Abstract: A storage system including: a controller; and, a plurality of physical storage devices coupled to the controller and constituting a RAID group; wherein the controller provides one or more logical volumes belonging to the RAID group, each of the one or more logical volumes having a plurality of storage areas; and one or more virtual volumes, wherein, when receiving a write request to a virtual volume of the one or more virtual volumes, the controller is configured to: allocate a storage area in a logical volume to the virtual volume, as an allocated storage area, where reliability of the storage area is used as a criterion in a selection of the storage area for allocation to the virtual volume; and write data to the allocated storage area, wherein, the controller is configured to selectively perform a RAID allocation process to a storage area allocated to a virtual volume.

Abstract: Availability of an information system including a storage apparatus and a host computer is improved. A host system includes a first storage apparatus provided with a first volume for storing data, and a second storage apparatus for storing the data sent from the first storage apparatus. In case of a failure occurring in the first storage apparatus, the host sends the data to be sent to the first storage apparatus to the second storage apparatus.

Abstract: Information system, including: first and second storage apparatuses connected to a host computer and including volumes designated by a common volume identifier, but being accessible via differing paths of differing priorities. A failure detection storage apparatus connected to the storage apparatuses includes a third volume. Any I/O request designating the common volume identifier, is first sent to the first volume though the first access path, but upon error is then sent to the second volume thorough the second access path. The first or second storage apparatus detecting failure stores, in the third volume, a failure information flag. Upon receiving an I/O request through the second access path, the second storage apparatus determines whether the failure information flag is stored in the third volume, and sends an error reply of the I/O request to the host computer if the failure information flag is stored in the third volume.

Abstract: There is disclosed a data storage system used in a computer environment where there are plural host computers and plural storage array controllers. When a remote copy is made while assuring the order of writing across plural storage array controllers, one of the host computers gains copy information about all the storage array controllers associated with the remote copy as a representative. The representative one of the storage array controllers collects and stores copy statuses which are individually managed by the storage array controllers for which a remote copy is made. The host computer gains the copy statuses from the representative controller using an instruction to gain the copy statuses.

Abstract: A storage system including: a controller; and, a plurality of physical storage devices coupled to the controller and constituting a RAID group; wherein the controller provides one or more logical volumes belonging to the RAID group, each of the one or more logical volumes having a plurality of storage areas; one or more virtual volumes, wherein, when receiving a write request to a virtual volume of the one or more virtual volumes, the controller allocates a storage area in a logical volume to the virtual volume; and writes data to the allocated storage area, wherein, when a physical storage device of the plurality of physical storage devices fails, the controller selectively performs a RAID restore process to a storage area allocated to a virtual volume.

Abstract: Information system, including: first and second storage apparatuses connected to a host computer and including volumes designated by a common volume identifier, but being accessible via differing paths of differing priorities. A failure detection storage apparatus connected to the storage apparatuses includes a third volume. Any I/O request designating the common volume identifier, is first sent to the first volume though the first access path, but upon error is then sent to the second volume thorough the second access path. The first or second storage apparatus detecting failure stores, in the third volume, a failure information flag. Upon receiving an I/O request through the second access path, the second storage apparatus determines whether the failure information flag is stored in the third volume, and sends an error reply of the I/O request to the host computer if the failure information flag is stored in the third volume.

Abstract: A computer system includes: a first storage apparatus; a second storage apparatus; a first volume of the first storage apparatus; and a second volume of the second storage apparatus; wherein the first volume and the second volume have a copy pair relationship and a host system recognizes the second volume as the same volume as the first volume; and wherein the first storage apparatus sends reservation information of the first volume to the second storage apparatus; and the second storage apparatus controls access from the host system on the basis of the received reservation information.

Abstract: Even when a host does not give a write time to write data, consistency can be kept among data stored in secondary storage systems. The present system has plural primary storage systems each having a source volume and plural secondary storage systems each having a target volume. Once data is received from a host, each of the plural storage systems creates write-data management information having sequential numbers and reference information and sends, to one of the primary storage systems, the data, sequential number and reference information. Each of the secondary storage systems records reference information corresponding to the larges sequential number among serial sequential numbers and stores, in a target volume in an order of sequential numbers, data corresponding to reference information having a value smaller than the reference information based on the smallest value reference information among reference information recorded in each of the plural secondary storage systems.

Abstract: Availability of an information system including a storage apparatus and a computer is improved. First and second storage apparatuses execute remote copy of copying data written into a first primary volume from the computer to a second primary volume, at least one of the first and second storage apparatuses executes local copy of copying the data written into the first or second primary volume in a self-storage apparatus to the corresponding first or second secondary volume, and the computer switches the destination of a write request of the data from the first storage apparatus to the second storage apparatus in case of a failure occurring in the first storage apparatus.

