International Business Machines Corporation

Jeremy Michael Pinson

Karl Allen Nielsen

Michael Howard Hartung

Robert Akira Kubo

Thomas Charles Jarvis

Steven Robert Lowe

Binny Sher Gill

Carl Evan Jones

Matthew John Fairhurst

Steven T Broadbent

An apparatus, system, and method are disclosed for efficiently verifying writes. A storage module stores a plurality of data sets in a storage controller memory. A write module writes the plurality of data sets through a first write channel to a hard disk drive. A verification module verifies whether a representative data set of the plurality of data sets is successfully written to the first write channel or not. A mitigation module rewrites the plurality of data sets in response to an unsuccessful write of the representative data set.

Apparatus, system, and method for efficiently verifying writes

Provided are a method, system, and program for destaging a track from cache to a storage device. The destaged track is retained in the cache. Verification is made of whether the storage device successfully completed writing data. Indication is made of destaged tracks eligible for removal from the cache that were destaged before the storage device is verified in response to verifying that the storage device is successfully completing the writing of data.

Demoting tracks from cache

System and program for demoting tracks from cache

A method of destage management of redundant data copies in a cache storage subsystem includes providing a plurality of target storage devices, each of the plurality of target storage devices capable of storing a complete copy of a data image. The data image and the plurality of target storage devices are subdivided into a plurality of sub-regions, each of the plurality of sub-regions organized such that a minimum cumulative total of the plurality of sub-regions on the target storage devices equals a number of sub-regions required to form the complete copy of the data image. Data is destaged from a write cache to the plurality of sub-regions on the target storage devices in an order such that a minimum number of sub-regions can be combined to restore the complete copy of the data image.

Destage management of redundant data copies

Provided are techniques for processing read and write request operations. Regions of a first storage device and a second storage device are designated as primary regions and secondary regions for read request operations and write request operations falling within the regions. At least one write request operation is processed. Upon determining that a write threshold has been reached, the designations of regions of the first storage device and the second storage device are switched.

Mirrored redundant array of independent disks (RAID) random access performance enhancement

The write operations to the storage devices are managed so that the write operations that would force a storage device to reposition its read/write head outside its read optimization boundary are queued until a threshold is reached. Upon reaching the write queue threshold, the write operations are sent to the storage devices in a burst mode that limits the impact of storage device seek operations that force the device read/write head out of position relative to the data that is assigned as it's primary read region, keeping the read/write head in it's primary locality to optimize the performance of read operations.

System and method of mirrored RAID array write management

An apparatus and method to check integrity when handling data. The method provides a storage array which includes a plurality of sectors. The method defines (N) data state identifiers and (N) parity state identifiers. The method receives a command to handle data, where that command designates a target sector. The method determines the data state identifier assigned to the target sector, determines the parity state identifier assigned to the target sector, and compares the data state identifier and the parity state identifier. If the method determines that the data state identifier and the parity state identifier are the same, the method performs the command to handle data. Alternatively, if the method determines that the data state identifier and the parity state identifier differ, the method generates an error message.

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Tucson, AZ, United States of America

Jeremy Michael Pinson