Firefly Powers Down Disk Drives

The Firefly DM backup library, available to the general market this quarter, stands just short of 6 feet tall and comes in configurations ranging from 12 TB to 48 TB.

The device supports various RAID levels for data protection. But make no mistake, Asaca executives say: This product is not just another RAID controller. Asaca is marketing it as a library. So what makes the FireFly machine different from a big, fat disk array? The answer lies in a cool aspect of the technology that helps conserve energy.

Within the FireFly, a maximum of 48 drives can be spinning at any time. The data input and output is monitored, and if there is a period of extended inactivity in I/O, the drives are automatically powered down. Like tapes in a library, the disk drives remain in a dormant state until data needs to be recalled. But once information needs to be pulled, it only takes up to six seconds to retrieve data, whereas it takes about a minute to do the job with tape.

This kind of power-management technology is unusual, says Dianne McAdam, a senior analyst at Data Mobility Group. Disk subsystems from EMC and Hitachi Data Systems are always powered on, consuming energy even when the disk drives are not transferring data.

"Spinning a disk drive down is unheard of. In our market it is extremely unusual," says Chuck Larabie, a product manager at Asaca. "EMC disk drives don't power down because they are still bound by the definition of being a RAID system."

FireFly does support various levels of RAID, but even when the RAID is in place, it does not force the disk drives in the FireFly to be spinning all the time. Larabie says the power-down capability was not the initial focus of the technology.

Which companies are interested? "Broadcast companies," Larabie explains. "Companies that go through a huge undertaking when they make a request for another 10,000 watts of power every hour. So many companies are facing power issues in their data centers. One person, fresh from the California power crisis, told Larabie, "'It's amazing that it takes an economic disaster to create a power-managed storage device.'"

Each library can sustain up to a maximum of 400 MBps of I/O compared with tape speeds of 20 MBps. More important, FireFly makes use of another type of technology that is not often found in disk-based systems. The Self-Monitoring Analysis and Reporting Technology (SMART) tool helps avoid data loss by serving as an early warning system to disk failure. Most disks degrade over time. Originally established by IBM in the 1990s, SMART is included in most drive technologies by IBM, Maxtor and Seagate Technology. But not many make use of it, Larabie says.

Can disk finally become a viable backup alternative to tape? "We think so," Larabie says. "The per-megabyte cost of disk drives has dropped faster than any other media format. So we think it can compete in the tape market."