The disk array apparatus, control method, and control program

(Challenge) in the read instruction is often the system of data from the host device, to provide a disk array apparatus that makes it possible to reduce the power consumption of. (SOLUTION) disk array device, by a command from the host device and executes the reading and writing of data. Disk array device, by a command from the host device and executes the reading and writing of data. The disk array apparatus, the a disk device, data that allows the first capable of executing the writing and reading processing of data state and said first than in the state the power consumption is small second state when performing writing processing to the disk device, and a control unit for changing the disk device from the second state to the state of the first. .FIELD 1