Depending on whom you ask, questions about where virtualization should reside in a storage environment and how to make the best use of it will garner different responses. Storage magazine spoke with Ken Steinhardt, EMC's director of technology analysis, who described the company's virtualization philosophy, and offered a glimpse into what EMC has up its sleeve.
"The crux of virtualization," Steinhardt says, is simply "fooling a component into thinking it's seeing something that's probably more complex than what it seems." The point of a virtualization abstraction layer, he adds, is almost always to maximize utilization and hide complexity. By that definition, EMC has been in the virtualization game since 1990 with the first Symmetrix, Steinhardt says, which fooled the mainframe's host operating system into thinking it was working with a traditional disk.
Fast forward 15 years, and the hot topic is network-based storage virtualization, which EMC thinks shouldn't supplant virtualization at the server and arrays levels. Servers should continue to run applications such as clustering and application failover, while storage arrays own functions such as RAID. "To arbitrarily move something to the network because you can, introduces problems," Steinhardt notes. That said, the network should be home to any intelligent storage pooling functions, in partnership with intelligent switch platform vendors such as Brocade, Cisco and McData.
EMC then plans to take storage virtualization one step further and virtualize the entire storage network, much in the same way VMware (an EMC company) virtualizes server hardware.
Together, a virtualized storage network and intelligent switches are enabling a feature EMC is calling dynamic volume migration. "Imagine being able to migrate a volume in real-time between heterogeneous storage platforms without having to shut down your systems, and at top performance," says Steinhardt. Today, volume migration entails either a planned outage or, if you're migrating data while online, causes you to take a significant performance hit.
All this fulfills another of Steinhardt's requirements for virtualization--that it "helps people do things they haven't been able to do before."