It seems that every one I talk to about backups on *nix has their own method of doing things. Some people use a “Towers of Hanoi” algorithm to do level based backups using dump to tape drives. Some people use a clever scheme using rsync to create a snapshot backup. Still others use proprietary services to dump their data to multiple physical locations around the world. The bottom line when it comes to choosing a system is a combination of the bottom line (how much it costs) and how valuable your data is.

My personal backup choice is a practical application of GNU tar’s listed incremental backup plan. It is fairly simple and can be easily configured for any number of directories or filesystems. This is a conglomeration of about ten different scripts I found or friends have pointed be to. This is by no means the end all of backups, but it is what I use; I just stick it in /etc/cron.daily, and let it run. It keeps 3 (or however many you configure) weeks of incremental backups with a full backup each week. It uses gz compression to save space. it is simple, short and sweet.

I am always open for comment. What do you use? Why is it better (or worse)?

# incremental backups
# Created by Josh Bryan 2006-09-25


MACHINE=Pavillion_a1540n                                    # name of this computer
DIRECTORIES="/home /root /etc /var"        # directoris to backup
BACKUPDIR="/path/to/backup"       # where to store the backups
TAR=/bin/tar                                                 # name and locaction of tar


DOW=`date +%a`                          # Day of the week e.g. Mon

#The list used to keep track of this weeks backups

# Move Last Weeks Backups for archive
if [ $DOW = "Sun" -a -f "$LIST" ]; then
	mkdir -p $BACKUPDIR/$NUM_WEEKS-weeks_ago
	rm $BACKUPDIR/$NUM_WEEKS-weeks_ago/\*
	while [ "$NUM_WEEKS" -gt "1" ]; do
		mkdir -p $BACKUPDIR/$NUM_WEEKS-weeks_ago
		mv $BACKUPDIR/$NUM_WEEKS-weeks_ago/\* $BACKUPDIR/$OLD_NUM-weeks_ago/

# Make incremental backup in 1-weeks_ago

$TAR --listed-incremental $LIST -czf $BACKUPDIR/1-weeks_ago/INC-$MACHINE-$DOW.tar.gz $DIRECTORIES