Abstract: Each actual page inside a pool is configured from a plurality of actual tracks, and each virtual page inside a virtual volume is configured from a plurality of virtual tracks. A storage control apparatus of a mainframe system has management information that includes information denoting a track in which there exists a user record, which is a record including user data (the data used by a host apparatus of a mainframe system). Based on the management information, a controller identifies an actual page that is configured only from tracks that do not comprise the user record, and cancels the allocation of the identified actual page to the virtual page.

Abstract: A host I/F unit has a management table for managing an MPPK which is in-charge of the control of input/output processing for a storage area of an LDEV, and if a host computer transmits an input/output request for the LDEV, the host I/F unit transfers the input/output request to the MPPK which is in-charge of the input/output processing for the LDEV based on the management table, an MP of the MPPK performs the input/output processing based on the input/output request, and the MP of the MPPK also judges whether the MPPK that is in-charge of the input/output processing for the LDEV is to be changed, and sets the management table so that an MPPK which is different from the MPPK that is in-charge is to be in-charge of the input/output processing for the LDEV.

Abstract: A plurality of modules (1) and (2) comprise a plurality of virtual volumes with which the same volume identification number is associated. A module (2), which receives a write request from a computer, searches for an unallocated real area from among a plurality of real areas in the module (2) rather than from among a plurality of real areas in the other module (1) if a real area has not been allocated to a write-targeted virtual area in accordance with the write request. The module (2) allocates the real area retrieved from the module (2) to the write-targeted virtual area, and writes data according to the write request to this real area.

Abstract: A host I/F unit has a management table for managing an MPPK which is in-charge of the control of input/output processing for a storage area of an LDEV, and if a host computer transmits an input/output request for the LDEV, the host I/F unit transfers the input/output request to the MPPK which is in-charge of the input/output processing for the LDEV based on the management table, an MP of the MPPK performs the input/output processing based on the input/output request, and the MP of the MPPK also judges whether the MPPK that is in-charge of the input/output processing for the LDEV is to be changed, and sets the management table so that an MPPK which is different from the MPPK that is in-charge is to be in-charge of the input/output processing for the LDEV.

Abstract: Improvement of read/write access performance with respect to a disk is proposed. A controller manages a first volume format LDEV, in which each distributed user data area and each distributed information area among a plurality of the distributed user data areas for storing a data part and a plurality of the distributed control information area for storing a control information part, are targets that capacity is changed. The controller also manages a second format LDEV, which include a plurality of groups each of which is formed from one distributed user data area and one distributed control information area, and in which each group is a unit that capacity is expanded in a real storage area.

Abstract: A backup system and backup method with which the processing time can be shortened without increasing the overhead and burden on the system administrator in a two-stage backup. In a backup system which executes a two-stage backup, the storage apparatus searches for a secondary volume which can be paired with a primary volume on the basis of the pair create instruction, determines whether the volume size of the secondary volume obtained as a search result is greater than the volume size of the primary volume and, if the volume size of the secondary volume is greater than the volume size of the primary volume, sets the volume size of the secondary volume as the same size as the volume size of the primary volume without changing the substantial volume size of the secondary volume, and notifies the host of information on the set volume size of the secondary volume and information indicating that a pair has been created.

Abstract: Improvement of read/write access performance with respect to a disk is proposed. A controller manages a first volume format LDEV, in which each distributed user data area and each distributed information area among a plurality of the distributed user data areas for storing a data part and a plurality of the distributed control information area for storing a control information part, are targets that capacity is changed. The controller also manages a second format LDEV, which include a plurality of groups each of which is formed from one distributed user data area and one distributed control information area, and in which each group is a unit that capacity is expanded in a real storage area.

Abstract: A host I/F unit has a management table for managing an MPPK which is in-charge of the control of input/output processing for a storage area of an LDEV, and if a host computer transmits an input/output request for the LDEV, the host I/F unit transfers the input/output request to the MPPK which is in-charge of the input/output processing for the LDEV based on the management table, an MP of the MPPK performs the input/output processing based on the input/output request, and the MP of the MPPK also judges whether the MPPK that is in-charge of the input/output processing for the LDEV is to be changed, and sets the management table so that an MPPK which is different from the MPPK that is in-charge is to be in-charge of the input/output processing for the LDEV.

Abstract: A virtualization system, upon judging that a write operation from a higher-level device is an operation to write in the format of the virtual volume, even when the write position of the write operation is in a virtual area different from a virtual area to which an allocated actual area has been allocated, if there is an unused area in the allocated actual area, writes management information to the unused area according to the write operation, and if there is no unused area in the allocated actual area, newly allocates an unallocated actual area, and writes management information to the newly allocated actual area according to the write operation.

Abstract: A host I/F unit has a management table for managing an MPPK which is in-charge of the control of input/output processing for a storage area of an LDEV, and if a host computer transmits an input/output request for the LDEV, the host I/F unit transfers the input/output request to the MPPK which is in-charge of the input/output processing for the LDEV based on the management table, an MP of the MPPK performs the input/output processing based on the input/output request, and the MP of the MPPK also judges whether the MPPK that is in-charge of the input/output processing for the LDEV is to be changed, and sets the management table so that an MPPK which is different from the MPPK that is in-charge is to be in-charge of the input/output processing for the LDEV.

