As with all things "cloud" these days, there's an interesting dichotomy between those who are head over heels excited about the huge potential of private cloud approaches and those who see it as a marketing-driven rebrand of what everyone is already doing: virtualizing the data center. In the end, the truth is somewhere in between.
Although the private cloud has the potential to solve many of the scalability and service-delivery challenges that larger IT departments wrestle with, it is not magic. Really reaping the benefits of the private cloud requires an IT-savvy customer base, a willingness from the executive suite to adopt a chargeback model, and no small amount of work to configure it in such a way that it will actually save everyone time in the end.
At the same time, a true private cloud implementation is not just data-center virtualization with a new coat of paint. Although it's true that much of the gear you might use in a private cloud ends up being put together in the same way as you would in a traditional virtualization model, the self-service nature of the private cloud demands a completely different mindset from those planning and building the underlying virtualization and storage infrastructures.
[ In the data center today, the action is in the private cloud. InfoWorld's experts take you through what you need to know to do it right in our "Private Cloud Deep Dive" PDF special report. | Also check out our "Cloud Security Deep Dive," our "Cloud Storage Deep Dive," and our "Cloud Services Deep Dive." ]
What's different about private cloud storage
The pitfalls of delivering storage in the private cloud
Those challenges are certainly not insurmountable, but the solutions come with their own pitfalls. For example, budgeted IT infrastructure investments are typically a fairly substantial projects that might implement an entire year's worth of expected storage growth at once. As anyone who has shopped for enterprise storage knows, vendors are typically much happier to give you a steep discount on a few hundred thousand dollars of investment executed at all once than they are for a few tens of thousands of dollars spent here and there throughout the year.
Solving that challenge usually requires negotiating with the vendor to get a fixed discount and accurate lead-time expectations on storage gear for the entire year. That way, you can match your chargeback rates to your underlying costs -- whether you're buying a whole new SAN or just a few disks.
The demand for that sort of incremental growth may also sway your thought process when it comes to what kind of storage gear you opt to use. Some storage hardware is simply impossible to grow in small increments, whereas others may scale gracefully up to a point where an expensive and disruptive forklift upgrade is required. Fortunately, storage vendors have recognized this challenge. Some are increasingly delivering scale-out storage gear that can grow linearly. Others are focusing on built-in storage virtualization layers that cluster multiple scale-up storage infrastructures to achieve similar results. Both approaches try to avoid the pain of the forklift upgrade.
Putting it all together