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 asynchronous pausing of the formation of consistency groups. A first copy operation is initiated to copy the source data from the first storage to the first data copy in the second storage. A second copy operation is initiated to copy the first data copy in the second storage to a second data copy in response to forming a consistency group of the source data at the first data copy forms consistent as of a point-in-time with respect to the source data. The first copy operation is suspended to allow for further processing of the first data copy in response to completing the second copy operation. The formation of a next consistency group is restarted between the source data and the first data copy in response to receiving a resume command.

Abstract: A storage controller receives a request to establish a point-in-time copy operation by placing a space efficient source volume in a point-in-time copy relationship with a space efficient target volume, wherein subsequent to being established the point-in-time copy operation is configurable to consistently copy the space efficient source volume to the space efficient target volume at a point in time. A determination is made as to whether any track of an extent is staging into a cache from the space efficient target volume or destaging from the cache to the space efficient target volume. In response to a determination that at least one track of the extent is staging into the cache from the space efficient target volume or destaging from the cache to the space efficient target volume, release of the extent from the space efficient target volume is avoided.

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: Techniques for switching between mirrored volumes are described. A system may comprise a multi-path device driver and a processor device, in communication with the multi-path device driver, operable in the computing storage environment. The processor device creates a copy relation identification (ID) between mirrored volumes for using the copy relation ID in conjunction with a multi-path device driver for switching input/output (I/O) for applications between a first path to a second path between the mirrored volumes.

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: A data preservation function is provided which, in one embodiment, includes indicating by a map, usage of a particular map extent range by a relationship between a source extent range of storage locations on a source storage device containing data to be preserved in the source extent range, and a target extent range mapped to the map particular extent range. In another aspect, in response to receipt of a data preservation command, a data preservation operation is performed including determining whether a map indicates availability of a map extent range mapped to the identified target extent range. Upon determining that a particular map indicates availability of a map extent range mapped to the identified target extent range, a relationship between the identified source extent range and the identified target extent range is established. Other features and aspects may be realized, depending upon the particular application.

Abstract: A data preservation function is provided which, in one embodiment, includes mapping in a plurality of maps for a target storage device, map extent ranges of each map, to corresponding target extent ranges of storage locations on the target storage device. Usage of a particular map extent range by a relationship between a source extent range of storage locations on a source storage device containing data to be preserved in the source extent range, and the target extent range mapped to the map particular extent range, may be indicated by the map. In another aspect, in response to receipt of a data preservation command, a data preservation operation is performed including determining whether a map indicates availability of a map extent range mapped to the identified target extent range.

Abstract: A plurality of tracks is examined for meeting criteria for a discard scan. In lieu of waiting for a completion of a track access operation, at least one of the plurality of tracks is marked for demotion. An additional discard scan may be subsequently performed for tracks not previously demoted. The discard and additional discard scans may proceed in two phases.

Abstract: A storage controller receives a request to establish a point-in-time copy operation by placing a space efficient source volume in a point-in-time copy relationship with a space efficient target volume, wherein subsequent to being established the point-in-time copy operation is configurable to consistently copy the space efficient source volume to the space efficient target volume at a point in time. A determination is made as to whether any track of an extent is staging into a cache from the space efficient target volume or destaging from the cache to the space efficient target volume. In response to a determination that at least one track of the extent is staging into the cache from the space efficient target volume or destaging from the cache to the space efficient target volume, release of the extent from the space efficient target volume is avoided.

Abstract: Provided are a computer program product, system, and method for asynchronous pausing of the formation of consistency groups. A first copy operation is initiated to copy the source data from the first storage to the first data copy in the second storage. A second copy operation is initiated to copy the first data copy in the second storage to a second data copy in response to forming a consistency group of the source data at the first data copy forms consistent as of a point-in-time with respect to the source data. The first copy operation is suspended to allow for further processing of the first data copy in response to completing the second copy operation. The formation of a next consistency group is restarted between the source data and the first data copy in response to receiving a resume command.

Abstract: Provided are techniques for local locking in a bi-directional synchronous mirroring environment. In response to receiving a write operation for a block of data on a first volume, a lock is obtained on a corresponding block of data on a second volume to obtain exclusive access to that block of data on the second volume. in response to determining that an active write indicator is set to indicate that there is not an active write on the second volume, updated data for the corresponding block of data is written to cache for the second volume, the lock is released to remove exclusive access to the corresponding block of data on the second volume, and a transfer complete message is sent to the first volume.

Abstract: A storage controller receives a request to establish a point-in-time copy operation by placing a space efficient source volume in a point-in-time copy relationship with a space efficient target volume, wherein subsequent to being established the point-in-time copy operation is configurable to consistently copy the space efficient source volume to the space efficient target volume at a point in time. A determination is made as to whether any track of an extent is staging into a cache from the space efficient target volume or destaging from the cache to the space efficient target volume. In response to a determination that at least one track of the extent is staging into the cache from the space efficient target volume or destaging from the cache to the space efficient target volume, release of the extent from the space efficient target volume is avoided.

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 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 travelling up the cascaded architecture until the source of the data is found. 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: For dynamically adjusting write pacing, a calculation module calculates an interval as a maximum threshold for a primary volume divided by a first maximum pacing level for a first importance level. The calculation module further calculates a first pacing level as a number of record sets that have not been mirrored to a secondary volume divided by the interval. The first pacing level is set to the first maximum pacing level if the first pacing level is greater than the first maximum pacing level. The calculation module also selects a first pacing delay associated with the first pacing level from a delay table. A pacing module delays writes for a first channel command word writing to the primary volume by the first pacing delay.

Abstract: Provided are a computer program product, system, and method for assigning device adaptors and background tasks to use to copy source extents to target extents in a copy relationship. A relation is provided of a plurality of source extents in source ranks to copy to a plurality of target extents in target ranks in the storage system. One target rank in the relation is used to determine an order in which the target ranks in the relation are selected to register for copying. For each selected target rank in the relation selected according to the determined order, an iteration of a registration operation is performed to register the selected target rank and a selected source rank copied to the selected target rank in the relation.

Abstract: A plurality of tracks is examined for meeting criteria for a discard scan. In lieu of waiting for a completion of a track access operation, at least one of the plurality of tracks is marked for demotion. An additional discard scan may be subsequently performed for tracks not previously demoted. The discard and additional discard scans may proceed in two phases.

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: Provided are a computer program product, system, and method for asynchronous pausing of the formation of consistency groups. A first copy operation is initiated to copy the source data from the first storage to the first data copy in the second storage. A second copy operation is initiated to copy the first data copy in the second storage to a second data copy in response to forming a consistency group of the source data at the first data copy forms consistent as of a point-in-time with respect to the source data. The first copy operation is suspended to allow for further processing of the first data copy in response to completing the second copy operation. The formation of a next consistency group is restarted between the source data and the first data copy in response to receiving a resume command.