A20 LIME2-eMMC disable ligthdm at boot

[megamax]

Hi,
I need to disable lightdm (and X11) at boot; I tried with "update-rc.d -f lightdm remove", "systemctl -r disable lightdm.service" and search it in rc.local or /root/.bashrc but nothing to do, it always start at boot. How can I disable it in a clean way? I don't like methods such as "chmod -x /usr/sbin/lightdm".

Thanks a lot in advance for suggestions.

[srxa]

edit /etc/X11/default-display-manager and replace only line with /usr/sbin/true.

[megamax]

Ok, it works without systemd errors.

Thanks again!