A two-dimensional parity method and system for rotating parity information
in a disk array, such as a RAID, to provide multiple disk fault tolerance
with reduced write bottlenecks, is presented. The method includes forming
a plurality of blocks, each block comprising a plurality of stripes
extending across multiple disks, reserving at least one stripe in each
block for parity, dividing each block into a plurality of chunks, wherein
at least one of the chunks in the block comprises parity information, and
shifting the position of each parity chunk in each block to a different
disk with respect to the parity chunk in adjacent blocks. The method
further includes shifting the position of each parity strip in the at
least one stripe in each block to a different disk with respect to the
parity chunk in adjacent blocks. A system for translating information in
a disk array includes an array controller configured to shift parity
chunks and parity strips.