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: 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 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: 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: 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: A computer-implemented method for transferring a reserve to a target host, according to one embodiment, includes granting to a source system, by a control unit, a reserve for a volume of a storage device. A push reserve command is received from the source system. The push reserve command specifies: a transfer of the reserve to a target system, parameter data identifying the target system, and path information specifying the source system. The reserve is transferred only to the target system in response to release of the reserve by the source system.

Abstract: An abstraction for storage class memory is provided that hides the details of the implementation of storage class memory from a program, and provides a standard channel programming interface for performing certain actions, such as controlling movement of data between main storage and storage class memory or managing storage class memory.

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: 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 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: A method for suppressing data mirroring between a primary storage system and a secondary storage system is disclosed. In one embodiment, such a method includes defining a data class with an attribute designed to suppress mirroring of data from a primary storage system to a secondary storage system. The method assigns a data set to the data class, thereby causing the data set to inherit the attribute. In certain embodiments, assigning the data set to the data class includes recording the attribute in one or more of a volume-table-of-contents (VTOC) and a catalog used to reference the data set. The method automatically suppresses mirroring of the data set from the primary storage system to the secondary storage system in accordance with the assigned attribute. A corresponding system and computer program product are also disclosed.

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 resource allocation in accordance with one embodiment of the present description, in which a resource allocation such as a buffer credit allocation for a port in a storage area network is initialized as a function of a measurement of a length of a communication link for the port of the storage area network. In one embodiment, the length measurement is a function of a minimum command response time of a command issued over the communication link. Other aspects of resource allocation in accordance with the present description are described.

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: A computer-implemented method, according to one approach, includes: receiving a first request to perform a write operation from a host, and performing the write operation. Metadata corresponding to the first request is sent to the secondary data storage device, and metadata corresponding to a second request to perform the write operation is received from the secondary data storage device, where the second request was received at the secondary data storage device from the host. The metadata corresponding to the first and second requests is used to determine whether the write operation has been mirrored across the primary and secondary data storage devices. In response to determining that the write operation has been mirrored across the primary and secondary data storage devices, a response is sent to the secondary data storage device which indicates that the write operation has been reconciled across the primary and secondary data storage devices.

Abstract: Provided are a computer program product, system, and method for verification of a boot loader program at a control unit to be provided to a host system to load an operating system. A stored value is generated from a cryptographic function applied to portions of a boot loader program stored in the storage. The boot loader program is read from the storage in response to execution of a boot loader request from the host system. The cryptographic function is applied to at least a portion of the read boot loader program to produce a calculated value. The host system is provided access to the boot loader program to use to load the operating system from the storage into the host system in response to the calculated value matching the stored value.

Abstract: A computer-implemented method, according to one approach, includes: receiving a first request to perform a write operation from a host, and performing the write operation. Metadata corresponding to the first request is sent to the secondary data storage device, and metadata corresponding to a second request to perform the write operation is received from the secondary data storage device, where the second request was received at the secondary data storage device from the host. The metadata corresponding to the first and second requests is used to determine whether the write operation has been mirrored across the primary and secondary data storage devices. In response to determining that the write operation has been mirrored across the primary and secondary data storage devices, a response is sent to the secondary data storage device which indicates that the write operation has been reconciled across the primary and secondary data storage devices.

Abstract: A method for suppressing data mirroring between a primary storage system and a secondary storage system is disclosed. In one embodiment, such a method includes defining a data class with an attribute designed to suppress mirroring of data from a primary storage system to a secondary storage system. The method assigns a data set to the data class, thereby causing the data set to inherit the attribute. In certain embodiments, assigning the data set to the data class includes recording the attribute in one or more of a volume-table-of-contents (VTOC) and a catalog used to reference the data set. The method automatically suppresses mirroring of the data set from the primary storage system to the secondary storage system in accordance with the assigned attribute. A corresponding system and computer program product are also disclosed.