Abstract: A method and apparatus which provide solutions for avoiding journal overflow in after and before journal methods of a backup and recovery system used with a storage system. The after journal method solutions, which are conducted when the amount of free space reaches a threshold, include periodically taking a new snapshot and deleting the oldest journal, periodically taking a new logical snapshot and deleting the oldest journal, stopping the taking journal entries when the journal volume is full, and stopping the taking journal entries when the journal volume is full and then switching to bitmap management. The before journal method solution, which is conducted when the amount of free space reaches a threshold, includes applying wrap-around overwriting to overwrite the oldest journal entry by the newest journal entry.

Abstract: A storage control system judges whether the data pattern of data exchanged with a higher-level device (hereafter “data”) conforms to one or a plurality of write-excluded data patterns comprised in write-excluded data pattern information prepared in advance. If a negative judgment result is obtained, the storage control subsystem stores the data in a logical device formed on a disk storage device. If, on the other hand, a positive judgment result is obtained, the storage control subsystem erases the data without storing in a logical device.

Abstract: Disclosed is a method to synchronize the state of an application and an application's objects with data stored on the storage system. The storage system provides API's to create special data, called a marker journal, and stores it on a journal volume. The marker contains application information, e.g. file name, operation on the file, timestamp, etc. Since the journal volume contains markers as well as any changed data in the chronological order, IO activities to the storage system and application activities can be synchronized.

Abstract: A storage apparatus is provided with a storage area for storing data sent from a host computer, and a virtual/logical volume to which a dynamically variable storage area is allocated from within the storage area, the volume being provided to the host computer, and this storage apparatus is configured to include: a pool area generation unit for generating a plurality of pool areas composed from the storage area; a setting unit for setting, for each of the plurality of pool areas generated by the pool area generation unit, an allocation unit size for allocating a storage area from within the storage area provided by the pool area to the virtual/logical volume; a selecting unit for selecting, when data to be stored in the storage area is sent from the host computer, a pool area from among the plurality of pool areas having the allocation unit size set by the setting unit, in accordance with the size of the sent data; and an allocation unit for allocating a storage area from within the storage area provided by th

Abstract: In creating replicas to data of a storage volume in a storage system, a technique in which labor for issuing instructions from a processor can be reduced and then data consistency of related volumes can be secured is provided. A single replication instruction including designated information is issued for data of a logical unit serving as a copy source and a copy destination from a replication-control program of the processor. A control unit of the storage system possesses a multiple-replica creation program which enables a processing for creating replicas while securing the data consistency when an access such as a update or reference occurs for a group including a plurality of pairs of copy-source volume and copy-destination volume based on reception of the instruction. A save volume is provided to identify and control data save and update state by copy-source save information and copy-destination update information at the shared memory.

Abstract: The invention provides a storage system which can estimate a necessary capacity at the time of acquiring a snap shot copy without actually sampling the snap shot copy, and a control method of the same. In a storage system, a disk control unit monitors a write instruction from a host machine for a fixed period, and calculates a capacity necessary at the time of a snap shot, on the basis of the monitored information for the fixed period, in the case of receiving an instruction of calculating the capacity necessary at the time of acquiring the snap shot which makes it possible to refer to the data at a certain time point within a disk unit.

Abstract: A method for handling a remote copy request in a distributed storage includes providing a plurality of primary volumes within a primary storage system that is coupled to a primary host via a first network, the primary storage system being coupled to a secondary storage system via a second network. A first request is selected from a plurality of requests placed in a queue based on priority information associated with the requests. A first path group is selected from one or more path groups that could be used to transmit the request. The first request is transmitted to the secondary storage system using the first path group, the secondary storage system including a plurality of secondary volumes that are paired to the plurality of primary volumes.

Abstract: A computer system which has a plurality of computers and a storage device subsystem connected to the plurality of computers. The storage device subsystem has a plurality of storage devices and a plurality of interfaces, through which the subsystem is connected to the computers. One of the plurality of computers has a management means for holding therein data indicative of the storage devices and a connection relationship between the computers and storage device subsystem. Each computer, when wanting a new device, informs the management means of its capacity and type. The management means receives its notification and selects one of the storage devices which satisfies the request. And the management means instructs the storage device subsystem to set predetermined data in such a manner that the computer can access the selected device.

Abstract: A data processing system includes a first storage system including a first host and a first storage subsystem. The first host has access to a first copy manager that is operable to manage a data replication operation. A second storage system includes a second host and a second storage subsystem. The second host has access to a second copy manager that is operable to manage a data replication operation. A first communication link is coupled to the first storage system and the second storage system to exchange management information between the first and second storage systems in order to manage the data replication operation. A data transfer path is configured to transfer data stored in the first storage subsystem to the second storage subsystem and replicate the data of the first storage subsystem in the second storage subsystem. The data transfer path is different from the first communication link.

