Abstract: First and second storage apparatuses respectively and internally set a remote copy pair for copying data of a first volume to a second volume and associate a third volume with a remote copy pair according to an external command. When an I/O request to the first volume ends in an error, a host computer sends an I/O request directed to the second volume to the second storage apparatus. If the first and the second storage apparatuses detect a failure in the first or the second storage apparatus of the other side or a connection failure between the first and the second storage apparatuses, the first and the second storage apparatuses store in the third volume a failure information flag showing that the failure was detected.

Abstract: A storage system comprises a primary storage device having a primary storage area, a first secondary storage device having a first secondary storage area, and a second secondary storage device having a second secondary storage area. Responsive to host request from a host computer, the primary storage device writes requested host data to the primary storage area. Furthermore the primary storage device sends a first and second copy request to the first and second secondary storage devices, respectively, to store copy data in the first and second secondary storage areas, the first and second copy request containing the copy data which is a copy of the host data. Here the second secondary storage area is identified by a virtual identifier used to identify the second secondary storage area as the virtual storage area within the primary storage device.

Abstract: To provide a computer system constituting a multitarget array and utilizing a remote copy technique for backing up data, in which when a failure occurs in a primary site, a new pair is formed between remaining two secondary sites without copying all data. A first secondary site is associated with the primary site by synchronous remote copy. A second secondary site is associated with the primary site by asynchronous remote copy. A storage system of the first secondary site includes a difference bitmap indicating an area to which data has been written from a host computer. When a failure occurs in a host computer of the primary site, only data of an area indicated by the difference bitmap is transferred to a storage system of the second secondary site.

Abstract: When an event occurs in a storage system that is not recognized by a host, it is not possible to recover data at the point before and after this event. Provided is a storage system including a first storage area storing data to be used by a computer, and a second storage area for storing updated data and its update log information when there is an update request from the computer to the first storage area. This storage system monitors its own storage system and detects an event, and creates a recovery point and its update log information based on the event. When the storage system receives a recovery command at a certain recovery point, it recovers data of the first storage area at the time of recovery point by writing, in a replication storage area at a certain point of the first storage area, update data up to the recovery point among the update data stored in the second storage area.

Abstract: There is provided a storage system having a host computer for transmitting and receiving data, and a plurality of storage apparatus provided with volumes for storing the data sent by the host computer including a check point setting unit for setting check points as markers during recovery of each volume of the plurality of storage apparatus, a check point management unit for managing the check points set by the check point setting unit, and a recovery order unit for ordering recovery of the volumes up to the state of the check point for each of the volumes managed by the check point management unit to the plurality of storage apparatus.

Abstract: During the normal operation state of a computer system 1000, the data stored in a primary storage system 200P is copied to an intermediate storage system 200I via synchronous copying and the data stored in the intermediate storage system 200I is copied to a secondary storage system 200R via asynchronous copying. During the reverse operation state, however, the data stored in the secondary storage system 200R is copied to the intermediate storage system 200I via asynchronous copying and the data stored in the intermediate storage system 200I is copied to the primary storage system 200P via synchronous copying. In this way, practical remote copying can be carried out in a computer system in which three or more storage devices are installed at different locations and connected serially.

Abstract: Composition of a consistency group is changed easily without releasing a volume pair of the consistency group concerning a remote copying system and a remote copying method using a sequence number. In order to change the composition of the consistency group, predetermined data sent from a data sending side after the relevant change is received. At that time, a reflection operation of the predetermined data on a logical storage area is started on a data receiving side after reflection of the predetermined data sent from the data sending side before the relevant change on the logical storage area is terminated.

Abstract: The present invention maintains mapping information denoting which real areas have been allocated to which virtual areas for a virtual volume, the capacity of which is dynamically expanded. The present invention also maintains real area management information denoting which real areas have been allocated to which virtual areas. The real area management information is referenced to determine whether or not a low-reliability real area, which is a real area for which reliability has been lowered by the occurrence of a failure in a certain physical storage device, and which belongs to a RAID group comprising this certain physical storage device, has been allocated to a virtual area. A data restore process is not carried out for a low-reliability real area that has not been allocated to a virtual area, but a data restore process is carried out for a low-reliability real area that has been allocated to a virtual area.

