Abstract: In a computer system of the present invention, whether or not master data has been updated is managed for each division key as master data management information. If the master data has been updated, a job is re-executed, but when the job is re-executed, data is divided using only a division key corresponding to updated master data, and thereby a sub-job which is a re-execution target is localized with the division key unit so as to re-execute a job.

Abstract: In a computer system of the present invention, whether or not master data has been updated is managed for each division key as master data management information. If the master data has been updated, a job is re-executed, but when the job is re-executed, data is divided using only a division key corresponding to updated master data, and thereby a sub-job which is a re-execution target is localized with the division key unit so as to re-execute a job (refer to FIG. 1).

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 data transferring method is provided which can perform a data transfer without stopping transactions, without introducing a new device or without halting an access to a tape device by a higher-level device as would otherwise be required by a data transfer procedure. A technology is provided whereby a host computer controls an access request to a tape volume by managing and using information about source/destination tape devices (e.g., magnetic tape library management table and virtual tape management table) or data transfer state in a journal. As a result, even if an access request is issued from other device to a tape volume currently being data-transferred, the access can be made to the tape volume of interest without stopping transactions, i.e., a data transfer can be realized without an interruption of service.

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 technology in which a magnetic disk apparatus executes data relocation involves the problems how to cope with new setup of file management and hardware failure and performance drop at the time in a data relocation. The invention provide a technology capable of executing data relocation without moving physical data position by a magnetic disk control apparatus when a disconnection operation of a logical volume is made, while keeping setup of an existing file management system. Therefore, the magnetic disk control apparatus is provided with means for keeping a file position information list inside a logical volume, executing optimal data reorganization in such a fashion as to eliminate fragmentation of the list and updating a physical/logical address mapping table. Reorganization of the logical file position is made without the data movement.