Fujitsu Corporation

Sony Corporation

Yukio Taniyama

Yoshikazu Nakamura

Daijirou Okihara

Hideto Suzuki

Yasuhiko Hanaoka

Tomonori Mase

Osamu Shimura

Tetsuo Nagahori

Shoichi Okumura

Shinji Hamada

Tetsuo Isaka

Kaoru Kanda

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.

Data processing apparatus and method for recording data

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.

Virtual library apparatus and method for diagnosing physical drive

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.

Method for controlling magnetic tape unit

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.

Magnetic recording and/or reproducing apparatus having a search pattern

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.

Data recording and/or reproducing apparatus and method

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.

Data recording and/or reproducing apparatus

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.

Device for processing file data with erasing identification data

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. With this system, the control units can be correctly operated in accordance with priority by simple circuit construction without employing a scanning system, and further, the number of control units can be increased without increasing the cost of the selection system.

Growing community of inventors

Kawasaki, Japan

Yukio Taniyama