International Business Machines Corporation

Gary Steven Domrow

James A O'Connor

Lee Nee Helgeson

James P Allen

Stephen M Tee

Ian A MacQuarrie

Shawn T Wright

Carol Santich Mellgren

Sanket Rathi

Jared Michael Minch

John Leslie Neemidge

Nicholas S Ham

Purna Chandra R Jasti

Jeffrey Michael Barnes

Methods and apparatuses for protecting data integrity in a multiple path input/output environment are provided. When sending a write command that includes data to be written to a target device from an initiator device over a specified first path of a plurality of paths by which the target device is in communication with the initiator device when a fault in the first path is detected and the status of the write command indicates that the write command was fully transmitted to the target device, a second path of a plurality of paths is selected, a reset command is sent over the second path from the initiator device to the target device, and after sending the reset command, the data are retransmitted in a second write command that a path other than the first path from the initiator device to the target device.

Protecting data integrity in a multiple path input/output environment

An aspect includes detecting a recurring intermittent error in a path of a network in a system that includes at least one data transmission port configured for connection to at least one shared data storage device via a plurality of paths of the network. It is determined by a path control module (PCM) in the network, whether a path recovery action has been initiated by a fiber channel protocol driver in the network. In response to determining that the path recovery action has not been initiated, the data transmission port is prevented from accessing the path for a specified time period by moving the path into a degraded sub-state, and subsequent to the specified time period the data transmission port is provided access to the path. In response to determining that the path recovery action has been initiated, the data transmission port is provided access to the path.

Multipath driver cognitive coordination

An aspect includes detecting a recurring intermittent error in a path of a network in a system that includes at least one data transmission port configured for connection to at least one shared data storage device via a plurality of paths of the network. It is determined whether a cause of the recurring intermittent error is a previous path recovery action. In response to determining that the cause of the recurring intermittent error is not a previous path recovery action, the data transmission port is prevented from accessing the path for a specified time period by moving the path into a degraded sub-state, and subsequent to the specified time period the data transmission port is provided access to the path. In response to determining that the cause of the recurring intermittent error is a previous path recovery action, the data transmission port is provided access to the path.

Multipath driver cognitive analysis

Techniques for switching between mirrored volumes are described. A system may comprise a multi-path device driver and a processor device, in communication with the multi-path device driver, operable in the computing storage environment. The processor device creates a copy relation identification (ID) between mirrored volumes for using the copy relation ID in conjunction with a multi-path device driver for switching input/output (I/O) for applications between a first path to a second path between the mirrored volumes.

Switching between mirrored volumes

A method, system, and computer usable program product for an improved data storage device driver are provided in the illustrative embodiments. For managing an elevator queue, several requests are stored in the elevator queue. A determination is made whether the elevator queue is sorted. A number of requests in the elevator queue is determined if the elevator queue is unsorted. The unsorted elevator queue is monitored. Reaching a threshold condition in the unsorted elevator queue is detected. Sorting of the unsorted elevator queue is initiated. The requests may be I/O requests for a data storage device. The elevator queue may be sorted according to an ascending or descending order of data block addresses in the requests. The monitoring may monitor a remaining number of unsorted requests in the elevator queue as requests are removed from the elevator queue. The threshold condition may be associated with a threshold value.

Data storage device driver

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Austin, TX, United States of America

Gary Steven Domrow