Patent ID: 7730235

Claim:
A storage apparatus for storing data, comprising: a controller unit to carry out processing according to an access request from a host computer; a plurality of intermediary devices connected to the controller unit and having a plurality of ports; and a plurality of disk devices including first disk devices and second disk devices, connected respectively to the plurality of ports of each of the plurality of intermediary devices, wherein the first disk devices are connected respectively to a plurality of ports of a first intermediary device included in the plurality of intermediary devices; and wherein the second disk devices are connected respectively to a plurality of ports of a second intermediary device included in the plurality of intermediary devices; wherein said first intermediary device stores first management information indicating whether an operating mode of each of the first disk devices that are connected thereto is a power saving mode, wherein said second intermediary device stores second management information indicating whether an operating mode of each of the second disk devices that are connected thereto is a power saving mode, and wherein, upon receipt of an I/O request sent from the controller unit to a first disk device A of the first devices, each of the plurality of the first-intermediary device determines whether the operating mode of the first disk device A is a power saving mode based on the first management information, and sends a command for spin-up to the first disk device A if the operating mode of the first disk device A is a power saving mode, wherein a threshold value is set to each of the intermediary devices, and wherein each of the intermediary devices sends a command for spin-down to one of the disk devices connected thereto if elapsed time after an I/O request to the one of disk devices exceeds the threshold value.