A file input/output control device for dividing a file into a plurality of fragments which are distributed to a plurality of storage devices. The file input/output control device 200, upon receiving a file from a client, constructs a plurality of fragments from a file with reference to a predetermined number of divisions and redundancy. The file input/output control device allows the fragments to be stored on a single storage device, but distributes fragments to the storage devices to avoid sending a single type of fragment to any one storage device, and to avoid sending all types of fragments to any one storage device, thereby ensuring security.