I've installed Ubuntu (tried 17.10 and 18.04 pre-release), since I have a 4k monitor I went to Settings - Devices - Displays and set
Everything looks fine until I resize a VM's window (including opening it fullscreen): Ubuntu resets the scale to 100% and everything becomes small.
How can I avoid this and "lock" the scale at 200%?
I tried this with
VMWare Player with the same results.
I know there is a "scale factor" in VirtualBox's settings but it is not the same and it makes pictures blurry.