I have a headless Ubuntu machine that I connect to with a combination of ssh and vnc.
When I've got a monitor attached (which is rare), the vnc connection is the full resolution of the attached monitor (of course).
But, when I connect using vnc when there's no monitor connected, I get a much lower-resolution connection than I would like. It's as if the computer has a tiny monitor connected.
I have looked through Settings and haven't found anything promising (resolution was grayed out without a monitor connected).
How can I change the 'virtual resolution' that I get when I connect using VNC?
I'm not interested in recommendations for other vnc software now, I just want to know how to do the above with the built-in vnc server.