Abstract: An information processing apparatus includes a write control unit that executes in parallel a first process in which a writing unit writes, to a storage device, data that are requested to be written to the storage device, and a second process in which a compression unit compresses the data and the writing unit writes compressed data obtained by the compression to the storage device. The write control unit specifies the data written by one of the first and second processes that takes less processing time as valid write data in the storage device.

Abstract: A tape library system includes a plurality of cartridge cells for accommodating a plurality of tape cartridges respectively, a tape drive for writing and reading data to and from the tape cartridge inserted therein, a diagnosis drive for diagnosing the tape cartridge inserted therein, an cartridge carriage mechanism for inserting and ejecting the tape cartridge into and from the tape drive and the diagnosis drive, and a diagnosis controller for controlling the cartridge carriage mechanism to load the tape cartridge into the diagnosis drive and for controlling the diagnosis drive to diagnose the tape cartridge inserted therein.

Abstract: A virtual tape system includes an actual tape device having a magnetic tape which stores data. The virtual tape system includes a virtual tape storage device which stores data stored in the actual tape device as a virtual tape volume, first computers to be connected to a host computer which instructs a storing of data in the actual tape device, and a reading of data from the actual tape device, control an interface with the host computer, second computers which control the virtual tape volume of the virtual tape storage device, third computers which control a writing of the data into the actual tape device, and a local disk controller which stores the data in one of storage devices mounted one in each of the first computers, each of the second computers, and each of the third computers.

Abstract: The computer system is capable of improving performance, reliability and redundancy. The computer system comprises: a plurality of server computers having different functions, the server computers being mutually connected by communication lines; a standby server computer being connected to each of the server computers by the communication lines, the standby server computer being capable of performing the function of each of the server computers; a detection unit for detecting an abnormal state of each of the server computers; and a take-over unit for controlling the standby server computer to take over the action of the abnormal server computer when the abnormal state of the abnormal server computer is detected by the detection unit.

Abstract: A tape library system includes a plurality of cartridge cells for accommodating a plurality of tape cartridges respectively, a tape drive for writing and reading data to and from the tape cartridge inserted therein, a diagnosis drive for diagnosing the tape cartridge inserted therein, an cartridge carriage mechanism for inserting and ejecting the tape cartridge into and from the tape drive and the diagnosis drive, and a diagnosis controller for controlling the cartridge carriage mechanism to load the tape cartridge into the diagnosis drive and for controlling the diagnosis drive to diagnose the tape cartridge inserted therein.

Abstract: The storage virtualization switch is capable of correctly designating a virtual target when a host computer accesses the virtual target. A dummy virtual target, which corresponds to a virtual target, is put into an effective state after the virtual target is put into the ineffective state when the virtual target is put into the ineffective state, and the virtual target is put into an effective state after the dummy virtual target, which corresponds to the virtual target, is put into the ineffective state when the virtual target is put into the effective state.

Abstract: A virtual tape system includes an actual tape device having a magnetic tape which stores data. The virtual tape system includes a virtual tape storage device which stores data stored in the actual tape device as a virtual tape volume, first computers to be connected to a host computer which instructs a storing of data in the actual tape device, and a reading of data from the actual tape device, control an interface with the host computer, second computers which control the virtual tape volume of the virtual tape storage device, third computers which control a writing of the data into the actual tape device, and a local disk controller which stores the data in one of storage devices mounted one in each of the first computers, each of the second computers, and each of the third computers.

Abstract: The computer system is capable of improving performance, reliability and redundancy. The computer system comprises: a plurality of server computers having different functions, the server computers being mutually connected by communication lines; a standby server computer being connected to each of the server computers by the communication lines, the standby server computer being capable of performing the function of each of the server computers; a detection unit for detecting an abnormal state of each of the server computers; and a take-over unit for controlling the standby server computer to take over the action of the abnormal server computer when the abnormal state of the abnormal server computer is detected by the detection unit.

Abstract: The storage virtualization switch is capable of omitting to control (exclusion-control) a reserve condition on a physical storage unit without decreasing fault tolerance and reliability, so that overhead of access to the storage unit can be smaller. The storage virtualization switch comprises: a storage virtualization unit for constituting a virtual storage unit by using a storage area of the physical storage unit; a communication unit for communicating with another storage virtualization switch; and a zoning unit for making a host computer recognize an external virtual storage unit constituted in another storage virtualization switch connected by the communication unit, the zoning unit making the host computer access the external virtual storage unit via the communication unit when the host computer requests to access the virtual storage unit.

Abstract: The storage virtualization switch is capable of correctly designating a virtual target when a host computer accesses the virtual target. A dummy virtual target, which corresponds to a virtual target, is put into an effective state after the virtual target is put into the ineffective state when the virtual target is put into the ineffective state, and the virtual target is put into an effective state after the dummy virtual target, which corresponds to the virtual target, is put into the ineffective state when the virtual target is put into the effective state.

Abstract: A system is provided in which a server which provides a service to a client terminal, a disk array device upon which data used by the server is stored, and a monitor terminal which detects a bottleneck on the disk array device, are connected via a network. The disk array device or the server calculates performance information including the number of IO requests issued by the server, the times required for processing the IO requests, and a resource utilization ratio for each resource included in the disk array device. The monitor terminal establishes a reference point based upon an average response time obtained by dividing the processing time included in the performance information by the number of the IO requests. And the system is characterized in that a resource is identified as a bottleneck, based upon the resource utilization ratio in a predetermined interval before the reference point.