Are you using Ubuntu in combination with a HiDPI 4K display? Then you are definitely familiar with your windows and text being too small after logging in into your Gnome session; a typical result of wrong scaling settings indeed.
This guide will demonstrate how to permanently set your Ubuntu scaling factor to 200%.
To start off, open up a new file in which the user-desired scaling factor is defined:
sudo nano /usr/share/glib-2.0/schemas/90_hidpi.gschema.override
Set the scaling factor to the value of 2 (meaning 200%):
Now save your configuration file and exit from your editor.
Apply the changes with the following command:
sudo glib-compile-schemas /usr/share/glib-2.0/schemas
That’s it. Now reboot your computer and enjoy your applied 200% scaling factor.