8.4 Differential backup and data synchronization

Differential backup and data synchronization can be implemented with several methods:

• rcs: backup and history, text-only

• rdiff-backup: backup and history. symlink OK.

• pdumpfs: backup and history within a filesystem. symlink OK

• rsync: 1-way synchronization

• unison: 2-way synchronization

• cvs: multi-way synchronization with server backup and history, text-only, mature. See Concurrent Versions System (CVS), Section 12.1.

• arch: multi-way synchronization with server backup and history, no such thing as a "working directory".

• subversion: multi-way synchronization with server backup and history, Apache.

Combination of one of these with the archiving method described in Copy and archive a whole subdirectory, Section 8.3 and the automated regular job described in Schedule activity (cron, at), Section 8.6.27 will make a nice backup system.

I will explain three easy-to-use utilities.