Abstract: One general aspect of device reservation state synchronization in accordance with the present description, device reservation management logic ensures synchronization of reservation states of primary and secondary volumes of a mirror relationship in the event of a change in the state of the mirroring relationship such as achieving full data synchronization between the volumes. Other features and aspects may be realized, depending upon the particular application.

Abstract: Provided are a computer program product, system, and method for using a machine learning module to determine when to replace a storage device. Input on attributes of the storage device is provided to a machine learning module to produce an output value. A determination is made whether the output value indicates to replace the storage device. Indication is made to replace the storage device in response to determining that the output value indicates to replace the storage device.

Abstract: Provided are a computer program product, system, and method for using mirror path statistics in recalling extents to a primary storage system and a secondary storage system from a third storage system, A recall request is received to recall extents from the third storage that were migrated from the primary storage or the secondary storage to the third storage. A determination is made as to whether mirror paths used to migrate extents from the primary storage to the secondary storage exceed a degradation criteria. Commands are sent to cause the recall extents to be recalled from the third storage to both the primary storage and the secondary storage in response to determining that the mirror paths exceed the degradation criteria.

Abstract: Provided are a computer program product, system, and method for using storage access statistics to determine mirrored extents to migrate from a primary storage system and a secondary storage system to a third storage system. A determination is made of access statistics with respect to mirrored extents of data at the primary storage mirrored to the secondary storage to migrate to the third storage. A first set of the mirrored extents associated with access statistics indicating a highest level of access of the mirrored extents are migrated from the secondary storage to the third storage. A second set of the mirrored extents associated with access statistics indicating a lower level of access than the mirrored extents in the first set are migrated from the primary storage to the secondary storage.

Abstract: Provided are a computer program product, system, and method for using storage access statistics to determine mirrored extents to migrate from a primary storage system and a secondary storage system to a third storage system. A determination is made of access statistics with respect to mirrored extents of data at the primary storage mirrored to the secondary storage to migrate to the third storage. A first set of the mirrored extents associated with access statistics indicating a highest level of access of the mirrored extents are migrated from the secondary storage to the third storage. A second set of the mirrored extents associated with access statistics indicating a lower level of access than the mirrored extents in the first set are migrated from the primary storage to the third storage.

Abstract: Provided are a computer program product, system, and method for using trap cache segments to detect malicious processes. A trap cache segment to the cache for data in the storage and indicated as a trap cache segment. Cache segments are added to the cache having data from the storage that are not indicated as trap cache segments. A memory function call from a process executing in the computer system reads data from a region of a memory device to output the read data to a buffer of the memory device. A determination is made as to whether the region of the memory device includes the trap cache segment. The memory function call is blocked and the process is treated as a potentially malicious process in response to determining that the region includes the trap cache segment.

Abstract: A method for reporting incidents of data loss in a storage environment comprising redundant arrays of independent disks (RAIDs) is disclosed. In one embodiment, such a method monitors storage drive failures in a storage environment. For a storage drive failure detected in the storage environment, the method reports the RAID type in which the storage drive failure occurred and whether data loss occurred in the RAID as a result of the storage drive failure. In certain embodiments, the method reports whether the data loss could have been prevented had the RAID type been converted to a more robust RAID type. In other or the same embodiments, the method reports whether the data loss was prevented by the RAID type. A corresponding system and computer program product are also disclosed.

Abstract: Copy source to target operations may be selectively and preemptively undertaken in advance of source destage operations. In another aspect, logic detects sequential writes including large block writes to point-in-time copy sources. In response, destage tasks on the associated point-in-time copy targets are started which include in one embodiment, stride-aligned copy source to target operations which copy unmodified data from the point-in-time copy sources to the point-in-time copy targets in alignment with the strides of the target. As a result, when write data of write operations is destaged to the point-in-time copy sources, such source destages do not need to wait for copy source to target operations since they have already been performed. In addition, the copy source to target operations may be stride-aligned with respect to the stride boundaries of the point-in-time copy targets. Other features and aspects may be realized, depending upon the particular application.

Abstract: A plurality of extents of a plurality of logical volumes are stored in a plurality of ranks, where each logical volume of the plurality of logical volumes is comprised of a plurality of extents including a first extent. In response to determining that first extents stored in each rank of the plurality of ranks have become unbalanced in number in the plurality of ranks, a balancing of the first extents in the plurality of ranks is performed by redistributing the first extents in the plurality of ranks.

Abstract: A computer-implemented method according to one embodiment includes identifying a request to migrate data associated with a volume from a source storage pool having a first rank extent size to a destination storage pool having a second rank extent size smaller than the first rank extent size, creating a correspondence between logical volume extents of the volume and physical offset locations within rank extents of the source storage pool, and migrating data from one or more ranks of the source storage pool to one or more ranks of the destination storage pool, utilizing the correspondence between the logical volume extents of the volume and the physical offset locations within the rank extents of the source storage pool.

Abstract: Provided are a computer program product, system, and method for detecting potentially malicious code in a host system accessing data from a storage. A trap storage unit is configured for data in the storage and the trap storage unit is indicated as a trap. Storage units are configured for data in the storage that are not indicated as a trap. A request is received to access the trap storage unit from a process executing in a host system. Notification is returned to the host system that the process requesting to access the trap storage unit is a potentially malicious process.

