US Patent 7404035 System for controlling spinning of disk

A system for controlling spinning of a disk is provided to prevent deterioration of the access response speed and to suppress the power consumption. The system includes a controller controlling a file system, and a disk array system storing data of the file system. The disk array system includes a plurality of logical volumes, each of which is configured by at least one disk device, and a disk controller controlling data input/output to/from the plurality of logical volumes. The plurality of logical volumes includes at least one first type logical volume which is controlled so that spinning of a disk device that configures the logical volume can be stopped, and at least one second type logical volume which is controlled so that spinning of a disk device that configures the logical volume cannot be stopped. Data satisfying a predetermined condition is stored in the second type logical volume.