computers 1401 a and 1401 b as its servers the file system client 1452 regards the server computers 1402 a and 1402 b as its servers fig1 illustrates operations of the parallel file system client module 1450 first at step s 1501 the parallel file system client module receives a request for file manipulation from the user application next at step s 1502 the parallel file system client module separates the request into a request for manipulation of file property and a request for manipulation of file data then the parallel file system client module requests the file system client 141 to manipulate the file properties at step s 1503 next at determination step s 1504 the parallel file system client module determines whether the contents of the processing involve an access to the contents of the file if the determination at step s 1504 is that the contents of the processing involve an access to the contents of the file the parallel file system client module requests the file system client 1451 or 1452 to access the file at step s 1505 since the operations of the file system clients 141 1451 and 1452 are the same as those in the foregoing embodiment 1 explanation is omitted here if the determination at.