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: Provided are a computer program product, system, and method for after swapping from a first storage to a second storage, mirroring data from the second storage to the first storage for data in the first storage that experienced data errors. A swap operation redirects host Input/Output (I/O) requests to data from the first server to the second server in response to a health condition at the first server. A determination is made of data errors with respect to data in the first storage that experienced data errors. The second server is instructed to mirror data in the second storage to the first server including data for the data in the first storage that experienced the data errors to store in the first storage in response to determining that the first server is available for the data mirroring operations.

Abstract: A secondary storage controller determines one or more tracks of one or more volumes in which data loss has occurred in the secondary storage controller. The secondary storage controller suspends a peer to peer remote copy operation between the secondary storage controller and a primary storage controller. Information on the one or more tracks of the one or more volumes in which the data loss has occurred is transmitted to the primary storage controller.

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: A computer-implemented method, according to one embodiment, includes: using a supplemental data storage volume at a secondary location to track a first set of data updates to a primary data storage volume at a primary location in response to a failure event at the primary location; retrieving a second set of tracked data updates to the primary data storage volume stored in a secondary data storage volume at the secondary location; merging the second set of tracked data updates into the first set of tracked data updates in the supplemental data storage volume; and transitioning the merged data updates from the supplemental data storage volume at the secondary location to the primary data storage volume at the primary location. Other systems, methods, and computer program products are described in additional embodiments.

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.

Abstract: Provided are a computer program product, system, and method for establishing a point-in-time copy relationship between source logical addresses and target logical addresses. A point-in-time (PiT) copy establish command specifies a source set comprising a subset of source logical addresses in at least one storage and a target set comprising a subset of target logical addresses in the at least one storage. The source set of source logical addresses are copied to the target set of target logical addresses. The source logical addresses map to source tracks and wherein the target logical addresses map to target tracks. Copy information is generated indicating whether the source logical addresses in the source set have been copied to the target set. Complete is returned to the PiT copy establish command after generating the copy information and before copying all the source logical addresses to the target logical addresses.

Abstract: A method for releasing storage space in a space-efficient secondary volume includes placing a first lock on a free-space data structure stored on the space-efficient secondary volume. The method reads a copy of the free-space data structure into memory while the first lock is in place, and releases the first lock. The method then analyzes the copy to determine which storage elements in the space-efficient secondary volume are not being used. The method then places a second lock on the free-space data structure and, while the second lock is in place, analyzes the free-space data structure to determine which storage elements had their usage status change during analysis of the copy. The method then releases storage elements in the space-efficient secondary volume that are not being used and releases the second lock. A corresponding system and computer program product are also disclosed.

Abstract: A method for releasing storage space in asynchronously mirrored space-efficient secondary volumes is disclosed. In one embodiment, such a method includes reading a first copy of a free-space data structure stored on a space-efficient secondary volume. The free-space data structure tracks the usage status of storage elements in the space-efficient secondary volume. The method analyzes the first copy to determine which storage elements in the space-efficient secondary volume are not being used. Upon completion of a consistency group on the space-efficient secondary volume, the method reads a second copy of the free-space data structure and compares the first copy to the second copy to determine which storage elements had their usage status change during analysis of the first copy. The method releases storage elements in the space-efficient secondary volume that are not being used. A corresponding system and computer program product are also disclosed.

Abstract: In one general embodiment, a computer-implemented method includes using a supplemental data storage volume at a secondary location to track a first set of data updates to a primary data storage volume at a primary location in response to a failure event at the primary location. A second set of tracked data updates, which are updates to the primary data storage volume stored in a secondary data storage volume at the secondary location, are retrieved. The second set of tracked data updates is merged into the first set of tracked data updates in the supplemental data storage volume. The merged data updates are transitioned from the supplemental data storage volume at the secondary location to the primary data storage volume at the primary location. The secondary data storage volume is used to track further data updates to the primary data storage volume made at the primary location.

Abstract: A method for performing a write to a volume x in a cascaded architecture is described. In one embodiment, such a method includes determining whether the volume x has a child volume, wherein each of the volume x and the child volume have a target bit map (TBM) associated therewith. The method then determines whether the TBMs of both the volume x and the child volume are set. If the TBMs are set, the method finds a higher source (HS) volume from which to copy the desired data to the child volume. Finding the HS volume includes comparing ages of mapping relationships upstream from the volume x in order to determine a source of the data. Once the HS volume is found, the method copies the data from the HS volume to the child volume and performs the write to the volume x. A method for performing a read is also disclosed herein.

