RAID 6 — Characteristics And Advantages

Double-parity RAID (redundant array of independent disks), also called diagonal-parity RAID, Advanced Data Guarding (RAID_ADG), or RAID 6, is a method of protecting against multiple storage drive failures by creating two sets of parity data on an array of hard disks.

RAID 6 is an extension of RAID 5 which allows for additional fault tolerance by using a second independent distributed parity scheme (dual parity). For RAID 6 parity is calculated using the Reed-Solomon ECC Code in addition to the traditional XOR parity scheme. These two independent calculations are then written separately on the disks within the RAID 6 set along with the data. With the addition of a second independent parity scheme RAID 6 provides for an extremely high level of fault tolerance and can sustain two simultaneous drive failures of any drive in the RAID group making this solution the highest capacity/fault-tolerance solution available. With these features RAID 6 is ideally suited for mission critical applications.