Patent ID: 6799283
Filing Date: 2004-09-28
Classification: G06F,G11B

Abstract:
A disk array device for executing a read operation for reading data recorded therein in response to a first read request from a host device, said disk array device having recorded therein data blocks generated by dividing the data and redundant data generated from the data blocks, said disk array device comprising:m disk drives across which the data blocks and the redundant data are distributed, wherein m&gE;2; a parity calculation part operable to calculate parity from (mâˆ’2) of the data blocks and the redundant data to recover a remaining data block; and a control part operable to control the read operation, wherein said control part is operable to: calculate a timeout period for at least one of said m disk drives based on previously required reading times of said at least one of said m disk drives; issue second read requests to read the data blocks and the redundant data from said m disk drives in response to the first read request sent thereto; when (mâˆ’1) of said m disk drives complete reading, detect whether a partial set of the data blocks and the redundant data has been read from said (mâˆ’1) disk drives; when detected that the partial set of the data blocks and the redundant data has been read, issue a recovery instruction to said parity calculation part to recover the remaining data block not read from one remaining disk drive of said m disk drives after the timeout period corresponding to said one remaining disk drive has elapsed; and when the remaining data block is recovered by the calculation of parity in said parity calculation part, execute an operation for transmitting the data to the host device.