Abstract: Embodiments of dynamically increasing the resources for a partition to compensate for an input/output (I/O) recovery event are provided. An aspect includes allocating a first set of resources to a partition that is hosted on a data processing system. Another aspect includes operating the partition on the data processing system using the first set of resources. Another aspect includes, based on detection of an input/output (I/O) recovery event associated with operation of the partition, determining a compensation for the I/O recovery event. Another aspect includes allocating a second set of resources in addition to the first set of resources to the partition, the second set of resources corresponding to the compensation for the I/O recovery event. Another aspect includes operating the partition on the data processing system using the first set of resources and the second set of resources.

Abstract: A first device determines whether an indicator is configured to allow use of an increased value for an information unit pacing credit that is greater than a default value for the information unit pacing credit, where the information unit pacing credit indicates a number of information units that a second device is allowed to send to the first device without waiting for any additional response from the first device. In response to determining that the indicator is configured to allow use of the increased value for the information unit pacing credit that is greater than the default value for the information unit pacing credit, the first device adjusts the information unit pacing credit via a response sent from the first device to the second device, to the increased value that is greater than the default value.

Abstract: Provided are a computer program product, system, and method for non-disruptive encoding of source data in a source data set migrated to a target data set. The source data in the source data set is migrated to a target data set by encoding the source data to produce encoded source data to copy to a target data set. In response to receiving write data for the source data set, the write data is encoded to produce encoded write data to copy to the target data set. Input/Output (“I/O”) requests to the source data set are redirected to the target data set having encoded data for the source data set.

Abstract: Aspects include providing automatic access control and security for a synchronous input/output (I/O) link. Providing automatic access control and security includes initializing devices of a storage environment over a first link to verify that the devices are available within the storage environment; building a table of identifiers, where each of the identifiers is assigned one of the devices that have been initialized; and verifying a first device attempting to perform synchronous I/O commands across the synchronization I/O link by confirming that an identifier assigned to the first device is within the table of identifiers.

Abstract: A storage controller is configured to communicate with a host over a first storage area network. Data controlled via the storage controller is mirrored to another storage controller over a second storage area network. The storage controller receives a request from the host to provide read diagnostic parameters of the second storage area network. In response to receiving the request, the storage controller secures the read diagnostic parameters of the second storage area network. The storage controller transmits the read diagnostic parameters of the second storage area network to the host.

Abstract: A host is configured to communicate with a storage controller over a first storage area network. A request is transmitted from the host to the storage controller to provide read diagnostic parameters of a second storage area network that is used to mirror data controlled by the storage controller to another storage controller. The host receives the read diagnostic parameters of the second storage area network from the storage controller.

Abstract: Provided are a computer program product, system, and method for processing a chain of a plurality of write requests including a commit wait flag and plurality of write requests, wherein each write request group includes write transactions directed to the storage. A determination is made as to whether the commit wait flag has a first value or a second value. The write requests are processed by requiring a current write request comprising one of the write requests being processed to complete before beginning to write data for a next write request following the current write request in the write request chain in response to the commit wait flag having the first value. The write requests are processed by processing the next write request before completing the current write request in response to the commit wait flag having the second value.

Abstract: A method for utilizing parallel paths of differing performance to improve efficiency is disclosed. In one embodiment, such a method includes transmitting, over a faster path, a first command to perform first actions intended to improve efficiency of second actions associated with a second command. The method transmits, over a slower path in parallel with the faster path, the second command. Alternatively, a method for utilizing parallel paths of differing performance to improve efficiency includes receiving, over a faster path, a first command to perform first actions intended to improve efficiency of second actions associated with a second command. The method executes the first command to perform the first actions. The method receives, over a slower path in parallel with the faster path, the second command and executes the second command to perform the second actions. Corresponding systems and computer program products are also disclosed.

Abstract: Provided are a computer program product, system, and method for sharing alias addresses among logical devices for a control unit managing access by hosts to logical devices configured with capacity from attached physical devices. An alias management group of logical devices and alias addresses assigned to the logical devices is configured. A plurality of requests to establish an association of the host with a logical device and the alias addresses assigned to the logical devices in the alias management group are received from a host. Acknowledgment is made to the host that the association is established in response to determining that the host is assigned the logical devices and alias addresses of the logical devices in the alias management group. The host can use one available alias address assigned to any one of the logical devices to access any one of the logical devices indicated in the association.

Abstract: Provided are a computer program product, system, and method for generating a chain of a plurality of write requests including a commit wait flag and plurality of write requests. The commit wait flag is set to one of an indicated first value or a second value. The commit wait flag is set to the first value to cause a storage server to process the write requests by requiring a current write request being processed to complete before transferring data for a next write request following the current write request. The commit wait flag is set to the second value to cause the storage server to process the write requests by transferring data for the next write request before completing the current write request preceding the next write request. The write request chain is sent to the storage server to apply the write requests to the storage.