Abstract: A host I/F unit has a management table for managing an MPPK which is in-charge of the control of input/output processing for a storage area of an LDEV, and if a host computer transmits an input/output request for the LDEV, the host I/F unit transfers the input/output request to the MPPK which is in-charge of the input/output processing for the LDEV based on the management table, an MP of the MPPK performs the input/output processing based on the input/output request, and the MP of the MPPK also judges whether the MPPK that is in-charge of the input/output processing for the LDEV is to be changed, and sets the management table so that an MPPK which is different from the MPPK that is in-charge is to be in-charge of the input/output processing for the LDEV.

Abstract: Improvement of read/write access performance with respect to a disk is proposed. A controller manages a first volume format LDEV, in which each distributed user data area and each distributed information area among a plurality of the distributed user data areas for storing a data part and a plurality of the distributed control information area for storing a control information part, are targets that capacity is changed. The controller also manages a second format LDEV, which include a plurality of groups each of which is formed from one distributed user data area and one distributed control information area, and in which each group is a unit that capacity is expanded in a real storage area.

Abstract: Each actual page inside a pool is configured from a plurality of actual tracks, and each virtual page inside a virtual volume is configured from a plurality of virtual tracks. A storage control apparatus of a mainframe system has management information that includes information denoting a track in which there exists a user record, which is a record including user data (the data used by a host apparatus of a mainframe system). Based on the management information, a controller identifies an actual page that is configured only from tracks that do not comprise the user record, and cancels the allocation of the identified actual page to the virtual page.

Abstract: A virtualization system, upon judging that a write operation from a higher-level device is an operation to write in the format of the virtual volume, even when the write position of the write operation is in a virtual area different from a virtual area to which an allocated actual area has been allocated, if there is an unused area in the allocated actual area, writes management information to the unused area according to the write operation, and if there is no unused area in the allocated actual area, newly allocates an unallocated actual area, and writes management information to the newly allocated actual area according to the write operation.

Abstract: A virtualization system, upon judging that a write operation from a higher-level device is an operation to write in the format of the virtual volume, even when the write position of the write operation is in a virtual area different from a virtual area to which an allocated actual area has been allocated, if there is an unused area in the allocated actual area, writes management information to the unused area according to the write operation, and if there is no unused area in the allocated actual area, newly allocates an unallocated actual area, and writes management information to the newly allocated actual area according to the write operation.

Abstract: A plurality of global LDEV managed by a plurality of controller modules are provided above local LDEV under the control of each controller module. Each global LDEV is correlated to any of the plurality of local LDEV. The controller modules judge whether or not a local LDEV correlated to a global LDEV specified by an I/O request received from a host device or a first other controller module is a management target itself, and if the result of that judgment is affirmative, the controller modules access the local LDEV correlated to the specified global LDEV, while if the result of the judgment is negative, the controller modules transfer the received I/O request to a second other controller module.

Abstract: A host I/F unit has a management table for managing an MPPK which is in-charge of the control of input/output processing for a storage area of an LDEV, and if a host computer transmits an input/output request for the LDEV, the host I/F unit transfers the input/output request to the MPPK which is in-charge of the input/output processing for the LDEV based on the management table, an MP of the MPPK performs the input/output processing based on the input/output request, and the MP of the MPPK also judges whether the MPPK that is in-charge of the input/output processing for the LDEV is to be changed, and sets the management table so that an MPPK which is different from the MPPK that is in-charge is to be in-charge of the input/output processing for the LDEV.

Abstract: A host I/F unit has a management table for managing an MPPK which is in-charge of the control of input/output processing for a storage area of an LDEV, and if a host computer transmits an input/output request for the LDEV, the host I/F unit transfers the input/output request to the MPPK which is in-charge of the input/output processing for the LDEV based on the management table, an MP of the MPPK performs the input/output processing based on the input/output request, and the MP of the MPPK also judges whether the MPPK that is in-charge of the input/output processing for the LDEV is to be changed, and sets the management table so that an MPPK which is different from the MPPK that is in-charge is to be in-charge of the input/output processing for the LDEV.

Abstract: A virtualization system, upon judging that a write operation from a higher-level device is an operation to write in the format of the virtual volume, even when the write position of the write operation is in a virtual area different from a virtual area to which an allocated actual area has been allocated, if there is an unused area in the allocated actual area, writes management information to the unused area according to the write operation, and if there is no unused area in the allocated actual area, newly allocates an unallocated actual area, and writes management information to the newly allocated actual area according to the write operation.

Abstract: A controller unit for the storage apparatus executes the following: giving each data block, which is a data constituent unit, an identification number indicating that the relevant data has been sent from a host computer in response to an arbitrary write request from the host computer; storing, in a memory unit, a storage location in a hard disk drive unit to store the data, as well as the identification number, as an expected value, for the data to be stored in the hard disk drive unit; and in response to a read request from the host computer, comparing the identification number given to each data block, the constituent unit of the data read from the hard disk drive unit, with the expected value of the read data, thereby verifying that the read data is the data written to the hard disk drive in response to the arbitrary write request.