Abstract: A method for distributing drivers from a storage system to one or more host systems includes maintaining, in a storage system, a driver database containing drivers for different host systems. The drivers enable the different host systems to effectively communicate with the storage system. The method further determines whether a specific host system is configured with an appropriate driver. In the event the specific host system is not configured with the appropriate driver, the method retrieves the appropriate driver from the driver database. The method then transmits the appropriate driver from the storage system to the specific host system for installation thereon. By using the storage system as a central repository for the latest device drivers, the method ensures that connected host systems are always configured with the latest drivers. A corresponding apparatus, system, and computer program product are also disclosed herein.

Abstract: A main data storage system has a main storage control and data storage, and a user interface, the main storage control in communication with a local storage control of a local data storage system with local data storage. In response to a request to increase data storage from the user interface, the main control determines whether the main data storage is out of space. If so, the main control sends a command to the local control to create data space in local data storage. The local control creates the data space and associates the data space with the main control; and, in response to the local control creating data space in the local data storage and notifying the main control, the main control updates its metadata with respect to the data space, creating the impression that all the data is stored in the main data storage.

Abstract: To prevent loss of a data volume by unintended deletion, including various versions of the data volume, the data is preserved, and, when needed, is regenerated at a different volume address than that of the deleted volume. In a computer-implemented data storage system, a method responds to a received command to delete a volume of data identified by a volume address, preserving data of the volume prior to deletion, and generates a unique token associated with the volume and version of the volume as of the deletion. The unique token is communicated as associated with the received delete command. The method responds to a received command to regenerate the data of the deleted volume, generating a command to find the data identified by the unique token, and creating a new, different, volume address for the data of the preserved deleted volume, thereby keeping both volume versions.

Abstract: A method, apparatus, and computer program product for handling a failure condition in a storage controller is disclosed. In certain embodiments, a method may include initially detecting a failure condition in a storage controller. The failure condition may be associated with a specific host and a specific storage device connected to the storage controller. The method may further include determining a failure ID associated with the failure condition. Using the failure ID, en entry may be located in a data collection and recovery table. This entry may indicate one or more data collection and/or recovery processes to execute in response to the failure condition. The method may then execute the data collection and/or recovery processes indicated in the entry. While executing the data collection and/or recovery processes, connectivity may be maintained between hosts and storage devices not associated with the failure condition.

Abstract: A method for verifying an input/output (I/O) hardware configuration is provided. A verification command is processed. The verification command includes a software device address range associated with a logical control unit (LCU) of the I/O hardware. The LCU utilizes a first logical path. The software device address range utilizing the first logical path is compared with an existing software device address range utilizing at least one additional logical path. The verification command is accepted if the software device address range and the existing software device address range match.

Abstract: A host reserves a device controlled by a controller that is coupled to the host. The controller starts a first timer, in response to a completion of input/output (I/O) operations on the device by the host, wherein the host continues to reserve the device after the completion of the I/O operations. The controller sends a notification to the host after an expiry of the first timer, wherein the notification requests the host to determine whether the device should continue to be reserved by the host. The controller starts a second timer, in response to receiving an acknowledgement from the host that the notification has been received by the host, wherein reservation status of the device reserved by the host is determined by the controller on or prior to an expiry of the second timer.

Abstract: A method for identifying the cause of degraded I/O performance between a host system and a storage controller includes initially monitoring I/O performance between the host system and the storage controller. The method further detects degraded I/O performance between the host system and the storage controller using any suitable technique. Once degraded I/O performance is detected, the method determines the cause of the degraded I/O performance by analyzing historical configuration records in the storage controller. These historical configuration records enable the storage controller to correlate the degraded I/O performance with configuration changes in the storage controller and/or the connected host systems. The method then notifies one or more host systems of the cause of the degraded I/O performance. A corresponding apparatus and computer program product are also disclosed herein.

Abstract: A method to minimize performance degradation during communication path failure in a data processing system, comprising a host computer, a storage controller, and a plurality of physical communication paths in communication with the host computer and the storage controller, where the method establishes a threshold communication path error rate, and determines an (i)th actual communication path error rate for an (i)th physical communication path, wherein that (i)th communication path is one of the plurality of physical communication paths. If the (i)th actual communication path error rate is greater than the threshold communication path error rate, the method discontinues use of the (i)th physical communication path.

Abstract: A system and method for recovering from logical path failures is set forth. More specifically, when a host detects a logical path failure, the host enters a path discovery mode of operation. If the host continues to detect a logical path failure while operating in the logical path discovery mode of operation, the host removes the logical path from a logical path mask, and the host does not use the removed logical path again. Additionally, the system and method facilitates recovery of the failed logical paths by using a plurality of logical path masks. A first mask is referred to as an intermediate failure logical path mask and a second mask is referred to as a permanent failure logical path mask.

Abstract: A storage control unit detects a change in a configuration of a plurality of logical subsystems included in the storage control unit. The storage control unit sends a notification, wherein the notification indicates the change in the configuration of the plurality of logical subsystems. The storage control unit receives data transfer requests directed at available logical subsystems in the storage control unit, wherein the available logical subsystems are determined based on the configuration of the plurality of logical subsystems.

