Patent ID: 7870402

Claim:
A method for controlling a storage system, the storage system including a storage device configured to store data in a logic volume having a logically defined physical storage area and the storage system including an information processing device configured to transmit a data I/O request to the storage device and having a first power supply which activates a function for transmitting the data I/O request, wherein the storage device is configured to communicate with the information processing device, the storage device having a second power supply which activates a function for accepting the data I/O request which is transmitted from the information processing device, and the method comprising transmitting from the storage device to the information processing device a power-on request for turning on the first power supply when the storage device is in a state in which the storage device can accept the data I/O request being transmitted from the information processing device; when the storage device accepts a stop instruction of the second power supply, the storage device transmitting a stop-power request for turning off the first power supply to the information processing device; and if the storage device did not receive a report that the first power supply was stopped from the information processing device after a given period time passed, the storage device transmitting a power-off request for turning off the first power supply to the information processing device.