Virtualization Buyers Keep Exit Open

NEW YORK -- Storage Decisions -- Early adopters have this piece of advice for organizations looking to implement block storage virtualization: Make sure you have an easy way out of your first cut at the technology.

Three virtualization customers on a panel here today agreed it's best to make sure you can reverse your decision if you change your mind about how best to virtualize. There are several reasons for this.

First, many products used for storage virtualization -- especially those involved with intelligent switches -- are new. Something better might come along. Also, it is possible to implement the virtualization in more than one way -- in-bound, out-of-band, in appliances, with intelligent switches, or in the array. A storage manager may decide the first try isn't the best fit after all. And the benefits in managing and organizing storage that virtualization brings can be negated if the solution locks the customer into one vendor.

Each panelist offered a different implementation perspective. Chevron senior project manager Malcolm Hope is adding block virtualization carefully. Hope says he's running FalconStor IPStor software on two appliances outside the data path as part of his initiative to consolidate hardware and software following a series of mergers and acquisitions. He has an eye on adding in-band devices if all goes well.

"We're moving through this fairly slowly. We'll roll it out in one place and make sure it works," he says. "You have to spoon-feed this to your environment. When you say in-band, people in your organization think it will degrade performance. You have to prove it works 'side band' before you introduce it in-band."Hope says he went with FalconStor in part because its software works on any hardware. "We wanted something hardware agnostic, we didn't want to get locked into one vendor."

Nick Otto, IT Manager for Circuit City, went with an in-band device -- IBM's SAN Volume Controller (SVC). The goal was to cut $1 million out of his disk storage budget by introducing more tier two and tier three storage on cheaper disk.

Otto uses SVC to migrate data from his high-end IBM DSS 8100 to midrange IBM DSS 4800, 4500, and 4100 SANs with SATA drives. He says a four-node SVC with 16 Gbytes of cache helped him move data to the cheaper systems without a performance hit and increased performance on the lower-tiered systems. He also can administer all the systems from one interface. He intends to retire aging systems holding 50 Tbytes of data over the next three years and move most data to tier two and three SANs.

But while he admits he "bet the farm" on virtualization, Otto says he's keeping an open mind as to the best way to do it.

"We can back out of SVC if we want," he says. "There's still a running debate on where you want to put virtualization, and if you want to put it on an appliance."But unlike Hope, Otto doesn't describe his foray into storage virtualization as cautious. "I got aggressive and put everything behind it fast," he says.

Jeff Boles, IT manager for the City of Mesa, Ariz., says he got into virtualization as fast as he could -- after he took years to find the right path. He considered now-defunct Veritas Storage Foundation for networks and Maxxan intelligent switches several years ago, but recently decided on Incipient's Network Storage Platform (NSP) software running on a Cisco intelligent switch. (See Veritas, Cisco Ship Switch App and A Baby Step for Storage Virtualization.)

"One of my guiding principles is, I want to be cautious about how much I invest in my virtualization solution," Boles says. "I want to be able to back out of any solution I'm in. Incipient's software is easy to implement and easy to yank out if I make a decision to virtualize another way."

But Boles says he has no intention to back out of the overall strategy of virtualizing his storage now that he's into it. "If you're virtualizing, you have to be fully committed."

He says virtualization allows him to add storage as he needs it and as it becomes more affordable, instead of overbuying up front or having to go back to one vendor for more disk."Disk is a commodity, so I can bring in the best bang for the buck," he says.

Dave Raffo, Senior Editor, Byte and Switch