I would agree with what Sanjay has to say. Just that your organization is in the bucket of a SMB, does not say much about your infrastructure. Ask the following questions, and if most turn out to be a "Yes", then a Network Attached Storage could be the way to go.
- You need an effective , scalable storage for user data.
- You may be running a virtualization platform such as Hyper-V ( Microsoft) or ESXi (VMware).
- You do not have any applications that demand very high performance.
- You have a database with very low to moderate count of concurrent users.
- All users and applications are local.
- The network bandwidth is 1Gb E and is being upgraded to 10 GbE in the near future.
- My users are a mix of Windows and Linux (MAC).
- I have the need to provide a storage quota for the users for them to store their corporate data.
- I have a Authorization mechanism such as Microsoft Active Directory, which is optional, but useful.
Most NAS vendors out there do support iSCSI, just in case you require a block level protocol at a later date. Double check that the vendor does support them. Ensure performance is not impacted by having the NAS uplinks to the switch on 10GbE if your switch supports the same. Ensure that your NAS ethernet ports are the same as the switch ethernet ports. I have seen many purchasing a NAS with SFP+ ports and in trouble as their switch has only RJ45 (copper ) ports.
Performance is a very open word. IOPS is not a numbers used in the world of NAS. Rather they talk nFS OPS and believe me there is no straight forward conversion. Check to see if one can provide you with some assistance in measuring the performance requirements especially if there are databases that are critical. User data does not demand very high performance and as such they may face some latencies owing to congestion, but they do not timeout like Databases.
I guess that's all there is to it.