Computers fail, people make mistakes, environmental disasters happen. We recommend you back up your important data, as it is a small price to pay compared to data loss.
Full copy—copy all files from the backup source to the backup destination. Subsequent full backups may cause files that already exist on the destination to be copied anyway. In many cases this method uses far more time and bandwidth resources than what is necessary.
Differential—copy only the files that changed since the previous backup. This method is much less time, bandwidth, and energy resources than the full copy method. It is almost always the preferred method.
Remote (off-site)—don't put all your eggs in the same basket.
tar + Gzip (+ GnuPG)
duplicity, or it's user-friendly font-ends deja-dup and duply, combines tar, Gzip, Rsync, GnuPG, and a hybrid style backup for the ultimate backup solution.
- Gzip - compression utility
- tar - file archiver
- GnuPG - encryption utility
- Rsync - remote directory synchronizer
- luckyBackup - GUI for Rsync (uses Rsync)
- rdiff - like diff, but designed better for binary files rather than source code
- rdiff-backup - remote incremental directory synchronizer (uses Rsync and rdiff)
- duplicity - remote versioned encrypted backup (uses tar, GnuPG, Rsync, and rdiff)
- Déjà Dup - GUI for duplicity (uses duplicity)
- rsnapshot - remote versioned backup (uses Rsync and UNIX hard links)