مفهوم Unified Storage
I’m sure I’ll get some comments on this section from religious zealots who disagree with parts, but here goes. Unified storage refers to a single logical system that is capable of presenting both dedicated LUNs (SAN) as well as folders within a file system (NAS).
Where do the zealots play into this? Basically in how this is performed. There are unified storage systems where the SAN blocks are actually sitting on top of a file system and the translation happens within the storage controller. There are other unified systems where there are dedicated controllers for SAN functions and separate controllers for NAS functions, but there is a management wrapper that creates a single logical system to manage. Who am I to say which is right, or for that matter, why a NAS Gateway connected to a SAN array couldn’t be a form of unified storage?
Since we’ve already covered NAS and SAN to some degree of depth (and I’ve presented that unified is largely a congruence of these two under a common logical system umbrella), I’m going to make this a relatively short focus area. However, I will suggest that customers need to very carefully examine the individual application performance attributes of what they are storing and how they are storing it vs. automatically jumping to the conclusion that “unified” is somehow the best of both worlds. Depending on how that unified storage is deployed, you might end up with sub-par application performance in the pursuit of perceived management simplicity. The truth is that SAN management has come a long way since unified storage first came on the scene and now many dedicated disk arrays are designed to be managed by IT generalists using server-oriented management tools. Simplicity is not really the best decision criteria to use when looking at dedicated NAS and SAN vs. unified approaches. As Forrest Gump might say, “that’s all I’ve got to say about that.”