Method for performing a RAID stripe write operation using a drive XOR command set

Abstract

Method for implementing a stripe write operation in a RAID device having XOR command set enabled disk drives on a common interface bus. The method of the present invention improves upon prior designs which do not use the XOR command set by eliminating the need for the RAID controller to include XOR (parity) generation computational elements. Further, the method of the present invention improves upon the stripe write method suggested by the XOR command set specifications in which a stripe is performed by a series of xdwrite XOR command operations issued to the data drives of the RAID array. Rather, the method of the present invention performs parallel standard writes of the data portions of the stripe write, then issues a rebuild XOR command to the parity disk drive to rapidly regenerate the parity blocks in the stripe just written. The method of the present invention reduces the worst case rotational latency delay of the stripe write operation to two rotational latency periods.

Dependencies are inferred from the claim text.