Abstract: A method for handling a remote copy request in a distributed storage includes providing a plurality of primary volumes within a primary storage system that is coupled to a primary host via a first network, the primary storage system being coupled to a secondary storage system via a second network. A first request is selected from a plurality of requests placed in a queue based on priority information associated with the requests. A first path group is selected from one or more path groups that could be used to transmit the request. The first request is transmitted to the secondary storage system using the first path group, the secondary storage system including a plurality of secondary volumes that are paired to the plurality of primary volumes.

Abstract: A storage system maintains a journal and a snapshot of one or more data volumes. Two journal entry types are maintained, an AFTER journal entry and a BEFORE journal entry. Two modes of data recovery are provided: “fast” recovery and “undo-able” recovery. A combination of both recovery modes allows the user to quickly recover a targeted data state.

Abstract: A storage control system judges whether the data pattern of data exchanged with a higher-level device (hereafter “data”) conforms to one or a plurality of write-excluded data patterns comprised in write-excluded data pattern information prepared in advance. If a negative judgment result is obtained, the storage control subsystem stores the data in a logical device formed on a disk storage device. If, on the other hand, a positive judgment result is obtained, the storage control subsystem erases the data without storing in a logical device.

Abstract: A storage control system judges whether the data pattern of data exchanged with a higher-level device (hereafter “data”) conforms to one or a plurality of write-excluded data patterns comprised in write-excluded data pattern information prepared in advance. If a negative judgment result is obtained, the storage control subsystem stores the data in a logical device formed on a disk storage device. If, on the other hand, a positive judgment result is obtained, the storage control subsystem erases the data without storing in a logical device.

Abstract: A multiple disk system comprises plural physical drives organized as plural groups of disks. Each group is accessed as a plurality of logical volumes. One of the logical drives is considered a primary volume and one or more other logical volumes are considered as secondary volumes, which together constitute a mirroring group. Data contained in a memory records such organization. The data is consulted to select a secondary volume when the disk group containing a primary volume fails.

Abstract: A storage apparatus is provided with a storage area for storing data sent from a host computer, and a virtual/logical volume to which a dynamically variable storage area is allocated from within the storage area, the volume being provided to the host computer, and this storage apparatus is configured to include: a pool area generation unit for generating a plurality of pool areas composed from the storage area; a setting unit for setting, for each of the plurality of pool areas generated by the pool area generation unit, an allocation unit size for allocating a storage area from within the storage area provided by the pool area to the virtual/logical volume; a selecting unit for selecting, when data to be stored in the storage area is sent from the host computer, a pool area from among the plurality of pool areas having the allocation unit size set by the setting unit, in accordance with the size of the sent data; and an allocation unit for allocating a storage area from within the storage area provided by th

Abstract: A cluster computing system, comprises: a production host group; a standby host group coupled to the production host group by a network; and a remote mirror coupled between the production host group and the standby host group, the remote mirror including a production site heartbeat storage volume (heartbeat PVOL) and a standby site heartbeat storage volume (heartbeat SVOL) coupled by a remote link to the heartbeat PVOL, with the production host group configured to selectively send a heartbeat signal to the standby host group by use of at least one of the network and the remote link.

Abstract: A storage system maintains a journal of journal entries and at lease one snapshot of one or more data volumes. By assigning a unique sequence number to journal and snapshot, it is easy to find a journal which can be applied to the snapshot. A technique is described for detecting an overflow condition of running out of journal space and recovering the journal space.

Abstract: In creating replicas to data of a storage volume in a storage system, a technique in which labor for issuing instructions from a processor can be reduced and then data consistency of related volumes can be secured is provided. A single replication instruction including designated information is issued for data of a logical unit serving as a copy source and a copy destination from a replication-control program of the processor. A control unit of the storage system possesses a multiple-replica creation program which enables a processing for creating replicas while securing the data consistency when an access such as a update or reference occurs for a group including a plurality of pairs of copy-source volume and copy-destination volume based on reception of the instruction. A save volume is provided to identify and control data save and update state by copy-source save information and copy-destination update information at the shared memory.

Abstract: A storage system maintains a journal of journal entries and at lease one snapshot of one or more data volumes. By assigning a unique sequence number to journal and snapshot, it is easy to find a journal which can be applied to the snapshot. A technique is described for detecting an overflow condition of running out of journal space and recovering the journal space.

Abstract: In a storage system having local and remote disk systems, a system is described for selectively controlling the security of data on a volume by volume basis, for transparently exchanging encryption keys between the local and remote disk systems, and for controlling when encryption is used in the storage of data.