Patent ID: 8131962

Claim:
A storage system coupled to a computer comprising: a controller coupled with a first storage system and a second storage system, wherein the controller is configured to: set a first storage region of the first storage system to which first data sent from the computer is written by the controller; set a second storage region of the second storage system to which second data written into the first storage region is written, as journal data, in a manner where the journal data can be identified in chronological order; set a third storage region of the second storage system to which the second data of the first storage region is written by the controller, if the controller has received a write request from the computer; acquire a snapshot of the first storage region at a predetermined time; write a snapshot journal of the snapshot into the second storage region; manage a management table of the snapshot; acquire a recovery point journal to be used to create a virtual recovery volume designated by the computer; write the recovery point journal into the second storage region; replicate, upon creating the virtual recovery volume, the management table of the snapshot corresponding to the snapshot journal that is chronologically before the recovery point journal corresponding to the designated virtual recovery volume; and create the virtual recovery volume by updating the management table replicated with a snapshot management table replication unit based on the journal data written into the second storage region from the snapshot journal up to the recovery point journal corresponding to the designated virtual recovery volume.