How to Configure gdm3 to allow root login?
Ubuntu 18.04 comes with GDM (Gnome Display Manager) as a default Display Manager. For Security reason user can’t login with root
user.
For development and advanced operation, some user may prefer to login as root
.
Follow the steps to enable root login on Ubuntu 18.04 GDM display manager.
Step-1: Modify GDM conf
file.
Before doing any changes take a back up:
$ sudo cp /etc/gdm3/custom.conf /etc/gdm3/custom.conf.original
Now open up /etc/gdm3/custom.conf
with vi
editor as follows:
$ sudo vi /etc/gdm3/custom.conf
Copy and paste the following two lines below [Security]
directive.
[Security]
AllowRoot = true
AllowRemoteRoot = true
Save and exit from the editor.
Step-2: Modify PAM conf
file.
Now modify PAM (Pluggable Authentication Modules) configuration file.
Before doing any changes take a back up:
$ sudo cp /etc/pam.d/gdm-password /etc/pam.d/gdm-password.original
Now open up /etc/pam.d/gdm-password
with vi
editor as follows:
$ sudo vi /etc/pam.d/gdm-password
In the file, search for the following line:
auth required pam_succeed_if.so user != root quiet_success
To comment the line just add #
in front of the line as shown below:
#auth required pam_succeed_if.so user != root quiet_success
Save and exit from the editor.
Note: This step was incomplete in the youtube link provided in the post by the Questioner.
Step-3: Reboot
After reboot, you will reach login screen where there will be a display of not listed?
option just under username. If you click it, you will get another screen where you can enter root
as username and then press next
button. Now, the next screen appears which collects password
. You enter root password. After successful authentication you will be logged in as root
.
Conclusion:
Questioner @Rogério Dec
attempts to look for username root
from lightdm
login screen.
This procedure is for gnome GDM according to the youtube video.
If you have not installed gnome desktop, then install the same using the following command:
$ sudo apt install ubuntu-gnome-desktop
If you have already installed both lightdm
as well as gdm3
, then you need to switch to gdm
through following command:
$ sudo dpkg-reconfigure gdm3
After switched to gdm3
, follow step-3 to login as root
.