Management information updating method and mass storage system employing

Abstract

Management information necessary to manage storage media in a mass storage system. A rotatable cell drum has a plurality of cells arranged in a plurality of cell columns disposed in spaced circumferential relationship parallel to the axis of the drum and in a plurality of shelves disposed in spaced relationship transverse to the axis of the drum. A housing of the cell drum has an opening which confronts N cell columns of the cell drum, wherein 1.ltoreq.N< the desired number of cell columns, thereby to enable manual storage of a storage medium in, or retrieval of a storage from, a corresponding cell in the N cell columns made accessible through the opening in the load/eject mode of operation of the mass storage system. The updating method includes (a) determining whether or not storage or retrieval of a storage medium has been made in the load/eject mode via the opening with respect to a cell in an arbitrary cell column which currently confronts the opening, (b) storing the management information related to the arbitrary cell column, which currently confronts the opening, in the load/eject mode if the storage or retrieval of the storage medium is detected in the step (a), (c) investigating the management information related to the storage medium in each of the cells in the arbitrary cell column, and (d) updating only that management information which is related to the arbitrary cell column and which is stored in the step (b) by the management information obtained in the step (c).