Abstract: In one example implementation according to an embodiment described herein, a computer-implemented method includes detecting input/output (I/O) interrupts for executing I/O operations occurring over a period of time. The method further includes calculating an I/O interrupt delay time (IIDT) for each I/O interrupt occurring during the period of time. The method further includes binning the IIDT for each I/O interrupt occurring during the period of time into one of a plurality of bins based on a value of the IIDT, each of the plurality of bins storing a count of IIDT values within a defined range. The method further includes determining a highest IIDT value. The method further includes identifying a performance degradation based at least on one of the count of IIDT values of each of the plurality of bins or the highest IIDT value. The method further includes implementing a corrective action to mitigate the performance degradation.

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: An embodiment of restricted command set management permits a storage controller to execute commands of a restricted command set if authorized. A command determined to be within the restricted command set is encrypted by a host prior to sending the encrypted command to a storage controller for execution. The command may be encrypted using a key shared between the host and the storage controller. The shared key may be generated by the host and encrypted by the host using a public key of a public-private key maintained by the storage controller. The encrypted shared key may be decrypted by the storage controller using the private key of the public-private key maintained by the storage controller. Execution of commands of the restricted command set is prevented absent proper decryption of the commands sent by the host. Other features and aspects may be realized, depending upon the particular application.

Abstract: A method for accelerating transaction execution across geographically dispersed clusters is disclosed. In one embodiment, such a method includes receiving a request to read data in a data replication system comprising a primary storage system and a secondary storage system in a synchronous mirroring relationship with the primary storage system. The method determines whether at least one of the following conditions is true: (1) the secondary storage system is closer from a communication standpoint; and (2) a high speed communication technology is available to communicate with the secondary storage system that is not available to communicate with the primary storage system. In the event either of the conditions is true, the method directs the request to the secondary storage system. In the event neither of the conditions is true, the method directs the request to the primary storage system. A corresponding system and computer program product are also disclosed.

Abstract: Provided are a computer program product, system, and method for processing a write of records to maintain atomicity for writing a defined group of records to multiple tracks. A write is received comprising defined groups of records to write to a plurality of tracks in the primary storage system. Sub-writes are generated to write the records in the defined groups in the write. At least one of the sub-writes includes records to write for at least one of the defined groups that spans multiple tracks in response to determining that at least one of the defined groups includes records that will be written to multiple tracks. The sub-writes are transmitted to the primary storage system to mirror to the secondary storage system to cause the secondary storage system to return complete in response to completing writing to all the tracks written to by the sub-write.

Abstract: One general aspect of device reservation management in accordance with the present description, is directed to a host issuing I/O data requests to a primary device which synchronously mirrors data to a secondary data storage device wherein both devices are reserved for exclusive use by the host for I/O data requests. In response to a loss of communication connectivity on all paths to the primary storage controller controlling the primary device, the host confirms whether a communication path to the primary device has been established and whether the primary device remains reserved to the host. Upon successful confirmations, the reservation of the primary device is repaired such that I/O data requests to the reserved primary device continue. Other features and aspects may be realized, depending upon the particular application.

Abstract: Provided are a computer program product, system, and method for mirroring writes of records to maintain atomicity for writing a defined group of records to multiple tracks. Sub-writes are received from a host system to write records in defined groups in a write, wherein at least one of the sub-writes includes records to write for at least one of the defined groups that spans multiple tracks. For each of the sub-writes including records for at least one of the defined groups that spans multiple tracks, the tracks in the sub-write with to the secondary storage system to cause the secondary storage system to apply the tracks upon receiving all the tracks for the sub-write. Complete is returned for the sub-write to the host system upon receiving confirmation from the secondary storage system that all the tracks for the sub-write have been applied to the secondary storage system.

Abstract: A system for accelerating database transaction processing by controlling data replication includes a first control unit configured to manage a first storage device and at least one second control unit configured to manage a second storage device. The first control unit writes first data to the first storage device and sends the first data to the second control unit responsive to receiving from a host a first write command including the first data. The first control unit writes second data to the first storage device without sending the second data to the second control unit responsive to receiving from the host a second write command. The second control unit writes the first data to the second storage device responsive to receiving the first data. The second control unit writes the second data to the second storage device responsive to receiving from the host a third write command.

Abstract: Provided are a computer program product, system, and method for generating a chain of a plurality of write requests including a commit wait flag and plurality of write requests. The commit wait flag is set to one of an indicated first value or a second value. The commit wait flag is set to the first value to cause a storage server to process the write requests by requiring a current write request being processed to complete before transferring data for a next write request following the current write request. The commit wait flag is set to the second value to cause the storage server to process the write requests by transferring data for the next write request before completing the current write request preceding the next write request. The write request chain is sent to the storage server to apply the write requests to the storage.

Abstract: Aspects include sending a request to perform a unit of work that includes a synchronous I/O operation. The sending is from an operating system (OS) executing on a server to firmware located on the server. The synchronous I/O request includes a command request block that includes an operation code identifying the synchronous I/O operation and an identifier of a persistent storage control unit (SCU). The OS waits for the synchronous I/O to complete and the unit of work remains active during the waiting. The firmware detects that the synchronous I/O operation has completed. A command response block that includes completion status information about the synchronous I/O operation is received by the OS from the firmware. The unit of work is completed in response to the I/O operation completing.