Troubleshooting Low Resolution on Ubuntu 22.04 Server After Desktop Conversion

When transforming an Ubuntu 22.04 server into a workstation by installing the ubuntu-desktop package, users may encounter a low resolution display issue, particularly when the server was initially deployed using MAAS (Metal as a Service). This problem often manifests as the system being stuck at a 1024×768 resolution, especially when running kernel version 5.15.0-73. Interestingly, the same installation process using a USB drive might not produce this resolution problem. This article explores potential points to investigate to resolve this issue on your Ubuntu2204 Server.

The user reported successful scenarios with USB installations, contrasting with a low resolution issue when installing on an ubuntu2204 server deployed via MAAS. Here’s a summary of the tested combinations:

• Ubuntu 22.04 Desktop (kernel 6.x) then installed kernel 5.15.0-73 – OK (USB boot)
• Ubuntu 22.04 Server + ubuntu-desktop + kernel 5.15.0-73generic – OK (USB boot)
• Ubuntu 22.04 Server + ubuntu-desktop + kernel 5.15.0-73 – LOW Resolution (MAAS Installed)

System information indicates the graphics are being handled by llvmpipe and the Windowing System is X11.

Graphics: llvmpipe(LLVM 15.0.7, 256 bits)
Windowing System : X11

Hardware details are as follows:

Motherboard: Asus x670-e
CPU : Ryzen 5 7600

To understand the root cause, let’s analyze the output of lshw -C video in both scenarios: when the resolution is OK and when the resolution is low.

Scenario 1: Resolution OK (USB Installation)

This output shows the video controller is recognized but marked as “UNCLAIMED”, suggesting a generic driver is in use. However, the EFI VGA graphics are configured correctly with a resolution of 1680×1050.

sudo lshw -C video *-display UNCLAIMED description: VGA compatible controller product: Advanced Micro Devices, Inc. [AMD/ATI] vendor: Advanced Micro Devices, Inc. [AMD/ATI] physical id: 0 bus info: pci@0000:0f:00.0 version: c6 width: 64 bits clock: 33MHz capabilities: pm pciexpress msi msix vga_controller bus_master cap_list configuration: latency=0 resources: iomemory:fc0-fbf iomemory:fc0-fbf memory:fce0000000-fcefffffff memory:fcf0000000-fcf01fffff ioport:e000(size=256) memory:fce00000-fce7ffff *-graphics product: EFI VGA physical id: 1 logical name: /dev/fb0 capabilities: fb configuration: depth=32 resolution=1680,1050

Scenario 2: Low Resolution Problem (MAAS Installation)

In the problematic scenario with MAAS installation, the lshw -C video output is similar in terms of the “UNCLAIMED” VGA controller. However, the EFI VGA graphics configuration now shows a low resolution of 1024×768.

sudo lshw -C video *-display UNCLAIMED description: VGA compatible controller product: Advanced Micro Devices, Inc. [AMD/ATI] vendor: Advanced Micro Devices, Inc. [AMD/ATI] physical id: 0 bus info: pci@0000:0f:00.0 version: c6 width: 64 bits clock: 33MHz capabilities: pm pciexpress msi msix vga_controller bus_master cap_list configuration: latency=0 resources: iomemory:fc0-fbf iomemory:fc0-fbf memory:fce0000000-fcefffffff memory:fcf0000000-fcf01fffff ioport:e000(size=256) memory:fce00000-fce7ffff *-graphics product: EFI VGA physical id: 1 logical name: /dev/fb0 capabilities: fb configuration: depth=32 resolution=1024,768

Points to Investigate for Resolution:

1. Graphics Drivers: The “UNCLAIMED” status suggests that a specific graphics driver for the AMD/ATI VGA controller might not be loaded or properly configured in the MAAS environment. While llvmpipe provides software rendering, it may not be utilizing the full capabilities of the hardware, leading to the low resolution. Investigate installing the appropriate AMD graphics drivers.

2. Kernel Modules: Ensure that the necessary kernel modules for the graphics card are loaded. The difference in behavior between USB and MAAS installations might be due to different kernel module loading configurations or missing modules in the MAAS-deployed ubuntu2204 server.

3. Display Configuration: Check the X server configuration files. It’s possible that the X server is not correctly detecting the monitor’s capabilities in the MAAS environment. Configuration files like xorg.conf or files in /etc/X11/xorg.conf.d/ might need adjustments to specify the correct resolution or driver.

4. MAAS Environment Specifics: MAAS provisioning process might have specific configurations that are affecting the graphics setup. Investigate if MAAS is setting any display related configurations during deployment that could be causing this issue. Compare the environment variables and system configurations between a MAAS-deployed server and a USB-installed server.

5. EDID (Extended Display Identification Data): The system might be failing to read the EDID information from the monitor correctly in the MAAS environment. EDID helps the graphics driver understand the monitor’s supported resolutions. Issues with EDID can lead to fallback resolutions like 1024×768.

By focusing on these areas, particularly graphics drivers and display configurations within the MAAS-deployed ubuntu2204 server, you should be able to pinpoint and resolve the low resolution issue when converting your server to a desktop environment.