Comment 21 for bug 1762940

This looks to me as if Ubuntu (the kernel, Wayland, and/or the X server, depending on when the problem occurs) is delivering a video mode that the display device can't handle. (With VGA, the display should deliver its capabilities to the computer via EDID, but this doesn't always work correctly.) Thus, the first question is what that "display device" is. The screen shots look like a remote KVM of some sort. Is that the BMC's built-in screen-sharing tool, a network-accessible KVM hardware device (like a Raritan or Avocent), or something else? If possible, I recommend testing in person with a plain monitor plugged directly into the computer, at least as a diagnostic procedure. If that works, then it's likely that the issue is either a matter of a restrictive set of video modes in the remote-access tool, miscommunication between the remote-access tool and the kernel/Wayland/X, or both. Also, if a physical monitor is plugged into the server while it's being accessed remotely, it's conceivable that the kernel/Wayland/X is taking its cues about video mode from the physical monitor rather than from the remote-access tool, thus creating a mismatch. If the problem is caused by the remote access tool, or by an interaction between that and the kernel/Wayland/X, then updating the remote access tool's firmware may fix the problem.

Note that the video mode used can vary depending on the kernel version, X vs. Wayland, EFI vs. BIOS boot mode, and other factors. Such variables likely explain why earlier kernels worked but newer ones don't.

As a workaround, it might be possibly to forcibly reconfigure the system to use a video mode that will work with the display device. Unfortunately, there are a lot of different ways to do this, depending on the subsystem involved. For instance:

* Kernel parameters can set the kernel's video mode. Unfortunately, there are
  a lot of possibilities even here, including, but not limited to:
  * nomodeset
  * video=vga16fb:off
  * vga16fb.modeset=0
  * video=efifb:width:640,height:480
  * Try Googling "kernel video mode setting" or something similar for
    additional possibilities.
* X configuration
  * If you can get X working, even temporarily, you can use the GUI
    setup tools to change the resolution.
  * The xrandr tool can be used to probe and set video options; see
    https://www.x.org/wiki/Projects/XRandR/
  * I've not kept up with text-mode (manual) X configuration, but
    you may be able to find some documentation on how to get it
    to change video mode. Start here:
    https://help.ubuntu.com/community/VideoDriverHowto#Xorg.conf.d
* Wayland configuration
  * I'm even less of an expert on this, so I suggest you try
    Googling "wayland set resolution" or something similar.

Finally, note that Ubuntu server certification doesn't cover display devices, so this is NOT a certification blocker.