Abstract: Provided are a computer program product, system, and method for using a forward log storage and backward log storage to recover a storage to a forward or backward point-in-time. In response to receiving writes to source data after establishing point-in-time copies, point-in-time data of the source data is copied to a backward log storage storing point-in-time data for multiple of the point-in-time copies. The point-in-time data in the backward log storage is applied to a recovery source data to roll-back the source data to a backward point-in-time of one of the point-in-time copies. Before applying the point-in-time data from the backward log storage, point-in-time data in the recovery source data, is copied to a forward log storage. The point-in-time data in the forward log storage is applied to the recovery source data to roll forward the recovery source data to a forward point-in-time subsequent to the backward point-in-time.

Abstract: One general aspect of device reservation state preservation in accordance with the present description, provides for an intermediate reservation state, referred to herein as a “peer” reservation state, which may be maintained by a storage controller in the event of a total loss of communication connectivity to the reserving host so long as a peer or partner storage controller of a mirror relationship still has communication connectivity to the host. The peer reservation state as used herein, is a reservation state intermediate between a full reservation state for a device, and a fully released state in which a reservation of the device has been completely released. Other features and aspects may be realized, depending upon the particular application.

Abstract: Provided are a computer program product, system, and method for managing health conditions to determine when to restart replication after a swap triggered by a storage health event. A determination is made of a health condition with respect to access to a first storage that triggers a swap operation. The swap operation redirects host Input/Output (I/O) requests to data from a first server to a second server in response to determining the health condition. After the swap operation the I/O requests are directed to the second server and a second storage. The second server is instructed to mirror data in the second storage to the first server to store in the first storage in response to determining that the health condition is resolved.

Abstract: In one embodiment, a local copy target is also a local primary of an incomplete consistency group of an ongoing asynchronous mirror relationship. Completion of the consistency group is facilitated notwithstanding that the local copy operation was initiated after the consistency group was initiated. In one aspect, asynchronous data mirroring logic, prior to the overwriting of existing data of the target, reads the existing data of the target for purposes of mirroring the read data to a remote secondary target of the consistency group. As a result, existing data of the local copy target which is also a local primary source of the consistency group, may be safely overwritten. Other features and aspects may be realized, depending upon the particular application.

Abstract: Provided are techniques for performing a recovery copy command to create a recovery volume for a consistency group. In response to receiving a recovery copy command, a recovery copy data structure is created with indicators for storage locations and a recovery target data structure is created with indicators for storage locations. In response to receiving a write operation for a storage location to a cache on a host for a recovery volume, while the recovery copy command is being processed, it is determined that data is to be staged to the cache and, based on a value of an indicator in the recovery copy data structure for the storage location and a value of an indicator in the recovery target data structure for the storage location, the data is staged from one of the production volume, the recovery volume, and a backup volume.

Abstract: Provided are a computer program product, system, and method for forming a consistency group comprised of volumes maintained by one or more storage controllers. At least one storage controller is caused to perform reservation operations for point-in-time copies of storage units to allocate storage resources and a data structure for a point-in-time copy. Upon successfully completing the reservation operations for all the point-in-time copies, Input/Output (I/O) operations to the storage units of the point-in-time copies are suspended. If I/O operations were successfully suspended at the storage units for all of the point-in-time copies, then suspension of I/O operations is ended I/O operations are allowed to continue at the storage units of the point-in-time copies. The point-in-time copies at the storage units are formed at which the suspension of I/O operations was ended after being successfully suspended. The point-in-time copies are consistent as of a same point-in-time.

Abstract: One general aspect of asynchronous local and remote generation of consistent point-in-time snap copies in consistency groups in accordance with the present description, is directed to receiving a local-remote pair point-in-time snap copy establish command to establish a local point-in-time snap copy in a local data storage system, and a remote point-in-time snap copy in a remote data storage system. In one aspect, establishment of the remote point-in-time snap copy relationship may be delayed as a function of the state of a consistency group formation process upon receipt of the local-remote pair point-in-time snap copy establish command. As a result, consistency of the local-remote pair of point-in-time snap copies may be realized, notwithstanding an asynchronous relationship between the local and remote storage systems. Other features and aspects may be realized, depending upon the particular application.

Abstract: Provided are a computer program product, system, and method for processing a recall request for data migrated from a primary storage system having data mirrored to a secondary storage system mirroring data from the primary storage system to the at least one secondary storage system. The primary storage system receives a recall request to recall a data object that was migrated from the primary storage system to a remote storage location. The recall request is transmitted to each of the at least one secondary storage system to cause each of the at least one secondary storage system receiving the recall request to directly retrieve the data object from the remote storage location. The primary storage system retrieves the data object from the remote storage location in response to the recall request. The primary storage system returns complete to the recall request in response to the data object being confirmed as restored to the primary storage system and the at least one secondary storage system.

Abstract: Remote copy operations are performed to copy data from a primary storage controller to a secondary storage controller, wherein input/output (I/O) requests are received at the primary storage controller from a host both via a bus interface and a network interface while the remote copy operations are in progress, and wherein consistency groups are formed during the remote copy operations to copy the data consistently. Quiescing of I/O operations performed via the bus interface are performed while a current consistency group is being replaced by a next consistency group during the remote copy operations.

