A method and apparatus for recording/reproducing information on an optical disk using the UNIX operating system. The optical disk has a plurality of partitions. An open table is provided to prevent the removal of the optical disk when the optical disk device is in use. The open table manages the use situation of the plurality of partitions. The optical disk is prohibited from being removed from the optical disk device when one partition is opened earlier than the other partitions. The removal prohibition of the optical disk is released when the final partition is closed.