rdiff-backup error policy

This page describes the intended reaction of rdiff-backup to various errors which may occur during a backup session. Subject to various limitations (see below), no error should cause rdiff-backup to lose data. The below should be accurate for rdiff-backup versions 0.11.2 and later.


Firstly, note that rdiff-backup cannot correctly respond to every possible error that could occur. For instance, rdiff-backup may not correctly handle programming errors I have caused, even though these may exist. In particular, rdiff-backup assumes that:

  1. The rdiff-backup destination directory is only written to by rdiff-backup. If other programs modify the directory structure of the destination directory, or regular files in that directory, unanticipated circumstances could arise.
  2. The underlying file system respects calls like fsync(), which require that data be physically written to disk in a certain order. Also the file system needs to maintain its own integrity, including treating certain operations like rename() as atomic. This could become important if the computer is reset during an rdiff-backup session.

Error types

The anticipated errors fall into four categories:
Last modified: Sun Feb 23 22:05:08 PST 2003