We are heavily using VirtualBox on our developer workstations. Since we share the images with other developers quite often, I have tried to automate this process as much as possible (cleaning up ap-get cache, removing tmp and log files...). We are using Ubuntu 11.10 with KDE 4.7.4, by the way.
Now I have stumbled over one little annoyance. At the login screen there is a user name prefilled and I could not figure out where this is stored. The problem is, if people get a VirtualBox image and don't realise that the pre-filled user name is not their own and enter their password a couple of time, they lock the said user on our LDAP.
Any idea where is this user name is stored, so I could remove it..?
By default, the login screen (KDM) will preselect the the last logged-in user and I'm not sure where it gets this information. However, you can configure KDM to always preselect the same user in /etc/kde4/kdm/kdmrc:
# Greeter config for all displays
[X-*-Greeter]
...
# Specify, if/which user should be preselected for log in.
# "None" - do not preselect any user
# "Previous" - the user which successfully logged in last time
# "Default" - the user specified in the DefaultUser option
# Default is None
PreselectUser=Default
# The user to preselect if PreselectUser=Default.
# Default is ""
DefaultUser=johndoe
...
Of course, you can set PreselectUser=None if you don't want to select any user.