideally one I/O cycle includes ( one File i/o in /mnt + one Block i/o for Server A to the Hard Disk). hence the speed is slow, reliablity is less as compared to SAN. where there is only one Block i/o, no File i/o.
well, even though nowadays file i/o can be speed up by using Gigabit ethernets, high cache memory in Sever A.
i hope this could make u understand.
regards,
ALok Sharma.