Patent ID: 8325438

Claim:
A storage system comprising: a controller coupled to a computer; a plurality of disk devices coupled to the controller that provide a plurality of logical volumes; a plurality of cooling devices located to cool the disk devices; and a plurality of power supply modules configured to supply electric power to the controller, the disk devices and the cooling devices, wherein, in response to a notice that one of the logical volumes has a possibility of being accessed above a first predetermined amount, the controller is configured to start one or more disk devices that provide the logical volume and one or more of the cooling devices necessary to cool the one or more disk devices, or insert a request related to the notice into a waiting queue, wherein, in response to a notice that one of the logical volumes has a possibility of being accessed below a second predetermined amount, the controller is configured to stop one or more disk devices that provide the logical volume with the possibility of being accessed below said second predetermined amount, and determine whether to execute a request in the waiting queue.