Patent ID: 7028140

Claim:
A storage system that is accessed from a host device, comprising: a storage device comprising a plurality of logical volumes; a storage device control section that controls said storage device; an interface section that receives a snapshot acquisition instruction and snapshot utilization instruction from said host device; and a snapshot processing device that executes processing for acquisition and utilization of snapshots in accordance with said snapshot acquisition instruction and said snapshot utilization instruction received by said interface section; wherein said snapshot processing device, in response to said snapshot acquisition instruction, selects a logical volume that is capable of use as a snapshot target from said plurality of logical volumes, instructs said storage device control section to acquire a snapshot of the logical volume of the snapshot source, designated in said snapshot acquisition instruction for the selected logical volume, and holds generation information that associates the generation number specified in said snapshot acquisition instruction with an address of said selected logical volume, and in response to said snapshot utilization instruction, specifies a logical volume where the snapshot corresponding to the generation number specified in said snapshot utilization instruction is held, by referring to said generation information, and allocates an address accessible by said host device to said specified logical volume.