By Heidi Biggar
When it comes to provisioning, 3PAR appears to have all the bases covered—and then some. The five-year-old vendor of InServ Storage Servers not only automates the manual process of provisioning storage capacity but also minimizes the amount of storage that is actually used.
According to some estimates, as little as 25% of allocated physical capacity is actually ever consumed in user environments. For a variety of reasons (notably, the need to service application demands as they occur), IT administrators tend to overbuy disk capacity, which can send overall capital and operating costs skyward.
Instead of dedicating capacity on allocation (which requires users to buy capacity up-front before volumes have actually been written), 3PAR's "thin provisioning" allows users to allocate large logical volumes up-front from a common pool among multiple applications. The idea is that by making such a large allocation up-front, users will only have to allocate capacity once for each application.
Actual physical capacity is consumed only when an application writes data to the disk array. When the storage system needs more capacity, it pulls capacity from the reserve cache, or "common buffer pool." When this pool runs low, the array notifies 3PAR and more disk capacity is sent.
"All you need to buy is what you need to cover your writes plus a buffer," says Geoff Hough, manager of product marketing at 3PAR.
The advantages of this type of approach are several, says Gruener. "You don't have all the capacity challenges associated with traditional provisioning methods, you can deploy new applications more quickly, and you don't have to retrofit provisioning tools to your environment."
Over the past year, a variety of vendors, including AppIQ, CreekPath, FalconStor, IBM, InterSAN, Softek, and others, have announced software products that automate various aspects of the provisioning process. While these tools may do a good job of automating the workflow process (and minimizing user time spent scripting provisioning tasks), Gruener says they do not address the utilization problem in the same way that 3PAR does. Also, other vendors tend to approach the problem in "piecemeal" fashion, often requiring users to buy multiple products (e.g., a provisioning tool and storage resource management software) to accomplish the task, he says.
On the other hand, the 3PAR approach requires users to "buy into" the 3PAR infrastructure, which means purchasing InServ Storage Servers. "It's either integrated and simple, or piecemeal," explains Gruener. "Buying an integrated system simplifies the whole process, but it typically means you have to buy more storage."
InServ Storage Servers come with 3PAR's "trivial provisioning," a stripped-down version of thin provisioning that, like traditional provisioning approaches, requires users to set aside physical capacity up-front to support the exported logical capacity (see figure on p. 8).
However, both techniques are faster than traditional techniques due to the way in which the InServ platform virtualizes and load balances the environment, according to 3PAR officials. Users can reportedly create virtual volumes in less than 15 seconds; no LUN planning or mapping is necessary.
Thin provisioning is available as an option (as part of the Express Suite) and is priced at $0.005 per megabyte of used raw capacity.
3PAR says 60% to 70% of its disk arrays are sold with thin provisioning installed. An Internet marketing firm, for example, recently purchased the software for its e-mail applications. By implementing thin provisioning, the firm says it was not only able to allocate storage more quickly but also cut its capacity requirements by more than 50%.