Abstract: Information about remote copy target volumes of other storage systems 2 each having one and the same original volume V1 is registered for each remote copy target volume in advance. When there occurs a failure in a copy source storage system 2, a copy source volume for remote copy target volumes using the storage system 2 having a failure as their copy source is selected newly from the registered copy source volumes, and remote copy is resumed.

Abstract: A computing system and encryption/decryption method realizes assurance of security and improvement of throughput in a remote system. For this purpose, encrypted data is written to a storage system, it is determined whether data in the storage system is ciphertext or plaintext, and encrypted data is read, decrypted and re-written in storage asyncronously with writing encrypted data to storage.

Abstract: For a storage system having plural control units to which plural disk devices are connected, in the method for creating replication in a volume of the disk devices connected to different control units, when receiving update I/O of a replication source during an initial copy for replication, the reflection of update to the replication destination is performed on an extension of the same I/O. When a pair is divided after the completion of copying, the update position is retained on the differential bitmap disposed in the individual control units, and the differential bitmap is merged to one of the control units at a time of resynchronization to perform copy processing.

Abstract: In a cluster storage system, storage areas scattered in a plurality of storage nodes are coupled into a single storage area for access by a host computer. The cluster storage system has a first storage node and a second storage node, each of which has a disk and a control processor for controlling input/output to/from the disk, and a host interface node for connecting the first and second storage nodes to a computer. The first storage node manages a storage area having a first storage area existing in the first storage node and a second storage area existing in the second storage node as a logical device. Upon receipt of an access request having identification information corresponding to the logical device from the computer, the host interface node forwards the access request to the first storage node.

Abstract: A remote copy technique according to which data of a primary volume is migrated while continuing remote copy processing and receiving access requests from a host. A remote copy system comprises a first storage system having a first primary volume, a second storage system having a second primary volume and a third storage system having a secondary volume, and remote copying is performed between the first primary volume and the second volume. When data in the first primary volume is migrated to the second primary volume, an access request from the host to the primary volume is transferred to the second primary volume. Further, the second storage system stores write data received from the host and data of the first primary volume received from the storage system, into the second primary volume. Out of data stored in the second primary volume, the second storage system sends data determined by management information received from the first storage system, to the third storage system.

Abstract: In a storage system having a plurality of control units each connected with a plurality of disk units, it is provided that a replication is created in the volume of the disk units connected to different control units. The replication creation unit of a given control unit creates a replication in the volume of the disk unit connected to other control units in such a manner that the original volume information, the replication volume information in the control unit and information on the other control units are registered as volume pair information. Based on this volume pair information, a replication creation request is transmitted to the other control units.

Abstract: When storage controllers are added to a storage system to change the storage system from a configuration having only one storage controller to a configuration having plural storage controllers, or when storage controllers are removed from the storage system to change the storage system from a configuration having plural storage controllers to a configuration having only one storage controller, a controller-internal management-information memory controller carries out a copy process to copy management information from each of the storage controllers to a management-information-memory switch or vice versa at the same time as processing of read and write requests for access to the management information, made by a channel interface or a disc interface, in order to change storage locations of the management information while processing the read and write requests made by the host.

Abstract: When storage controllers are added to a storage system to change the storage system from a configuration having only one storage controller to a configuration having plural storage controllers, or when storage controllers are removed from the storage system to change the storage system from a configuration having plural storage controllers to a configuration having only one storage controller, a controller-internal management-information memory controller carries out a copy process to copy management information from each of the storage controllers to a management-information-memory switch or vice versa at the same time as processing of read and write requests for access to the management information, made by a channel interface or a disc interface, in order to change storage locations of the management information while processing the read and write requests made by the host.

Abstract: Information about remote copy target volumes of other storage systems 2 each having one and the same original volume V1 is registered for each remote copy target volume in advance. When there occurs a failure in a copy source storage system 2, a copy source volume for remote copy target volumes using the storage system 2 having a failure as their copy source is selected newly from the registered copy source volumes, and remote copy is resumed.

Abstract: There is raised a demand for a storage system having a configuration easy to change and having a capability of executing centralized management of management information so as to prevent performance to access the management information from deteriorating. It is also desirable to provide a storage system which allows a host to make accesses to a disc storage of the storage system without suspending the operation of the storage system even while the configuration of the storage system is being changed.

Abstract: A computing system and encryption/decryption method realizes assurance of security and improvement of throughput in a remote system. For this purpose, encrypted data is written to a storage system, it is determined whether data in the storage system is ciphertext or plaintext, and encrypted data is read, decrypted and re-written in storage asynchronously with writing encrypted data to storage.

Abstract: A storage system having a plurality of rewritable removable media and a method for controlling that system are disclosed. The storage system has a controller that updates medium update count management information every time contents of any medium are updated. When the update count for a medium is judged to have exceeded a predetermined threshold value, the controller starts a spare medium copy process whereby the contents of the medium with its update count found higher than was predetermined are copied to a spare medium. After the copying, the spare medium is transported to a cabinet for storage therein in place of the original medium whose contents have been copied, and the original medium is ejected from an outlet port. When a spare medium loading process is started from a service terminal, a spare medium put through an inlet port is loaded into the cabinet to replenish the spare medium inventory.