Abstract: Provided is a method for correcting pinned data in a primary storage. A primary storage controller may detect a pinned data set on a primary storage. In response to detecting the pinned data set, the primary storage controller may instruct a secondary storage controller to transmit a copy of the pinned data set to the primary storage controller. The copy of the pinned data set may be stored in a secondary storage that is communicatively coupled to the secondary storage controller. The secondary storage may include a synchronous copy of the primary storage. The primary storage controller may receive the copy of the pinned data set from the secondary storage controller. The primary storage controller may also write the copy of the pinned data set over the pinned data set on the primary storage.

Abstract: Provided is a method for correcting untrusted data and avoiding logical device swapping for at least one logical subsystem of at least one computer system. A processor may monitor a primary storage for one or more errors that indicate untrusted data on the primary storage. An error indicating that a data set on the primary storage is an untrusted data set may be identified. In response to the error being identified, a corresponding uncompromised version of the data set may be read from a secondary storage. The corresponding uncompromised version of the data set may be written over the untrusted data set on the primary storage.

Abstract: A method, system, and computer program product are provided for determining whether a control unit for an attached device has lost knowledge of a supported host enabled facility associated with the attached device. I/O instructions are initiated that include a first instruction to determine whether the control unit currently has knowledge of the host enabled facility and a second instruction providing knowledge of the host enabled facility by the control unit. Based on responses from the control unit to the I/O instructions, it is determined whether the control unit has transitioned from not having knowledge of the host enabled facility to having such access. If it is determined that the control unit has made such transition as a result of the sequence of I/O instructions, parameters for use with the host enabled facility are initialized; otherwise, such initialization is prevented.

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: A computer program product for optimizing page table manipulations is provided and includes a computer readable storage medium having program instructions that are readable and executable by a processing circuit to cause the processing circuit to create and maintain a translation table with a translation look-aside buffer (TLB) disposed to cache priority translations, update the translation table upon de-registration of a DMA address, allocate entries in the translation table from low to high memory addresses during memory registration, maintain a cursor for identifying where to search for available entries upon performance of a new registration, advance the cursor from entry-to-entry in the translation table and wrap the cursor from an end of the translation table to a beginning of the translation table and issue a synchronous TLB invalidation instruction to invalidate the TLB upon at least one wrapping and an entry being identified and updated.

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.

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: In one general embodiment, a computer-implemented method is provided for storage controller-mediated volume transformation in a shared-resource environment. The computer-implemented method includes receiving, utilizing a processor, a command, from an initiating host system, to send a notification to at least one other host system connected to a shared volume. The computer-implemented method also includes broadcasting an interrupt to the at least one other host system connected to the shared volume, and receiving a response from one or more of the at least one other host system connected to the shared volume. The computer-implemented method further includes notifying the initiating host system of the response(s) received from the one or more of the at least one other host system connected to the shared volume.

Abstract: Provided is a method for correcting pinned data in a primary storage. A primary storage controller may detect a pinned data set on a primary storage. In response to detecting the pinned data set, the primary storage controller may instruct a secondary storage controller to transmit a copy of the pinned data set to the primary storage controller. The copy of the pinned data set may be stored in a secondary storage that is communicatively coupled to the secondary storage controller. The secondary storage may include a synchronous copy of the primary storage. The primary storage controller may receive the copy of the pinned data set from the secondary storage controller. The primary storage controller may also write the copy of the pinned data set over the pinned data set on the primary 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 a 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.

Abstract: Provided is a method for correcting untrusted data and avoiding logical device swapping for at least one logical subsystem of at least one computer system. A processor may monitor a primary storage for one or more errors that indicate untrusted data on the primary storage. An error indicating that a data set on the primary storage is an untrusted data set may be identified. In response to the error being identified, a corresponding uncompromised version of the data set may be read from a secondary storage. The corresponding uncompromised version of the data set may be written over the untrusted data set on the primary storage.

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: Provided are a computer program product, system, and method for managing access requests from a host to tracks in storage. A cursor is set to point to a track in a range of tracks established for sequential accesses. Cache resources are accessed for the cache for tracks in the range of tracks in advance of processing access requests to the range of tracks. Indication is received of a subset of tracks in the range of tracks for subsequent access transactions and a determination is made whether the cursor points to a track in the subset of tracks. The cursor is set to point to a track in the subset of tracks and cache resources are accessed for tracks in the subset of tracks for anticipation of access transactions to tracks in the subset of tracks.

Abstract: Provided are a computer program product, system, and method for managing access requests from a host to tracks in storage. A cursor is set to point to a track in a range of tracks established for sequential accesses. Cache resources are accessed for the cache for tracks in the range of tracks in advance of processing access requests to the range of tracks. Indication is received of a subset of tracks in the range of tracks for subsequent access transactions and a determination is made whether the cursor points to a track in the subset of tracks. The cursor is set to point to a track in the subset of tracks and cache resources are accessed for tracks in the subset of tracks for anticipation of access transactions to tracks in the subset of tracks.

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: In one general embodiment, a computer-implemented method is provided for storage controller-mediated volume transformation in a shared-resource environment. The computer-implemented method includes receiving, utilizing a processor, a command, from an initiating host system, to send a notification to at least one other host system connected to a shared volume. The computer-implemented method also includes broadcasting an interrupt to the at least one other host system connected to the shared volume, and receiving a response from one or more of the at least one other host system connected to the shared volume. The computer-implemented method further includes notifying the initiating host system of the response(s) received from the one or more of the at least one other host system connected to the shared volume.

Abstract: A method, system, and computer program product are described for a machine selecting a selected adapter among two or more adapters that perform a same function. The method includes generating a request, at the machine, for the function, and calculating a time indicator associated with each of the two or more adapters based on a respective adapter queue time factor (QTF) associated with each of the two or more adapters, the adapter QTF associated with each of the two or more adapters being a computed value. The method also includes selecting the selected adapter and submitting one or more requests to the selected adapter of the two or more adapters to perform the function based on a comparison of the time indicator associated with each of the two or more adapters.

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: 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: In one embodiment, a computer-implemented method includes making a determination, by a computer, to perform a transforming operation on a shared volume. A notify command is sent to a storage controller of the shared volume, the notify command including an action to be taken by other hosts connected to the shared volume. A message is received from the storage controller, the message indicating that responses have been received from the other host systems connected to the shared volume. A determination is made as to whether to perform the transforming operation based on the responses. The transforming operation is performed on the shared volume in response to the responses from the other host systems indicating that the other host systems successfully performed the action specified in the notify command.