Patent ID: 7840766

Claim:
A storage system coupled to a computer comprising: a controller coupled with the storage regions, the storage regions including a plurality of storage devices wherein the controller is configured to: set a first storage region to which first data sent from the computer is written by the controller; set a second storage region 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 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, wherein the controller selects and reads from either the first storage region or the second storage region if the controller receives a read request for the virtual recovery volume from the computer.