In a storage area network system in which storage subsystems each containing disk devices are connected to servers through fiber channels and fiber channel switches, one of disk devices in each of the storage subsystems is used as either a storage control master device or a storage control replica device in which group setting information concerning classification of disk devices into a storage management group and a storage access definition group or storage access definition groups is stored. When a server starts, the server is made to selectively recognize the storage control master device or the storage control replica device, to read the group setting information from the recognized storage control device, and further to recognize only disk devices belonging to a group in association with the server.