Netapp, Inc.

Vignesh Sukumar

Andy Kahn

David A Grunwald

John K Edwards

Yong Cho

Maya Palem

A network storage server includes a tool for detecting and fixing errors while the network storage server remains online (available for servicing client requests), which includes enabling a user to approve or disapprove remedial changes before the changes are committed. The technique bypasses the usual consistency point process for new or modified data blocks representing potential remedial changes. At a consistency point, dirty data blocks representing the potential remedial changes are written to a change log file residing outside the volume. The modified data blocks are written in sequential order to logical blocks of the change log file. In response to a user input indicating that a potential change should be committed, the corresponding modified data blocks are read from the change log file in the order in which they were written to the change log file, and they are written to persistent storage in that order.

Online data consistency checking in a network storage system with optional committal of remedial changes

This disclosure presents checking file system consistency for a storage server. During a start up phase of a file system, a consistency checker, upon receiving a request from an internal client for a part of data managed by a file system of the storage server, checks file system consistency only for a part of metadata. The part of metadata is used to maintain consistency of the requested data. After the consistency check of the part of metadata is completed, the internal client is allowed to access the requested data before a remainder of the metadata is checked for consistency.

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Santa Clara, CA, United States of America

Vignesh Sukumar