Cannot get beyond 1920x1080 resolution using Hyper V and Ubuntu 20.04

Question

I am running a monitor which has a 2560 by 1080 resolution, and using HyperV to run an Ubuntu 20.04 virtual machine in it. I have used these instructions, that is editing /etc/default/grub file and making this change: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video=hyperv_fb:1920x1080", and then running sudo update-grub.

That works fine, but if I increase it to GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video=hyperv_fb:2560x1080" then it seems to ignore all resolution information and go back to the tiny default screen size for virtual machines.

Is there a way to go beyond 1920x1080? Is the problem a resolution one, or an aspect ratio one, because my monitor is 21x9.

Answer 1

Check the video settings (limits) for the VM in Powershell using Get-VMVideo <vm-name>.

Modify the video settings for the VM in Powershell using Set-VMVideo -VMName <vm-name> -HorizontalResolution <hres> -VerticalResolution <vres>.