The Virtualization Factor

Is there a connection between the use of virtualization and other newfangled storage technologies? If your business is moving to virtualization, for instance, is it likely to install an iSCSI SAN as well?

One storage VAR answers "yes" to both questions. For the last several months, since VMware released Infrastructure 3 with iSCSI support, demand for iSCSI has burgeoned, says Barron Mertens, CEO of DSG Storage Inc., a VAR based in London, Ontario. (See VMware 3 Gains Rapid Adoption.) "We've seen a sizeable growth in demand," he notes.

"Generally speaking, people who are eager to get ESX 3 into production see that it's pointless to save on the server side and spend a wad of cash on Fibre Channel," he says.

Most of his customers who are intent on consolidating their servers are starting with a blank slate. They follow the thread of savings by initiating a new storage network based on iSCSI.

Mertens says the customers who are buying iSCSI alongside virtualization range from very large (a government agency with 800-plus servers) to medium-sized (a handful of servers).There are other factors that boost iSCSI adoption in virtualized networks. "Disaster recovery is particularly easy to do with iSCSI," he says. "And sync replication is cheaper and easier with iSCSI compared with Fibre Channel."

Of course, Mertens has an axe to grind, since he sells iSCSI systems. But there are industry hints that his empirical claims may have a solid foundation. Both virtualization and iSCSI appear to be taking off and there are signs they may often be doing so hand in hand.

Consider, for instance, the growing roster of products that support iSCSI and virtualization. DataCore's SANsymphony will soon sport multi-path I/O drivers that allow use of Fibre Channel and iSCSI paths for failover and thin provisioning. (See In-Band's Virtual Song.) Qlogic's latest iSCSI HBAs also support VMware Infrastructure 3. (See QLogic Supports VMware.) Adaptec has made a point of its plans to combine iSCSI virtualization with NAS. (See Adaptec Looking to Adapt and Adaptec Launches Software.)

One analyst sees a more direct link between virtualization and iSCSI. "The success of LeftHand and Equallogic as well as NetApp with iSCSI has been in part due to their underlying non-hyped virtualization and abstraction capabilities," asserts Greg Schulz of the StorageIO Group consultancy. While some would argue that these vendors don't support virtualization in the same technical sense as vendors like VMware, he says key functions of the iSCSI SAN arrays are clearly analogous — replication, abstracting of physical hardware, and storage pooling, for instance.

There is still much debate about both iSCSI and virtualization. (See Users Talk Virtual Tension.) But there is also growing evidence, at least anecdotally, that the same drive to make the most of capacity and bandwidth are shared by buyers of both. In the coming year, we'll be on the lookout for hard numbers that illustrate a connection.— Mary Jander, Site Editor, Byte and Switch