Abstract: In a data processing system in which a host processing apparatus and a storage subsystem are connected via a channel interface, the present invention makes it possible to expand the number of logical device addresses in excess of the device address limitations of the channel interface, and also enhances the performance of parallel access processing for the same logical device. When an access request is generated for a logical device, the host processing apparatus stores the logical device address to be accessed in a prefix command of a channel command word (CCW) for the access request, sets this CCW in a device information block of a frame which complies with the channel interface, sets a parallel access identifier for identifying a plurality of accesses for the same device in a device address of this frame, and then sends this frame to the storage subsystem.

Abstract: For using a plurality of files contained in one logical device with a plurality of processing systems, sharing of a data storage unit among the plurality of processing systems is realized without need for a host processing system to check use states of the files in a server storage unit. Information concerning extent (extent range) of an input/output processing request issued by a host processor is stored in a control memory incorporated in a control unit for allowing the control unit to make decision as to overlap of the extents of the input/output processings to thereby effectuate exclusive control on an extent-by-extent basis.

Abstract: A method and system are provided that can realize data migration between volumes accessed by a host computer without stopping the host computer accessing the volumes. A host computer 10 is connected to a storage subsystem 14 via paths 54 and 56, and the storage subsystem 14 is connected to a storage subsystem 12 via a path 58 (or paths 58 and 60). While data is being copied from an old volume 62 in the storage subsystem 12 (a migration source) to a new volume 64 in the storage subsystem 14 (a migration destination) via the path 58 (or paths 58 and 60), if a request for I/O processing is sent from the host computer 10, the storage subsystem 14 responds and handles that I/O processing.

Abstract: For using a plurality of files contained in one logical device with a plurality of processing systems, sharing of a data storage unit among the plurality of processing systems is realized without need for a host processing system to check use states of the files in a server storage unit. Information concerning extent (extent range) of an input/output processing request issued by a host processor is stored in a control memory incorporated in a control unit for allowing the control unit to make decision as to overlap of the extents of the input/output processings to thereby effectuate exclusive control on an extent-by-extent basis.

Abstract: A data processing system including a disc unit having a plurality of logical devices, a central processing unit for issuing commands with the plurality of logical devices designated as a processing range, and a disc controller for executing the commands for all of the logical devices designated as the processing range. The commands are issued by the central processing unit to the disc controller by executing an initial program load or channel path online.

Abstract: In a data processing system in which a host processing apparatus and a storage subsystem are connected via a channel interface, the present invention makes it possible to expand the number of logical device addresses in excess of the device address limitations of the channel interface, and also enhances the performance of parallel access processing for the same logical device. When an access request is generated for a logical device, the host processing apparatus stores the logical device address to be accessed in a prefix command of a channel command word (CCW) for the access request, sets this CCW in a device information block of a frame which complies with the channel interface, sets a parallel access identifier for identifying a plurality of accesses for the same device in a device address of this frame, and then sends this frame to the storage subsystem.

Abstract: In the host, an IP issues CCW, and a CH encodes the CCW and a CCW chain by the encode program to create a code including the description of controlling a conditional branch with the DKC and transmits the code to a PORT in the DKC. In the DKC, the PORT decodes the code by the decode program, and a CP sequentially processes each command obtained by the decoding and returns a return code representing the end state of the processing. The host receives the return code to recognize the end state of the processing.

Abstract: A data look-ahead control is provided to realize a high cache hit rate and improves responsiveness in an information processing system. In the data look-ahead control, when it is determined that the current input/output request is an access to a specific database that was the subject of a recent input/output request and whose I/O count exceeds a predetermined value, and it is also determined that a cache memory can be occupied to some extent and that there would be no impact on other input/output requests, data including one or more blocks (logical tracks) larger than a block that is the subject of the current I/O request are loaded to the cache memory.

Abstract: A storage system, which can execute sort processing of data without affecting online service, is disclosed. A storage control device 12 receives a sort instruction specifying a record group for sorting and a sort key from a host device 1, reads the record group from an external storage device 11 into cache memory 123, and uses the cache memory 123 and a work area secured in the external storage device 11 to execute sort processing of the above record group, and again stores the sorted record group in a prescribed output area within the external storage device 11. When a plurality of sort instructions are received, work areas are allocated automatically without overlapping work areas. When record updates occur during online service, a snapshot of the updated records is taken, and sorting of the snapshot is performed.

Abstract: A storage device system in which migration of data from an existing storage device to a higher-standard storage device is unnecessary, and in which discarding of existing storage devices by the user can be prevented. A CHF 61 receives a Read Capacity command from a new-type storage device 25 (S101). Using LDEV, LUN and other information tables, an LUN 87 is converted into a mapped LDEV (S102). A check is performed to determine whether the LDEV emulation type is read-only, write-only, or read/write (S103). If none of these, a check is performed to determine whether the emulation type is newly created (S104). If newly created, the size of all storage areas of the LDEV are set as the Max LBA in a response to the new-type storage device 25 (S105). If the result of S103 is YES, the size of the user area in the LDEV is set as the Max LBA in a response to the new-type storage device 25 (S106). If not newly created, processing proceeds to the processing of S106.

