CentOS 7 - Change GDM Login Screen Shield Background

While it is very simple to configure and change your desktop wallpaper and  screen shield backgrounds, it is a little more involved changing the GDM login screen shield that appears after a period of time if you do not login right away.

Why would we want to change it? Have you seen it? See below.

Screen 01:

Open a terminal and enter the command line below and press ENTER on the keyboard.

sudo vim /etc/dconf/profile/gdm

Once open, insert the text below.

user-db:user
system-db:gdm
file-db:/usr/share/gdm/greeter-dconf-defaults

Once done. Save and exit the file.

Still in the terminal. Enter the command line below and press ENTER on the keyboard.

sudo vim /etc/dconf/db/gdm.d/00-login-screen

Once open, insert the text below.

[org/gnome/desktop/screensaver]
picture-uri='file:///usr/share/backgrounds/gnome/yourimage.filename'
picture-options='zoom'

Note: Change yourimage.filename to the image file of your choosing. If it is a custom image, be sure to copy it to the path above or one of your choice.

Once done. Save and exit the file.

Now we have added the necessary files, we must update dconf.

Still in the terminal. Enter the command line below and press ENTER on the keyboard.

sudo dconf update

Finally we need to reboot.

Still in the terminal. Enter the command line below and press ENTER on the keyboard.

sudo reboot

Once rebooted, you will now have your personal screen shield at login.