System and method to repair file system metadata

摘要

A system and method for repairing potentially corrupt file systems are provided. A request to repair an original file system, including a current set of metadata, is received. A metasave image is accessed, in response to the request. The metasave image includes a copy of the metadata included in the original file system at a point-in-time and information identifying a location of each block of metadata in the metasave image. Using the metasave image information, the current set of metadata in the original file system is replaced with the metadata in the metasave image.

主权项

1. A method comprising:
maintaining a set of metasave images for an original file system, wherein
each of the metasave images in the set of metasave images comprises a copy of metadata included in the original file system at a particular point-in-time,the each of the metasave images in the set of metasave images excludes file system data described by the metadata,the each of the metasave images in the set of metasave images represents a plurality of changes made to the metadata during a given time period,the given time period begins when a previous metasave image is generated and continues until a log of changes to the metadata reaches a certain capacity, andthe log of changes reaching the certain capacity triggers creation of the each of the metasave images; receiving a request to repair the original file system, wherein
the original file system comprises the file system data,the original file system further comprises a current set of metadata at a time that the request is received,the current set of metadata describes the file system data within the original file system, andthe current set of metadata is potentially damaged at the time that the request is received; in response to the request, selecting a metasave image from the set of metasave images, wherein
the request specifies a point-in-time, andthe selecting is based on the point-in-time; accessing the metasave image, wherein
the metasave image comprises the particular point-in-time copy of metadata included in the original file system at the particular point-in-time and information identifying a location of each block of metadata in the metasave image; and repairing the original file system by replacing the current set of metadata with the metadata included in the metasave image, wherein
the receiving, the accessing, and the replacing are performed by a computing device implementing a file system repair module, andthe replacing is performed instead of performing an operation to analyze each metadata item of the current set of metadata that is potentially damaged and repair any metadata items that comprise an error.