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: 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.

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: 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: 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: 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: 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: Provided are a computer program product, system, and method for using a cascade flag to process a copy relationship having a backward cascade copy relationship. Each of a plurality of copy relationships indicates to copy source data to target data and has a cascade flag. The cascade flag for a forward copy relationship of the copy relationships is set to a first value in response to determining that the source data for the forward copy relationship comprises target data for a backward copy relationship and that a background copy operation specified to copy source data to target data of the backward copy relationship has not completed. The cascade flag for the forward copy relationship is set to a second value in response to determining that the backward copy relationship does not have an uncompleted background copy operation.

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: Provided are a computer program product, system, and method for using a cascade flag to process a copy relationship having a backward cascade copy relationship. Each of a plurality of copy relationships indicates to copy source data to target data and has a cascade flag. The cascade flag for a forward copy relationship of the copy relationships is set to a first value in response to determining that the source data for the forward copy relationship comprises target data for a backward copy relationship and that a background copy operation specified to copy source data to target data of the backward copy relationship has not completed. The cascade flag for the forward copy relationship is set to a second value in response to determining that the backward copy relationship does not have an uncompleted background copy operation.

Abstract: Provided are a computer program product, system, and method for updating change information for current copy relationships when establishing a new copy relationship having overlapping data with the current copy relationships. A first copy relationship indicates changed first source data to copy to first target data. An establish request is processed to create a second copy relationship to copy second source data in to second target data. A second copy relationship is generated, in response to the establish request, indicating data in the second source data to copy to the second target data. A determination is made of overlapping data units in the first source data also in the second target data. Indication is made in the first copy relationship to copy the overlapping data units. The first source data indicated in the first copy relationship is copied to the first target data, including data for the overlapping data units.

Abstract: Provided are a computer program product, system, and method for using a cascade flag to process a copy relationship having a backward cascade copy relationship. Each of a plurality of copy relationships indicates to copy source data to target data and has a cascade flag. The cascade flag for a forward copy relationship of the copy relationships is set to a first value in response to determining that the source data for the forward copy relationship comprises target data for a backward copy relationship and that a background copy operation specified to copy source data to target data of the backward copy relationship has not completed. The cascade flag for the forward copy relationship is set to a second value in response to determining that the backward copy relationship does not have an uncompleted background copy operation.

Abstract: The method includes determining a state of a local storage volume variable. The method also includes executing a local relation-withdraw command if the local storage volume variable is in a ready-to-remove state. The method also includes sending a copy command to a remote storage volume and setting the local storage volume variable to a remove-pending state if the local storage volume variable is not set to ready-to-remove. The method also includes executing a local relation-withdraw command after a notification from the remote storage volume that the remote copy operation is complete and if the local storage volume variable is in the remove-pending state. The method also includes setting the local storage volume variable to ready-to-remove after notification from the remote storage volume that the remote copy operation at the remote storage volume is complete and if the local storage volume variable is not set to the remove-pending state.

Abstract: Provided are a computer program product, system, and method for performing a remote point-in-time copy to a source and target storages in further mirror copy relationships. Each of a plurality of source copy relationships is from the source storage to one corresponding source copy storage. Each of a plurality of target copy relationships is from the target storage to one corresponding target copy storage, where in each relationship an indicator indicates whether to use a remote first type copy operation. The first type copy operation is used to copy data from the source storage to the target storage and copy data from the source copy storage to the target copy storage for the determined source and target copy relationships having the indicator set. A second type of copy operations is used for source and target relationships not having the indicator set.

Abstract: Provided are a computer program product, system, and method for performing a remote point-in-time copy to a source and target storages in further mirror copy relationships. Each of a plurality of source copy relationships is from the source storage to one corresponding source copy storage. Each of a plurality of target copy relationships is from the target storage to one corresponding target copy storage, where in each relationship an indicator indicates whether to use a remote first type copy operation. The first type copy operation is used to copy data from the source storage to the target storage and copy data from the source copy storage to the target copy storage for the determined source and target copy relationships having the indicator set. A second type of copy operations is used for source and target relationships not having the indicator set.

Abstract: Provided are a computer program product, system, and method for managing updates and copying data in a point-in-time copy relationship expressed as source logical addresses and target logical addresses. A copy relationship indicates a source set of a subset of source logical addresses to copy to a target set comprising a subset of target logical addresses. An update is received to a source logical address that has not been copied. Determinations are made of the target logical address corresponding to the source logical address to be updated according to the copy relationship, a target group of target logical addresses in the target set that include the determined target logical address, and the source logical addresses in the source set that correspond to the target logical addresses in the target group. The determined source logical addresses are copied to the target logical addresses in the determined target group.

Abstract: Provided are a computer program product, system, and method for performing a remote point-in-time copy to a source and target storages in further mirror copy relationships. Each of a plurality of source copy relationships is from the source storage to one corresponding source copy storage. Each of a plurality of target copy relationships is from the target storage to one corresponding target copy storage, where in each relationship an indicator indicates whether to use a remote first type copy operation. The first type copy operation is used to copy data from the source storage to the target storage and copy data from the source copy storage to the target copy storage for the determined source and target copy relationships having the indicator set. A second type of copy operations is used for source and target relationships not having the indicator set.

Abstract: Provided are a computer program product, system, and method for processing a copy command indicating a source set comprising a subset of source logical addresses to copy to an indicated target set comprising a subset of target logical addresses. Complete is expected to be returned to the copy command in response to completing the copying of the source set to the target set. A point-in-time (PiT) copy establish command is generated in response to receiving the copy command, indicating the source and target sets in the copy command, The generated PiT copy command is executed to generate copy information indicating the source and target sets of source logical addresses and whether they have been copied to the target set. Complete is returned to the copy command after generating the copy information and before copying all the source logical addresses to the target logical addresses.