Abstract: A storage system, which can execute sort processing of data without affecting online service, is disclosed. A storage control device 12 receives a sort instruction specifying a record group for sorting and a sort key from a host device 1, reads the record group from an external storage device 11 into cache memory 123, and uses the cache memory 123 and a work area secured in the external storage device 11 to execute sort processing of the above record group, and again stores the sorted record group in a prescribed output area within the external storage device 11. When a plurality of sort instructions are received, work areas are allocated automatically without overlapping work areas. When record updates occur during online service, a snapshot of the updated records is taken, and sorting of the snapshot is performed.

Abstract: For using a plurality of files contained in one logical device with a plurality of processing systems, sharing of a data storage unit among the plurality of processing systems is realized without need for a host processing system to check use states of the files in a server storage unit. Information concerning extent (extent range) of an input/output processing request issued by a host processor is stored in a control memory incorporated in a control unit for allowing the control unit to make decision as to overlap of the extents of the input/output processings to thereby effectuate exclusive control on an extent-by-extent basis.

Abstract: There is provided a data processing system which, from a point of view of increasing process efficiency of the entire data processing system to exhibit a maximum effect, may assign an alias device to a logic device. The data processing system of this invention comprises a host processing device (10) and a storage control device (20) connected thereto via a communication means (50), where the storage control device (20) has a deciding means for deciding, at a time of processing an I/O request of a certain base device, whether there is a need to newly assign an alias device to the base device according to a use situation of a physical device (203). When assignment is decided as necessary, the host processing device (10) is notified of such via the communication means, and the host processing device (10) newly assigns an alias device to the base device when there is the notification from the storage control device (20).

Abstract: For using a plurality of files contained in one logical device with a plurality of processing systems, sharing of a data storage unit among the plurality of processing systems is realized without need for a host processing system to check use states of the files in a server storage unit. Information concerning extent (extent range) of an input/output processing request issued by a host processor is stored in a control memory incorporated in a control unit for allowing the control unit to make decision as to overlap of the extents of the input/output processings to thereby effectuate exclusive control on an extent-by-extent basis.

Abstract: There is provided a data processing system which, from a point of view of increasing process efficiency of the entire data processing system to exhibit a maximum effect, may assign an alias device to a logic device. The data processing system of this invention comprises a host processing device (10) and a storage control device (20) connected thereto via a communication means (50), where the storage control device (20) has a deciding means for deciding, at a time of processing an I/O request of a certain base device, whether there is a need to newly assign an alias device to the base device according to a use situation of a physical device (203). When assignment is decided as necessary, the host processing device (10) is notified of such via the communication means, and the host processing device (10) newly assigns an alias device to the base device when there is the notification from the storage control device (20).

Abstract: There is provided a data processing system which, from a point of view of increasing process efficiency of the entire data processing system to exhibit a maximum effect, may assign an alias device to a logic device. The data processing system of this invention comprises a host processing device (10) and a storage control device (20) connected thereto via a communication means (50), where the storage control device (20) has a deciding means for deciding, at a time of processing an I/O request of a certain base device, whether there is a need to newly assign an alias device to the base device according to a use situation of a physical device (203). When assignment is decided as necessary, the host processing device (10) is notified of such via the communication means, and the host processing device (10) newly assigns an alias device to the base device when there is the notification from the storage control device (20).

Abstract: For using a plurality of files contained in one logical device with a plurality of processing systems, sharing of a data storage unit among the plurality of processing systems is realized without need for a host processing system to check use states of the files in a server storage unit. Information concerning extent (extent range) of an input/output processing request issued by a host processor is stored in a control memory incorporated in a control unit for allowing the control unit to make decision as to overlap of the extents of the input/output processings to thereby effectuate exclusive control on an extent-by-extent basis.

Abstract: For using a plurality of files contained in one logical device with a plurality of processing systems, sharing of a data storage unit among the plurality of processing systems is realized without need for a host processing system to check use states of the files in a server storage unit. Information concerning extent (extent range) of an input/output processing request issued by a host processor is stored in a control memory incorporated in a control unit for allowing the control unit to make decision as to overlap of the extents of the input/output processings to thereby effectuate exclusive control on an extent-by-extent basis.

Abstract: For using a plurality of files contained in one logical device with a plurality of processing systems, sharing of a data storage unit among the plurality of processing systems is realized without need for a host processing system to check use states of the files in a server storage unit. Information concerning extent (extent range) of an input/output processing request issued by a host processor is stored in a control memory incorporated in a control unit for allowing the control unit to make decision as to overlap of the extents of the input/output processings to thereby effectuate exclusive control on an extent-by-extent basis.

Abstract: A data look-ahead control is provided to realize a high cache hit rate and improves responsiveness in an information processing system. In the data look-ahead control, when it is determined that the current input/output request is an access to a specific database that was the subject of a recent input/output request and whose I/O count exceeds a predetermined value, and it is also determined that a cache memory can be occupied to some extent and that there would be no impact on other input/output requests, data including one or more blocks (logical tracks) larger than a block that is the subject of the current I/O request are loaded to the cache memory.