ubuntu 18. root login GUI

• Modify the file

vim /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf

• Add two lines:

greeter-show-manual-login=true

all-guest=false

• Enter /etc/pam.d directory

  cd /etc/pam.d

Modify gdm-autologinand gdm-passwordfile

vim gdm-autologin

Commented auth required pam_succeed_if.so user != root quiet_success

vim gdm-password

Commented auth required pam_succeed_if.so user != root quiet_success

• Modify /root/.profile file

vim /root/.profile

The end of the file mesg n || truethis line modified totty -s&&mesg n || true

• Reboot the system, enter the root user name and password to log into the system