DISK SUBSYSTEM AND METHOD FOR RESTORING DATA IN DISK SUBSYSTEM

摘要

PROBLEM TO BE SOLVED: To realize a disk subsystem capable of preventing the system itself from being turned to a unusable state due to a state that data necessary for the restoring processing of data generating a fault can not be read out from a magnetic disk device generating no fault. SOLUTION: In the case of restoring data in a magnetic disk device generating a fault to a spare magnetic disk device in a disk subsystem 110 constituting a redundant array of inexpensing disk(RAID), data read out from the magnetic disk device generating the fault are stored in the spare magnetic disk device, data not read out from the magnetic disk device generating the fault are restored from data stored in a magnetic disk device generating no fault out of plural magnetic disk devices constituting the RAID by operation and the restored data are stored in the spare magnetic disk device by a data restoring means 3.