Netapp, Inc.

Martin Parrish

Donald Roman Humlicek

Wei Sun

Theresa Lynn Segura

Kent D Prosch

Gordon Hulpieu

Alan Stewart

Greg William Achilles

A system and method for maintaining operation of a storage array with one or more failed storage devices and for quickly recovering when failing devices are replaced are provided. In some embodiments, the method includes receiving a data transaction directed to a volume and determining that a storage device associated with the volume is inoperable. In response to determining that the storage device is inoperable, a data extent is recorded in a change log in a storage controller cache. The data extent is associated with the data transaction and allocated to the storage device that is inoperable. The data transaction is performed using at least one other storage device associated with the volume, and data allocated to the storage device is subsequently reconstructed using the recorded data extent.

Data tracking for efficient recovery of a storage array

Atomic write operations for storage devices are implemented by maintaining the data that would be overwritten in the cache until the write operation completes. After the write operation completes, including generating any related metadata, a checkpoint is created. After the checkpoint is created, the old data is discarded and the new data becomes the current data for the affected storage locations. If an interruption occurs prior to the creation of the checkpoint, the old data is recovered and any new is discarded. If an interruption occurs after the creation of the checkpoint, any remaining old data is discarded and the new data becomes the current data. Write logs that indicate the locations affected by in progress write operation are used in some implementations. If neither all of the new data nor all of the old data is recoverable, a predetermined pattern can be written into the affected locations.

Atomic write operations for storage devices

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Boulder, CO, United States of America

Martin Parrish