Abstract: Provided is a storage system (1200) including a first volume providing a storage area, a second volume providing another storage area including a difference from the first volume, and a volume management unit releasing an area allocated to a second specific partial storage area in a storage area in a storage device allocated to the second volume when accepting a delete request for specific data, in accordance with a result of confirmation of sameness between data included in the second specific partial storage area and data included in a first specific partial storage area. The second specific partial storage area is a partial storage area in the second volume including the specific data. The first specific partial storage area is a partial storage area in the first volume and associated with the second specific partial storage area.

Abstract: Provided is a storage system (1200) including a first volume providing a storage area, a second volume providing another storage area including a difference from the first volume, and a volume management unit releasing an area allocated to a second specific partial storage area in a storage area in a storage device allocated to the second volume when accepting a delete request for specific data, in accordance with a result of confirmation of sameness between data included in the second specific partial storage area and data included in a first specific partial storage area. The second specific partial storage area is a partial storage area in the second volume including the specific data. The first specific partial storage area is a partial storage area in the first volume and associated with the second specific partial storage area.

Abstract: A storage region providing device provides a physical storage region (a physical region) as a virtual storage region (a logical region). The device accepts a writing request including data and information for specifying a partial logical region that is part of the logical region. In a case that part of the physical region is not allocated yet to a partial logical region specified by a writing request, the device allocates at least part of an initial allocation region of the physical allocation region to the partial logical region. The device moves data stored in the partial physical region included in the initial allocation region, to a movement destination region that is at least part of a reallocation region other than the initial allocation region of the physical region, and reallocates the movement destination region to the partial logical region.

Abstract: A storage region providing device provides a physical storage region (a physical region) as a virtual storage region (a logical region). The device accepts a writing request including data and information for specifying a partial logical region that is part of the logical region. In a case that part of the physical region is not allocated yet to a partial logical region specified by a writing request, the device allocates at least part of an initial allocation region of the physical allocation region to the partial logical region. The device moves data stored in the partial physical region included in the initial allocation region, to a movement destination region that is at least part of a reallocation region other than the initial allocation region of the physical region, and reallocates the movement destination region to the partial logical region.