Abstract: A method for converting from one asynchronous data replication technology to another is disclosed herein. In one embodiment, such a method includes utilizing a first asynchronous data replication technology to asynchronously replicate data from a primary volume to a secondary volume. The method initiates, at time T1, tracking of post-T1 changes to the primary volume and waits for all pre-T1 changes to the primary volume to be propagated to the secondary volume. When all pre-T1 changes have been propagated to the secondary volume, the method suspends operation of the first asynchronous data replication technology and replicates all post-T1 changes from the primary volume to the secondary volume. The method further sets up and initiates a second asynchronous data replication technology to asynchronously replicate data from the primary volume to the secondary volume. A corresponding system and computer program product are also disclosed herein.

Abstract: A method, computer system, and a computer program product for collecting performance data on a consistency group boundary is provided. The present invention may include positioning a plurality of software applications into idle mode. The present invention may also include starting a consistency group based on a command from a Global Mirror Master. The present invention may then include collecting a plurality of performance data associated with the started consistency group. The present invention may then include removing a plurality of remaining data associated with the collected plurality of performance data. The present invention may further include ending the collection of the collected plurality of data.

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: 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 are a computer program product, system, and method for determining space to release in a target volume to which tracks from a source volume are mirrored. A copy of a source volume table for the source volume providing a state of the tracks in the source volume for a consistency group is received. Tracks received from the source volume are written to the target volume to form the consistency group of tracks in the source volume at the target volume. A determination is made of tracks available to release from the copy of the source volume table and space allocated to the determined tracks is replaced. A point-in-time copy is created of the target volume for the consistency group. Complete is returned to forming the consistency group in response to releasing the space and creating the point-in-time copy.

Abstract: Provided are a computer program product, system, and method for determining tracks to release in a target volume mirroring tracks from a source volume. Tracks received from the source volume are written to the target volume to form a consistency group of tracks in the source volume at the target volume. A determination is made of tracks available to release from a volume table providing a state of the tracks in the target volume and space allocated to the determined tracks is released. A point-in-time copy of the target volume is crated and complete is returned to forming the consistency group in response to releasing the space and creating the point-in-time copy.

Abstract: A simulation tool provides candidate volume mirror simulation in a data storage system. In one embodiment, user selections are received including a user selection of one or more candidate volumes of a primary data storage system for simulating mirroring to a secondary data storage system. As a function of received user selections, host-to-primary I/O activity to a candidate volume is simulated, recorded and measured over a selected interval of time. In addition, primary-to-secondary mirroring of a selected candidate volume to the secondary data storage system is simulated, recorded and measured over the interval of time. Performance measurements of the candidate volume mirror simulation are output by the simulation tool. Other features and aspects may be realized, depending upon the particular application.

Abstract: A method, system, and program product are provided for processing a host write operation during a recovery operation of a point-in-time copy restore. Provided are blocking the host write operation to the source volume based on whether a track on the source volume is copied to the target volume. A host and the point-in-time copy restore synchronize simultaneous access to the track using a track lock on track access, causing a requestor without the track lock to be queued until the track lock is available.

Abstract: Provided are techniques for determining which target is most ahead in a multi-target mirroring environment between data from a consistent synchronous mirror copy operation and data from a consistent asynchronous mirror copy operation. It is determined that data is to be retrieved from one of a sync secondary storage of a sync secondary storage controller and an async secondary storage of an async secondary storage controller. Then, it is determined which one of data of a consistent synchronous mirror copy operation on the sync secondary storage and data of a consistent asynchronous mirror copy operation on the async secondary storage is a most current copy of the data. The most current copy of the data is retrieved and used for further processing.

Abstract: Provided are a computer program product, system, and method for determining tracks to release in a source volume being copied to a target volume. A consistency group is formed of tracks in the source volume to copy to the target volume. A volume table providing information on the tracks allocated to the source volume is copied to a volume table copy in a memory providing a state of the tracks in the source volume as of a consistency group time. A determination is made of tracks in the source volume to release for tracks that are indicated in the volume table copy as available to release excluding tracks in the source volume that are written after the consistency group time. Space allocated to the determined tracks is released.

Abstract: A method for more intelligently managing storage space in journal volumes is disclosed herein. In one embodiment, such a method includes maintaining, on a primary storage system, a change recording data structure that documents updated storage elements of a primary volume on the primary storage system. The method further determines in which extents of the primary volume the updated storage elements reside. These extents are recorded in an extent-based data structure. The method transmits the extent-based data structure from the primary storage system to a secondary storage system that is in an asynchronous mirroring relationship with the primary storage system. The extent-based data structure is then read at the secondary storage system. The method frees, from a journal volume on the secondary storage system, extents that are not recorded in the extent-based data structure. A corresponding system and computer program product are also disclosed herein.

