Abstract: RAID information and physical position information of hard disk units are managed by a disk controller in a mapped fashion. When the physical position of the hard disk units is changed, the information mapping is retried. Further, the positional information of the hard disk units accommodated in a disk array system under the administration of the disk controller, is calculated so as to form n-dimensional coordinate system information, and the resulting information is stored in each of the hard disk units. When the hard disk units are inserted into the disk array system, the n-dimensional coordinate system information is read from each hard disk unit. If it is detected that there is difference from the current coordinate system information, then information before removal and that after the insertion are compared with each other and a data link is reconstructed.

Abstract: N_Port_Name information capable of distinctly identifying a host computer has seen set in a microprocessor 42 of a storage controller 40 prior to start-up of host computers 10, 20, 30; upon startup of the host computers 10, 20, 30, when the storage controller 40 receives a frame issued, then the microprocessor 42 operates to perform comparison for determining whether the N_Port_Name information stored in the frame has been already set in the microprocessor 42 and registered to the N_Port_Name list within a control table maintained. When such comparison results in match, then continue execution of processing based on the frame instruction; if comparison results in failure of match, then reject any request.

Abstract: N_Port_Name information capable of distinctly identifying a host computer has seen set in a microprocessor 42 of a storage controller 40 prior to start-up of host computers 10, 20, 30; upon startup of the host computers 10, 20, 30, when the storage controller 40 receives a frame issued, then the microprocessor 42 operates to perform comparison for determining whether the N_Port_Name information stored in the frame has been already set in the microprocessor 42 and registered to the N_Port_Name list within a control table maintained. When such comparison results in match, then continue execution of processing based on the frame instruction; if comparison results in failure of match, then reject any request.

Abstract: N_Port_Name information capable of distinctly identifying a host computer has seen set in a microprocessor 42 of a storage controller 40 prior to start-up of host computers 10, 20, 30; upon startup of the host computers 10, 20, 30, when the storage controller 40 receives a frame issued, then the microprocessor 42 operates to perform comparison for determining whether the N_Port_Name information stored in the frame has been already set in the microprocessor 42 and registered to the N_Port_Name list within a control table maintained. When such comparison results in match, then continue execution of processing based on the frame instruction; if comparison results in failure of match, then reject any request.

Abstract: A disk array device comprises: a hard disk drive module including a disk for recording information thereon and having one side that has a length substantially equal to the diameter of the disk; a battery module; an operation module; a fan module having at least one cooling fan; a controller module having a controller; a power supply module provided for supplying power to the modules; a circuit board to which the above-mentioned modules are connected via electrical connectors; and a substantially box-shaped chassis in which the modules and the circuit board are housed. A front surface and a rear surface of the chassis are opened in a rectangular shape. A length of one side of the opened front surface of the chassis is substantially the same length as the one side of the hard disk drive module.

Abstract: N_Port_Name information capable of distinctly identifying a host computer has seen set in a microprocessor 42 of a storage controller 40 prior to start-up of host computers 10, 20, 30; upon startup of the host computers 10, 20, 30, when the storage controller 40 receives a frame issued, then the microprocessor 42 operates to perform comparison for determining whether the N_Port_Name information stored in the frame has been already set in the microprocessor 42 and registered to the N_Port_Name list within a control table maintained. When such comparison results in match, then continue execution of processing based on the frame instruction; if comparison results in failure of match, then reject any request.

Abstract: A storage system to be connected to a large-scale computer includes a plurality of host adaptors connected to a host device, a plurality of storage device for storing data from the host device, a plurality of disk adaptors connected to the storage devices, a plurality of caches for temporarily storing data transferred between the host adaptors and the disk adaptors, and two buses connected to the host disk adaptors, and the caches. The buses transfer data among the host and disk adaptors and the caches.

Abstract: A storage system to be connected to a large-scale computer includes a plurality of first logical units connected to a host device, a plurality of second logical units connected to a storage device, a plurality of cache memories, and a common bus wired between these logical units and memories. The plurality of first logical units, the plurality of second logical units, and the plurality of cache memories are all made in the form of modules. The modules are detachably mounted to the common bus disposed on a back plane. The storage device can be made up of a plurality of small-size storage units arranged in an array. Thus, the storage system realizes its scalability. Since the plurality of first logical units, the plurality of second logical units, and the plurality of cache memories are duplexed and the common bus is made in the form of 2 channels, the storage system can perform degrade operation.

Abstract: N_Port_Name information capable of distinctly identifying a host computer has seen set in a microprocessor 42 of a storage controller 40 prior to start-up of host computers 10, 20, 30; upon startup of the host computers 10, 20, 30, when the storage controller 40 receives a frame issued, then the microprocessor 42 operates to perform comparison for determining whether the N_Port_Name information stored in the frame has been already set in the microprocessor 42 and registered to the N_Port_Name list within a control table maintained. When such comparison results in match, then continue execution of processing based on the frame instruction; if comparison results in failure of match, then reject any request.

Abstract: N_Port_Name information capable of distinctly identifying a host computer has seen set in a microprocessor 42 of a storage controller 40 prior to start-up of host computers 10, 20, 30; upon startup of the host computers 10, 20, 30, when the storage controller 40 receives a frame issued, then the microprocessor 42 operates to perform comparison for determining whether the N_Port_Name information stored in the frame has been already set in the microprocessor 42 and registered to the N_Port_Name list within a control table maintained. When such comparison results in match, then continue execution of processing based on the frame instruction; if comparison results in failure of match, then reject any request.

