I am trying to set the wallpaper on my login screen, but i cant seem to get anything to stick. I have used gsettings set com.canonical.unity-greeter background '/path/to/pic.jpg' as user 'lightdm'. However, i then get the output (process:6517): dconf-CRITICAL **: unable to create directory '/run/user/1000/dconf': Permission denied. dconf will not work properly. Any ideas? Thanks
I found a solution. Though it displays an error message, the lightdm background does in fact change to whatever new background image you set.
Open a terminal and get root
(Type sudo password)
Allow the user lightdm to create a connection to the X server
Switch user to lightdm. I had to use sudo to do this, other guides do not do so.
Make sure you have turned off the option to dynamically change lightdm's background to match the user's desktop background.
Finally, set your desired lightdm background.
This returns an error about dconf, ignore it. The new lightdm background should be present when you log out. To double check, you can run
twice, once to get out of lightdm and once to get out of root. Then run
Which should return the path of the image you chose. Similarly, running
Gets you to a nice GUI. Choosing the drop-down for com, then canonical, then unity-greeter lets you check the path of lightdm's background image, and should allow you to edit it as well but I was never able to make a valid change from there.
Hope this helps.
after logging out does NOT return the new image path, but when lightdm is next used, the correct new image is set. I know there's a way to run lightdm in test mode, which may be a more accurate way to test if the new background is set. I did not test that method, as the above method I used to change the background image worked for me.