[ramkumar]

Hello Team, i am new to this Forum. Hope you are well.

I have a query regarding NAS and SAN.

Can any one please provide the major differences between SAN AND NAS in a practical way. Please help with with Example without fail.

Thank you so much in advance

[Stoyan Varlyakov]

ramkumar, on 27 November 2012 - 02:31 AM, said:

Hello Team, i am new to this Forum. Hope you are well.

I have a query regarding NAS and SAN.

Can any one please provide the major differences between SAN AND NAS in a practical way. Please help with with Example without fail.

Thank you so much in advance

Just take a look here:
http://www.techrepub...comparison/3766
NAS is in general file based storage
SAN is in general block based storage

Then keep on googling, a proper answer will need at least a book to explain.

[Relax_nl]

My 2cents explanation:

NAS devices allow a client to access the storage resources using high-level file-oriented protocols like NFS,SMB/CIFS, AFP, while SAN devices allow to access the storage resources using low-level block-oriented protocols like iSCSI.

[ramkumar]

Hi Team,

Thanks for the post.

I need a explanation in a practical way. so that it would be easy to understand.

for example: if you attache a hard disk in a desktop machine that is cabinet. then it becomes DAS.

Can any one explain me in that way?

[ramkumar]

I just want to know what is file based and what is block based. i have a big confusion how file base looks and block base looks.

I need it with diagram. is that possible. please help me to understand

This post has been edited by ramkumar: 29 November 2012 - 06:39 AM

[Stoyan Varlyakov]

NAS - can be accessed by end users and devices. Provides services to share data like word files, folders and .zips
SAN - can be accessed only by devices which are capable of talking to the type of SAN, because there are many. A typical SAN client is a cluster environment.

There is no easier way to explain it, or at least I am not able to.

If you find that hard to understand, please start reading about file based storage and block based storage.
There is no quick and dirty way to become an storage expert unfortunately.

[ramkumar]

Hello Stoyan,

thanks for post. i have read the documents regarding NAS and SAN before . But the problem is not able to gather details in a practical way.

I could understand theoretically and i would say as a storage expert theatrical knowledge is not enough to shine.

[ramkumar]

From my knowledge i would say that,

SAN Can able to extend the Storage Box where is NAS cannot be able to extend Storage Box.

Can any one tell me, whether SAN has inbuilt Operating system like NAS has ?

[Stoyan Varlyakov]

SAN can be in general anything - from JBOD units to OS Based block sharing over iSCSI, iFC etc... So it is rather difficult to answer simply.
In a pure hardware form SAN is a Network - this means many devices are concerned.
1 Device by itself cannot form a SAN.
You could build a SAN using FC, SAS, and TCP based implementations like TCP over InfiniBand, iSCSI in 1G and 10G Ethernet...

10 years ago SAN was limited to Fibre Channel
so in this form all you needed was a firmware and a SAN switch. Now however you have the so-called hybrid storage which has a SAN part (Nexenta, OpenFiler, even typical Server OS with iSCSI Target installed could be considered SAN member...) and a NAS part (Sharing files over SMB/CIFS ; NFS ; AFP ...).

The difference is that in a SAN you have a number of blocks to be accessed which then you have to control using the client to form a volume and install an file system over it, whereas in a NAS application, the Filesystem and OS should not matter - it is a different protocol which is in the base of the whole thing.
In Windows Networks the network file sharing protocol is calles System Message Block (SMB) also known as Common Internet File System (CIFS), and the linux daemon for this type of access is usually samba or smbd.

So go back to my first post - there is not a simple way to explain SAN and NAS with diagrams and examples. You have to get the whole picture to know what is the one and what is the other.

[ramkumar]

That's really great to get this information.

and thanks for sharing the information.

And also i would say block level access is more faster compare to file level access.

Is there any opposition for this point?