Patent ID: 7827194

Claim:
A system, comprising: a shared disk device provided on a storage area network; a server apparatus connected to the storage area network independently of the shared disk device; and a client apparatus directly connected to the storage area network independently of the server apparatus and the shared disk device for directly accessing a file in a file system created in said shared disk device; wherein the client apparatus is configured such that, when the client apparatus executes an open function for opening the file, the client apparatus communicates with the server apparatus to acquire a file handle for the file from the server apparatus; and wherein the client apparatus is configured such that, when the client apparatus executes a read function for reading data from the file, the client apparatus (i) transmits a request including the file handle to the server apparatus and (ii) receives information including at least one of a physical address of the file, an I/O size of the file, and an offset value of the file from the server apparatus in response to the request and (iii) directly accesses the file using the received information to read the data from the file, wherein the open function and the read function are installed within the client apparatus as part of a user program of the client apparatus by utilizing a dynamic link library, the dynamic link library defining the open function and the read function in the same names as used in an application interface which is called by the user program, wherein said server apparatus comprises acquiring means for acquiring the file handle for the file, wherein said client apparatus comprises means for executing a proxy process which is a process executed in a privileged mode on the client apparatus to open, on behalf of the user program, a driver for accessing said shared disk device, wherein said dynamic link library includes a function for setting a search path of said dynamic link library implemented as a portion of the user program such that the access processing of the client apparatus is dynamically linked previously to the dynamic link library performing ordinary file access processing.