Patent ID: 7421596

Claim:
A disk array system having a storage device and a storage control device for controlling data storing to the storage device, wherein the storage control device has a structure of multiplexed clusters, each cluster has a processor, a memory, and a power judging circuit that judges power source conditions of at least another one of the clusters by directly inputting therein a power from a power source of said another cluster thereby outputting a signal to the processor thereof, and the storage control device has multiplexed power source units that respectively supply power to the clusters, and in performing control that is executed by one operating cluster in response to a case where at least a portion of another cluster stops operation first at a failure: as the control at failure, said operating cluster blocks the stopped portion of said another cluster, judges a power source condition of said another cluster on the basis of the signal from the power judging circuit to determine whether a power failure occurs in the power source of said another cluster, and then said operating cluster records and stores information showing the power source condition of said another cluster and a in result to the memory thereof, and as the control at recovery, if the operating cluster determines that the blocked portion of said another cluster is in blocked condition owing to the power failure occurs in the power source, the operating cluster recovers the blocked portion to operate normally, and if the cluster determines that the blocked portion of said another cluster is in blocked condition not owing to the power failure occurs in the power source, the operating cluster does not recover the blocked portion.