Abstract: A computer-implemented method, according to one embodiment, includes: monitoring data requests that are performed on a logical volume in memory at a source location, and tracking changes that are made to data in the logical volume as a result of performing the data requests. A determination is made as to whether a preestablished amount of the data in the logical volume has been changed as a result of performing the data requests since a previous snapshot of the logical volume was captured. Moreover, in response to determining that a preestablished amount of the data in the logical volume has been changed as a result of performing the data requests since a previous snapshot of the logical volume was captured, a new snapshot of the logical volume is captured.

Abstract: A computer-implemented method, according to one embodiment, includes: monitoring data requests that are performed on a logical volume in memory at a source location, and tracking changes that are made to data in the logical volume as a result of performing the data requests. A determination is made as to whether a preestablished amount of the data in the logical volume has been changed as a result of performing the data requests since a previous snapshot of the logical volume was captured. Moreover, in response to determining that a preestablished amount of the data in the logical volume has been changed as a result of performing the data requests since a previous snapshot of the logical volume was captured, a new snapshot of the logical volume is captured.

Abstract: Managing storage volumes in a point-in-time copy cascade. The cascade includes a first source volume, a first target volume and a second target volume. The method detects a corruption of the first source volume and, if a first restoration of the first source volume from the first target volume is in progress, creates a third target volume from the second target volume and directs I/O operations for the first source volume to the third target volume. The first source volume is then restored from the third target volume.

Abstract: Method and system are provided for storage handling guidance for host input/output (I/O) operations. The method includes: providing a guidance array of indications of storage operations handling instructions, the guidance array having multiple dimensions of performance characteristics with each dimension having multiple levels; and associating a reference vector with one or more I/O operations, wherein the reference vector points to a level for each dimension of the array to obtain an indication of a storage operations handling instruction at an intercept of the dimension levels for application by a storage system controller for the one or more I/O operations.

Abstract: Method and system are provided for data validation during data recovery in a log-structure array (LSA) storage system. The method includes reading a log record of a recovery log for a logical address to obtain a physical address at a storage backend for the data at the time of the log record; reading reference metadata at the obtained physical address, wherein the reference metadata indicates the logical address that last wrote data to the physical address; validating that the physical address for the log record contains valid data for the logical address of the log record by comparing the logical address of the reference metadata to the logical address of the log record; and replaying the log record if the physical address is validated for recovery of virtual domain logical metadata mapping the logical address to the physical addresses of the log record.

Abstract: Method and system are provided for data validation during data recovery in a log-structure array (LSA) storage system. The method includes reading a log record of a recovery log for a logical address to obtain a physical address at a storage backend for the data at the time of the log record; reading reference metadata at the obtained physical address, wherein the reference metadata indicates the logical address that last wrote data to the physical address; validating that the physical address for the log record contains valid data for the logical address of the log record by comparing the logical address of the reference metadata to the logical address of the log record; and replaying the log record if the physical address is validated for recovery of virtual domain logical metadata mapping the logical address to the physical addresses of the log record.

Abstract: Method and system are provided for storage handling guidance for host input/output (I/O) operations. The method includes: providing a guidance array of indications of storage operations handling instructions, the guidance array having multiple dimensions of performance characteristics with each dimension having multiple levels; and associating a reference vector with one or more I/O operations, wherein the reference vector points to a level for each dimension of the array to obtain an indication of a storage operations handling instruction at an intercept of the dimension levels for application by a storage system controller for the one or more I/O operations.

Abstract: A method, computer system, and a computer program product for point-in-time copy with target write optimization in a cascading copy-on-write process is provided. The present invention may include receiving a request to perform a point-in-time copy operation to create a point-in-time copy from a source volume to a target volume. The present invention may include creating an intermediate volume, an intermediate map, and a map for the target volume. The present invention may include making the intermediate volume dependent on the source volume in a dependency chain based on the intermediate map. The present invention may include making the target volume dependent on the intermediate. The present invention may include allocating a new stream identifier to the target volume. The present invention may also include updating upstream volumes to inherit the new stream identifier as well as maintaining any existing stream identifiers.

Abstract: Managing storage volumes in a point-in-time copy cascade. The cascade includes a first source volume, a first target volume and a second target volume. The method detects a corruption of the first source volume and, if a first restoration of the first source volume from the first target volume is in progress, creates a third target volume from the second target volume and directs I/O operations for the first source volume to the third target volume. The first source volume is then restored from the third target volume.

Abstract: A method, computer system, and a computer program product for point-in-time copy with target write optimization in a cascading copy-on-write process is provided. The present invention may include receiving a request to perform a point-in-time copy operation to create a point-in-time copy from a source volume to a target volume. The present invention may include creating an intermediate volume, an intermediate map, and a map for the target volume. The present invention may include making the intermediate volume dependent on the source volume in a dependency chain based on the intermediate map. The present invention may include making the target volume dependent on the intermediate. The present invention may include allocating a new stream identifier to the target volume. The present invention may also include updating upstream volumes to inherit the new stream identifier as well as maintaining any existing stream identifiers.

