RAID 6: Independent Data disks with two independent distributed parity schemes
Characteristics/Advantages
1. RAID 6 is essentially an extension of RAID level 5 which allows for additional fault tolerance by using a second independent distributed parity scheme (two-dimensional parity)
2. Data is striped on a block level across a set of drives, just like in RAID 5, and a second set of parity is calculated and written across all the drives; RAID 6 provides for an extremely high data fault tolerance and can sustain multiple simultaneous drive failures
3. Perfect solution for mission critical applications
http://www.sansky.net/wp-content/2007/06/windowslivewriterraid6-9ca5clip-image003.gifDisadvantages
1. Very complex controller design
2. Controller overhead to compute parity addresses is extremely high
3. Very poor write performance
4. Requires N+2 drives to implement because of two-dimensional parity scheme
http://www.sansky.net/wp-content/2007/06/windowslivewriterraid6-9ca5clip-image001.gif
