Backup entire installed OS

sudo rsync -aAXv /* /mnt/backup_vol --exclude={/dev/*,/proc/*,/sys/*,/tmp/*,/run/*,/mnt/*,/media/*,/lost+found}

The above command will backup all the OS files with the regular attributes and SELinux attributes. rsync also allows the backups to updated. The backup path should be to a Linux filesystem.

To restore the OS from the backup, and more details see: https://wiki.archlinux.org/index.php/Full_System_Backup_with_rsync