International Business Machines Corporation
Verification of the integrity of data files stored in copy-on-write (CoW) based file system snapshots

Abstract:

A computer-implemented method according to one embodiment includes performing a first process for each chunk of data of each file of a snapshot of a file system. The first process includes reading a given chunk of data of a given file of a first snapshot of the file system, and reading shadow records of a shadow file of the first snapshot. The given chunk of data is compared with the shadow records for determining whether a coherent state exists between the given chunk of data and one or more of the shadow records that were recorded in a snapshot creation window. In response to determining that no coherent state exists, an indication is recorded that the given chunk of data is corrupt. In response to determining that a coherent state exist, an indication is recorded that the given chunk of data is accurate.