However, late last month, IBM quietly nixed plans to implement virtualisation in Shark. Instead, the company plans to develop an enterprisewide virtualisation technology that sits on the network close to the switch â€" in an area also known as the "SAN [storage area network] cloud."
IBM's change of direction underscores a growing debate in the storage industry revolving around virtualisation and the frustration of IT managers anxiously awaiting the technology's promise of interoperability between storage systems and networks.
With storage virtualisation, IT managers would have the ability to logically move terabytes of data with a few simple keystrokes as well as more easily manage the vast and disparate storage devices they oversee.
But there's disagreement among vendors as to just where within the storage framework the virtualisation should reside, on the server, within the SAN cloud or in the applications. As a result, IT managers are worried that storage vendors from separate camps will end up squaring off.
The result could be the same problem that plagues other areas of storage: technology from one vendor that does not communicate with another vendor's products.
"I hope these companies are talking to SNIA [Storage Networking Industry Association] and the standards bodies as they are developing these products," said Rick Bauer, CIO of The Hill School. "I have five different network-attached storage products, and none of them talk to each other, and none can see each other.
"There is no single tool that virtualises them all," Bauer said. "That is the virtualisation Holy Grail I'm looking for. Everybody wants virtualisation, but then there are the NIMBYs, those who don't want to provide the hooks into other storage."
Compaq is working on a virtualisation software piece called VersaStor, and both it and IBM's Tank are expected out by year's end. Earlier this month, Kom Networks announced its Virtual Storage Works, which virtualises storage at the file level.
Storage service providers such as NaviSite want to see virtualisation done at the application level, so the application decides to move storage based on where it is needed.
"I want to solve the problem on the software layer, by making the application aware at the file level of the storage assets," said Peter Kirwan, vice president of business strategies at NaviSite.
When Shark was first delivered about 18 months ago, IBM planned to put virtualisation within the disk array. Now the focus is on Tank, a policy-based management virtualisation for data sharing on heterogeneous server platforms. Internally, IBM did not find a compelling reason to put virtualisation in Shark, according to analysts. For example, the company found a different way to execute the snapshot copy feature.
"Those [customers] that were expecting [virtualisation with Shark] I'm sure are disappointed. But I actually don't think many people were expecting it because IBM was soft-pedaling it from the start," said John Webster, an analyst with Illuminata.
IBM declined to comment, instead referring to its press release issued late last year outlining plans for Tank.
Virtual storage
- Compaq's VersaStor: SAN-wide virtualisation software helps erase boundaries between disparate systems
- IBM's Tank: Enterprisewide technology for policy-based management and data sharing
- Kom's Virtual Storage Works: File-level virtualisation