Abstract: In one embodiment of the present description, mirroring is provided for a pair of storage units in bidirectional synchronous mirror relationships, and a tertiary storage unit. The mirroring includes multi-target mirroring to write updates written to the first storage unit to both the second storage unit and to a third storage unit. Similarly, for updates written to the second storage unit, multi-target mirroring is employed to write those to both the first storage unit and to the third storage unit. Other aspects are described.

Abstract: Provided are a computer program product, system, and method for assigning device adaptors to use to copy source extents in source ranks to target extents in target ranks in a copy relation. A determination is made of an order of the target ranks in the copy relation. Target ranks in the copy relation are selected according to the determined order. For each selected target rank, indication is made in a device adaptor assignment data structure of a source device adaptor and target device adaptor of the device adaptors to use to copy the source rank to the selected target rank indicated in the copy relation, wherein indication is made for the selected target ranks according to the determined order. The source ranks are copied to the selected target ranks using the source and target device adaptors indicated in the device adaptor assignment data structure.

Abstract: A storage controller receives a write command with respect to a track, from a host. A first process determines that the track is a source track and also determines that at least one corresponding target track is in an incremental copy relation to the source track. A second process is generated to modify a target change recording structure, where the second process executes in parallel with the first process.

Abstract: In one embodiment of the present description, mirroring is provided for a pair of storage units in bidirectional synchronous mirror relationships, and a tertiary storage unit. The mirroring includes multi-target mirroring to write updates written to the first storage unit to both the second storage unit and to a third storage unit. Similarly, for updates written to the second storage unit, multi-target mirroring is employed to write those to both the first storage unit and to the third storage unit. Other aspects are described.

Abstract: In one embodiment of the present description, a copy relationship is established between a storage location at a first site and a storage location at a second site in a data storage system, wherein a dynamically assignable bitmap preset to one of a plurality of different predetermined bit patterns is selected as a function of both the availability of the selected bitmap and the type of predetermined bit pattern identified for the selected bitmap. The selected bitmap may be assigned as an out-of-sync bitmap wherein updates to the storage location at one site, which are to be copied to the storage location at the other site, are indicated in the selected bitmap, and data writes being written to the storage location at the one site, are copied to the storage location at the other site, using the selected bitmap as an out-of-sync bitmap. Other aspects are described.

Abstract: Provided are a computer program product, system, and method for assigning device adaptors to use to copy source extents in source ranks to target extents in target ranks in a copy relation. A determination is made of an order of the target ranks in the copy relation. Target ranks in the copy relation are selected according to the determined order. For each selected target rank, indication is made in a device adaptor assignment data structure of a source device adaptor and target device adaptor of the device adaptors to use to copy the source rank to the selected target rank indicated in the copy relation, wherein indication is made for the selected target ranks according to the determined order. The source ranks are copied to the selected target ranks using the source and target device adaptors indicated in the device adaptor assignment data structure.

Abstract: A method for reclaiming space in a journal is disclosed. In one embodiment, such a method includes identifying a plurality of ranks in a storage system. The method creates a destage wait list for each rank, where the destage wait list identifies metadata tracks to destage from a cache to the corresponding rank. The method dispatches one or more threads for each destage wait list. The threads destage metadata tracks identified in the destage wait lists from the cache to the corresponding ranks. In certain embodiments, the method moves metadata tracks to the destage wait lists only if performing such will not cause occupied space in the journal to fall below a low watermark. Once metadata tracks are destaged from the cache, the method releases, from the journal, entries associated with the destaged metadata tracks. A corresponding system and computer program product are also disclosed.

Abstract: A storage controller receives a write command with respect to a track, from a host. A first process determines that the track is a source track and also determines that at least one corresponding target track is in an incremental copy relation to the source track. A second process is generated to modify a target change recording structure, where the second process executes in parallel with the first process.

Abstract: A method for more efficiently reclaiming space in a journal is disclosed. In one embodiment, such a method includes identifying a plurality of ranks in a storage system. The method creates a destage wait list for each rank, where the destage wait list identifies metadata tracks to destage from a cache to the corresponding rank. The method dispatches one or more threads for each destage wait list. The threads destage metadata tracks identified in the destage wait lists from the cache to the corresponding ranks. In certain embodiments, the method moves metadata tracks to the destage wait lists only if performing such will not cause occupied space in the journal to fall below a low watermark. Once metadata tracks are destaged from the cache, the method releases, from the journal, entries associated with the destaged metadata tracks. A corresponding system and computer program product are also disclosed.