Patent ID: 7509466

Claim:
A data backup method for a computer system that includes a request-source server device, a request-source storage device coupled to the request-source server device, a request-destination storage device coupled to the request-source storage device via a first communication line, a request-destination server device coupled to the request-destination storage device and coupled to the request-source server device via a second communication line, and a backup storage device coupled to the request-destination server device, the request-source storage device having a disk drive for storing data, and a disk control unit for controlling input and output of data to and from the disk drive, the data backup method comprising: providing, by the disk control unit, the request-source server device with a storage area of the disk drive as at least one logical volume; determining, by the request-source server device, upon receiving a request to back up data stored in a first logical volume which is one of the logical volumes, whether a second logical volume which constitutes a copy pair with the first logical volume is present in the request-source storage device; requesting, by the request-source server device, upon determining that the second logical volume is not present, the request-source storage device to produce the second logical volume; and transmitting, by the request-source server device, a request to execute a process to back up data stored in one of the existing second logical volume and the produced second logical volume to the backup storage device to the request-destination server device.