"Storage virtualization has been around for a very long time," says Garry Barker, chairman of the local Storage Networking Industry Association, also known as SNIA.

"The current interest is in storage area networks (SANs) for open systems, which have been around for about three years. The marketplace is slowly adopting these rather than jumping in. 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."