does someone of you know how to totally disable the graphical interface and start the system only in the terminal mode?
Eng. Silvano Bertoldo, PhD
Try this as sudo user (and perhaps test it first in a non-critical set-up):
This should show you the current setting, i.e. graphical.target
Then confirm that the terminal mode is available (it's called multi-user.target) in the list of target files:systemctl list-unit-files --type=target
systemctl list-unit-files --type=target
If you have multi-user.target in the list of target files you can proceed with setting it as the new default target:systemctl set-default multi-user.target
If you now reboot the system it will boot into terminal mode, i.e. it will give you a shell with login prompt instead of the desktop
systemctl set-default multi-user.target
You can of course get back to the graphical mode bysystemctl set-default graphical.target and reboot
systemctl set-default graphical.target
I'll try it!