RHEL 9 System Boot Stuck at GNOME Display Manager (GDM) : Troubleshooting Guide

Recently, after updating and upgrading my RHEL 9 system using dnf, I encountered an issue where the system froze at "Starting GNOME Display Manager (GDM)." This guide outlines the troubleshooting steps I followed to successfully resolve it. Table of Contents What is GNOME Display Manager (GDM)? Common Causes of GDM Hanging Issues Troubleshooting Steps 1. Switch to a TTY Console 2. Restart GDM Service 3. Review GDM Logs for Errors 4. Reset GNOME Desktop Settings 5. Boot into Multi-User Mode for Deeper Troubleshooting GNOME Session Shows "Unsupported Session Type" Conclusion Let's Connect on LinkedIn What is GNOME Display Manager (GDM)? The GNOME Display Manager (GDM) is a graphical login manager for Linux systems that use the GNOME desktop environment. Its key functions include: User Authentication: Provides a secure graphical interface for login. Session Management: Starts and manages user sessions. Customizable Interface: Offers a user-friendly login screen. Display Server Support: Works with both X11 and Wayland display servers. In simple terms, GDM acts as a bridge between the user and the GNOME desktop environment. Common Causes of GDM Hanging Issues The "Starting GNOME Display Manager" hang can occur due to: Package conflicts or incomplete updates. Graphics driver issues. Misconfigured system services. Troubleshooting Steps 1. Switch to a TTY Console When the system is stuck: Press Ctrl + Alt + F2 (or F3/F4, depending on the system) to access a text-based terminal. Log in with your credentials. 2. Restart GDM Service In the terminal, restart the GDM service: sudo systemctl restart gdm Sometimes, a simple restart can fix a stuck GDM. 3. Review GDM Logs for Errors If restarting didn’t work, check the system logs: journalctl -xeu gdm Look for specific error messages that can guide your next steps. 4. Reset GNOME Desktop Settings If there are misconfigurations in the GNOME settings, resetting them might help: dconf reset -f /org/gnome/ Then, restart GDM: sudo systemctl restart gdm 5. Boot into Multi-User Mode for Deeper Troubleshooting If the problem persists: Reboot and access the GRUB menu (press Esc or Shift during boot) Edit the boot entry and add: systemd.unit=multi-user.target Press Ctrl + X to boot This boots into a command-line environment (without GUI), allowing safer troubleshooting. GNOME Session Shows "Unsupported Session Type" Error: Window Manager Warning: Unsupported session type How to Fix: Check the session type: echo $XDG_SESSION_TYPE If it shows tty instead of x11 or wayland, your graphical session isn't active. Start GNOME manually: startx Set the system to boot into graphical mode by default: Check the default target: systemctl get-default If it returns multi-user.target, change it: sudo systemctl set-default graphical.target reboot Conclusion If you ever encounter a GNOME Display Manager issue in RHEL 9, these steps should guide you to a solution. Always check system logs, verify configuration settings, and ensure your graphics drivers are up-to-date. Let’s connect on LinkedIn (https://www.linkedin.com/in/chiamaka-chielo?utm_source=share&utm_campaign=share_via&utm_content=profile&utm_medium=android_app) As I automate my journey into RHCE and Ansible, I’d love to connect with fellow learners and professionals. Feel free to reach out and join me as I share tips, resources, and insights throughout this 30-day challenge. cloudwhistler #30daysLinuxchallenge

Apr 26, 2025 - 15:43

RHEL 9 System Boot Stuck at GNOME Display Manager (GDM) : Troubleshooting Guide

Recently, after updating and upgrading my RHEL 9 system using dnf, I encountered an issue where the system froze at "Starting GNOME Display Manager (GDM)."

This guide outlines the troubleshooting steps I followed to successfully resolve it.

What is GNOME Display Manager (GDM)?
Common Causes of GDM Hanging Issues
Troubleshooting Steps
1. Switch to a TTY Console
2. Restart GDM Service
3. Review GDM Logs for Errors
4. Reset GNOME Desktop Settings
5. Boot into Multi-User Mode for Deeper Troubleshooting
GNOME Session Shows "Unsupported Session Type"
Conclusion
Let's Connect on LinkedIn

What is GNOME Display Manager (GDM)?

The GNOME Display Manager (GDM) is a graphical login manager for Linux systems that use the GNOME desktop environment.
Its key functions include:

User Authentication: Provides a secure graphical interface for login.
Session Management: Starts and manages user sessions.
Customizable Interface: Offers a user-friendly login screen.
Display Server Support: Works with both X11 and Wayland display servers.

In simple terms, GDM acts as a bridge between the user and the GNOME desktop environment.

Common Causes of GDM Hanging Issues

The "Starting GNOME Display Manager" hang can occur due to:

Package conflicts or incomplete updates.
Graphics driver issues.
Misconfigured system services.

Troubleshooting Steps

1. Switch to a TTY Console

When the system is stuck:

Press Ctrl + Alt + F2 (or F3/F4, depending on the system) to access a text-based terminal.
Log in with your credentials.

2. Restart GDM Service

In the terminal, restart the GDM service:

sudo systemctl restart gdm

Sometimes, a simple restart can fix a stuck GDM.

3. Review GDM Logs for Errors

If restarting didn’t work, check the system logs:

journalctl -xeu gdm

Look for specific error messages that can guide your next steps.

4. Reset GNOME Desktop Settings

If there are misconfigurations in the GNOME settings, resetting them might help:

dconf reset -f /org/gnome/

Then, restart GDM:

sudo systemctl restart gdm

5. Boot into Multi-User Mode for Deeper Troubleshooting

If the problem persists:

Reboot and access the GRUB menu (press Esc or Shift during boot)

Edit the boot entry and add:

systemd.unit=multi-user.target

Press Ctrl + X to boot

This boots into a command-line environment (without GUI), allowing safer troubleshooting.

GNOME Session Shows "Unsupported Session Type"

Error:

Window Manager Warning: Unsupported session type

How to Fix:

Check the session type:

echo $XDG_SESSION_TYPE

If it shows tty instead of x11 or wayland, your graphical session isn't active.

Start GNOME manually:

startx

Set the system to boot into graphical mode by default:

Check the default target:

systemctl get-default

If it returns multi-user.target, change it:

sudo systemctl set-default graphical.target
reboot

Conclusion

If you ever encounter a GNOME Display Manager issue in RHEL 9, these steps should guide you to a solution.

Always check system logs, verify configuration settings, and ensure your graphics drivers are up-to-date.

Let’s connect on LinkedIn

(https://www.linkedin.com/in/chiamaka-chielo?utm_source=share&utm_campaign=share_via&utm_content=profile&utm_medium=android_app)

As I automate my journey into RHCE and Ansible, I’d love to connect with fellow learners and professionals. Feel free to reach out and join me as I share tips, resources, and insights throughout this 30-day challenge.

cloudwhistler #30daysLinuxchallenge