I'm using Ubuntu 11.04 Natty on an HP laptop and I cannot figure out how to get Unity on the external monitor! I have my desk set up with my monitor in front of me, and my laptop working as a secondary about 45 degrees on the left. I've tried a few different suggestions, including trying (and not being able to find) nVidia-Settings. But as I am a relatively new Linux user, I am having a lot of difficulties understanding what I'm being instructed to do.
If your video card is xrand compilant (everything but NVIDIA, IRC), you can use this command:
You will need to open a terminal: click on the dash and write Term. When the terminal, a blank screen with a cursor open, type the above command.
Note that the VGA1 parameter is just a good (I hope) guess. If it didn't work you should type in the terminal
And it will show you a list of the connected monitors and the resolutions that they support. In my laptop:
The names between the ** are the screen names. Take note of yours and change VGA1 in the above command for the name that apply to you.
You will need to issue this command just once, it will be remembered between reboots.
You should be able to do this with the monitors Application, and with the nVidia control app as well.