Nexsan paints SAS green

Nexsan claims to be the first supplier with an energy-efficient SAS storage system. The company has taken its AutoMAID technology, which throttles back the power usage of hard drives that are not currently being accessed, and applied it to a SAS array.

The result is high-performance storage for fixed content, said Bob Woolery, Nexsan's senior VP of marketing. He added that there is an increasing amount of content that doesn't change once it has been created, but which still needs to be available fast, such as medical images, video content, intranet content, and some databases.

Nexsan's previous fixed-content systems used cheaper but slower SATA drives. SAS drives yield faster random access and faster streaming than SATA, but so far SAS arrays have been too power-hungry for high volume storage, according to Woolery.

"Some of our fixed-content customers said they would like a faster response in some applications - for example, pushing log files to faster SAS drives - so we married SAS with AutoMAID to make it energy-efficient," he explained.

MAID (massive array of idle disk) technology turns off unused drives completely. That cuts power consumption by 100 percent but can introduce delays of several seconds when they have to spin up again. AutoMAID instead aims to offer a happy medium, with multiple energy saving modes that range from simply parking the read/write head and cutting power use by perhaps 20 percent, to turning off the disk's motor and saving 60 percent.

"From the perspective of the host OS, SASboy acts like any SAS RAID while opportunistically looking for ways to save power," Woolery said. He claimed that it has little competition, with other fixed-content storage suppliers such as EMC, NetApp, IBM and HP "all mostly offering primary storage, repackaged with SATA drives."

SASboy provides both iSCSI and Fibre Channel connectivity, and includes redundant components and RAID for resilience. Woolery predicted that the smallest configuration available - 14 drives of 300GB each, in a 3U chassis - would have a street price of around £15,000 for 4.2TB of storage.