Ubuntu Hyper-V Guest Display Resolution

Question

Good afternoon,

I am trying to set up an Ubuntu guest on a Hyper-V server. I am relatively new to Linux so please bear with me, the VM is a test machine to get the hang of things and give Ubuntu a try. One of the new features of Server 2012 R2 is the improved display capabilities as mentioned here at blogs.technet.com

I don't think I am alone in finding this doesn't "just work". Some advice found online suggests updating the kernel, which I have done to 3.11.6 as described in one post, and to the latest 3.12.1. In both cases I could only see resolutions listed under the display options up to 1152x864, which is what Linux has always been limited to under Hyper-V.

Another clue was found in the next link (in Japanese) - the poster has added "video=hyperv_fb:1920x1080" to /boot/grub2/grub.cfg. When I went to repeat this I noted the message about not editing /boot/grub2/grub.cfg directly so I have added the line in /etc/default/grub instead.

yamanxworld.blogspot.co.uk

This has not given the option for the full 1920x1080 resolution either, and at this point I have run out of things to try and would not know if this is now a Hyper-V issue or something more fundamental and this would not have worked on a physical or other hypervisor machine.

If anyone can shed some light I would be most grateful.

Answer 1

Good afternoon,

I had the same issue and when I was looking for help I remember seeing your post. Now when I finally got it to work I might as well document it here:

1. Upgraded linux-image and headers sudo apt-get install linux-image-3.11.0-15-generic linux-headers-3.11.0-15-generic (Perhaps virtual would work just as well as the generic one.):

2. Installed linux-image-extras with the hyperv-drivers: sudo apt-get install linux-image-extra-virtual

3. Set video mode (Pretty much what you already did):
   Set GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video=hyperv_fb:1680x1050" in /etc/default/grub.

4. Update grub: sudo update-grub
5. Reboot

I guess the critical part was installing the updated hyperv-drivers with linux-image-extra-virtual. Also make sure they are loaded.

Answer 2

copat's answer worked for me, but only after I changed my resolution down from 1920x1200 to 1920x1080.

Looking in the Linux source file hyperv_fb.c there is the comment: "This is the driver for the Hyper-V Synthetic Video, which supports screen resolution up to Full HD 1920x1080 with 32 bit color on Windows Server 2012, and 1600x1200 with 16 bit color on Windows Server 2008 R2 or earlier."

Answer 3

With the methods described, it didn't work for me. What worked was: I can leave my host screen at 1920x1200, but the text size increased to 125% then I get full screen in my Ubuntu guest session;