Patent ID: 7567514

Claim:
A RAID apparatus including a first processing device and a second processing device that perform a volume input/output process, wherein a process request received by the first processing device through an interface connection with a host device is transmitted to the second processing device through an interdevice communication for a hierarchical process and an end response is transferred from the second processing device via the first processing device to the host device for releasing the interface connection, the RAID apparatus comprising: an elapsed-time detecting unit that detects an elapsed time from a time when the first processing device receives the process request from the host device until transmitting the process request to the second processing device through the interdevice communication; and an interdevice communication monitoring unit that calculates a variable timeout time by subtracting the elapsed time from a predetermined fixed timeout time for monitoring the interdevice communication between the first processing device and the second processing device, and monitors an elapsed time of the interdevice communication.