Abstract: Aspects of the present disclosure relate to transmitting prioritized path data to a device based on a set of topology rules and metrics associated with a storage target. A storage target path discovery request is received from the device. In response to the storage target path discovery request, metrics associated with the storage target are collected. Based on the collected metrics, available paths to the storage target are identified. A set of topology rules are then determined. Based on the topology rules and the collected metrics, a subset of available paths are selected. The subset of available paths are then prioritized into prioritized path data. The prioritized path data is then stored and transmitted to the device.

Abstract: Embodiments for space-efficient cascading point-in-time copying of source data by creating a plurality of cascading point-in-time target copies, the target copies being created at different points in time, are provided. Data is physically copied form the source to a repository to create a physical copy, and a data mapping is created that associates the physical copy with a most recent target copy.

Abstract: A data handling system includes multiple storage devices that each have a limited number of write and erase iterations. In one scheme, a deterministic endurance delta is created between a storage device (benchmark storage device), and the other storage devices so that the benchmark storage device has less endurance than the other storage devices. The benchmark storage device will likely reach endurance failure prior to the other storage devices and the probability of non-simultaneous endurance failure increases. In another scheme, a deterministic endurance delta is created between each of the storage devices so that each of the storage devices have a different endurance level than the other storage devices. By implementing the endurance delta simultaneous endurance failures of the storage devices may be avoided.

Abstract: Aspects of the present disclosure relate to transmitting prioritized path data to a device based on a set of topology rules and metrics associated with a storage target. A storage target path discovery request is received from the device. In response to the storage target path discovery request, metrics associated with the storage target are collected. Based on the collected metrics, available paths to the storage target are identified. A set of topology rules are then determined. Based on the topology rules and the collected metrics, a subset of available paths are selected. The subset of available paths are then prioritized into prioritized path data. The prioritized path data is then stored and transmitted to the device.

Abstract: A mechanism is provided in a data processing system comprising a processor and a memory, the memory comprising instructions that are executed by the processor to specifically configure the processor to implement an initiator entity in a symmetric split-direction connection. The initiator entity generates a custom keepalive command and sends the custom keepalive command to a target entity via the symmetric split-direction connection. Responsive to the initiator entity determining a number of consecutive acknowledgement commands received in response to custom keepalive commands exceed a first threshold, the initiator entity reports the symmetric split-direction connection as sufficient. Responsive to the initiator entity determining a second number of consecutive keepalive commands sent without receiving an acknowledgement is greater than a second threshold, the initiator entity reports the symmetric split-direction connection as insufficient.

Abstract: Aspects of the present disclosure relate to transmitting prioritized path data to a device based on a set of topology rules and metrics associated with a storage target. A storage target path discovery request is received from the device. In response to the storage target path discovery request, metrics associated with the storage target are collected. Based on the collected metrics, available paths to the storage target are identified. A set of topology rules are then determined. Based on the topology rules and the collected metrics, a subset of available paths are selected. The subset of available paths are then prioritized into prioritized path data. The prioritized path data is then stored and transmitted to the device.

Abstract: Methods, computing systems and computer program products implement embodiments of the present invention that include identifying, in a storage system including multiple storage devices having respective sets of storage regions, respective default low storage region thresholds that are used for garbage collection. For each given storage region, a time threshold and an alternative low storage region threshold greater than the default low storage region threshold for the given storage device are defined. While processing input/output operations for each given storage device, a count of unused storage regions in the given storage device is maintained, a timer is initialized, and upon the timer matching the time threshold for the given storage device, a garbage collection operation is initiated. In some embodiments, processing the input/output operations includes using a log-structured array format.

Abstract: Embodiments for space-efficient cascading point-in-time copying of source data by creating a plurality of cascading point-in-time target copies, the target copies being created at different points in time, are provided. Data is physically copied form the source to a repository to create a physical copy, and a data mapping is created that associates the physical copy with a most recent target copy.

Abstract: Embodiments for space-efficient cascading point-in-time copying of source data by creating a plurality of cascading point-in-time target copies, the target copies being created at different points in time, are provided. Data is physically copied form the source to a repository to create a physical copy, and a data mapping is created that associates the physical copy with a most recent target copy.

