Patent ID: 7529965

Claim:
A computer-readable storage medium which stores a program for allowing a computer to execute: an error determining step that determines a suspect disk drive when an addition value of error statistics of a disk drive included in a disk array of a redundancy configuration exceeds a predetermined threshold value and sets a recovery mode to recover data from the suspect disk to a spare disk drive located under the same device adapter with the suspect disk drive; a read processing step that reads data from a normal disk drive, which is any disk of the disk array excluding the suspect disk drive, and responds in case a read command was received from a host while the setting of the recovery mode was in progress and reads data from the suspect disk drive and responds in case the read from the normal disk drive failed; a write processing step that writes data into the normal disk drive, the suspect disk drive, and the spare disk drive in case a write command was received while the setting of the recovery mode was in progress, and registers a write failure address range to a management table if the write failure was determined for the suspect disk drive; a recovery processing step that specifies an address range of the suspect disk drive while the setting of the recovery mode is in progress and at the same time starts to copy the data in the suspect disk drive sequentially to the spare disk drive to recover the data and rebuilds the data in the normal disk drive located under a different device adapter to the spare disk drive to recover the data when the address range corresponds to the write failure address range of the management table or the recovery processing from the suspect disk drive to the spare disk drive failed and separates the suspect disk drive upon the completion of the recovery and replaces the suspect disk drive with the spare disk drive.