International Business Machines Corporation

Dinh Hai Le

Juan A Coronado

Roger Gregory Hathorn

Daniel J Perkin

Bret Wayne Holley

Aaron Eugene Taylor

Warren Keith Stanley

Clarisa Valencia

Jayson Elliott Tsingine

Adelaide Margaret Richards

Beth Ann Peterson

Ezequiel Cervantes

Brian Dow Clark

Eric Steven Shell

Minghao M Chu

A method for verifying an input/output (I/O) hardware configuration is provided. Data from an input/output data set (IOCDS) is extracted for building a verification command. The IOCDS contains hardware requirements that define at least software devices associated with a logical control unit (LCU). The 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.

Verification of hardware configuration

A method for replacing logical path resources, a host is able to replace a logical path it owns with a new logical path. Such a system is especially applicable when the condition of 'out of resources' has been reached for a port. With this system, a host is guaranteed that it can replace a logical path it owns with a new logical path. It is not necessary for a control unit to have reached its maximum number of logical paths per port. A host is able to replace one logical path with a new logical path any time.

Method to allow a host to replace logical path resources it owns

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.

Verification of input/output hardware configuration

A method to concurrently execute multiple primitive commands in a command line interface (CLI) is provided. Each of a plurality of signal parameters is designated for each of a plurality of primitive commands. The plurality of primitive commands is encapsulated into a header CLI command. The CLI command is executed.

Concurrent execution of multiple primitive commands in command line interface

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.

Method to recover from logical path failures

A system and method for recovering from a single logical path failure. More specifically, although a host has not grouped its logical paths, the host knows which logical paths it has available. 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. In the case of ungrouped logical paths, the host aborts its process because it does not have more paths available to continue its process. Additionally, in certain embodiments, a pseudo path group for ungrouped logical paths is created.

Method to recover from ungrouped logical path failures

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.

Apparatus and method to preserve one or more logical communication paths in a data processing system

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.

Apparatus, system, and method to prevent queue stalling

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.

Dynamic timer configuration for monitoring a long busy state in a remote mirror and copy environment

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.

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Tucson, AZ, United States of America

Dinh Hai Le