Abstract: In a system in which data employed by a computer is stored in a storage system, the storage system transfers this data to another storage system and a copy of the data is maintained in the other storage system. The consistency of the copy is maintained even when data is written, to the storage system by a computer, without having a write time applied. A source storage system, when a write time is applied to a write request, records the write time and applies this write time to the received write data and, when no write time is applied, applies the recorded write time to the received write data and transfers the write data with this write time applied thereto, to a target storage system. The target storage system stores the write data in a logical volume in the target storage system in accordance with the write time.

Abstract: An information system including: a first and second storage apparatus including a first and second volume; a failure detection storage apparatus including a third volume; wherein, for backup purposes, the first and second volumes form a remote copy pair, and, for I/O request purposes, are recognized as a single volume labeled with a same volume identifier, but accessible by alternative access paths designated with differing priorities; wherein, if one apparatus detects a failure in the other or a connection failure, the apparatus detecting the failure stores, in the third volume, a failure information flag showing failure; wherein, upon receiving the I/O request through the second access path, the second storage apparatus determines whether the failure information flag is stored in the third volume, and sends an error reply of the I/O request to the host computer if the failure information flag is stored in the third volume.

Abstract: A storage system for managing a plurality of asynchronous remote copy proceedings between a plurality of first storage control devices and a plurality of second storage control devices, wherein each of a plurality of second storage control devices stores one or more update data corresponding to one or more update data related information including the same update reflection time information with the one that is received or older update reflection time information than this in a one or more second logical volume and changes status of the one or more second logical volumes to suspend status.

Abstract: Efficient data processing is implemented by using the functions of an external storage apparatus which is connected to the virtual storage apparatus. A storage apparatus which is connected to a host apparatus which requests data I/Os and to an external storage apparatus comprising a storage device respectively via a network, comprising a storage device storing data which is read and written by the host apparatus; and a control device which controls data writing to a storage area, wherein the control device provides a predetermined storage area of the storage device of the external storage apparatus to the host apparatus as one or more virtual volumes, and manages the virtual volumes and function information indicating the functions of the external storage apparatus in association with one another.

Abstract: There is disclosed a data storage system used in a computer environment where there are plural host computers and plural storage array controllers. When a remote copy is made while assuring the order of writing across plural storage array controllers, one of the host computers gains copy information about all the storage array controllers associated with the remote copy as a representative. The representative one of the storage array controllers collects and stores copy statuses which are individually managed by the storage array controllers for which a remote copy is made. The host computer gains the copy statuses from the representative controller using an instruction to gain the copy statuses.

Abstract: A switch connected to a network system including a computer and a storage apparatus: controlling read/write request from the computer to the storage apparatus and controlling to store journal data in the storage apparatus; wherein the storage apparatus includes a first storage area for storing data to be used by the computer and a second storage area for storing journal data including write data and first update log information corresponding to the write data when there is a write request from the computer for writing data in the first storage area; wherein when the switch detects an event of status change related to the network system, the switch marks a first point of time corresponding to the event as a recovery request point, and creates second update log information corresponding to the recovery request point.

Abstract: Availability of an information system including a storage apparatus and a host computer is improved. A host system includes a first storage apparatus provided with a first volume for storing data, and a second storage apparatus for storing the data sent from the first storage apparatus. In case of a failure occurring in the first storage apparatus, the host sends the data to be sent to the first storage apparatus to the second storage apparatus.

Abstract: Availability of an information system including a storage system that performs remote copy between two or more storage apparatuses and a host computer using such storage system is improved. A third storage apparatus including a third volume is coupled to a first storage apparatus, a fourth storage apparatus including a fourth volume is coupled to a second storage apparatus, the first and third storage apparatuses perform remote copy of copying data stored in a first volume to the third volume, the first and second storage apparatuses perform remote copy of copying data stored in the first volume to a second volume, and the third and fourth storage apparatuses perform remote copy of copying data stored in the third volume to the fourth volume.

Abstract: A storage system for managing a plurality of asynchronous remote copy proceedings between a plurality of first storage control devices and a plurality of second storage control devices, wherein each of a plurality of second storage control devices stores one or more update data corresponding to one or more update data related information including the same update reflection time information with the one that is received or older update reflection time information than this in a one or more second logical volume and changes status of the one or more second logical volumes to suspend status.

Abstract: A remote copy system includes a plurality of storage systems. Each first storage system assigns a sequential number to write data received from the host and sends the write data with the sequential number to the second storage system. One of the first storage systems defers the processing of the write request received from the host and instructs each of the first storage systems to create a marker that includes a sequential number that is a marker number. The second storage systems receive the marker from the first storage system and store the marker number included in the marker.

Abstract: In a system in which data employed by a computer is stored in a storage system, the storage system transfers this data to another storage system and a copy of the data is maintained in the other storage system. The consistency of the copy is maintained even when data is written, to the storage system by a computer, without having a write time applied. A source storage system, when a write time is applied to a write request, records the write time and applies this write time to the received write data and, when no write time is applied, applies the recorded write time to the received write data and transfers the write data with this write time applied thereto, to a target storage system. The target storage system stores the write data in a logical volume in the target storage system in accordance with the write time.