L~$ id -nG victor0000
victor0000 dialout cdrom plugdev lpadmin admin sambashare libvirtd
L~$ id -nG mo
mo
L~$ sudo usermod -G dialout,cdrom,plugdev,lpadmin,admin,sambashare,libvirtd,mo mo
L~$ id -nG mo
mo dialout cdrom plugdev lpadmin admin sambashare libvirtd
L~$ id -nG victor0000
victor0000 dialout cdrom plugdev lpadmin admin sambashare libvirtd
L~$ sudo usermod -G mo mo
L~$ id -nG mo
mo
L~$
пример