Network Appliance has introduced RAID technology which it claims is 1000 times more reliable than the RAID-4 version it uses today, and more efficient than mirrored RAID. Called RAID-DP, the new scheme uses two parity disks per array, instead of one, yet with no loss of storage efficiency.

"This adds an extra parity drive, so instead of two sets of 6+1, say, it would now be 12+2," says Stuart Gilks, NetApp's systems engineering director for Northern Europe.

"It can survive the loss of two drives, although a more likely problem is you lose one drive, then have a media error on a second drive during reconstruction." With RAID-DP, that error could still be recovered, he adds.

NetApp has also added SAN/NAS filers and a broader range of disk-based backup to its product line, and certified its gFiler NAS head for use with IBM's Shark enterprise storage system.

Gilks says that RAID-DP will be standard on the new NearStore R200, which provides 8 to 96TB of online disk-based backup, and will be an option on the FAS980, which extends NetApp's SAN/NAS range to a maximum of 64TB.

NetApp also announced load balancing software for its gFiler range. Called SnapMover, this allows virtual NAS servers to be created within the SAN, and then be moved from one NAS head to another as needed. Because this works by transferring ownership of the logical volumes in the SAN, it avoids the need to physically migrate data.