Abstract: A host computer includes a virtual disk control part for controlling an input/output request into a virtual disk. A plurality of storage subsystems includes a load monitoring part for measuring a load on a physical disk by the input/output request and storing load information in a disk management table. The virtual disk control part identifies, upon receiving the input/output request into a not-ever-outputted space in a virtual disk, an appropriate logical disk on the virtual disk based on the load information in the disk management table, sends the input/output request to the storage subsystem having the identified logical disk, and updates, upon receiving a completion acknowledgement of the input/output request, the load information in the disk management table based on the load information in the logical disk map information table.

Abstract: A tape management method capable of easily using a file on a virtual tape from a plurality of programs in a system virtually emulating a magnetic tape apparatus by a disk apparatus. When a use request is generated from other program to a volume of a virtual tape used by one program, a host computer generates and uses a volume of a temporal virtual tape and can thus permit the use of the temporal tape volume from a plurality of programs without drastically changing the specification of an existing tape interface. The volume of the virtual tape temporarily generated is generated in a virtual tape management table and a virtual tape file uses a file of the same type.

Abstract: A host computer includes a virtual disk control part for controlling an input/output request into a virtual disk. A plurality of storage subsystems includes a load monitoring part for measuring a load on a physical disk by the input/output request and storing load information in a disk management table. The virtual disk control part identifies, upon receiving the input/output request into a not-ever-outputted space in a virtual disk, an appropriate logical disk on the virtual disk based on the load information in the disk management table, sends the input/output request to the storage subsystem having the identified logical disk, and updates, upon receiving a completion acknowledgement of the input/output request, the load information in the disk management table based on the load information in the logical disk map information table.

Abstract: A tape management method capable of easily using a file on a virtual tape from a plurality of programs in a system virtually emulating a magnetic tape apparatus by a disk apparatus. When a use request is generated from other program to a volume of a virtual tape used by one program, a host computer generates and uses a volume of a temporal virtual tape and can thus permit the use of the temporal tape volume from a plurality of programs without drastically changing the specification of an existing tape interface. The volume of the virtual tape temporarily generated is generated in a virtual tape management table and a virtual tape file uses a file of the same type.

Abstract: An object of the present invention is to shorten a transfer time when a virtual tape volume is used on another computer. A system A incorporating a virtual tape unit is connected to a system B at a remote place via a network. A virtual tape transfer processing unit of the present invention inputs and outputs a virtual tape volume of the system A between virtual tape management information and a virtual tape file. The virtual tape file is copied using a copy function between magnetic disk drives so as to be asynchronous to the systems. An input/output request conversion part allows a tape using task of the system B to use the virtual tape file as a magnetic tape file.

Abstract: An object of the present invention is to shorten a transfer time when a virtual tape volume is used on another computer. A system A incorporating a virtual tape unit is connected to a system B at a remote place via a network. A virtual tape transfer processing unit of the present invention inputs and outputs a virtual tape volume of the system A between virtual tape management information and a virtual tape file. The virtual tape file is copied using a copy function between magnetic disk drives so as to be asynchronous to the systems. An input/output request conversion part allows a tape using task of the system B to use the virtual tape file as a magnetic tape file.