Abstract: Managing storage volumes in a point-in-time copy cascade. The cascade includes a first source volume, a first target volume and a second target volume. The method detects a corruption of the first source volume and, if a first restoration of the first source volume from the first target volume is in progress, creates a third target volume from the second target volume and directs I/O operations for the first source volume to the third target volume. The first source volume is then restored from the third target volume.

Abstract: A system, method, and computer program product for managing storage volumes in a point-in-time copy cascade. A processor swaps a host portion of a source volume with a host portion of a snapshot point-in-time copy volume. Responsive to an I/O request to overwrite a first data value in a grain of the source volume with a second data value, a processor writes the second data value in a corresponding grain of the snapshot point-in-time copy volume. Responsive to a corresponding grain of a clone point-in-time copy volume not comprising the first data value, a processor copies the first data value to the corresponding grain of the clone point-in-time copy volume.

Abstract: A method includes monitoring port login requests initiated by elements of a storage system, the storage system comprising interconnection cabling, constructing a connection graph corresponding to the port login requests, wherein each edge of the connection graph corresponds to a specific port login request and each vertex of the connection graph corresponds to a port within the storage system, and using the connection graph to evaluate the interconnection cabling of the storage system. A corresponding computer program product and computer system are also disclosed herein.

Abstract: Point-in-time backup copies of a production volume that include volume maps between adjacent source and target volumes can be created in a cascade of data volumes. An empty volume map having the backup copy as the target can be created. The empty volume map can include a first bitmap used to indicate that data is stored in the source or the target, a second bitmap for use in managing and optimizing background copying, and an index for tracking a status of background copying. The volume map can be populated so that the first bitmap indicates data is stored in the source, and the index set to a start value. Production volume data regions can be sequentially background copied to the backup copy, while tracking using the index. Upon backup copy completion, the values of the volume map having the backup copy as the target can be stored.

Abstract: Point-in-time backup copies of a production volume that include volume maps between adjacent source and target volumes can be created in a cascade of data volumes. An empty volume map having the backup copy as the target can be created. The empty volume map can include a first bitmap used to indicate that data is stored in the source or the target, a second bitmap for use in managing and optimizing background copying, and an index for tracking a status of background copying. The volume map can be populated so that they first bitmap indicates data is stored in the source, and the index set to a start value. Production volume data regions can be sequentially background copied to the backup copy, while tracking using the index. Upon backup copy completion, the values of the volume map having the backup copy as the target can be stored.

Abstract: A system, method, and computer program product for managing storage volumes. A processor creates a first point-in-time copy cascade, where the first point-in-time copy cascade comprises a source volume, a first snapshot point-in-time copy volume, and a second snapshot point-in-time copy volume; the first volume is a snapshot copy of the source volume and the second volume is a snapshot copy of the first volume. A processor creates a third snapshot point-in-time copy volume from the first volume. A processor maps the third volume to create a second cascade, wherein the second cascade comprises the source volume, the first volume, and the third volume but not the second volume. A processor directs an I/O operation for the first copy volume to the third volume.

Abstract: A system, method, and computer program product for managing storage volumes in a point-in-time copy cascade. A processor swaps a host portion of a source volume with a host portion of a snapshot point-in-time copy volume. Responsive to an I/O request to overwrite a first data value in a grain of the source volume with a second data value, a processor writes the second data value in a corresponding grain of the snapshot point-in-time copy volume. Responsive to a corresponding grain of a clone point-in-time copy volume not comprising the first data value, a processor copies the first data value to the corresponding grain of the clone point-in-time copy volume.

Abstract: A method and system are provided for storage checkpointing in a mirrored virtual machine system. The method includes a storage controller receiving a modifying operation to storage from a virtual machine and carrying out the modifying operation in a non-destructive manner by saving the modifying operation data to a checkpointing region of storage and preserving the stored previous data state. The method also includes receiving a checkpoint notification and committing modifying operation data from the checkpointing region and releasing the stored previous data state. If a failover notification is received, the storage controller rolls back the physical storage to match a checkpoint state.

Abstract: A method and system are provided for storage checkpointing in a mirrored virtual machine system. The method includes a storage controller receiving a modifying operation to storage from a virtual machine and carrying out the modifying operation in a non-destructive manner by saving the modifying operation data to a checkpointing region of storage and preserving the stored previous data state. The method also includes receiving a checkpoint notification and committing modifying operation data from the checkpointing region and releasing the stored previous data state. If a failover notification is received, the storage controller rolls back the physical storage to match a checkpoint state.

Abstract: A system, method, and computer program product for managing storage volumes in a point-in-time copy cascade. A processor swaps a host portion of a source volume with a host portion of a snapshot point-in-time copy volume. Responsive to an I/O request to overwrite a first data value in a grain of the source volume with a second data value, a processor writes the second data value in a corresponding grain of the snapshot point-in-time copy volume. Responsive to a corresponding grain of a clone point-in-time copy volume not comprising the first data value, a processor copies the first data value to the corresponding grain of the clone point-in-time copy volume.