Abstract: N_Port_Name information capable of distinctly identifying a host computer has seen set in a microprocessor 42 of a storage controller 40 prior to start-up of host computers 10, 20, 30; upon startup of the host computers 10, 20, 30, when the storage controller 40 receives a frame issued, then the microprocessor 42 operates to perform comparison for determining whether the N_Port_Name information stored in the frame has been already set in the microprocessor 42 and registered to the N_Port_Name list within a control table maintained. When such comparison results in match, then continue execution of processing based on the frame instruction; if comparison results in failure of match, then reject any request.

Abstract: A method and system which prevents starting-up problems in plural magnetic disk storage devices included in a disk array system during restart following halt of the magnetic disk storage devices after long term operation. The disk array system includes the plural magnetic disk storage devices, a microprocessor unit (MPU) which controls the magnetic disk storage devices, a control memory, a parity calculator, and cache memory. The control memory contains a operation time control table in which a tolerable continuous operation time Ti and a halt time Ts are stored. Each of the magnetic disk storage devices is intentionally stopped individually for the halt time Ts at time interval of the tolerable continuous operation time Ti.

Abstract: For providing a storage control unit to be connected to a fiber channel, in which a new storage control unit is added onto the fiber channel network during on-line operation and succeeds control information of a logical unit from the storage control unit which has been existing before, so as to be in charge of a process request issued to that logical unit from a host computer thereafter, wherein a control memory being able to memorize the control information is provided in each of the storage control units 30 and 40, which information is necessary when succeeding or taking over the logical unit and is represented by such as construction information of a magnetic disk drive within a disk drive unit 20 and construction information of the logical unit, so on. The contents of the control memory within the storage control unit 30 is copied into the control memory of the storage control unit 40 when the new storage control unit 40 is added onto the fiber channel network.

Abstract: N_Port_Name information capable of distinctly identifying a host computer has seen set in a microprocessor 42 of a storage controller 40 prior to start-up of host computers 10, 20, 30; upon startup of the host computers 10, 20, 30, when the storage controller 40 receives a frame issued, then the microprocessor 42 operates to perform comparison for determining whether the N_Port_Name information stored in the frame has been already set in the microprocessor 42 and registered to the N_Port_Name list within a control table maintained. When such comparison results in match, then continue execution of processing based on the frame instruction; if comparison results in failure of match, then reject any request.

Abstract: For providing a storage control unit to be connected to a fiber channel, in which a new storage control unit is added onto the fiber channel network during on-line operation and succeeds control information of a logical unit from the storage control unit which has been existing before, so as to be in charge of a process request issued to that logical unit from a host computer thereafter, wherein a control memory being able to memorize the control information is provided in each of the storage control units 30 and 40, which information is necessary when succeeding or taking over the logical unit and is represented by such as construction information of a magnetic disk drive within a disk drive unit 20 and construction information of the logical unit, so on. The contents of the control memory within the storage control unit 30 is copied into the control memory of the storage control unit 40 when the new storage control unit 40 is added onto the fiber channel network.

Abstract: N_Port_Name information capable of distinctly identifying a host computer has seen set in a microprocessor 42 of a storage controller 40 prior to start-up of host computers 10, 20, 30; upon startup of the host computers 10, 20, 30, when the storage controller 40 receives a frame issued, then the microprocessor 42 operates to perform comparison for determining whether the N_Port_Name information stored in the frame has been already set in the microprocessor 42 and registered to the N_Port_Name list within a control table maintained. When such comparison results in match, then continue execution of processing based on the frame instruction; if comparison results in failure of match, then reject any request.

Abstract: In an external storage, an I/O process is continued without any intervention of a user or a host system at failure of a controller. When a failure occurs in a controller, a host system recognizes the failure of the controller. Before the failure is notified to the user and application to stop the job, the substitutive controller reads the SCSI-ID possessed by an SCSI port of the failed controller from a shared memory, registers the SCSI-ID of the SCSI port to the SCSI port associated with the substitutive controller, and erases by a port address resetting facility of the substitutive controller the SCSI-ID possessed by an SCSI port of the failed controller.

Abstract: N_Port_Name information capable of distinctly identifying a host computer has seen set in a microprocessor 42 of a storage controller 40 prior to start-up of host computers 10, 20, 30; upon startup of the host computers 10, 20, 30, when the storage controller 40 receives a frame issued, then the microprocessor 42 operates to perform comparison for determining whether the N_Port_Name information stored in the frame has been already set in the microprocessor 42 and registered to the N_Port_Name list within a control table maintained. When such comparison results in match, then continue execution of processing based on the frame instruction; if comparison results in failure of match, then reject any request.

Abstract: A storage system to be connected to a large-scale computer includes a plurality of host adaptors connected to a host device, a plurality of storage device for storing data from the host device, a plurality of disk adaptors connected to the storage devices, a plurality of caches for temporarily storing data transferred between the host adaptors and the disk adaptors, and two buses connected to the host disk adaptors, and the caches. The buses transfer data among the host and disk adaptors and the caches.

Abstract: A storage system to be connected to a large-scale computer includes a plurality of host adaptors connected to a host device, a plurality of storage device for storing data from the host device, a plurality of disk adaptors connected to the storage devices, a plurality of caches for temporarily storing data transferred between the host adaptors and the disk adaptors, and two buses connected to the host disk adaptors, and the caches. The buses transfer data among the host and disk adaptors and the caches.