"Heterogeneous virtualization" is a mouthful, but Chuck Long has no problem singing the technology's praises. A storage administrator for Safelite Autoglass, Long discovered he could recapture unused disk capacity and better utilize his storage by virtualizing his mixed IBM storage environment with the vendor's SAN Volume Controller.

In turn, that has meant recouping the cost of extra storage and saving time on management and maintenance.

"I can create a [partition] on the Shark and carve it up and assign it to servers as I want. If later the need for that disk disappears, I can add it back into the common pool," Long says, adding that he's used IBM's virtualization scheme on a Cisco MDS director-level switch at the Columbus, Ohio, company since last summer.

IBM was the first of the large systems vendors to introduce virtualization of heterogeneous arrays with its SAN Volume Controller software, which resides on Intel Xeon servers or on Cisco's MDS 9000 Series Fibre Channel switches. Now, heterogeneous virtualization is the au courant promise of all major storage systems vendors, with all agreeing that this is a necessary starting point for easier management, improved utilization, and data services such as replication and information life-cycle management (ILM).

Long says he has virtualized about two-thirds of the data on his storage-area network (SAN) and hopes to virtualize all 27T bytes of data residing on IBM storage systems. "Virtualization has allowed us to resolve the issue of those 'pesky' little 1 to 5 Gig spaces that are left over on a volume and are just too small to use. We are able to bring all those smaller logical volumes into the SAN Volume Controller and combine them to make a larger usable space. This lets us use 100% of our storage with no wasted space," Long says.

"We can also use the migration tool to move logical volumes from one storage device to another or just move it to another area on the same device without the end users ever losing connection," he adds. "This allows us to do maintenance on storage devices without causing downtime for the host."

Moving data from one array to another is a breeze, Long says. "With the SAN Volume Controller, all the drivers are there. We migrated 2T bytes in an hour and a half. Nobody had any idea it was being done," he says.