The trick to the whole thing is where to perform the virtualization or mapping of the data from one place to another. This is where the battle will commence and where Compaq, in particular, is staking out ground.
The server vendors love virtualization, as it can be located on the application host; the switch vendors claim it is a natural function of traffic management within the storage network; and the storage device manufacturers say it must obviously be located where the storage resides.
Compaq meanwhile, is quietly infiltrating all three fronts.
Since June of last year, the company has been developing its "VersaStor" technology, which will provide block-level virtualization through a dedicated appliance on the SAN, says Mark Sorenson, VP of storage software and solutions for Compaq's enterprise storage group. To maximize portability across operating systems, Compaq's technical strategy is to utilize the existing paradigm -- whereby the operating system "thinks" it is writing to a physical disk -- while mapping to the virtual storage pool is handled by the VersaStor technology and appliance.
This appliance will map the logical storage to its physical location, calculate how to automatically move data within the SAN storage pool, and send the latest versions of the mapping tables to agents that will use these mapping tables to store and retrieve data.