The problem that most people are trying to solve when they start to dabble with storage virtualization is basically utilization. IT managers realize that most of their storage assets are way under utilized in terms of capacity, so they naturally want to look at ways of creating pools of storage across multiple devices that can be easily shared by any number of applications and servers.

To accomplish that, IT organizations have typically had to either upgrade to new storage hardware that supports the ability to pool storage or look for a software-based approach that would allow them to create virtual pools of storage from arrays supplied by different vendors. In either event, there are tradeoffs to be made. The upgrade to new storage virtualization is expensive and the systems themselves can be difficult to manage in terms of allocating pools of storage resources across application sets that can change dynamically. It takes a lot of finesse and skill to make that scale across the entire enterprise. Furthermore, if they take a software-based approach to storage virtualization, they basically wind up turning off a lot of the value-added capabilities of their storage hardware as the intelligence for managing the storage infrastructure moves from being embedded in the hardware into what amounts to a generic storage application.

Against that backdrop the folks at Pillar Data Systems have decided to issue an interesting challenge as part of the release of their new Axiom 600MC storage controller. The company is guaranteeing customers that they will see 80 percent disk utilization, which they say is the highest in the industry and about twice as much utilization the average customer sees from any other storage solution.

The reason Pillar Data Systems can make this claim is because of their approach to policy-based storage management. By using a set of pull-down menus to essentially profile the storage requirements of each application, the Axiom 600MC makes sure that applications with similar performance requirements don't sit on the same array. This means that customers should only see a very limited amount of storage bottlenecks because the applications accessing any given disk array at the same time will have substantially different I/O performance characteristics. Essentially, this means that Pillar Data Systems is managing the process of intelligently distributing where the data resides across the arrays to both maximize utilization and reduce bottlenecks.

This really opens up the whole question of the value of storage virtualization given the fact that at least one vendor is now guaranteeing utilization rates of 80 percent. Essentially, IT organizations now need to ask themselves if they really need to go through the pain of creating and managing virtual pools of storage when they now have a more efficient way of basically throwing more hardware at the storage growth problem.

Time will tell if the whole issue of storage virtualization is going to be carried along by the rising momentum of server virtualization. There's certainly a lot of powerful marketing behind the storage virtualization concept. But the first question that any IT organization should really ask before they follow everybody down the virtualization path is exactly what problem are they trying to solve? And when they stop to think about that, they may just want to pause long enough to consider all the possibilities.