Although it rhymes with RAID (redundant array of inexpensive disks), MAID (massive array of inactive disks) is a completely new approach to storing data. It's an approach that is carving out its own niche among tape-based and disk-based data-protection solutions. (For a primer on MAID and some of the players in the market, see "MAID technology challenges tape.")
To rival tape drives, MAID solutions treat disk drives as start/stop devices, powering on units only when access is needed to store or retrieve data. For that reason, in MAID solutions you will find parallel or serial ATA drives, engineered to survive repeated power cycles unlike the more vulnerable SCSI drives.
Copan Systems, one of the pioneers of MAID solutions, has released its first product, the Revolution 200T. The 200T is a capacity hog, storing as much as 224TB of backup data in a 3-foot wide, 7-foot-high cabinet.
Fully configured, the Revolution 200T can emulate as many as 56 distinct tape libraries from major vendors, and can be the target of backup applications from BakBone, Galaxy, and Veritas, ensuring a transparent migration from tape libraries to the Copan box.
Copan claims an unrivaled data transfer rate of 2.4TB per hour for its Revolution 200T. They also estimate a TCO of 40 percent to 50 percent, compared to other disk-to-disk-to-tape approaches. Currently the Revolution 200T, with its FC and GbE connectivity, doesn’t offer WORM (write once, read many) capabilities, but Copan plans to add that feature in future releases to attract customers with those compliance requirements.
The architecture of the Revolution 200T is intriguing, although you may have to adjust to its gargantuan storage proportions in its extremely compact build. The unit mounts 250GB SATA (serial ATA) drives from Hitachi, Maxtor, or Seagate. Its core is a canister, essentially a narrow drawer where 14 drives stand vertically over two facing rows. Group eight canisters to make a shelf, and pile as many as eight shelves to fill the cabinet with an amazing 896 (yes, almost 900) drives. Adopters may start with a minimum configuration of 56TB on two shelves and increase capacity in 28TB increments.
Whatever the configuration, typically only 25 percent of the drives will be active at any given time, which helps keep environmental factors such as noise, heat, and power consumption down, but which creates some unprecedented challenges in maintaining data reliability. To that end, Copan has surrounded the unit with three tiers of management software and has developed custom technologies such as Power Managed Raid and Disk Aerobic that ensure parity protection across canisters and monitors disk drive integrity.
If you feel that the Revolution 200T turns the tables on our conventional way of using disk drives, you are right. Copan’s new product may not have rendered tape libraries obsolete, but may significantly reduce their deployment target. I wouldn’t be surprised to see MAID arrays become part of tape library offerings in the near future.