Strange Resolution Behaviour

[ej3718]

Hello,

I have just installed Ubuntu Linux 20.04.3 and I am running it in VirtualBox. I have had some strange resolution behavior I cannot fix. My laptop (with an integrated display) has a resolution of 2560x1440. I went through the process of setting a custom resolution but when I applied it the screen went blank before reverting after the 15-second timer elapsed. I thought that I had done something wrong, but when I repeated the process for a resolution of 2000x1440 it worked. Anything higher than 2000 does not work for some reason. Does anyone have any possible fixes for this?

Cheers.

 

[f33dm3bits]

You probably need to install virtualbox-guest-additions.

 

[KGIII]

It's Ubuntu, so before installing the guest additions you'll need to install 'build-essential'.

sudo apt install build-essential

 

[shibaa987]

Usually installing the guest additions will allow to allocate more RAM for graphics.
But there could be another angle as well.
Sometimes if you are not on fullscreen mode on Virtualbox, and if you set a higher resolution then the guest OS screen becomes so big that it does not fit in the display to show. In that case you might see some scroll bars on the right and bottom of the screen.