Abstract: Provided are a computer program product, system, and method for using a space release data structure to indicate tracks to release for a space release command to release space of tracks in a consistency group being formed. A space release command is received to free a release space of tracks in a source storage or target storage while transferring changed data in a consistency group to a target storage. A space release data structure is created indicating for each track of the tracks in the release space whether to release or not release the track. The space release data structure is initialized to indicate that each of the tracks is to be released. The tracks in the space release data structure are indicated to be released after the consistency group has completed.

Abstract: Withdrawal of a point-in-time snap copy relationship or a portion of such a relationship, is managed in a manner which can obviate disruption of consistency groups due to the withdrawal. If the withdrawal request is directed to a subrange of the original snap copy relationship, the snap copy relationship is split by creating one or more point-in-time snap copy relationships over one or more subranges of tracks of the snap copy source. A determination is made as to whether to delay execution of the withdrawal request to temporarily preserve data of the withdrawal range. Disruptions to completion of consistency groups may be avoided by selectively delaying the withdrawal of a snap copy relationship corresponding to the withdrawal subrange. In so far as the host is involved, a host may treat the withdrawal request as immediately granted without delay. Other aspects may be realized, depending upon the particular application.

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: Withdrawal of a point-in-time snap copy relationship or a portion of such a relationship, is managed in a manner which can obviate disruption of consistency groups due to the withdrawal. If the withdrawal request is directed to a subrange of the original snap copy relationship, the snap copy relationship is split by creating one or more point-in-time snap copy relationships over one or more subranges of tracks of the snap copy source. A determination is made as to whether to delay execution of the withdrawal request to temporarily preserve data of the withdrawal range. Disruptions to completion of consistency groups may be avoided by selectively delaying the withdrawal of a snap copy relationship corresponding to the withdrawal subrange. In so far as the host is involved, a host may treat the withdrawal request as immediately granted without delay. Other aspects may be realized, depending upon the particular application.

Abstract: Consistency groups are asynchronously copied to a remote computational device, from a local computational device, wherein point in time copy operations are performed at the local computational device while the consistency groups are being asynchronously copied to the remote computational device. Indicators are stored at the remote computational device to identify those point in time copy operations that are to be restored as part of a recovery operation performed at the remote computational device in response to a failure of the local computational device.

Abstract: Provided are a computer program product, system, and method for copying data from multiple point-in-time copies to a log storage to use to roll-back a source storage managing point-in-time copies of a source storage. A plurality of point-in-time copies of a source storage at different point-in-times are established. In response to receiving writes to the source storage after establishing each of the point-in-time copies, point-in-time data in the source storage is copied, before being updated by the received writes, to a log storage, wherein the log storage stores point-in-time data for multiple of the point-in-time copies. The log storage is used to roll-back the source storage to a selected point-in-time of one of the point-in-time copies.

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 a computer program product, system, and method for copying data from multiple point-in-time copies to a log storage to use to roll-back a source storage managing point-in-time copies of a source storage. A plurality of point-in-time copies of a source storage at different point-in-times are established. In response to receiving writes to the source storage after establishing each of the point-in-time copies, point-in-time data in the source storage is copied, before being updated by the received writes, to a log storage, wherein the log storage stores point-in-time data for multiple of the point-in-time copies. The log storage is used to roll-back the source storage to a selected point-in-time of one of the point-in-time copies.

Abstract: Consistency groups are asynchronously copied to a remote computational device, from a local computational device, wherein point in time copy operations are performed at the local computational device while the consistency groups are being asynchronously copied to the remote computational device. Indicators are stored at the remote computational device to identify those point in time copy operations that are to be restored as part of a recovery operation performed at the remote computational device in response to a failure of the local computational device.

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 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 techniques for delayed consistent point-in-time copy from a secondary device in an asynchronous mirror relationship. A consistent asynchronous mirror copy that includes an asynchronous mirror copy from a primary volume to a secondary volume and a point-in-time copy from the secondary volume to a tertiary volume is performed. A point-in-time copy is created from the secondary volume to an accessible consistent copy volume. In response to receiving a request to access a track of the accessible consistent copy volume, it is determined whether to access the track of one of the secondary volume, the tertiary volume, and the accessible consistent copy volume. A response to the request is provided with data accessed from the determined one of the secondary volume, the tertiary volume, and the accessible consistent copy volume.

Abstract: Provided are techniques for delayed consistent point-in-time copy from a secondary device in an asynchronous mirror relationship. A consistent asynchronous mirror copy is performed that includes an asynchronous mirror copy from a primary volume to a secondary volume and a point-in-time copy from the secondary volume to a tertiary volume. An initiation of a point-in-time establish from the secondary volume to an accessible consistent copy volume is received. A point-in-time reservation is created by storing metadata for a point-in-time relationship from the secondary volume to the accessible consistent copy volume. In response to a commit of the point-in-time copy from the secondary volume to the tertiary volume, a point-in-time copy from the secondary volume to the accessible consistent copy volume to store a consistency group is completed.

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: Provided are a computer program product, system, and method for managing point-in-time copies for extents of data. A point-in-time copy for at least one range of extents in at least one volume for a point-in-time copy identifier is established. Change recording information is generated indicating each of the at least one range of extents less than all of the extents in the at least one volume. An update to data in the at least one range of extents in the point-in-time copy is received and data in the source storage in the at least one range of extents to be updated is copied as changed data to the target storage. Indication is made in the change recording information of the data in the at least one range of extents that has been updated.

Abstract: Provided are a computer program product, system, and method for managing point-in-time copies for extents of data. A point-in-time copy for at least one range of extents in at least one volume for a point-in-time copy identifier is established. Change recording information is generated indicating each of the at least one range of extents less than all of the extents in the at least one volume. An update to data in the at least one range of extents in the point-in-time copy is received and data in the source storage in the at least one range of extents to be updated is copied as changed data to the target storage. Indication is made in the change recording information of the data in the at least one range of extents that has been updated.

Abstract: Provided are techniques for delayed consistent point-in-time copy from a secondary device in an asynchronous mirror relationship. A consistent asynchronous mirror copy that includes an asynchronous mirror copy from a primary volume to a secondary volume and a point-in-time copy from the secondary volume to a tertiary volume is performed. A point-in-time copy is created from the secondary volume to an accessible consistent copy volume. In response to receiving a request to access a track of the accessible consistent copy volume, it is determined whether to access the track of one of the secondary volume, the tertiary volume, and the accessible consistent copy volume. A response to the request is provided with data accessed from the determined one of the secondary volume, the tertiary volume, and the accessible consistent copy volume.

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: Consistency groups are asynchronously copied to a remote computational device, from a local computational device, wherein point in time copy operations are performed at the local computational device while the consistency groups are being asynchronously copied to the remote computational device. Indicators are stored at the remote computational device to identify those point in time copy operations that are to be restored as part of a recovery operation performed at the remote computational device in response to a failure of the local computational device.

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.