The fourth outcome of invalidated assumptions is that we spend far too much on storage. Some sophisticated IT organizations have done post hoc analysis of their virtualization ROI, and the results are frustrating. As expected, the TCO of servers was significantly reduced. However, incremental spending on storage -- more hardware, higher-end hardware, more array software licenses, and increased operating expenses -- swamped the savings on the server side. In hindsight, server virtualization didn't save them any money. A dirty little secret of the virtualization industry.
InfoWorld: So with that said, what do you believe is the technical solution IT people are using to deal with these problems today?
Virsto: If you've been in IT long enough, you already know the answer. When all else fails, get a bigger hammer.
Many of the issues discussed above can be handled by throwing enough hardware and money at the problem. A cruel paradox of server virtualization is that the more we commoditize servers -- to the great benefit of enterprise and cloud datacenters -- the more we have to invest in mainframe-style storage to take advantage of the promise of virtual servers.
Want to dynamically allocate server workloads? No problem, you'll just need a bulge bracket SAN. Want to deal with the capacity bloat caused by VM sprawl? Just buy a higher-end storage system, load it up with expensive software features -- oh, and you'll need more specialized cache in the array.
The alternative is to scale back on deployment of virtualization. Don't fully load your servers, so you get a lower consolidation ratio. Or leave the I/O-intensive apps on physical servers. Certainly an option, but if the obstacles were removed, IT pros would virtualize a lot more of their apps.
Sometimes, overprovisioning is an acceptable answer. This time-honored technique is a standard part of an IT architect's toolkit. But any time IT pros systematically solve problems by overprovisioning, there's an opportunity to invent a more clever solution. Come to think of it, that's how we got server virtualization in the first place.
InfoWorld: So tell us, in your opinion, how should the industry proceed?
Virsto: IT pros, resellers, consultants, integrators, bloggers, and analysts need to get educated and open a dialog. Vendors love to gloss over the issues or claim that if only you're willing to spend enough, the problems have already been solved. For organizations that can throw money at the problem, that's fine, but what about the rest of us? What's really needed is fundamental innovation in storage for VMs, just as the hypervisor itself was a seminal innovation.