Abstract: A computer-implemented method, according to one embodiment, includes: determining, using a processor, whether a virtual machine is authorized to run using a data structure having metadata about properties of the virtual machine; determining, using the processor, whether a hypervisor is authorized to run the virtual machine using a digital signature of the data structure; and running the virtual machine on a computer system using the hypervisor in response to determining that the virtual machine is authorized to be run and that the hypervisor is authorized to run the virtual machine. Other systems, methods, and computer program products are described in additional embodiments.

Abstract: A method according to one embodiment includes determining to temporarily extend an initial volume to be defragmented, identifying a plurality of additional volumes pooled with the initial volume within a storage group, identifying an area on each of the plurality of additional volumes pooled with the initial volume within the storage group to use for temporarily extending the initial volume, allocating the identified area on each of the plurality of additional volumes as a temporary extension of the initial volume, including, for each of the plurality of additional volumes, creating an entry in a VTOC of the additional volume that indicates that a non-VSAM data set resides at a location of the identified area on the additional volume, setting a plurality of pointers within a VTOC of the initial volume, where the plurality of pointers includes a pointer to the identified area on additional volumes, and defragmenting the initial volume.

Abstract: Provided are a computer program product, system, and method for selecting pages implementing leaf nodes and internal nodes of a data set index for reuse in memory. Pages in the memory are allocated to internal nodes and leaf nodes of a tree data structure representing all or a portion of a data set index for the data set. At least at least one duration parameter indicates an amount of time after which an unused page implement one of the internal nodes or leaf nodes is eligible for reuse. Selection is made of at least one selected page allocated to at least one of the leaf nodes and the internal nodes that has not been used for one of the at least one duration parameter for reuse.

Abstract: Provided are a computer program product, system, and method to use data set copies for recovery of a data set in event of a failure. In response to an update to the data set, a determination is made of an update group to include at least one copy of the data set that was not in a last determined update group to which a previous update was applied and to exclude at least one copy of the data set that was in the last determined update group. The update to the data set is applied to the copies of the data set in the update group and not applied to the copies not in the update group. In response to a failure event, the data set is recovered from one of the copies of the data set in the update group or not in the update group.

Abstract: A new layer for runtime detection of vendor hooks, with respect to a program module, includes mapping of branching instructions and their respective targets. When the program module is compiled, branch instructions are mapped and recorded to generate one or more branch maps. A branch map includes target program module addresses (or associated respective placeholders) and respective instruction offsets. At runtime, placeholders are replaced with respective target program module addresses. At runtime, actual branching information is compared to branching information included in the branch map. If a discrepancy is detected between runtime branching information and the corresponding branching information recorded in the branch map, a responsive action is triggered.

Abstract: A method for dynamically modifying data set generation depth is disclosed herein. In one embodiment, such a method includes providing a data set comprising one or more data elements. For each data element, a maximum generations number is designated that specifies a maximum number of generations of the data element to retain in the data set. The method monitors an access rate (e.g., creation rate, update rate, etc.) for each data element and dynamically alters, for each data element, the maximum generations number in accordance with the data element's access rate. In certain embodiments, the maximum generations number of a data element is increased as its access rate increases. Similarly, the maximum generations number of a data element may be decreased as its access rate decreases. A corresponding system and computer program product are also disclosed.

Abstract: Provided are a computer program product, system, and method for using mirror indicators to indicate whether to mirror tracks in a data set in a primary volume mirrored to a secondary volume. A table includes a mirror indicator for each of a plurality of tracks in at least one data set in the primary volume indicating whether a track is to be mirrored to the secondary volume. In response to a write command of write data for one of the tracks in the primary volume, creating a record set in a cache for the primary volume including write data for the track to transfer to the secondary volume in response to the mirror indicator for the track indicating that the track is to be mirrored. The write data in the record set is transferred from the cache to the secondary volume.

Abstract: Provided are a computer program product, system, and method for copying data from multiple point-in-time copies to a log storage to use to roll-back a source storage managing point-in-time copies of a source storage. A plurality of point-in-time copies of a source storage at different point-in-times are established. In response to receiving writes to the source storage after establishing each of the point-in-time copies, point-in-time data in the source storage is copied, before being updated by the received writes, to a log storage, wherein the log storage stores point-in-time data for multiple of the point-in-time copies. The log storage is used to roll-back the source storage to a selected point-in-time of one of the point-in-time copies.

Abstract: Provided are a computer program product, system, and method for generating node access information for a transaction accessing nodes of a data set index. Pages in the memory are allocated to internal nodes and leaf nodes of a tree data structure representing all or a portion of a data set index for the data set. A transaction is processed with respect to the data set that involves accessing the internal and leaf nodes in the tree data structure, wherein the transaction comprises a read or write operation. Node access information is generated in transaction information, for accessed nodes comprising nodes in the tree data structure accessed as part of processing the transaction. The node access information includes a pointer to the page allocated to the accessed node prior to the transaction in response to the node being modified during the transaction.

Abstract: Provided are a computer program product, system, and method for using mirror indicators to determine whether to mirror tracks in a data set in a primary volume mirrored to a secondary volume. A table is read. The table is maintained by a primary controller managing the primary volume that includes a mirror indicator for each of a plurality of tracks in at least one data set configured in the primary volume indicating whether a track is to be mirrored to the secondary volume. Record sets are read from a cache of the primary controller for the tracks in primary volume having the mirror indicators in the table indicating that the track is to be mirrored.

