Abstract: A method of respectively reading and writing data to and from a plurality of physical disk units in response to I/O requests from a host computing system includes establishing a logical disk group having a number of logical disk elements, mapping each of the logical disk elements to corresponding physical disk units, receiving from the host computing system an I/O request for data to select a one of the number of logical disk elements, accessing the physical disk unit corresponding to the selected one logical disk to access for the data, and transferring the accessed data to the host computing system.

Abstract: A storage controller calculates an access frequency of each logical disk; selects a first logical disk device of which an access frequency exceeds a first predetermined value, the first logical disk device being allocated to a first physical disk device; selects a second logical disk device which has the access frequency equal to or less than a second predetermined value, the second logical disk device being allocated to a second physical disk device; and reallocates the first and second logical devices to the second and the first physical disk devices, respectively.

Abstract: The control unit arbitrarily with respect to the CPU, including according to an algorithm that is independent of the request a disk unit among the disk units that are inactive when the control unit receives an input/output request involving either read or staging. For a write request from the CPU, the control unit selects a specific disk unit in the disk unit group for the immediate writing of data. In the second kind of load distribution a disk unit is selected to execute read and staging other than the above-mentioned specific disk.

Abstract: A data mapping management server collects data mapping information about functions for providing virtual storage regions, and provides an administrator with a management view on which the virtual storage regions created/managed in each virtual storage region providing function can be comprehensively grasped based on the collected information. The order to migrate data with the destination after mapping alteration can be accepted on interactive views. The data mapping management server produces a procedure plan for carrying out the accepted data mapping alteration order, and presents it to the administrator. The administrator decides if this plan can be carried out. If the administrator permits this plan to be carried out, the server orders each virtual storage region providing function to migrate data and create new virtual storage regions according to the produced plan.

Abstract: When a bus is used as a data communication channel, data within a disk unit cannot be reproduced or copied into a spare disk while a control unit is making read/write processing based on a request from a host computer, or vice versa. Thus, a loop is constructed by a fiber channel capable of time division multiplex function, and the processing between the disk unit and the spare is performed not through the control unit so that the data within the disk can be copied into the spare while the processing between the host computer and the disk unit is being performed, or both processing operations can be executed in parallel.

Abstract: Data corresponding to an analog circuit diagram is generated and stored. Circuit connection information is extracted based on the analog circuit diagram data and stored. Devices to be paired are predicted and extracted based on the circuit connection information. The devices added as design constraints to the circuit connection information, and the result of addition is stored. Layout cells are placed on the basis of the circuit connection information including the design constraints. Routing of the layout cells is conducted.

Abstract: A plurality of magnetic disks are connected to a disk controller A through a fiber switch A and a fiber switch C. A disk controller B is connected to the plurality of magnetic disks through a fiber switch B and a fiber switch D. Access paths on the side of disk controller A and on the side of disk controller B are each interrupted by using associated fiber switches and a new disk controller is added between the fiber switches.

Abstract: A disk storage system has a control unit having a plurality of external ports connectable to a mirrored disk including two disks to which write data is written. When the control unit receives two read requests issued from a processor to the disk unit group, a first read operation is performed to read data requested by the first read request from one of the disks and a second read operation is performed to read data requested by the second read request from the other one of the disks. Also, a first transferring operation is performed to transfer data read by the first read operation to one external port of the control unit and a second transferring operation is performed to transfer data read by the second read operation to another external port of the control unit. Further, the data read by the two read operations is transferred to the processor via the external ports.

Abstract: A method for verifying data in a storage system is disclosed. A host computer transmits area management data to a storage controller. The area management data specifies a range of a storage area in a storage device to be used by an application program having a mechanism for verifying data suitability. Upon receipt of an input/output request transmitted from the host computer, the storage controller performs verification, which is usually performed by the application program, of the data that is to be processed according to the data input/output request and to be input/output to/from the storage area, which is specified in accordance with the received area management data.

Abstract: The present invention creates real data and parity data using plural hard disk control units without changing the number of disk adapters per hard disk control unit and distributes and stores data in a hard disk.

