Patent ID: 8285913

Claim:
A storage apparatus having first and second controllers for controlling data transfer between a host system and a storage device, the first and second controllers respectively comprising: a first switch unit and a second switch unit, each of the switch units is equipped with a first port for connecting either an interface unit for the host system or an interface unit for the storage device, and a second port for connecting the first controller with the second controller, and which permits or prohibits data transfer using each of the first port and the second port; a processor configured to control data transfer with the host system or the storage device via a respective of the first ports, while controlling data transfer between the first controller and the second controller via a respective second port, by controlling the first or the second switch unit; and a memory configured to store system configuration rules; wherein the first and second controllers are connected to each other via: a first path for connecting the second port of the first switch unit in the first controller to the second port of the first switch unit in the second controller; and a second path independent of the first path, for connecting the second port of the second switch unit in the first controller to the second port of the second switch unit in the second controller, wherein the system configuration rules set kinds of I/O modules which are physically positioned to respective of the first ports of the first and second switch units; wherein the processor is configured to verify the consistency of a current system configuration of each of the first ports of the first and second switch unit according to a currently set one of the system configuration rules.