Everyone will start virtualising storage because it's the best way tomanage lots of capacity.

Storage virtualization is recognized as one of the best ways for IT managers to streamline routine tasks like backup, archiving and recovery, but in terms of delivering benefits to the business, these advances are just the tip of the much larger iceberg.

Pooling network storage can deliver an array of benefits to your enterprise, including improvements to database performance, capacity utilization and application availability.

"Storage virtualization has been around for a very long time," says Garry Barker, chairman of the Australian Storage Networking Industry Association (SNIA).

"The current interest is in storage-area networks (SAN) for open systems. The marketplace is slowly adopting these rather than jumping in," Barker continued to say. "The main reason for gradual growth is because it is difficult for consumers to understand the benefits. But they are actually clear and huge."

Escaping the physical
Gartner's research vice president for storage, Phil Sargeant, says the easiest way to understand storage virtualization is as "divorcing the storage from the physical to the logical." With storage - NAS, DAS, or SAN - you have physical boxes, but when you make storage virtualized you create a mechanism to look at it from a virtual or "logical" perspective.

"The great thing about storage virtualization is it knows the true nature of the underlying storage, where the applications couldn't give a damn," Sargeant says. "The net effect is to make what appears to be complex, less complex - and simple as far as the applications and users are concerned."

Graham Penn, an IDC storage analyst, describes storage virtualization as a way to "better use the capacity you have." He points out that storage virtualization is also a good way to save on capital costs. "You get better use of what you've already got because it is all together, and you can manage it from a single point with the same tools, which helps reduce operational costs and manpower," Penn says.

"What we generally find is that, for most companies, their initial significant savings are in data migration - taking data from where it is to somewhere else in the pool. Once you have done that you can start to manage the excess capacity," Penn says.

There are a number of different ways to deploy virtualization within an enterprise: at the array level, at the server level or within the network. The choice of where the virtualization engine resides is a separate decision depending upon your particular computing environment and is best decided on a case-by-case basis.

Almost full
"If IT managers and CIOs aren't worried about the storage, they should be," Penn says. "Storage does not have elastic walls and it will continue to be a concern."

With the cost of new storage decreasing by about 30 percent a year, it is hardly surprising that many companies have opted to buy more cheap capacity rather than go through the complexity of network storage. But eventually, Penn says, companies will reach a point where they have too much capacity to manage.

"A lot of organizations have not reached the critical point, but in the next five years all medium and large organizations will encounter the issue - depending on the type of data they have," Penn says.

Over at the SNIA, the association is working on trying to get consistency of terminology and standards across the industry, particularly with regard to how storage virtualization should be placed in a SAN from an architectural perspective.

"SNIA's model offers an architectural view of how various layers of technology should fit together in a SAN, and storage virtualization is one such layer," Barker says.

IT executives curious about SNIA's model can check out their Web site where the association offers vendor-agnostic tutorials on storage virtualization, with more due over the coming months.

"Storage virtualization means you can do non-disruptive data movement and isolate the outside world from caring about what vendor provided the storage," Barker says. "This makes it to easy to change vendors for pricing and functionality, and use mixed vendor environments. It also gives you the option to choose the best vendor for your needs."