Abstract: A method for distributing I/O workload across a plurality of processor complexes is disclosed. In one embodiment, such a method includes providing a storage system environment comprising multiple processor complexes. Each processor complex provides access to one or more storage volumes. The processor complexes may be contained within a single storage system or spread across multiple storage systems. Upon allocating data sets in the storage system environment, the method selects storage volumes to store the data sets. In doing so, the method takes into account processor complexes that are associated with each of the storage volumes. More specifically, the method selects storage volumes in a way that more evenly distributes I/O workload across the multiple processor complexes. A corresponding system and computer program product are also disclosed.

Abstract: A method to more efficiently utilize data structures in an asynchronous data replication system is disclosed. In one embodiment, such a method includes maintaining, in memory of a primary storage system, a set of data structures for mirroring updates from the primary storage system to a secondary storage system. Each data structure has a status of either active or inactive. The method further establishes an upper threshold and lower threshold for each data structure. The method receives, into active data structures, updates that need to be mirrored to the secondary storage system. When updates in each of the active data structures reaches the upper threshold, the method activates a deactivated data structure. When updates in an active data structure fall below the lower threshold, the method deactivates and drains the data structure. A corresponding system and computer program product are also disclosed.

Abstract: Provided are a computer program product, system, and method for migrating jobs from a source server from which data is migrated to a target server to which the data is migrated. Mirrored data is copied from a source storage to a target storage. A determination is made of at least one eligible job of the jobs executing in the source server having execution characteristics indicating that the job is eligible for migration to the target server. The determined at least one eligible job is migrated to the target server to execute on the target server and perform operations with respect to the mirrored data in the target storage. The migrated eligible job is disabled at the source server.

Abstract: Provided are a computer program product, system, and method for using mirror indicators to determine whether to mirror tracks in a data set in a primary volume mirrored to a secondary volume. A table is read. The table is maintained by a primary controller managing the primary volume that includes a mirror indicator for each of a plurality of tracks in at least one data set configured in the primary volume indicating whether a track is to be mirrored to the secondary volume. Record sets are read from a cache of the primary controller for the tracks in primary volume having the mirror indicators in the table indicating that the track is to be mirrored. The write data in the read record sets is applied to tracks in the secondary volume mirroring the tracks in the primary volume.

Abstract: Methods, systems, and computer program products that can pre-emptively swap operations of a data production site to a disaster recovery (DR) site. A method includes providing, by a processor, one or more weighting factors to a set of metrics for an event occurring at a data production site based on information related to the event, analyzing the set of metrics based on the one or more weighting factors, and generating a recommendation related to swapping operations from the data production site to a DR site based on the analysis. Systems and computer program products for performing the above method are also provided.

Abstract: Provided are a computer program product, system, and method for using a forward log storage and backward log storage to recover a storage to a forward or backward point-in-time. In response to receiving writes to source data after establishing point-in-time copies, point-in-time data of the source data is copied to a backward log storage storing point-in-time data for multiple of the point-in-time copies. The point-in-time data in the backward log storage is applied to a recovery source data to roll-back the source data to a backward point-in-time of one of the point-in-time copies. Before applying the point-in-time data from the backward log storage, point-in-time data in the recovery source data, is copied to a forward log storage. The point-in-time data in the forward log storage is applied to the recovery source data to roll forward the recovery source data to a forward point-in-time subsequent to the backward point-in-time.

Abstract: A method for modifying a configuration of a storage system. The method includes a computer processor querying a network-accessible computing system to obtain information associated with an executing application that utilizes a storage system for a process of data mirroring. The method further includes identifying a set of parameters associated with a copy program executing within a logical partition (LPAR) of the storage system based on the obtained information, where the set of parameters dictates a number of reader tasks utilized by the copy program, where the copy program is a program associated with the process for data mirroring from the network-accessible computing system to the storage system. The method further includes executing the dictated number of reader tasks for the process of mirroring data associated with the executing application, from the network-accessible computing system to the storage system.

Abstract: A method for modifying a configuration of a storage system. The method includes one or more computer processors identifying data received at a logical partition (LPAR) of a storage system, wherein a copy program associated with a process for data mirroring executes within the LPAR. The method further includes determining a first rate based on analyzing a quantity of data received at the LPAR during the process of data mirroring. The method further includes creating a journal file from a set of records within the received data. The method further includes determining a second rate related to migrating the journal file from the LPAR to intermediate storage included in the storage system. The method further includes determining to modify a set of configuration information associated with the process of data mirroring by the storage system based, at least in part, on the first rate and the second rate.

Abstract: A method for configuring a storage system. The method includes a computer processor receiving at a storage system, an indication to initiate data mirroring for an application. The method further includes determining a set of information associated with a network-accessible computing system that hosts the application. The method further includes identifying an analysis of historic performance data associated with data mirroring to the storage system with respect to the application. The method further includes identifying a set configuration information associated with data mirroring from among a plurality of sets of configuration information associated with data mirroring based, at least in part, on the determined set of information associated with the network-accessible computing system and the identified analysis of performance data associated with data mirroring with respect to the application.

Abstract: A method for partially reorganizing a volume is disclosed. In one embodiment, such a method includes logically dividing a volume into multiple regions. The method further enables a computing system to perform a data reorganization operation on a particular region of the multiple regions, while enabling I/O to continue to the other regions. In the event a request for a data set allocation is received for the particular region while the data reorganization operation is taking place, the method automatically performs the data set allocation within other regions of the volume. When the data reorganization operation is complete, the method automatically moves the data set allocation from the region in which it was performed to the region associated with the original request.