Login screen ubuntu 12.04 not showing user's desktop

Question

I installed Ubuntu 12.04 (x64) and was really enjoying it, but it was a little too slow on my machine, so I've reinstalled with the x32 version (hopefully that terminology's correct). The only thing I did differently was to put the /home directory onto its own partition and set encryption of same.
When I used the x64 version, the login screen would change to show each user's desktop wallpaper, but it no longer does this... Is this a bug? Or something wrong with x32? Or is it something that I did when I partitioned and encrypted /home?

Answer 1

Run sudo nautilus in the terminal (Or Alt+F2 and gksudo nautilus, copy wallpapers into the /usr/share/backgrounds directory, and change the file permissions to match the default wallpapers. I haven't done exhaustive testing to see if it works for all my images, but it has worked for one that was previously giving me problems. Login screen now looks great.

I hope that helps. Take care.

P.S. System: Acer AOD270 Netbook

Answer 2

Regarding "For the feature to work properly the user's home should not be encrypted":

Alternative to home encryption: full disk encryption ("whole disk encryption"). This will require (of course) your disk password to be entered early on in boot, and if you do not additionally encrypt home dir, then because the whole OS is encrypted but at point of account login, it is all decrypted, voila, custom user login config is readable, AND encrypted (when OS is fully shut down at least (and presumably when hibernated also)).

WARNING: suspend implies exposure of decryption keys in memory while suspended.
See, for example:

• http://ubuntuforums.org/showthread.php?t=1249180
• I'm so confused about full disk encryption. help :(

Answer 3

Try changing the wallpaper, then changing it back and see if it updates. I have had an issue where it wouldn't show up for network users unless you did that. I'm not sure if it will work when your home folders are encrypted though...

Answer 4

With user's encrypted home there is the issue that the home folder is only mounted after login, that means that the Unity greeter cannot read the files inside it so no matter what desktop background you select for a user with an encrypted home folder it will fail to display in the login screen.

The location for the user's background is written in the config files inside the user home and if encrypted Unity greeter cannot read that configuration.

For the feature to work properly the user's home should not be encrypted.

Answer 5

I also have Ubuntu 12.04 (x64) and I encrypted my /home directory. I have set My_Wallpaper.png as my wallpaper and locate it in /home/my_username/Pictures. I wanted My_Wallpaper.png to appear in my login menu. sudo cp My_Wallpaper.png ... into the /usr/share/backgrounds directory does not work for me.

My workaround is a little bit of brute force:

1. Make a backup of the original warty-final-ubuntu.png file.

   cd /usr/share/backgrounds
   mv -f warty-final-ubuntu.png warty-final-ubuntu.bak
   

2. Copy the wallpaper you want in /usr/share/backgrounds (or, I suppose, in a location which is not encrypted).

   cp -i /home/my_username/Pictures/My_Wallpaper.png ./
   

3. Then create a symbolic link called warty-final-ubuntu.png to the file you want to use as login background.

   ln -s My_Wallpaper.png warty-final-ubuntu.png
   

This is not perfect: it is the same for all users, and warty-final-ubuntu.png might get updated in an upgrade.