Patent ID: 7840820

Claim:
A storage system comprising a plurality of storage devices and a controller for inputting/outputting data to/from said storage devices based on an access request from a host system, wherein said controller comprises: an access request processing unit which inputs/outputs data to/from said storage devices based on an access request issued from said host system; a prediction unit which predicts at least one or more next access target storage devices to be accessed next by said host system of said storage devices based on the access request received by said access request processing unit; a power control unit which stops the feeding of power from a power unit to a storage device that satisfies a predetermined condition among said storage devices, and which feeds power from said power unit to said next access target storage device; wherein an access sequence of said respective storage devices and a time between one access and after another are stored in a history record table, and said power control unit feeds power prior to the time required for said next access target storage device to be powered on and to be ready to access so that said next access target storage device is powered on and is ready to access at the time when said host system is predicted to access said next access target storage device.