Abstract: When a bus is used as a data communication channel, data within a disk unit cannot be reproduced or copied into a spare disk while a control unit is making read/write processing based on a request from a host computer, or vice versa. Thus, a loop is constructed by a fiber channel capable of time division multiplex function, and the processing between the disk unit and the spare is performed not through the control unit so that the data within the disk can be copied into the spare while the processing between the host computer and the disk unit is being performed, or both processing operations can be executed in parallel.

Abstract: A method for managing data stored in a hierarchical storage unit of a storage apparatus is disclosed. The storage unit includes a first storage medium having a first access speed and a second storage medium having a second access speed. The first access speed is different from the second access speed. The method comprises determining a first access frequency for information of first type, the first access frequency being associated with a first period of past time. A second access frequency of the information of first type is determined. The second access frequency is associated with a second period of past time and is different than the first access frequency. At least a portion of the information of first type is transferred from the first storage medium to the second storage medium prior to a second period based on the second access frequency determined in the determining-a-second-access-frequency step, the second period corresponding to the second period of past time.

Abstract: Data corresponding to an analog circuit diagram is generated and stored. Circuit connection information is extracted based on the analog circuit diagram data and stored. Devices to be paired are predicted and extracted based on the circuit connection information. The devices added as design constraints to the circuit connection information, and the result of addition is stored. Layout cells are placed on the basis of the circuit connection information including the design constraints. Routing of the layout cells is conducted.

Abstract: Data recorded in a disk of a hard disk unit is copied to another hard disk unit. A proxy mode, for making the other hard disk unit which has been copied with the data to perform an I/O process to the hard disk unit in place thereof, is performed. Meanwhile, the firmware of the original hard disk unit is updated, and contents of the disk is set up to a latest updated state. Then, the operation in the proxy mode is stopped, and the operation is switched to an operation in a normal mode where the I/O process is directly performed to the original hard disk unit.

Abstract: A host computer requests a storage device to perform a data transfer operation using information about the data transfer source/destination regions as a parameter. The storage device internally transfers data from a source disk device to a destination disk device. When the transfer of the data is completed, the storage device notifies the host computer that the operation has been completed. The host computer receives the notification and updates the storage location of the data to the destination region.

Abstract: Cell assignment section performs an automatic cell assignment according to circuit data 51. Distribution path determining section automatically determines a distribution path between cells. Distribution information extracting section extracts information regarding already determined distribution path. Prescribed-information recognizing section recognizes information on a prescribed portion (end or bend) of the distribution. Additional-distribution-data generating section generates additional distribution data for correcting the width of the prescribed portion. Additional-distribution-data lay-out section lays out the generated additional distribution data for the prescribed portion. This makes it possible to quickly obtain final pattern data in a state of designing a mask that is used for manufacturing a semiconductor integrated circuit device.

Abstract: A storage controller calculates an access frequency of each logical disk; that it selects a first logical disk device of which the access frequency exceeds a first predetermined value, the first logical disk device being allocated to a first physical disk device, selects a second logical disk device which has the access frequency equal to or less than a second predetermined value, the second logical disk device being allocated to a second physical disk device; and reallocates the first and second logical devices to the second and the first physical disk devices, respectively.

Abstract: A storage controller calculates an access frequency of each logical disk; that it selects a first logical disk device of which the access frequency exceeds a first predetermined value, the first logical disk device being allocated to a first physical disk device; selects a second logical disk device which has the access frequency equal to or less than a second predetermined value, the second d logical disk device being allocated to a second physical disk device; and reallocates the first and second logical device; and reallocates the first and second logical devices to the second and the first physical disk device, respectively.

Abstract: During recovery of a master system, a mismatch between data in the master system and that in a backup system is obviated quickly to shorten time consumed before resumption of operation of the master system. The backup system controls, as second difference information, update data generated over a substitutive operation period between occurrence of a disabled state of the master system and recovery thereof and when the master system is enabled to operate, a range of addition of first difference information inside the master system and the second difference information or only a range of the second difference information is copied to the master system to eliminate the data mismatch.

Abstract: A storage system stores multiple copies of data on physical storage implemented, for example, with multiple disk units. Input/output read requests are received from host systems and distributed in a manner that allows parallel read operations to be conducted over the multiple disk units of the physical storage.