Storage apparatus and method including page discard processing for primary and secondary volumes configured as a copy pair

摘要

A storage apparatus having a plurality of logical volumes includes a storage device, and a storage controller that operates each of the logical volumes as a virtual volume. A primary volume and a secondary volume are configured as a copy pair in which data in the primary volume can be copied to the secondary volume. If the primary volume receives a discard request for a unit physical storage area, the storage controller determines whether or not a unit physical storage area exists configuring the secondary volume corresponding to the unit physical storage area, which is a target of the discard request. If the unit physical storage area configuring the secondary volume exists, an instruction is transmitted to the secondary volume to discard the page or unit physical storage area assigned to the secondary volume.