RAID 6 concepts

RAID 6 protection protects data from being lost because of a disk unit failure or because of damage to a disk. RAID 6 protection protects up to two disk unit failures.

RAID 6

If more than two disk units fail, you must restore the data from the backup media. Logically, the capacity of two disk units is dedicated to storing parity data in a parity set. However, in practice the parity data is spread among multiple disk units.

The minimum number of disk units in a parity set is 4. The maximum number of disk units in a parity set is 18.

When a RAID 6 parity set is started, all of the disk units contain parity. Restoring data to a disk pool that has disk units with device parity protection may take longer than a disk pool that contains only unprotected disk units.

The Reed Soloman algorithm and the hardware finite field multiplier, are used to create the stripes of parity data in a RAID set. These features enhance performance and functionality.

Note: It is recommended that you use more than four disk units in a RAID 6 parity set, because the capacity of two disk units is dedicated to storing parity data in a parity set.