Want To Cut Storage Power? Turn Off Disks

If you’re running a data center, energy costs are a top concern. It takes power to run computers, store data and keep the place cool. In 2007, the U.S. spent $1.3B to power and cool drives, according to IDC. “We estimate that 60 to 80 percent of power costs in data centers are related to storage,” Suresh Panikar, director of worldwide marketing for storage controller maker Adaptec, says.

Most drives can shut down after a period of idleness to conserve power and reduce wear and tear. Unfortunately, many operating systems constantly write housekeeping data, such as registry information or timestamps, to attached drives. This keeps them spinning and, as a result, using power.

Adaptec is tackling the cost of storage with a line of RAID controllers that can reduce the power a drive uses by more than 70 percent, depending on the model, simply by powering it off. The new controllers — part of the company’s Green Power initiative — are smart enough to identify this housekeeping data. They store it in a battery-backed cache and only write to the drive when really needed. The controller can also periodically spin up long-idle drives to check their health.

System administrators can define power policies for storage systems, configuring when drives are idle, within the controllers’ configuration screens. Suresh believes the controllers may have other benefits, such as extending the lifespan of storage hardware and reducing the overall cooling of the data center.

There are limitations, of course. Only certain classes of applications, such as disk-to-disk backups, archival e-mail, and print servers will achieve the best power savings. And Suresh notes that many high-end storage systems already offer power management, so the new controllers are likely to primarily benefit OEMs and systems integrators.

But given the rising costs of data center operations, more efficient storage is a promising step in the right direction.