incremental backups with tar

This script uses GNU tar and gzip to create incremental backups.

installation

1. copy the backup-script somewhere to in your path (e.g. /usr/local/bin)
2. create a directory where you want to store your backup
3. in this directory, create a file `hostname` (i.e. a file named like your hostname) with all the paths you want to backup. Here's an example:

   /etc/
   /var/lib/portage/world
   /usr/src/linux/.config
   /lib/modules/
   /wurscht/
   /root/
   /var/log
   /usr/local/portage
   /public/
   /home/
   /boot/
   /public/spiele/elasto/
   /opt/foldingathome/

4. optional: create a file `hostname`-X with all the exceptions:

   /public/filme
   /public/freenet
   /public/spiele
   /public/movies/torrent
   /public/temp
   /public/burn
   /public/mldonkey
   /public/cvs
   /home/*/.galeon/favicon_cache
   /home/*/.galeon/mozilla/galeon/Cache
   /home/*/.pan
   /home/*/.phoenix
   /home/*/.mozilla
   /home/*/.thumbnails
   /home/*/.gnupg
   /home/*/tmp
   /etc/gconf
   /etc/sound

usage

To start a backup, change into the backup-directory and start the script.

The backups have to be restored in the order they were created, and you have to give the corresponding .incremental-file for every generation.

tar xzg herzeleid.07-04-16.incremental herzeleid.07-04-16-full.tgz
tar xzg herzeleid.07-04-18.incremental herzeleid.07-04-18.tgz
tar xzg herzeleid.07-04-19.incremental herzeleid.07-04-19.tgz

etc.

If you only need one file, the procedure is a bit easier. You can grep in the logfiles to find the archive the file is in, then just extract it without any special parameters. Only the file-list is incremental, all files that changed since the last backup are stored in full.

miscellaneous

• if no full-backup exists, it will create one
• if a full backup exists, it does an incremental backup
• the "*.incremental"-files are used by tar to save information about the incremental backup
• filenames are stored without the leading "/" (and have to be restored this way)
• tar is sloooow.

download

download the backup-script
there is a wrapper-script for cron. This one has to be adapted to your needs.