I got a call today from someone asking about a vendor’s claim that it offers enterprise storage. I asked myself again, what is the definition of enterprise storage? I also asked myself if it is changing or going to change anytime soon.
To me what differentiates enterprise storage is both the availability and the consistency of performance. To me, consistency of performance is a critical aspect of the definition of enterprise storage. So assuming you accept my definition, what needs to happen in and to a storage system to meet consistent performance? In my mind, that means two things:
1. A controller that allows consistent data access performance for both IOPS and streaming
2. A disk subsystem that provides data access performance for both IOPS and streaming
Number 1 is pretty obvious and most vendors claiming enterprise storage address the failover, address writing to any LUN to any port. This is well-known set of issues and technology solutions.
The real issue, in my opinion, is that SATA drive recovery takes too long because much of the recovery has to be done on the host side as compared with SAS/Fibre Channel drives. With the new crop of drives that offer SAS interfaces-- but actually have SATA hardware guts -- consistent performance will be possible with drives that historically have used SATA interfaces. This I believe might be good for the consumer, but bad for the drive vendors that make really SAS enterprise drives.