After searching and trying for a long, long time, I finally found a
solution which is acceptable for me. The situation is rather complex, so I
try to describe it as structured as possible.
GeForce GTX 970
You can either go with the open nouveau driver which is installed by
default, or use the proprietary nvidia driver. Next, the "plymouth" package
which enables you to configure the graphical boot up, is strongly involved.
Using the nvidia driver together with plymouth does not work for me, but for
all other 3 possible combinations, the solution is described below.
There are 2 issues here closely connected, one is being able to enter the
password for encrypted hard disks during boot, and the other is being able
to switch to the console when X is up and running. Both issues are described
Being able to enter the password for encrypted hard disks during boot
Nouveau driver with plymouth:
The Nouveau driver works "ok" - this means I have to press the down arrow on the
keyboard while booting so the text mode appears. There, the password is
asked. (Some stars may already be displayed - delete them before entering the
This solution was ok, but I needed the nvidia driver to work, because with
nouveau, for example, I had no proper 3D acceleration inside virtualbox.
Nvidia driver without plymouth:
The nvidia driver I use is nvidia-352 currently. I installed it via apt-get.
So I did not download and install the driver from the nvidia.com site
directly, but used the distribution (in my case: Ubuntu 15.10) package for
the nvidia driver instead.
For the nvidia driver to work, I had to disable plymouth. This can be done
for example by passing the "noplymouth" option to the kernel parameters.
--- /etc/default/grub (example) ---
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash noplymouth"
--- update-grub ---
Afterwards, execute update-grub from the command line:
With that changes, I can see the screen flicker shortly during the graphical
boot (obviously the password prompt appearing for a fraction of a second,
and then disappearing again). But now I know that the password
prompt is there, and I can start to type the password. The prompt will
reappear with the first character typed, having recognized the typed
If insecure whether the password prompt is ready or not, I can still press
the down arrow as described above.
Yes, that´s not a perfect solution - but after searching and trying for such
a long, long time: At least it is working - and you can get used to it.
Just out of curiosity, I also tried the nouveau driver with plymouth disabled:
In that case it works much smoother, as the password prompt really appears
and stays on the screen.
So it seems the free nouveau driver is doing something better than the
nvidia driver. I guess NVIDIA has some homework to do here!
Switch to console
With the nouveau driver, it is easily possible to switch to the console
With the nvidia-352 driver, switching to the console is NOT possible!
Pressing CTRL-ALT-F1 just does nothing.
A (n ugly) workaround I found for this is to restart the window manager from
within your X session. Working for me with lightdm as windows manager, not
tested for others. Please save all your open documents BEFORE doing this, as
all applications of your X session will be killed:
sudo service lightdm restart
So again, the nouveau driver does this better than the official nvidia
driver. I need to say that I´m really disappointed by NVIDIA about that!