Abstract: Provided are a computer program product, system, and method for determining an optimum number of threads to make available per core in a multi-core processor complex to execute tasks. A determination is made of a first processing measurement based on threads executing on the cores of the processor chip, wherein each core includes circuitry to independently execute a plurality of threads. A determination is made of a number of threads to execute on the cores based on the first processing measurement. A determination is made of a second processing measurement based on the threads executing on the cores of the processor chip. A determination is made of an adjustment to the determined number of threads to execute based on the second processing measurement resulting in an adjusted number of threads. The adjusted number of threads on the cores is utilized to execute instructions.

Abstract: A machine learning module receives inputs comprising attributes of a storage controller, where the attributes affect failures that occur in the storage controller. In response to a failure occurring in the storage controller, a plurality of output values corresponding to a plurality of recovery mechanisms to recover from the failure in the storage controller are generated via forward propagation through a plurality of layers of the machine learning module. A margin of error is calculated based on comparing the generated output values to expected output values corresponding to the plurality of recovery mechanisms, where the expected output values are generated from an indication of a correct recovery mechanism for the failure. An adjustment is made of weights of links that interconnect nodes of the plurality of layers via back propagation to reduce the margin of error, to improve a determination of a recovery mechanism for the failure.

Abstract: A computer-implemented method according to one embodiment includes identifying a request to migrate data associated with a volume from a source storage pool having a first rank extent size to a destination storage pool having a second rank extent size smaller than the first rank extent size, creating a correspondence between logical volume extents of the volume and physical offset locations within rank extents of the source storage pool, and migrating data from one or more ranks of the source storage pool to one or more ranks of the destination storage pool, utilizing the correspondence between the logical volume extents of the volume and the physical offset locations within the rank extents of the source storage pool.

Abstract: Provided are a computer program product, system, and method for using a machine learning module to determine when to perform error checking of a storage unit. Input on attributes of at least one storage device comprising the storage unit are provided to a machine learning module to produce an output value. An error check frequency is determined from the output value. A determination is made as to whether the error check frequency indicates to perform an error checking operation with respect to the storage unit. The error checking operation is performed in response to determining that the error checking frequency indicates to perform the error checking operation.

Abstract: Provided are a computer program product, system, and method for using trap cache segments to detect malicious processes. A trap cache segment to the cache for data in the storage and indicated as a trap cache segment. Cache segments are added to the cache having data from the storage that are not indicated as trap cache segments. A memory function call from a process executing in the computer system reads data from a region of a memory device to output the read data to a buffer of the memory device. A determination is made as to whether the region of the memory device includes the trap cache segment. The memory function call is blocked and the process is treated as a potentially malicious process in response to determining that the region includes the trap cache segment.

Abstract: Provided are a computer program product, system, and method for sharing alias addresses among logical devices by a host accessing logical devices provisioned with a capacity from physical devices managed by a control unit. The host establishes with the control unit an association of logical devices and alias addresses assigned to the logical devices, wherein the alias addresses are associated with an alias management group. Alias address pool information is generated indicating each of the logical devices and their assigned alias addresses indicated in the association. The host uses from the alias address pool information any one of the alias addresses in the alias address pool information to access any of the logical devices associated with the same alias management group as the alias address.

Abstract: A method according to one embodiment includes identifying a request to migrate data associated with a volume from a source storage pool to a destination storage pool, identifying volume segment table (VST) entries corresponding to rank extents within the source storage pool containing the data, allocating and synchronizing small VSTs for the identified VST entries within the volume, allocating one or more rank extents within the destination storage pool, transferring the data associated with the volume from the rank extents within the source storage pool containing the data to the one or more rank extents in the one or more ranks of the destination storage pool, updating the small VSTs to correspond to the transferred data in the one or more rank extents in the one or more ranks of the destination storage pool, and freeing the data from the one or more rank extents within the source storage pool.

Abstract: Copy source to target operations may be selectively and preemptively undertaken in advance of source destage operations. In another aspect, logic detects sequential writes including large block writes to point-in-time copy sources. In response, destage tasks on the associated point-in-time copy targets are started which include in one embodiment, stride-aligned copy source to target operations which copy unmodified data from the point-in-time copy sources to the point-in-time copy targets in alignment with the strides of the target. As a result, when write data of write operations is destaged to the point-in-time copy sources, such source destages do not need to wait for copy source to target operations since they have already been performed. In addition, the copy source to target operations may be stride-aligned with respect to the stride boundaries of the point-in-time copy targets. Other features and aspects may be realized, depending upon the particular application.

Abstract: Provided are a computer program product, system, and method for generating a health condition message on a health condition detected at a first server to send to a host system accessing the first server. A determination is made of a health condition with respect to access to a first storage. A determination is made of an estimated Input/Output (I/O) delay to access the first storage resulting from the determined health condition. A health condition message is generated indicating the estimated I/O delay. The health condition message is transmitted to the host system, wherein the host system uses the estimated I/O delay to determine whether to perform a swap operation to redirect host I/O requests to data from the first server to a second server.