When it comes to storage virtualization, everyone from the top vendors to enterprise users talks about it, but nobody does much about it.
That is, until now. The major storage companies are delivering products or planning to shortly, and the proof of the storage virtualization concept is coming to a datacenter near you.
Storage virtualization is the ability of IT managers to work with logical representation of physical storage. Using virtualization, IT managers can see and manage data as a single logical resource, regardless of where it physically resides in the typical disparate group of storage systems and networks. It should be noted that storage virtualization has existed in the mainframe world for many years. Bringing it into the open systems arena, where multi-vendor systems and operating systems proliferate, has proven a bit more difficult.
The promise of storage virtualization is cost savings, simplicity, and increased productivity. "For years, companies simply threw more storage at their storage problems, but now they've got a management problem. Virtualization promises to make all that storage easier to manage because it won't matter where the data is stored," said Randy Kerns, an analyst at the Evaluator Group.
For years, that is all storage virtualization was: promises. Granted, some smaller companies have offered storage virtualization products, but now most of the major players have introduced products or laid out their storage virtualization strategies. That means IT departments can begin to implement storage virtualization projects, said Kerns. "I think we're going to see some results before long. It's not going to happen overnight. IT managers aren't going to completely replace their storage systems, but we'll see how this works before long," he said.
IBM and Hitachi Data Systems have introduced storage virtualization products and EMC has shown its Storage Router offering. EMC says is plans to ship the Storage Router by the end of the second quarter. Last month, HDS unveiled multi-vendor virtualization capabilities for its TagmaStore Universal Storage Platform, raising its profile in the storage virtualization sweepstakes.
There is a key architectural difference between EMC's approach and that of IBM and HDS.
IBM's TotalStorage SAN Volume Controller is a controller that sits on the data path between applications and storage resources. EMC's Storage Router is out-of-band, with the router communicating with intelligent switches such as those from Cisco to establish a connection, allowing the application and storage devices to communicate directly, said Mark Lewis, executive vice president for storage software at EMC.
IBM argues that its system is much faster because it allows for caching near the application, said Jens Tiedemann,IBM's vice president of storage software."Our approach allows for companies to perform more services, such as copy services and data replication, over the network," he said. HDS's system is roughly similar to IBM's take on storage virtualization.
Kerns said both vendors' approaches are viable, but that users will likely dip their toes in the virtualization waters slowly. "I don't see too many storage managers going wholesale for virtualization initially. It will take a while to build," he said.
One of the companies taking the dip is Oakwood Healthcare System, a network of four hospitals in southern Michigan. According to Brian Perlstein, the information technology technical architect at Oakwood, he has already seen some results.