Troubleshooting GPU Passthrough in Ubuntu on Unraid: Display and Audio Issues

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Setting up Ubuntu with a GPU passed through can be challenging, especially when it comes to audio and video display issues. Here are some steps and considerations based on your query:

Display Issues

If your display shows for only a few seconds and then disappears, this could be related to several factors:

  1. VFIO Binding: Yes, you need to bind your GPU to VFIO at boot if you want to use it in a virtual machine. This ensures that the GPU is properly isolated from the host system, allowing the VM to take control of it. Make sure that you have configured your GRUB settings correctly to include the necessary parameters for VFIO.

  2. Unraid WebGUI: Binding the GPU to VFIO should not interfere with the Unraid webGUI as long as you are not passing through any devices that Unraid relies on for its operation. However, ensure you are not passing through any critical devices (like USB controllers) that might affect the management interface.

Audio Configuration

If you’re experiencing audio issues after passing through your GPU, consider the following:

  1. Audio Drivers: Ensure that your NVIDIA audio drivers are installed correctly. You can check this by running inxi -Axxx in the terminal to see if your NVIDIA audio device is recognized.

  2. PulseAudio and ALSA: Sometimes, issues arise from conflicts between PulseAudio and ALSA. You may want to restart PulseAudio or reconfigure it:

    killall pulseaudio
pulseaudio -k
rm -r ~/.config/pulse/*
pulseaudio --start

  3. Using alsamixer: Open alsamixer in the terminal and ensure that all relevant channels (especially HDMI) are unmuted and set to a high volume level.

  4. Testing Audio Output: Use aplay -l to list available audio devices and ensure your NVIDIA HDMI output is listed. If it’s not showing up, there might be an issue with driver installation or configuration.

  5. Check BIOS Settings: Sometimes, BIOS settings can disable certain audio functionalities. Ensure that onboard audio is enabled if you’re using it alongside your GPU.

Final Steps

  • After making these adjustments, reboot your system and check if the display and audio work as expected.

If you have further questions or need additional clarification on any step, feel free to ask below!