SAN vs NAS

A great big question for an interviewer for which you can take half an hour to explain the things to the interviewer.

It simply depends on your expertise level and exposure to this field,that how you going to tackle this question. :P

SAN (Storage Area Network)

• Its a technology which uses FC( Fibre Channel) to map a Host to the Storage Array. 
• It uses a Block Level architecture
• Most used protocol used in SAN are FCP ,iSCSI , FCoE (Fibre Channel over Ethernet)

SAN Hardware requirement :

1. Host with Host Bus Adapter (HBA)
2. Fabric Switches or SAN switch
3. FC cable (throughput is around 8Gbps)
4. Storage Array 

SAN is far more costlier than NAS to implement. 

Topology of SAN:

NAS (Network-Attached Storage)

• NAS will be using an Ethernet connection for sharing files over the network. The NAS device will have an IP address, and then will be accessible over the network through that IP address. Eg :When you access files on a file server on your windows system, its basically NAS.
• NAS uses File-Level Architecture 
• Protocols used here are NFS/CIFS and SMB

NAS Hardware requirement :

1. Ethernet cables
2. Standard switch/Hub (TCP/IP)
3. NAS server (can be a Windows server which is hosting a NAS file share)

Topology of NAS:

For more details regarding Block and File-level Storage visit:

http://cloud-stuff.blogspot.in/2016/06/block-vs-file-storage.html