Patent ID: 7020756

Claim:
A storage system for performing a backup operation of data from a source storage device to a backup storage device comprising: a first control unit which controls transfer of data between a host-computer and cache memory; a second control unit which controls transfer of data between said cache memory and said backup storage device; and a third control unit which controls transfer of data between said cache memory and said source storage device, wherein at least said first and second control units are coupled to a common memory which has stored therein a set of backup information, wherein said set of backup information includes at least a source volume address of an address in said source storage device of data to be backed up, the name of said second control unit, and the name of said backup storage device, wherein a start timing of a back operation is provided to said second control unit by a processor external of said storage system, and wherein said second control unit, upon receipt of said start timing of said backup operation, and based on said set of backup information, instructs said third control unit to read data from said source storage device at said source volume address and store said data in said cache memory, reads said data stored in said cache memory by said third control unit, and sends said data read from said cache memory to said backup storage device so as to backup said data therein.