Abstract: Embodiments for space-efficient cascading point-in-time copying of source data by creating a plurality of cascading point-in-time target copies, the target copies being created at different points in time, are provided. Data is physically copied form the source to a repository to create a physical copy, and a data mapping is created that associates the physical copy with a most recent target copy.

Abstract: An apparatus for optimizing a transaction comprising an initial sequence of computer operations, the apparatus includes a processing unit which identifies one or more idempotent operations comprised within the initial sequence, and which reorders the initial sequence to form a reordered sequence comprising a first sub-sequence of the computer operations followed by a second sub-sequence of the computer operations, the second sub-sequence comprising only the one or more idempotent operations.

Abstract: A computer implemented method for a space efficient cascading point-in-time copying of source data by creating a plurality of cascading point-in-time target copies, the target copies being created at different points in time. The method includes physically copying data from the source data to a repository to create a physical copy, and creating a data mapping that associates the physical copy with a most recent target copy. The method may be implemented in either of computer hardware configured to perform the method and computer software embodied in a non-transitory, tangible, computer-readable storage medium. Also disclosed are a corresponding computer program product and data processing system.

Abstract: An apparatus for optimizing a transaction comprising an initial sequence of computer operations, the apparatus includes a processing unit which identifies one or more idempotent operations comprised within the initial sequence, and which reorders the initial sequence to form a reordered sequence comprising a first sub-sequence of the computer operations followed by a second sub-sequence of the computer operations, the second sub-sequence comprising only the one or more idempotent operations.

Abstract: A method for optimizing a transaction consisting of an initial sequence of computer operations, the method including identifying one or more idempotent operations in the initial sequence. The method further includes reordering the initial sequence to form a reordered sequence consisting of a first sub-sequence of the computer operations followed by a second sub-sequence of the computer operations. The second sub-sequence has only the one or more idempotent operations.

Abstract: A system for managing variable sized pages of possibly non contiguous blocks in a Non-Volatile-Storage (NVS) for attaining a consistent NVS that survives malfunction events. Each page includes a self describing block or linked list of self describing blocks. the system includes: Volatile Storage storing auxiliary modules, means for performing an atomic “create a new page” procedure. Means for performing an atomic write “add block” procedure for adding a possibly non contiguous block to a page. The newly added block has a back pointer to a previous block in the page. Means for performing a “delete page” procedure for deleting all blocks in a page. Means for performing a recovery procedure for rolling backward the add block procedure and rolling forward the delete page procedure, in case of malfunction event, thereby attaining consistent NVS.

Abstract: A method for optimizing a transaction consisting of an initial sequence of computer operations, the method including identifying one or more idempotent operations in the initial sequence. The method further includes reordering the initial sequence to form a reordered sequence consisting of a first sub-sequence of the computer operations followed by a second sub-sequence of the computer operations. The second sub-sequence has only the one or more idempotent operations.

Abstract: Techniques are provided for performing a copy operation. A fast reverse restore command indicating a new source and a new target is received, wherein the new source is an original target and the new target is an original source. A synchronous scan is performed on the new target. A new target structure associated with the new target is updated using a new source structure associated with the new source. Techniques are also provided for performing a copy operation in which a fast reverse restore command is received after an instant virtual copy has been performed from a new target to a new source and wherein the fast reverse restore command is performed before a background copy has been performed by the instant virtual copy.

Abstract: A system for managing variable sized pages of possibly non contiguous blocks in a Non-Volatile-Storage (NVS) for attaining a consistent NVS that survives malfunction events. Each page includes a self describing block or linked list of self describing blocks. the system includes: Volatile Storage storing auxiliary modules, means for performing an atomic “create a new page” procedure. Means for performing an atomic write “add block” procedure for adding a possibly non contiguous block to a page. The newly added block has a back pointer to a previous block in the page. Means for performing a “delete page” procedure for deleting all blocks in a page. Means for performing a recovery procedure for rolling backward the add block procedure and rolling forward the delete page procedure, in case of malfunction event, thereby attaining consistent NVS.