Abstract: A storage system includes a storage apparatus, a control apparatus, and a host apparatus. The storage apparatus includes a recording medium. The control apparatus includes a detection unit and a control unit. The detection unit detects whether a recording medium loaded in the storage apparatus is a stand-alone-only recording medium that is used in a stand-alone mode. When the recording medium is the stand-alone-only recording medium, the control unit registers a physical volume of the stand-alone-only recording medium as a logical volume and automatically switches the operation mode of the control apparatus to the stand-alone mode.

Abstract: A storage system includes a storage apparatus, a control apparatus, and a host apparatus. The storage apparatus includes a recording medium. The control apparatus includes a detection unit and a control unit. The detection unit detects whether a recording medium loaded in the storage apparatus is a stand-alone-only recording medium that is used in a stand-alone mode. When the recording medium is the stand-alone-only recording medium, the control unit registers a physical volume of the stand-alone-only recording medium as a logical volume and automatically switches the operation mode of the control apparatus to the stand-alone mode.

Abstract: A data processing apparatus includes a calculating unit configured to calculate a compression ratio when a block selected from among the plurality of blocks is compressed; a determining unit configured to determine whether a block is to be compressed by comparing the calculated compression ratio with a threshold; a recording unit configured to record the block on the storage device in a compressed or uncompressed state on a basis of a result of the determination; a management information creating unit configured to create a management information in association with data identification information for identifying the data, state information indicating a compressed or uncompressed state is recorded to the management information in association with each block, when the each block is recorded on the storage device; and a storage processing unit configured to store the management information created by the management information creating unit on a memory.

Abstract: A virtual tape device connected to an upper device and a tape library device, and storing a tape volume includes: a storage unit to store the tape volume including a plurality of blocks; an identifier control unit to add to each block of the tape volume a first identification number which is incremented for each block, and a second identification number which is incremented only in a block subsequent to a leading block, a tape mark indicating a delimiter of a file, and a block subsequent to the tape mark; a first control unit to control a read and a write of the tape volume stored in the storage unit using the second identification number; and a second control unit to write the tape volume and the first identification number to the tape library device, and control the tape library device using the first identification number.

Abstract: A data processing apparatus includes a calculating unit configured to calculate a compression ratio when a block selected from among the plurality of blocks is compressed; a determining unit configured to determine whether a block is to be compressed by comparing the calculated compression ratio with a threshold; a recording unit configured to record the block on the storage device in a compressed or uncompressed state on a basis of a result of the determination; a management information creating unit configured to create a management information in association with data identification information for identifying the data, state information indicating a compressed or uncompressed state is recorded to the management information in association with each block, when the each block is recorded on the storage device; and a storage processing unit configured to store the management information created by the management information creating unit on a memory.

Abstract: A virtual library apparatus includes an exclusive control section that exclusively secures a logical drive and a physical drive according to an instruction from a host at a time of an occurrence of an error in the physical drive and a diagnostic section that performs a diagnostic process on the exclusively secured physical drive through the exclusively secured logical drive. The exclusive control section releases the exclusively secured logical and physical drives after the diagnostic section completes the diagnostic process for the physical drive.

Abstract: A virtual library apparatus includes an exclusive control section that exclusively secures a logical drive and a physical drive according to an instruction from a host at a time of an occurrence of an error in the physical drive and a diagnostic section that performs a diagnostic process on the exclusively secured physical drive through the exclusively secured logical drive. The exclusive control section releases the exclusively secured logical and physical drives after the diagnostic section completes the diagnostic process for the physical drive.

Abstract: A virtual tape device in between a host and a library device is provided. The virtual tape device includes a physical tape volume and that stores data sent from the host on a logical tape volume includes, a receiver that receives a mount/unmount command and a job identifier relating to the command which are sent from the host, a storage device that stores the logical tape volume, a storage table that stores the job identifier and a logical tape volume to be accessed by a job indicated by the job identifier, and a controller that controls, based on the storage table, transfer of data relating to the job identifier between the logical tape volume and the physical tape volume.

Abstract: A tape operation relating to EOF identification in an open process for a file is emulated, whereby the tape operation in the open process is simplified. Consequently, open-process, close-process performance, and process performance of a system accessing to a magnetic tape unit can be improved. In a method of this invention, a position of a head relative to a magnetic tape is fixed at a predetermined position in the open process for a file recorded on the magnetic tape, and when a command is received from a command issuing apparatus, emulation in which a tape operation according the command is virtually carried out in the magnetic tape unit without making said magnetic tape unit carry out a real tape operation, is executed.

Abstract: The present invention relates to a magnetic tape unit to which a cartridge having a magnetic tape therein is detachably attached and which accesses a magnetic tape in accordance with an access request from a host. Software of the host which accesses a conventional magnetic tape unit to which a cartridge accommodating a plurality of cartridges is attached is used as it is while using the cartridge accommodating a large-capacity magnetic tape. Management information of a plurality of volumes is written in the cartridge, and a LOAD command from the host is replaced by a command for accessing an actual cartridge.

Abstract: Work time for data transfer between a plurality of host computers is reduced by automatically notifying a host computer to which the data is transferred of insertion of the storage medium when a storage medium is conveyed from a housing unit to a turnout area.

Abstract: In a magnetic recording and/or reproducing apparatus applied to an external storage of computers, a recorded file can be searched easily. A recording track is helically formed on a magnetic tape to record file data, and management data are recorded at the beginning of the magnetic tape, and a search pattern is recorded on the recording track along the longitudinal direction at a location of the magnetic tape that corresponds to the management data of the beginning of the magnetic tape.

Abstract: A data recording and/or reproducing apparatus records and/or reproduces data and data management information corresponding to the data on helical recording tracks. It can be feasible to detect the use of the helical record tracks in reproducing and immediately access the recorded data, the data record region and the data management region in recording or reproducing.

Abstract: A data recording and/or reproducing apparatus records and/or reproduces file data by processing the file data on the unit of a predetermined block length, a data block and information data for identifying the data block on predetermined unit regions. A supplement data is recorded on a region other than the region recorded the file data, the block data and the information data for identifying within the unit regions. Thereby these data are recorded and/or reproduction processed at every predetermined units so that the bit error rate is remarkably improved.

Abstract: A data recording/reproducing device updates the identification data for identifying the recording data of recording track on the magnetic tape as the meaningless data. As a result, in a data recording reproducing device to be used for, such as an external memory device of the computer, the desired data can be erased easily.

Abstract: A selection system for an information processing system wherein a unit, such as a magnetic tape unit, is shared by a plurality of control units. At least first and second signal lines are connected between each control unit at a driver circuit and a receiver circuit pair. The two signal lines connected between each control unit correspond to a single shared unit, and each control unit provides a driver circuit and a receiver circuit connected so as to transmit and receive signals carried on each line. Each line is connected to a separate driver circuit and receiver circuit at each control units. A block signal is transmitted from one of the control units through a first signal line to the other control units to prevent them from starting their operation for accessing the shared unit, and selection signals are transmitted from possible plurality of started control units through the second signal line at different timings to thereby determine priority of the started control units for accessing the shared unit.