Patent ID: 8539156

Claim:
A storage subsystem comprising: a storage device including a plurality of storage units for storing data; a controller configured to control data input/output processing on the storage device based on an access request from an access requester; wherein the controller is configured to manage a plurality of logical units, which constitute a logical storage area of the storage device, by using setting information in which a relationship between a logical address of each logical unit and a data storage area corresponding to the logical address of each logical unit is set; wherein when receiving a command to delete a deletion target logical unit, which is a target to be deleted from among the plurality of logical units, from a management terminal connected to the controller, the controller is configured to retain setting information about the deletion target logical unit, from among the setting information, as reset information; and wherein when receiving a restoration command to restore the deletion target logical unit as an access target logical unit from the management terminal, the controller is configured to restore the retained reset information as the setting information corresponding to the access target logical unit; and a cache memory configured to temporarily store data which are a target of processing by the controller, wherein when receiving the deletion command from the management terminal, the controller is configured to judge whether or not any unreflected data, which are related to the deletion target logical unit and are not reflected in the storage device, exist in data stored in the cache memory; and when it is determined that the unreflected data exist in the cache memory, the controller is configured to reflect the unreflected data in the storage device in accordance with the setting information.