Patent ID: 11947811
Assignee: HITACHI, LTD.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 4:
5. The storage system according to claim 1, wherein
the controller is configured to:
manage latest generation information;
when restoring the logical volume from the snapshot, duplicate first control information of a snapshot of a restore source, associate the first control information with the logical volume, and increment the latest generation information;
specify the generation information of the first control information associated with the logical volume before the restoration as a target generation of the invalidation; and
when a generation associated with the second control information is newer than a one-generation old generation in a direct system of the target generation by comparison and is not referred to from a one-generation new generation in the direct system of the target generation, determine that the invalidation is possible for the second control information associated with the first control information of the target generation.