Linux: Backup and restore your system!

Get root access:

sudo su

To backup:

tar cvpzf backup.tgz --exclude=/proc --exclude=/lost+found --exclude=/backup.tgz --exclude=/mnt --exclude=/sys /

To restore:

tar xvpfz backup.tgz -C /

Source: http://ubuntuforums.org/showthread.php?t=35087

To backup on an other mount:

tar cvpzf /mnt/data/backup.tgz --exclude=/proc --exclude=/lost+found --exclude=/mnt --exclude=/sys /