A method for processing data multiplication in a disk array

摘要

The invention discloses a method and controller for processing data multiplication in a RAID system. The method relies on using the properties of a Galois field. The first step (200) produces map tables for values in a Galois field domain GF(2) according to the algebraic rules of a Galois field. In a second step (300) an XOR operation unit is enlarged to an appropriate length w to create a multiplication unit of w.a bits. The final step is to use the mapping tables and the operation rules to operate on a data sector of w bits to compute a multiplication of the Galois field online (400). The map tables can be generated in real time or at start up of the system. In a specific embodiment the method is used to reduce the number of calculations required when using parity sets to recover data from two or more disks having errors within a RAID6 array.