Q. I've a central Linux test server. It has GDM based GUI login screen. How do I remove both shutdown and reboot server options from the login screen?
A. GDM is gnome specific display manager. It is a display manager that implements all significant features required for managing attached and remote displays. GDM is highly configurable, and many configuration settings can affect security. The GDM daemon is responsible for managing displays on the system. This includes authenticating users, starting the user session, and terminating the user session.
GUI tool gdmsetup
The gdmsetup application can be used to configure GDM. Open terminal and type the command:
$ sudo gdmsetup
Select "Local" tab > unselect "Show Actions menu" > Close
Note: You can start gdmsetup by visiting System > Administration > Login Screen / Login Windows. You can also modify configuration file stored at /etc/gdm/ directory.