RAID 6
full spelling ： Redundant Arrays of Inexpensive Disks 6
alias ： Redundant Array of Independent Disks 6
RAID 6 is one of the levels of RAID. RAID 6 was added later as an enhancement for RAID 5 and was not one of the original RAID levels. RAID 6 extends RAID 5 by adding an additional parity block, thus it uses block level striping with two parity blocks distributed across all member disks. RAID 6 allows additional fault tolerance by using a second independent distributed parity scheme.
RAID Level 6 requires a minimum of 4 drives to implement. RAID 6 provides for an extremely high data fault tolerance and can sustain multiple simultaneous drive failures.