Unified storage has gone from a specialty item to something offered from nearly every storage vendor in recent years. In the beginning, vendors such as NetApp took added block capability to their file system storage and NetApp’s biggest rivals have since followed down that unified path.
The evolution continues, however, and multiprotocol systems will likely include more technological advances over the coming years.
As a refresher, I define Unified Storage as:
Unified Storage is a storage system that provides both file and block access simultaneously. The block access is accomplished through use of an interface such as Fibre Channel, SAS, or iSCSI over Ethernet. The file-based access is to a file system on the storage system using either CIFS or NFS over Ethernet.
An implied piece of unified storage is that it requires unified management, one storage system management for block and file data. Without that, the critical goal of consolidation and simplification is compromised.
Some vendors have provided block storage through both Fibre Channel and iSCSI, while others stick to iSCSI only because it is simpler to deliver. The following diagram gives a very general view that compares the implementations for block and file storage:
Unified storage systems are commonly offered by storage vendors, but that doesn’t mean every new storage system you buy must be unified. Certain high-end IT environments with specific usage requirements would use non-unified systems.If you only need high performance block storage, for instance, a unified system isn’t necessary.
However, there are excellent uses of unified storage:
But vendors haven’t just been combining block and file protocols in the same package. Recent features added to unified systems include automated tiering, solid state devices (SSDs) as a tier for higher performance, and support for cascading read/write-capable snapshots to add value for use cases such as virtual desktop infrastructures (VDIs).
What should be expected next for unified storage? It’s likely that vendors will package other capabilities together and call that the new “unified storage.” That would dilute the meaning of “unified” and require a qualifying phrase after it.