Patent ID: 6993524

Claim:
A disk unit, connectable to a server computer and a client computer via a network, wherein the server computer manages a plurality of function programs that the client computer requests to execute and manages data stored in the disk unit, the disk unit comprising: disk storage media for storing data; and a control unit which includes a memory for storing the function programs and function information relating to some of the plurality of function programs, wherein said control unit receives one of the function programs from the server computer and stores the received function program into the memory, wherein said control unit receives a function execution request from the server computer, requesting execution of one of the function programs, from the server computer, selects the requested function program from the memory, selects the function information in connection with the selected function program, and executes the selected function program according to a condition described in the selected function information, wherein the function execution request is sent from the client computer to the server computer to request execution of one of the function programs, and wherein said control unit examines, based on the selected function information, whether an access from external of said disk unit to the data stored in said disk storage media is allowable and restricts accesses to the data stored in the disk storage media from external of said disk unit during execution of the selected function program.