When thinking of NAS in relation to SAN, it’s just hard to say one is better than the other any more. How does one quantify something like that as “better” in today’s modern abstracted datacenter?
As a Technical Marketing Engineer for NFS, I could certainly think of reasons NAS is better, but even I could make a valid argument for SAN in some instances. Datacenters are not one-size-fits-all and not every nail uses the same hammer.
It’s another classic case of “it depends.”
For instance, if your workload uses a single server/cluster and doesn’t need to be accessed by multiple clients at the same time, doesn’t need to worry about ACLs and doesn’t need to be client-agnostic, then SAN might make more sense. But what about NAS?
Wait, aren’t SAN and NAS the same thing?
SAN and NAS are often confused with each other, given they use the same subset of letters in their acronyms and that the general concept is the same – accessing data over a network. In fact, when I’ve asked the question in interviews, people often stumble over what the difference between the two is, and instead, offer the acronym definitions.
SAN = Storage Area Network
NAS = Network Attached Storage
At the surface, they certainly don’t sound very different. However, there are many differences between the two.
- SAN is block-level and leverages SCSI commands. NAS is file-level and leverages standard NFS and SMB protocols.
- SAN can use iSCSI or FCP. NAS uses standard ethernet TCP/IP.
- iSCSI operates at a lower layer (session layer) of the OSI model than NAS does (all the way to application layer).
- FCP uses its own separate OSI-like model.
- NAS is older than SAN. Both had the goal to eliminate Direct Attached Storage (DAS). Both have succeeded.
So, why do I prefer NAS over SAN?
Find out at DataCenterDude.com!