Patent ID: 8725986

Claim:
A method for mapping a volume block number to a disk block number in a storage system, the method comprising: computing a table relative volume block number for the disk block number of a storage device of a storage device array implementing a redundancy technique, wherein the table relative volume block number is an entry in a two-dimensional mapping data structure, wherein a disk number of the storage device corresponds to an index of a first dimension of the two-dimensional mapping data structure, wherein a chunk is computed by dividing the disk block number by a chunk size, wherein a table stripe value is computed by taking the chunk modulo a repeat interval, wherein the table relative volume block number is identified by indexing into the two-dimensional mapping data structure using the table stripe value as an index of a second dimension of the two-dimensional mapping data structure and the disk number as the index of the first dimension, and wherein the two-dimensional mapping data structure is created using an initial number of disks field and a current number of disks field; identifying a logical disk number using the table relative volume block number; identifying a start of a volume block number range; computing a volume block number associated with the disk block number of the storage device; and maintaining the two-dimensional mapping data structure by excluding parity blocks from a volume block number space.