Patent ID: 6332177
Filing Date: 2001-12-18
Classification: G06F

Abstract:
A method for mirroring data blocks in a disk array storage system having a plurality of disk drives comprising the steps of:writing a data block to a disk drive of said plurality of disk drives in said disk array storage system;duplicating said data block in at least one duplicate block written on a corresponding disk drive of said plurality of disk drives in said disk array storage system; andmapping said data block prior to the step of writing to determine a disk drive for said data block to be written to said disk array storage system and to determine a disk drive for each duplicate block of said at least one duplicate block to be written to said disk array storage system,wherein the number of disk drives M in said plurality of disk drives is greater than the total number of blocks N written by the steps of writing and duplicating and wherein said data block is mapped to said disk drive and wherein said at least one duplicate block is mapped to said corresponding disk drive;wherein said data block is associated with a logical block address and wherein the step of mapping comprises the steps of:determining said disk drive for writing said data block as a function of said logical block address and N and M; anddetermining said disk drive for writing each duplicate block of said at least one duplicate block as a function of said logical block address and N and M.