Capacity planning for storage deployments is one of those tasks that IT personnel tend to dread. Despite the availability of all sorts of capacity planning tools, a wealth of research, and consulting services from storage management specialists, the determination of how much physical storage is necessary on the corporate network always involves a "best guess."
Nothing is inherently wrong with an educated guess when buying storage, but the nature of the beast is that you don't want to be continually reprovisioning your network's storage. As a result, you usually end up buying as much storage as your budget allows, even if you're pretty sure that you won't immediately need it.
An interesting dichotomy often appears at this point. After you've tried to anticipate the amount of storage your applications will need for the next few years and have bought all the storage hardware you can afford, some large percentage of that storage won't be used right away. In fact, it might never be used.
The nature of standard provisioning techniques is that you buy storage because you might need it, but there's no guarantee that you'll need it. As a result, you spend a lot of money on physical devices in a market in which the cost of the media continually drops. In other words, the money you spend today could easily purchase significantly more storage if you spent it later in your storage solution's useful life.
The typical approach to storage provisioning means that administrators often buy lots of unused storage that, as it turns out, they don't need. 3PAR has found a way to address that problem through its 3PAR Utility Storage product's Thin Provisioning technology. Thin Provisioning software is available only on 3PAR hardware, but the concept is so intriguing and offers such a large potential cost savings that it's been a deciding factor in winning storage contracts for the company, and I guarantee that other storage vendors will take notice.
In a nutshell, 3PAR's Thin Provisioning lets you fully provision your applications' projected storage needs without actually buying all the physical storage that you estimate those applications will eventually require. Using a three-layer virtualization technique, you provision the maximum storage requirement for an application (over its lifetime) just once. The application draws the physical storage that it needs from a common pool of physical storage that several applications share. As you need additional storage (i.e., as the available unassigned pool storage drops below a predetermined level), you buy it and add it to the common pool.
The Thin Provisioning concept makes provisioning application storage significantly easier. Overestimating required storage doesn't have a financial impact on the business because you buy only the amount of physical storage that you need right now. Departmental requests for storage requirements are often inflated because of a fear that sufficient storage won't be available; Thin Provisioning eliminates the cost associated with overestimating storage needs.
The most important fact is that, with Thin Provisioning, you buy only the storage that you actually need. With the need to justify every IT dollar spent, a solution that more efficiently uses those dollars and provides a quicker Return on Investment (ROI) demands consideration.
You can find complete information on 3PAR's Thin Provisioning technology and software at the second URL below. Hindsight might prove this provisioning approach to be the most significant advance in storage technology of the past few years.