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Massive array of idle disks (MAID) has become synonymous with disk spin-down, which has become synonymous with power savings. That's not the way MAID pioneer Copan Systems saw it when it rolled out the first MAID system in 2004. Power savings were merely one benefit, along with increasing the life of low-cost SATA drives by using them less and lowering the cost of disk-based backup and archiving.
As green computing has gained in popularity, vendors that followed Copan into the disk spin-down space have made it more about power savings. Hitachi Data Systems calls its spin-down technology Power Savings Storage Service, and offers it for Fibre Channel (FC) as well as SATA drives in its midrange storage arrays. Nexsan Technologies recently made its AutoMAID available on SAS drives.
And more is coming: EMC released its first spin-down product this year with plans to offer the technology on all of its disk products, and ONStor is planning to add MAID on its Pantera NAS boxes this year.
With other vendors now crowding its turf, Copan's new mantra is: There's more to MAID than disk spin-down.
"MAID wasn't developed only to save power; it was to add other functions to disk drives," says Chris Santilli, Copan's CTO. "First, we can put more disk drives into a single cabinet than other systems in the industry. And we add reliability and/or disk service life. If disk drives
| aren't on all the time, the MTBF [mean time between failure] will increase and you can have a longer drive life."
Santilli claims that drives in Copan's Revolution systems have an average MTBF that's five to six times as great as the average disk drive. He says Copan will support SAS drives soon, and the company recently added features to reduce the performance penalty of MAID, such as setting up a cache landing zone that keeps up to 40 drives separate from the MAID pool so those drives always spin and increase the ingestion rate while handling data dedupe.
Mark Peters, an analyst at Milford, MA-based Enterprise Strategy Group (ESG), backs Copan's claim that MAID is more than just spin-down. "Copan came out with an implementation of MAID, and now everyone else is doing spin-down, which isn't strictly MAID," he says. "With a MAID system, you couldn't run all the drives even if you wanted to. More and more people are putting a spin-down capability into drives, but you could run all the drives if you wanted to."
But with power costs soaring--Framingham, MA-based research firm IDC estimates data centers spent $1 billion powering and cooling drives in 2007--it's no wonder MAID is catching on for its green powers.
This was first published in August 2008