So whatever the reason is, if you ever wanted to prevent a package from changes in Debian or Ubuntu systems, this tutorial will help. You may not want to update a package that consumes more than 500 MB. Even though the developers tests the packages thoroughly before pushing them into the repositories, sometimes they might unknowingly push unstable packages which will break your system. The package you are about to update might be problematic.A particular version is required by another application in order to function properly.A current version of a package is just working fine, so you may think it is unnecessary to upgrade it.If only one display manager is installed, this command won't work.Īfter selecting a new default display manager, reboot your system.įor example, if you have both LightDM and GDM3 installed on your system, the command to switch to either GDM3 or LightDM can be both:Īny of these two commands work if you want to switch to either LightDM or GDM3, since both are installed in this example.įor the old GDM (used a while back - pre Ubuntu 16.04 for example), use gdm instead of gdm3 in the command. After running this command, it will list all installed display managers, allowing you to select the one to be used. In this command, replace some_installed_display_manager with one of the display managers installed on your system, for example gdm3, lightdm, sddm, lxdm, etc.

Sudo dpkg-reconfigure some_installed_display_manager So to change the default display manager, use this command: To change the default display manager on Debian, Ubuntu, Linux Mint, elementary OS and any Debian or Ubuntu-based Linux distribution we'll use dpkg-reconfigure, a tool provided by debconf, which can be used to reconfigure an already installed package by asking the configuration questions, much like when the package was first installed.