Home > Storage > PowerMax and VMAX > Storage Admin > Reliability, Availability, and Serviceability on PowerMax 2500 and 8500 Arrays > RAID 6
RAID 6 enables the rebuilding of data if two drives fail within a RAID group. Our implementation of RAID 6 calculates two types of parity. This is important during events when two drives within the same RAID group fail, because it still allows the data in this scenario to be reconstructed. Horizontal parity is identical to RAID 5 parity, which is calculated from the data across all disks in the RAID group. Diagonal parity is calculated on a diagonal subset of data members. For applications without demanding performance needs, RAID 6 provides the highest data availability. PowerMax systems support RAID 6 (6+2) with data striped across 8 drives (6 data, 2 parity).