CentOS / RHEL Linux: Remove GDM

To remove the GDM (GNOME Display Manager) from CentOS or Red Hat Enterprise Linux (RHEL), follow these steps:

1. Switch to the root user by typing the following command:

su -

2. Stop the GDM service by typing the following command:

systemctl stop gdm.service

3. Disable the GDM service so that it does not start automatically at boot time:

systemctl disable gdm.service

4. Remove the GDM package by typing the following command:

yum remove gdm

5. If you want to use a different display manager, such as LightDM, you can install it by typing the following command:

yum install lightdm

6. Enable the LightDM service so that it starts automatically at boot time:

systemctl enable lightdm.service

7. Reboot the system for the changes to take effect:

reboot

After the system reboots, the GDM will be removed and the specified display manager will be used.

Note: Removing the GDM may cause issues with the GNOME desktop environment. If you are using GNOME and you want to switch to a different display manager, it is generally recommended to switch to a different desktop environment that is compatible with the display manager you want to use.