Abstract: 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.

Abstract: A system and method for providing multiple disk fault tolerance in an N-column by R-row logical representation of stored elements in an array of N independent disks, R minus 1 being less than N divided by a number of disk failures F, includes assigning each strip containing data to at least F different parity groups so that each strip containing data in a respective column is assigned to parity groups different than other strips containing data in the column. The method also includes calculating, for each parity group, a parity value corresponding to all of the strips assigned to the parity group. The method further includes storing each of the parity values in strips of different columns, so that none of the strips containing data in a column are assigned to a parity group for which the parity value for the parity group is stored in the column.