Abstract: A storage apparatus includes a storage drive which writes and reads out a block of data with respect to a storage medium loaded on the storage apparatus, a processor which executes access control on a plurality of volumes assigned to the storage medium and a memory which stores a piece of management information that includes a piece of information indicating a usage frequency of each of the volumes. The processor executes a procedure including: determining a reallocation target volume from among a plurality of volumes assigned to the storage medium based on the management information, and moving the data of the reallocation target volume to a reallocation destination storage medium which is different from the storage medium.

Abstract: A redundant system includes a redundant apparatus and a control unit that controls power supplied to the redundant apparatus. The redundant apparatus includes a state management unit that manages an operational state of the redundant apparatus, and a response unit that returns the operational state to the control unit. The control unit includes a first requesting unit that requests a redundant apparatus that operates as an operation system for the operational state information, a first determination unit that determines whether the response to the request is returned within a predetermined time, a second determination unit that determines whether the operational state is normal if the response is returned within the predetermined time, and a shutdown unit that shuts down the power supply to the redundant apparatus, if the second determination unit determines that the operational state is not normal.

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 redundant system includes a redundant apparatus and a control unit that controls power supplied to the redundant apparatus. The redundant apparatus includes a state management unit that manages an operational state of the redundant apparatus, and a response unit that returns the operational state to the control unit. The control unit includes a first requesting unit that requests a redundant apparatus that operates as an operation system for the operational state information, a first determination unit that determines whether the response to the request is returned within a predetermined time, a second determination unit that determines whether the operational state is normal if the response is returned within the predetermined time, and a shutdown unit that shuts down the power supply to the redundant apparatus, if the second determination unit determines that the operational state is not normal.

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 header data storage unit stores therein header data that identifies each file. A header data reader reads the stored header data, from the header data of the first file written to a magnetic tape to the header data of a target file, in order in which the files have been written to the magnetic tape. Based on the number of files whose header data have been read, an input/output controller controls positioning of a magnetic head.

Abstract: A header data storage unit stores therein header data that identifies each file. A header data reader reads the stored header data, from the header data of the first file written to a magnetic tape to the header data of a target file, in order in which the files have been written to the magnetic tape. Based on the number of files whose header data have been read, an input/output controller controls positioning of a magnetic head.

Abstract: A tape apparatus increases throughput of data access requests by rearranging the sequence in which data access requests are processed in order to reduce repositioning of a tape medium. The tape apparatus includes a command queue for storing a plurality of instructions from a host apparatus, and a reordering mechanism for analyzing the stored instructions according to a predetermined set of rules. The sequence of the stored instructions are rearranged in order to minimize driving of the tape medium. The reordering mechanism can select N commands at a time from the head of the command queue, and determine a sequence for executing the N commands, yielding a minimum total driving distance of a medium tape from a current position of the tape medium.

Abstract: A library device is provided which can handle cartridges with back bar code labels only, side bar code labels only, and both back and side bar code labels. A bar code reader reads back bar code labels of cartridges, and a mirror is attached to a wall of each cell in the cell drum to guide a laser beam from the bar code reader to a label on one side surface of a cartridge, for side bar code reading by the bar code reader.

Abstract: A library system in which a recording and reproducing unit loads a recording medium after an accessor has retired from the recording and reproducing unit by exchanging data between the recording and reproducing unit and the accessor on the occasion that the recording and reproducing unit loads a recording medium carried from the accessor to the recording and reproducing unit. Moreover, the library system has an object to realize communication of the necessary data between the recording reproducing unit and accessor without increase of a load of the director for controlling the recording and reproducing unit and accessor.

Abstract: A library apparatus in which a plurality of cell drums are divided into two groups respectively placed on the left and right side of a recording/reproducing unit placed in a central part thereof. In this library apparatus, rails are placed in a direction along which the cell drums and the recording/reproducing unit are arranged. The conveying of media, which are contained in the cell drums placed on the left side of the recording/reproducing unit, is assigned to an accessor placed on the left side thereof. Simultaneously, the conveying of media, which are contained in the cell drums placed on the right side of the recording/reproducing unit, is assigned to an accessor placed on the right side thereof. A robot hand of each of the accessors is opened and closed by a turn of a motor. At that time, a power supply is turned off. Moreover, the robot hand is prevented by a locking mechanism from popping out of the accessor. Furthermore, ordinary cartridges are discriminated from cleaning cartridges.

Abstract: A library apparatus capable of being manufactured at low cost, in which a cartridge can be moved accurately without high mechanical precision. The library apparatus comprises a plurality of cells each for containing a cartridge, a reference cell unit, an accessor unit, a passage unit, at least a drum unit, at least a drive unit, a guide rail and an accessor. The accessor has a high-accuracy diagnostic cell. The error between the light axis of a photoelectric sensor of the accessor and the operation axis of a hand unit of the accessor is measured by inserting and withdrawing a high-accuracy diagnostic cartridge into and out of the diagnostic cell. Also, a position correction value and a sensor sensitivity correction value for the accessor actually moving to a cell are determined. On the basis of the error and correction values thus obtained, a table showing the relative positions of all the cells is prepared before the operation of the library apparatus.

Abstract: A library apparatus where multiple moving commands generated by several upper-order units are conveyed to a director. The moving commands may be sequentially conveyed through the same channel or may be simultaneously conveyed through different channels. The moving commands are then conveyed to an accessor controller which includes a real table and a plurality of virtual tables. The contents of one of the virtual tables is switched to the real table. Accessors are operative in accordance with the contents of the real table. The switching of contents from virtual tables to the real table enables the accessor controller to act as if two operation commands exist instead of one command so that a plurality of accessors can operate simultaneously.

Abstract: A library apparatus where multiple moving commands generated by several upper-order units are conveyed to a director. The moving commands may be sequentially conveyed through the same channel or may be simultaneously conveyed through different channels. The moving commands are then conveyed to an accessor controller which includes a queuing table for storing the commands. The queuing table permits the accessor controller to receive additional commands prior to the execution of the previous command. Therefore, the processing speed of the system is increased. Next, the commands are conveyed to a plurality of accessors which transfer the medium cartridges to the desired location. Several accessors may be operated simultaneously in parallel. The simultaneous operation of several accessors also increases the efficiency and speed of the system.

Abstract: A library apparatus where multiple moving commands generated by several upper-order units are conveyed to a director. The moving commands may be sequentially conveyed through the same channel or may be simultaneously conveyed through different channels. The moving commands are then conveyed to an accessor controller which includes a queuing table for storing the commands. The queuing table permits the accessor controller to receive additional commands prior to the execution of the previous command. Therefore, the processing speed of the system is increased. Next, the commands are conveyed to a plurality of accessors which transfer the medium cartridges to the desired location. Several accessors may be operated simultaneously in parallel. The simultaneous operation of several accessors also increases the efficiency and speed of the system.