gdm-restart

Restart the GNOME Display Manager application

$ gdm-restart

gdm-restart

The gdm-restart command is used to restart the GNOME Display Manager (GDM) service. GDM is a crucial component of the GNOME desktop environment, acting as the graphical login manager that handles user authentication, displays the login screen, and starts user sessions.

Restarting GDM effectively terminates all active graphical user sessions, returning the system to the login prompt. This action is commonly employed for troubleshooting display or login-related issues, applying changes to GDM's configuration files (like /etc/gdm3/custom.conf or /etc/gdm/custom.conf), or simply to force a new login screen without requiring a complete system reboot. Since it manages system-level services, executing this command typically requires administrative privileges or interaction with a system service manager like systemctl.

Restarting GDM will immediately terminate all active graphical user sessions, leading to the loss of any unsaved work. Users should ensure all applications are closed and data saved before executing this command.

It almost always requires root or sudo privileges, as it manipulates a system-level service. The exact service name might vary between distributions (e.g., gdm.service or gdm3.service), and the method of execution might also differ (e.g., direct script or a call to systemctl).

On most modern Linux distributions using systemd, the action of restarting GDM is typically achieved by issuing the command sudo systemctl restart gdm.service or sudo systemctl restart gdm3.service depending on the specific GDM package name used by the distribution (e.g., Fedora uses gdm, Debian/Ubuntu uses gdm3). The gdm-restart command, if it exists, is often a wrapper script that executes one of these systemctl commands internally.

It is crucial to understand that restarting GDM is a drastic action for active graphical users. It will immediately terminate all currently running graphical desktop sessions, causing any unsaved work in applications to be lost. Users will be returned to the graphical login screen, where they can log in again to start a new session.

The concept of restarting a display manager like GDM has been integral to managing graphical environments since the early days of X Window System display managers (like XDM). GDM itself was developed specifically for the GNOME desktop environment, providing a graphical login interface.

While the exact gdm-restart command might not have a distinct, long development history as a standalone utility, its functionality has been consistently achieved through various system management tools. In modern Linux distributions, its operation is primarily handled by systemd, which superseded older SysVinit or Upstart systems for service management. This transition streamlined the process of starting, stopping, and restarting system services, including GDM.

systemctl(1), gdm(8), gdm3(8), loginctl(1)