This has been tested with a working server of Debian5.
Login as root
Make a backup directory. It is best if you have the backup directory on another partition or another hard disk
mkdir -p /backup
Create a backup sh file with arguments to backup the whole system while excluding contents of proc sys dev and backup directory
tar -cvpf /backup/fullbackup.tar –directory=/ –exclude=proc –exclude=sys –exclude=dev/pts –exclude=backup .
Create a restore sh file which moves the fullbackup.tar file to / and then extracts it
mv /backup/fullbackup.tar /fullbackup.tar
tar -xvpf /fullbackup.tar
Change the file permissions to make it executable
chmod -R 750 /backup
Add an argument to crontab to make it run at 22:10 daily.
10 22 * * * /backup/backup.sh
To restore this backup, install a minimal version of the same linux flavor and then run /backup/restore.sh