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

Claim 0:
1. A storage system, comprising:
a controller configured to provide a logical volume to a host device; and
a physical storage device configured to store data,
the storage system being capable of creating a snapshot which is a duplicate of the logical volume, wherein
the controller is configured to:
form a pool volume corresponding to the logical volume using the physical storage device;
store first control information associated with the logical volume and the snapshot and second control information associated with data on the pool volume;
manage data of the logical volume and the snapshot by associating the first control information with each logical volume and the second control information related to data on the pool volume included in the snapshot;, in a case of creating a snapshot, copy first control information of the logical volume as first control information of the created snapshot,
manage a time series of the logical volume and one or a plurality of snapshots using generation information associated with the first control information;
manage, for each piece of data on the pool volume, generation information indicating a generation in which the data is created in association with the second control information;
execute invalidation of the first control information and/or the second control information asynchronously with a processing of data related to the logical volume and/or the snapshot; and
determine whether the invalidation is possible by referring to the generation information associated with the first control information and generation information associated with the second control information in the invalidation.