A. Fedora 10 uses pam module called pam_succeed_if.so. This module is designed to succeed or fail authentication based on characteristics of the account belonging to the user being authenticated. One use is to select whether to load other modules based on this test. This module blocks root login using GUI.
Login as root
01. Then open GUI terminal (bash prompt) and type the following command to become root user:
[uddika@daddylinux~]$ su –Fedora 10 update GDM config to allow root login
02. Type your root password. Next, make a backup of /etc/pam.d/gdm, enter:
[root@daddylinux~]# cp /etc/pam.d/gdm /root
03. Now open /etc/pam.d/gdm using nano or vi text editor, enter:
[root@daddylinux~]# nano /etc/pam.d/gdmOR
[root@daddylinux~]# vi /etc/pam.d/gdm
04. Alternatively, you can do everything in a one command:
[root@daddylinux~]# su -c 'nano /etc/pam.d/gdm'
05. Find line that read as follows:
auth required pam_succeed_if.so user != root quiet
06. Remove or comment out line by prefixing #.
[root@daddylinux~]# auth required pam_succeed_if.so user != root quiet
07. Save and close the file. Logout from terminal and from GUI itself. Now you should be able login as root user using GDM GUI login manager.