Abstract: Provided is a method for correcting untrusted data and avoiding logical device swapping for at least one logical subsystem of at least one computer system. A processor may monitor a primary storage for one or more errors that indicate untrusted data on the primary storage. An error indicating that a data set on the primary storage is an untrusted data set may be identified. In response to the error being identified, a corresponding uncompromised version of the data set may be read from a secondary storage. The corresponding uncompromised version of the data set may be written over the untrusted data set on the primary storage.

Abstract: Provided is a method for correcting pinned data in a primary storage. A primary storage controller may detect a pinned data set on a primary storage. In response to detecting the pinned data set, the primary storage controller may instruct a secondary storage controller to transmit a copy of the pinned data set to the primary storage controller. The copy of the pinned data set may be stored in a secondary storage that is communicatively coupled to the secondary storage controller. The secondary storage may include a synchronous copy of the primary storage. The primary storage controller may receive the copy of the pinned data set from the secondary storage controller. The primary storage controller may also write the copy of the pinned data set over the pinned data set on the primary storage.

Abstract: Methods and systems for releasing space on a secondary storage device for resynchronization are provided. A system for releasing space on a secondary storage device for resynchronization includes a suspension detection module that determines that the relationship between a primary computing device and a secondary computing device is suspended. The system also includes a relationship resumption module that determines that the relationship between the primary computing device and a secondary computing device is resumed. The system further includes an extent release module that directs the secondary computing device to release extents in a secondary storage device of the secondary computing device that correspond to free extents in a primary storage device of the primary computing device. Additionally, the system includes a synchronization module that synchronizes data stored on the secondary storage device and the primary storage device.

Abstract: Provided are a method, system, and computer program product in which a computational device stores a data structure that includes identifications of a plurality of volumes and identifications of one or more time locks associated with each of the plurality of volumes. The data structure is indexed into, to determine whether an input/output (I/O) operation from a host with respect to a volume is to be permitted.

Abstract: Provided are a computer program product, system, and method for releasing space allocated to a space efficient target storage in a copy relationship with a source storage. Source and target copy relationships indicate source data in the source storage to copy to target data in the target storage. The source copy relationship indicates source data that need to be copied to the target data before being updated, and the target copy relationship indicates target data tracks updated with data copied from corresponding source data. An operation is initiated that results in terminating the source and target copy relationships. Space allocated to the target data for the source and target copy relationships is released in response to determining that the target storage comprises the space efficient storage. The source and target copy relationships are removed.

Abstract: Remote copy operations are performed to copy data from a primary storage controller to a secondary storage controller, wherein input/output (I/O) requests are received at the primary storage controller from a host both via a bus interface and a network interface while the remote copy operations are in progress, and wherein consistency groups are formed during the remote copy operations to copy the data consistently. A relocation is performed of data written via the bus interface for a current consistency group from a cache to a sidefile, and subsequently data written via the bus interface for a next consistency group is stored in the cache.

Abstract: Methods and systems for releasing space on a secondary storage device for resynchronization are provided. A system for releasing space on a secondary storage device for resynchronization includes a suspension detection module that determines that the relationship between a primary computing device and a secondary computing device is suspended. The system also includes a relationship resumption module that determines that the relationship between the primary computing device and a secondary computing device is resumed. The system further includes an extent release module that directs the secondary computing device to release extents in a secondary storage device of the secondary computing device that correspond to free extents in a primary storage device of the primary computing device. Additionally, the system includes a synchronization module that synchronizes data stored on the secondary storage device and the primary storage device.

Abstract: A computational device receives a command to activate a time lock for a data set. In response to receiving the command to activate the time lock for the data set, a point in time copy of the data set is generated to allow write operations to be performed even if the time lock is activated.

Abstract: Provided are techniques for performing a recovery copy command to restore a safeguarded copy backup to a production volume. In response to receiving a recovery copy command, a production target data structure is created. A read operation is received for data for a storage location. In response to determining that the data for the storage location is in a cache of a host and a generation number is greater than a recovery generation number, the data is read from the cache. In response to determining at least one of that the data for the storage location is not in the cache and that the generation number is not greater than the recovery generation number, the data is read from one of the production volume and a backup volume based on a value of an indicator for the storage location in the production target data structure.

Abstract: Provided are techniques for performing a recovery copy command to create a recovery volume for a consistency group. In response to receiving a recovery copy command, a recovery copy data structure is created with indicators for storage locations and a recovery target data structure is created with indicators for storage locations. In response to receiving a write operation for a storage location to a cache on a host for a recovery volume, while the recovery copy command is being processed, it is determined that data is to be staged to the cache and, based on a value of an indicator in the recovery copy data structure for the storage location and a value of an indicator in the recovery target data structure for the storage location, the data is staged from one of the production volume, the recovery volume, and a backup volume.

Abstract: Provided are a computer program product, system, and method for forming a consistency group comprised of volumes maintained by one or more storage controllers. At least one storage controller is caused to perform reservation operations for point-in-time copies of storage units to allocate storage resources and a data structure for a point-in-time copy. Upon successfully completing the reservation operations for all the point-in-time copies, Input/Output (I/O) operations to the storage units of the point-in-time copies are suspended. If I/O operations were successfully suspended at the storage units for all of the point-in-time copies, then suspension of I/O operations is ended I/O operations are allowed to continue at the storage units of the point-in-time copies. The point-in-time copies at the storage units are formed at which the suspension of I/O operations was ended after being successfully suspended. The point-in-time copies are consistent as of a same point-in-time.