Abstract: According to the invention, techniques for detecting and recovering from errors occurring in disk drive subsystems having a controller and drive units connected by a fiber channel loop. Specific embodiments can provide storage subsystems, methods and apparatus for use in information processing environments, for example. Embodiments can determine when each drive is disconnected from the loop in the external storage subsystem structured by using the FC Loop, and thereupon, the FC Loop can be controlled by bridging the communication path using the PBC so that the loop is not broken.

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 structure of control units and storage units is provided in which, if a port for connecting the storage units fails, any storage unit in a plurality of storage unit groups can be accessed from one control unit. Specifically, a distinctively arranged structure is provided in which dual paths are provided, with each path connected to a plurality of storage unit groups, whereby, in normal operation, dual paths are used as data transfer paths to allow faster access. When a port or path failure occurs, the dual paths allow RAID functions to be maintained.

Abstract: A structure of control units and storage units is provided in which, if a port for connecting the storage units fails, any storage unit in a plurality of storage unit groups can be accessed from one control unit. Specifically, a distinctively arranged structure is provided in which dual paths are provided, with each path connected to a plurality of storage unit groups, whereby, in normal operation, dual paths are used as data transfer paths to allow faster access. When a port or path failure occurs, the dual paths allow RAID functions to be maintained.

Abstract: A disk storage subsystem allocating an equivalent number of hard disk drives to each loop, alternately connecting the connecting bays of hard disk drives to optical fiber channels provided with two or more fiber channel loops for optimizing load balancing.

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 storage subsystem allocating an equivalent number of hard disk drives to each loop, alternately connecting the connecting bays of hard disk drives to optical fiber channels provided with two or more fiber channel loops for optimizing load balancing.

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: A storage sub-system employs a staging control information table by which staging of data to be read and redundant data thereof can be executed together to reduce response time in the event of a data read failure. The staging control information table also permits pre-read staging to be executed in the forward, backward or both the forward and backward directions, to reduce response time.

Abstract: A storage control system comprises a plurality of controllers, each of the controllers receiving a data-input/output request inputted via an external communication path and sending a data-input/output command to storage means; and an internal communication path through which the controllers carry out the data-input/output command and data input/output. Each of the controllers comprises means for sending its own operational information towards other ones of the controllers via the internal communication path. The storage control system further comprises means for monitoring an operational state of each of the controllers based on the operational information sent from the sending means of the controllers.

Abstract: The storage regions under command of a storage controller can be simply enabled and disabled to access to by automatically registering connected host computers. Such system can be achieved by taking a step of acquiring N_Port_Name information included in a login frame from the host computers, and a step of displaying a table of access right of host computers to a logical unit under command of storage controller. A security table for the storage controller can be generated by supervisor's setting the access enable/disable flag information.

Abstract: A disk array unit connected to a host unit to give information thereto and receive information therefrom. The disk unit includes a plurality of disk units for storing information transmitted from the host unit and a management information recording device, formed by utilizing information storage areas in the disk units, for causing information relating to a logical unit for storing information from the host unit to correspond to information relating to the units. The invention further includes a control unit, when there is no access from the host unit to the logical unit for a predetermined time, for determining the disk units corresponding to the logical unit based on information recorded in the management information recording device and performing power saving of power supply for the disk units.

Abstract: A disk array unit connected to a host unit to give information thereto and receive information therefrom. The disk unit includes a plurality of disk units for storing information transmitted from the host unit and a management information recording device, formed by utilizing information storage areas in the disk units, for causing information relating to a logical unit for storing information from the host unit to correspond to information relating to the units. The invention further includes a control unit, when there is no access from the host unit to the logical unit for a predetermined time, for determining the disk units corresponding to the logical unit based on information recorded in the management information recording device and performing power saving of power supply for the disk units.

Abstract: In a storage system, a server apparatus and a storage apparatus are provided, while the server apparatus is connected via a LAN to one, or plural sets of computers so as to accept an access request of file data issued from the computers, whereas the storage apparatus is connected via a wide area network to the server apparatus so as to store thereinto the file data. A communication between the computers and the server apparatus is carried out by employing a network file protocol, whereas a communication between the server apparatus and the storage apparatus is performed by employing a block device protocol. The server apparatus and the storage apparatus are connected via the respective security protecting apparatus to the wide area network.

Abstract: A storage sub-system employs a staging control information table by which staging of data to be read and redundant data thereof can be executed together to reduce response time in the event of a data read failure. The staging control information table also permits pre-read staging to be executed in the forward, backward or both the forward and backward directions, to reduce response time.

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: The storage regions under command of a storage controller can be simply enabled and disabled to access to by automatically registering connected host computers. Such system can be achieved by taking a step of acquiring N_Port_Name information included in a login frame from the host computers, and a step of displaying a table of access right of host computers to a logical unit under command of storage controller. A security table for the storage controller can be generated by supervisor's setting the access enable/disable flag information.

Abstract: A backup method for a system including a network attached storage including a primary volume and a secondary volume, and a backup server connected to the network. The network attached storage performs a resynchronization process when a backup request is received at a time point that consistency of a file system can be guaranteed, the resynchronization process making the contents of the primary and secondary volumes coincide with each other, splits the secondary volume from the primary volume and transfers data of the secondary volume to the backup server while an online operation with the primary volume continues. The backup server stores the transferred data in a recording medium. The network attached storage performs again the resynchronization process for making the contents of the primary and secondary volumes coincide with each other, after backup completion.

Abstract: A disk array unit connected to a host unit to give information thereto and receive information therefrom. The disk unit includes a plurality of disk units for storing information transmitted from the host unit and a management information recording device, formed by utilizing information storage areas in the disk units, for causing information relating to a logical unit for storing information from the host unit to correspond to information relating to the units. The invention further includes a control unit, when there is no access from the host unit to the logical unit for a predetermined time, for determining the disk units corresponding to the logical unit based on information recorded in the management information recording device and performing power saving of power supply for the disk units.