Abstract: A method to preserve a logical communication path in a data processing system, that includes a host computer, a storage controller that comprises a first logical control unit (“LCU”), and a logical communication path that is in communication with the host computer and the first LCU, comprising deleting the first LCU and setting a first status for same. The method then configures a second LCU, and establishes a second status for same, wherein the second LCU includes all or a portion of the first LCU, but is not the same as the first LCU. The deleting, setting, configuring, and establishing are performed while maintaining the logical communication path, which is in communication with the second LCU.

Abstract: A method is disclosed to control access to stored information. The method supplies a control unit in communication with a computing device and in communication with stored information. If the computing device requests access to that stored information, the method determines if access to the stored information is available. When access to the stored information becomes available, then the method reserves a communication pathway interconnecting the control unit and the requesting computing device, thereby disallowing the sending of non-MPLF unsolicited status via that reserved communication pathway, and provides a message to the computing device, using that reserved communication pathway, granting access to the stored information.

Abstract: An apparatus, system, and method are disclosed for an alternate lock facility connection path. A request module receives a connection request to establish redundant connection paths between a control unit and a host. A primary connection module establishes a first connection path between the control unit and the host through a first communication channel. An alternate connection module establishes a second connection path between the control unit and the host through a second communication channel. A detection module detects a failure of the first connection path. A redirection module redirects communication between the control unit and the host through the second connection path upon detection of a failure of the first connection path.

Abstract: Provided is a system, deployment and program for resource allocation unit queuing in which an allocation unit associated with a task is classified. An allocation unit freed as the task ends is queued for use by another task in a queue at a selected location within the queue in accordance with the classification of said allocation unit. In one embodiment, an allocation unit is queued at a first end of the queue if classified in a first class and is queued at a second end of the queue if classified in said second class. Other embodiments are described and claimed.

Abstract: An apparatus, system, and method are disclosed to prevent queue stalling. The apparatus to prevent queue stalling is provided with a plurality of modules configured to functionally execute the necessary steps of detecting a connection failure on a first logical path, wherein the first logical path is associated with a first entry in a queue, and wherein the first logical path is configured to define a communication path between an entity associated with a first entry in the queue and a queue manager, scanning the queue to identify a second entry associated with a second logical path in response to the connection failure, and advancing the second entry to a position within the queue that is ahead of the first entry. These modules in the described embodiments include a detection module, a scanning module, and an advancing module.

Abstract: A host reserves a device controlled by a controller that is coupled to the host. The controller starts a first timer, in response to a completion of input/output (I/O) operations on the device by the host, wherein the host continues to reserve the device after the completion of the I/O operations. The controller sends a notification to the host after an expiry of the first timer, wherein the notification requests the host to determine whether the device should continue to be reserved by the host. The controller starts a second timer, in response to receiving an acknowledgement from the host that the notification has been received by the host, wherein reservation status of the device reserved by the host is determined by the controller on or prior to an expiry of the second timer.

Abstract: Provided are a method, system, and program for managing path groups to an Input/Output (I/O) device. Indication is made of a connection path on which a processing system initially communicated an establish request to establish a connection with an I/O device, wherein attention that the processing system may own a lock for the I/O device is transmitted down the indicated connection path. A request is received from the processing system to add a path to a path group with respect to the I/O device, wherein the added path is capable of comprising the connection path the processing system used to establish the connection with the I/O device. The received path is added to the path group.

Abstract: A system is disclosed that includes a host system to issue a write command, a primary storage device to write data to a primary volume, and a secondary storage device to mirror the data to a secondary volume. A task timer may be initiated upon sending the data from the primary storage device to the secondary storage device. The secondary storage device may also send an acknowledge signal to the primary storage device in the event it successfully mirrors the data to the secondary volume. In the event the acknowledge signal is not received before the timer expires, the primary storage device may notify the host system that the primary and secondary volumes are in a suspended state. To alter the duration of the timer, the host system may be further configured to dynamically alter the duration of the timer by sending a command to the primary storage device.

Abstract: A system is disclosed that includes a host system to issue a write command, a primary storage controller to write data to a primary volume, and a secondary storage controller to mirror the data to a secondary volume. In the event the secondary storage controller is unable to mirror the data due to a busy state, a busy signal may be sent to the primary storage controller. The primary storage controller may initiate a timer in the event it receives the busy signal, and, in the event the busy state does not end before expiration of the timer, notify the host system that the primary and secondary volumes are in a suspended state. To alter the duration of the timer, the host system may be configured to dynamically alter the duration of the timer by sending a command to the primary storage controller.

Abstract: A method is disclosed to control access to stored information. The method supplies a control unit in communication with a computing device and in communication with stored information. If the computing device requests access to that stored information, the method determines if access to the stored information is available. When access to the stored information becomes available, then the method reserves a communication pathway interconnecting the control unit and the requesting computing device, thereby disallowing the sending of non-MPLF unsolicited status via that reserved communication pathway, and provides a message to the computing device, using that reserved communication pathway, granting access to the stored information.