Abstract: Provided are a computer program product, system, and method for processing a space release command when mirroring data at a source storage to a target storage. A space release command is received to free a release space in the source storage while transferring changed data in a consistency group. A determination is made as to whether a transfer time to transfer remaining consistency group data in the consistency group for the release space that has not been transferred exceeds a response time to process a space release command. The remaining consistency group data in the release space is transferred to the target storage in response to determining that the transfer time does not exceed the response time. The release space for the space release command is freed in response to transferring the consistency group data in the release space to the target storage.

Abstract: According to one embodiment, a computer program product for read-once point-in-time copy includes a computer readable storage medium having program instructions embodied therewith. The computer readable storage medium is not a transitory signal per se, and the program instructions are executable by a storage system manager to cause the storage system manager to perform a method comprising: detecting a read access to one or more data tracks of a target data storage module; setting a value of one or more bits in response to detecting the read access to the one or more data tracks, each of the one or more bits being associated with one of the one or more data tracks. The value of the one or more bits is set to a value configured to prevent a copy-on-write operation being applied to the one or more data tracks to which the read access was detected.

Abstract: In a storage management interface to manage host ports in a computing system having a server and one or more hosts, a user interface is provided to facilitate assigning host ports to an associated host. In one embodiment, the user interface detects unassigned host ports which have not been identified as being assigned to an associated host, and generates a graphical user interface (GUI) page indicating unassigned host ports. User selection of at least one of the unassigned host ports indicated in the GUI page is received as well as user selection of a host to assign to the selected unassigned host ports. Once the assignment is completed, data structures storing host port assignment configuration data are updated to indicate the host assigned to the selected host ports.

Abstract: A method is disclosed for avoiding out-of-space conditions in an asynchronous data replication environment. In one embodiment, such a method creates a consistency group on a primary storage system of an asynchronous data replication environment. The method determines a number of additional extents that will be needed on a secondary storage system to accommodate the consistency group. The number of additional extents is compared to a number of free extents on the secondary storage system. In the event the number of additional extents does not exceed the number of free extents, the method transfers the data from the primary storage system to the secondary storage system. In the event the number of additional extents exceeds the number of free extents, the method automatically takes actions on the secondary storage system to provide the number of additional extents. A corresponding system and computer program product are also disclosed.

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: Event detection logic detects events which may be associated with a change in risk of potential data loss in a data replication system. Mode selection logic is responsive to detection of such an event to select a data replication mode such as a synchronous data replication mode, for example, as a function of a detected event for initiation of a switch to the selected mode. In one embodiment, upon detecting that the event which lead to initiation of a switch to the synchronous mode has been completed or otherwise resolved, the mode selection logic can initiation of a switch of the data replication mode of multi-mode data replication logic back to an asynchronous mode so that data is replicated in the asynchronous data replication mode. Other features and aspects may be realized, depending upon the particular application.

Abstract: A synchronization of data is performed via remote copy operations 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. A first data structure stores identification of tracks written via the network interface that are to be copied from the primary storage controller to the secondary storage controller for the synchronization of data. A second data structure stores identification of tracks written via the bus interface that are to be copied from the primary storage controller to the secondary storage controller for the synchronization of data.

Abstract: A simulation tool provides candidate volume mirror simulation in a data storage system. In one embodiment, user selections are received including a user selection of one or more candidate volumes of a primary data storage system for simulating mirroring to a secondary data storage system. As a function of received user selections, host-to-primary I/O activity to a candidate volume is simulated, recorded and measured over a selected interval of time. In addition, primary-to-secondary mirroring of a selected candidate volume to the secondary data storage system is simulated, recorded and measured over the interval of time. Performance measurements of the candidate volume mirror simulation are output by the simulation tool. Other features and aspects may be realized, depending upon the particular application.

Abstract: A method is disclosed for avoiding out-of-space conditions in an asynchronous data replication environment. In one embodiment, such a method creates a consistency group on a primary storage system of an asynchronous data replication environment. The method determines a number of additional extents that will be needed on a secondary storage system to accommodate the consistency group. The number of additional extents is compared to a number of free extents on the secondary storage system. In the event the number of additional extents does not exceed the number of free extents, the method transfers the data from the primary storage system to the secondary storage system. In the event the number of additional extents exceeds the number of free extents, the method automatically takes actions on the secondary storage system to provide the number of additional extents. A corresponding system and computer program product are also disclosed.