Abstract: During the normal operation state of a computer system 1000, the data stored in a primary storage system 200P is copied to an intermediate storage system 200I via synchronous copying and the data stored in the intermediate storage system 200I is copied to a secondary storage system 200R via asynchronous copying. During the reverse operation state, however, the data stored in the secondary storage system 200R is copied to the intermediate storage system 200I via asynchronous copying and the data stored in the intermediate storage system 200I is copied to the primary storage system 200P via synchronous copying. In this way, practical remote copying can be carried out in a computer system in which three or more storage devices are installed at different locations and connected serially.

Abstract: A remote copy system includes a plurality of first storage systems and a plurality of second 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, whereupon each of the first storage systems defers the processing of the write request, creates a marker including a sequential number and having a marker number, and sends the marker to the second storage system. Each of the second storage systems, when receiving a marker from the first storage system, stores the marker number included in the marker.

Abstract: The storage system of the present invention has a simple configuration and ensures redundancy of the system. The primary storage control device and the first secondary storage control device are connected by a synchronous read method, and the primary storage control device and the second secondary storage control device are connected by an asynchronous read method. The primary storage control device sets a management number in the update data and saves a journal data. The primary storage control device associates the management number with the update data and transmits them to the first secondary storage control device. The first secondary storage control device writes the update data to the first secondary volume, associates the management number with the storage destination address of the update data and stores them in the maintenance table. If the primary storage control device stops, the first secondary storage control device becomes anew a primary storage control device.

Abstract: A server system has servers that can be operated through switching as a primary system and a standby system, and a shared disk unit for storing data accessed by the servers. Each of the servers has a driver that acquires information on a configuration inside the shared disk unit after starting of the system. The driver sets the shared disk unit in an active state in which an access request can be sent to the shared disk unit. Access control determines whether the access request issued by an application should be sent on the basis of a management table indicating inhibited types of access requests for each access destination. The access control sends the access request to the driver when the access request is not inhibited for an access destination of the access request. By this arrangement, hot standby switching processing can be performed at high speed.

Abstract: A storage system includes a plurality of storage apparatuses respectively connected to a host apparatus via a network. A disk controller of each storage apparatus has DKC identifying information for recognizing itself, a logical device identifier created based thereon, and a virtual/logical device identifier set containing a real/logical device identifier and a virtual/logical device identifier. The storage apparatus defined with a pair relationship creates a virtual/logical device identifier set of a mirrored image relationship by replacing its own real/logical device identifier and using it as its own virtual/logical device identifier.

Abstract: A remote copy system includes a plurality of first storage systems and a plurality of second 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, whereupon each of the first storage systems defers the processing of the write request, creates a marker including a sequential number and having a marker number, and sends the marker to the second storage system.

Abstract: A first storage system misrepresents an identifier of the storage system and an identifier of a volume and provides the host computer with a first volume. A second storage system misrepresents an identifier of the storage system and an identifier of a second volume as being identical to those misrepresented by the first storage system and provides the host computer with a second volume. A management computer acquires, upon detection of a failure in an access, a status of copying, a status of the first storage system, and a status of the second storage system and controls an access from the host computer with reference to the plurality of acquired statuses. Accordingly, even when a fault occurs in one of the two storage systems, a network that connects the two storage systems, or the like, the host computer can access to latest data.

Abstract: During an asynchronous remote copy process for a plurality of asynchronous remote copy pairs, a copy of data in a migration source primary storage area is stored in a migration destination primary storage area, and the copy of data in the migration source primary storage area is also stored in a migration destination secondary storage area through a migration destination primary storage area or a migration source secondary storage area. Then, for an asynchronous remote copy pair established between the migration destination primary storage area and the migration destination secondary storage area together with the above-described asynchronous remote copy pairs, the asynchronous remote copy process is executed in such a method that a copy of writing data is stored in a plurality of secondary storage areas in accordance with the write request sequence issued by a computer.

Abstract: In a storage system that executes multi-target remote copying, the identity of data across two secondary storage subsystems may be quickly and flexibly ensured. The storage system includes a first storage subsystem that has a first storage area and multiple second storage subsystems that each have a second storage area to store duplicate data for data stored in the first storage area. In this storage system, a write process that writes write data to the first storage area is executed. In response to the write process, the write data is copied to the second storage area of each second storage subsystem. Furthermore, a write section that the copy information belongs to, wherein the copy information that corresponds to the write process, is determined for each write process. In addition, history information regarding each executed copy operation is created for each write section to which the copy information used for such operation belongs.

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: 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: 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.