Patent ID: 6922743

Claim:
A disk subsystem comprising: a disk unit; a disk access controller for controlling said disk unit; a channel controller for making communication with a host computer, wherein said channel controller has a plurality of I/O ports for passing signals for making communication with said host computer, wherein said I/O ports have control processors for controlling said signals passing said I/O ports, respectively, wherein said channel controller chooses, among said plurality of I/O ports, an I/O port through which a reply to said host computer is to be transmitted; and an access request table in which an identifier of an I/O port receiving a request from said host computer, and control information including an identifier of said I/O port chosen by said disk access controller are recorded, and wherein, when said I/O port receiving a request from said host computer is defined as a reception port, one of said control processors associated with the reception port transmits said request from said host computer to one of said control processors which is associated with said I/O port and which is chosen by said channel controller.