Nov 08 2010

The Skinny on Thin Provisioning

Thin provisioning helps IT departments manage data more efficiently and save money on energy and equipment costs.

Thin provisioning lets IT staff manage storage more efficiently.

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Not long ago, recopying data from tape when a hard drive died could take a day or two for the IT department at Ohio State's Fisher College of Business. Simply adding new storage when a disk filled up was a laborious process.

That changed when the college installed a Compellent storage area network with thin provisioning technology. Recovery from a failed disk now takes minutes, says Brian Wilson, the college's principal system developer.

“We no longer encounter downtime or the need for migration when we expand disk space for users,” Wilson says.

The SAN treats all attached storage devices as a virtual pool, and thin provisioning ensures that the storage devices are used almost to capacity before IT managers must purchase and install new storage. Other benefits of the combined technologies include enhanced security and storage efficiency and considerable cost savings. Fisher College now uses thin provisioning for 95 percent of its data storage, and allocating space is a snap, says Wilson.

Turn to Thin Provisioning

As the data storage needs of higher education institutions continue to grow, experts say more of them are turning to thin provisioning.

With traditional technology, discrete blocks of storage are set aside for every application or user who might need it. The tendency of users to overestimate storage needs frequently results in an over-allocation of storage capacity. The result is that utilization rates can be as low as 20 percent.

Mark Peters, a senior analyst at the Enterprise Strategy Group, says the inefficiency is like a bus that won't let on new riders despite being only 20 percent full because passengers are saving seats for friends and family members, including the unborn, who might want to ride in the future.

“The old way of provisioning led to appalling levels of utilization,” Peters says. “If other resources in the world were used as poorly as storage space once was, people would be laughed at.”

Inefficiency was tolerable when IT constituted a small part of organizations' operations and budgets, and the cost of storage generally declined at a rate that offset increased use. Recently, however, the cost of storage hasn't fallen fast enough to compensate for surging IT use and corresponding increase in demand for storage.

“Over the last few years there has been a massive focus on doing things not just effectively, but more efficiently in terms of using fewer resources,” Peters says. “The big mantra in IT is to do more with less.”

Thin provisioning delivers physical storage on demand. If a particular application experiences a rapid spike in storage needs, the system automatically dips into the shared storage pool to provide it. This lets IT managers allocate considerably more storage than the physical capacity they actually possess. Technicians can easily monitor the system, or any part of it, from a single computer screen. As the networked storage devices approach full capacity, the system alerts technicians to buy more.

The percentage of IT departments surveyed that now use thin provisioning

Source: TheInfoPro survey of 1,000 large organizations

Seattle University in Washington is also using thin provisioning technology. Bo Vieweg, the university's former CIO, says thin provisioning is a much more efficient way to manage data. He says the technology reduces the number of times users need to contact the IT staff.

“If a group of professors plans a big research project with their classes, they wouldn't have to worry about data storage filling up. The system handles that automatically,” Vieweg explains.

Seattle University uses thin provisioning for about one-third of the 20 terabytes of data it stores, mainly for the digital storage space provided to all faculty, staff and students. The university does not currently use the technology for its more critical operations, such as course management, student records and accounting. 

“Thin provisioning is a newer technology,” Vieweg says, adding that it won't be long before more IT managers will be willing to use it for all of a college's data storage.

This past May, Vieweg became the CIO at Greenville Technical College in South Carolina, where he is helping to draw up an IT plan. “I'm sure thin provisioning will have a role,” he concludes.

Why IT Loves Thin Provisioning

Here are the leading reasons IT departments embrace thin provisioning: 

  • Increased data storage capacity utilization: Typical increases are from about 25 percent to 80 percent.
  • Significant reduction in IT staff time for managing data storage: A decrease of 90 percent is not uncommon.
  • Smaller data center footprint: This results in lower electricity and cooling costs.
  • Equipment cost savings. More effective data management reduces and delays the purchase of storage devices.