Calculating the return on investment (ROI) for block-based storage virtualization products can be tricky because it often boils down to an estimation of the soft costs associated with moving data and managing disk arrays.
The virtualization software creates an abstraction layer that lets IT shops treat disk arrays from different vendors as a single pool of storage. One of its main use cases is migrating data between storage systems, with the advantage of minimal if any disruption to the applications.
Virtualization products able to manage block-based storage from multiple vendors include DataCore Software Corp.’s SANsymphony-V, EMC Corp.’s Vplex, FalconStor Software Inc.’s Network Storage Server (NSS), Hitachi Data Systems (HDS) Corp.’s USP and VSP, IBM’s SAN Volume Controller (SVC) and SVC-based Storwize V7000 array, and NetApp Inc.’s V-Series.
“Most of the time, there’s not a really effective calculation of the ROI,” said Andrew Reichman, a principal analyst at Cambridge, Mass.-based Forrester Research Inc. “It’s hard to come up with a real number. Really, what you’re going to do is compare a few different scenarios of how you are going to accomplish this data migration.”
Russ Fellows, a senior partner at Boulder, Colo.-based Evaluator Group Inc., said the calculating ROI is oftentimes difficult because in many cases the existing storage systems remain. Also, the gains in IT administrative productivity can be tough to quantify, he noted.
Many IT shops don’t even bother with a formal ROI calculation. The city of Coquitlam, British Columbia, bought Hitachi’s USP VM — the low-end version of the USP-V — in 2008 after learning that its HDS Thunder 9570 arrays weren’t certified to work with a new version of VMware Inc.’s server virtualization.
Darren Browett, the Canadian city’s technical services manager, saw no reason to compute the potential ROI for the USP VM. “We needed storage. We had to have it, and it was the right technology fit for us with what we were trying to do with virtualized servers and building towards the future,” he said.
The USP VM helped to extend the life of the 9570s that it virtualized, and last year, when the time came to retire the Thunder arrays, the storage virtualization functionality enabled Coquitlam to move to new HDS Adaptable Modular Storage (AMS) 2100s with no appreciable downtime.
Carol Sliwa (TechTarget)
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