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As head of storage management for insurance giant Aetna, Hartford, CT, Steve Pomposi has plenty of reasons to be excited about storage virtualization. After all, he manages a large, heterogeneous storage infrastructure at Aetna that contains well in excess of 100TB of data. Managing that complex infrastructure is an expensive task that demands the attention of senior technicians every time storage is added or reallocated within the environment.
Virtualized storage solutions are supposed to resolve these kinds of thorny issues. By placing a layer between the storage subsystem and the systems accessing it, virtualization should allow IT managers to add, configure and manage multivendor disk arrays with ease, letting applications and systems access a unified pool of storage. Adding a disk array in this environment doesn't require making infrastructure components aware of the new hardware. Rather, the virtual pool of storage grows incrementally and immediately becomes available to all devices on the other side of the abstraction.
There's just one problem: Most IT and storage managers at large enterprises aren't convinced that storage virtualization is ready for implementation. They cite a litany of obstacles, including a lack of standards, spotty interoperability, watered-down management functionality and the potential for show-stopping support conflicts.
For Pomposi, those concerns are so great Aetna won't consider deploying the technology for at least another
Pomposi's experience reflects that of many IT managers who are excited about the potential of storage virtualization, but see an emerging technology that's still nascent.
Few things define the state of the market like the confusion that has arisen around the phrase storage virtualization. Traditional storage vendors and upstarts apply varying degrees of virtualization in the switch, controller, host, storage subsystem or dedicated appliance, depending on the specific solution. The way these companies define the concept can vary just as widely.
"Storage virtualization is such a broad term that it's almost impossible to use it to describe any particular product feature," says Harald Skardal, senior consulting engineer at Sunnyvale, CA-based Network Appliance and a member of the technical council of the Storage Networking Industry Association (SNIA).
Fred van den Bosch, executive vice president of product strategy and new product initiatives for Veritas Software, Mountain View, CA, echoes Skardal's view that virtualization has become an overused, confusing term. "Two years ago, I told our marketing folks they should stop using the word virtualization," he says.
However, storage vendors still toss the word around like baseballs at spring training. Dan Tanner, senior analyst of storage and storage management at Aberdeen Group, isn't surprised vendors latched onto the virtualization term.
"If you are a marketer, you will use the latest buzzword to get attention," Tanner says. "Virtualization is any abstraction; there is no legal definition of the term."
As it turns it out, SNIA has crafted a formal definition for the term storage virtualization, although their wording leaves a lot of room for vendor interpretation:
- The act of abstracting, hiding or isolating the internal function of a storage (sub) system or service from applications, compute servers or general network resources for the purpose of enabling application and network independent management of storage or data.
- The application of virtualization to storage services or devices for the purpose of aggregating, hiding complexity or adding new capabilities to lower level storage resources. Storage can be virtualized simultaneously in multiple layers of a system, for instance to create HSM-like systems.
"For me it is a little bit frustrating," Skardal says. "Various companies have products in different corners of the storage infrastructure, and they are very eager to make sure they can reap some of the marketing benefits of doing virtualization." (For a rundown of virtualization products, see "Types of Virtualization")
Nearly every IT manager talked to in the course of this piece offered a similar opinion. Ken Horner, vice president of marketing for storage appliance maker DataCore, Ft. Lauderdale, FL, argues that some storage vendors, buying time for their own belated efforts, are poisoning the well.
"I don't think that the poisoning effect is at all unintentional - it's very intentional," says Horner. "Other companies that don't have products and have an installed base of customers they want to protect - they don't want to see this market move quickly. The paralysis and the confusion we've seen is classic FUD."
Compatibility and standards
Bruce Jacobs, director of information services at direct mail and database marketing firm ChoicePoint Direct, Alpharetta, GA, isn't so quick to criticize vendor marketing efforts. But he's wary of solutions that he feels will lock his shop into a single platform or vendor.
This was first published in June 2002