$ ssh-keygen -p -f ~/.ssh/id_rsa
Refer to Rsync#Full_system_backup for details.
# rsync -aAXv --exclude={"/dev/*","/proc/*","/sys/*","/tmp/*","/run/*","/mnt/*","/media/*","/lost+found"} / /path/to/backup/folder
# rsync -aAXv --exclude={"/dev/*","/proc/*","/sys/*","/tmp/*","/run/*","/mnt/*","/media/*","/lost+found"} /path/to/backup /destination/root/