US Patent 12124337 Storage system and storage control method

A data store volume (DSVOL) for a snapshot group which is a group of the PVOL and one or more SVOLs for the PVOL is a data storage region where data of which a storage destination is one volume (VOL) of the snapshot group and meta-information of the data are stored, and the meta-information is information including address mapping between a reference source address which is an address of a position of the data in the snapshot group and a reference destination address which is an address of a position of the data in the DSVOL. A process of a storage system increases the number of DSVOLs in the snapshot group when an input/output (I/O) load on the snapshot group exceeds a threshold.