I am having trouble passing a second GPU. My first GPU passthrough works great. Throughout my trials it disconnects the ability to write to the “domains” disk (for my system is it my cache drive), where I have to do a shutdown of the system and usually reformat the drive in the array.
Here is my system:
Motherboard: Micro-Star International Co., Ltd - B450 TOMAHAWK MAX (MS-7C02)
Processor: AMD Ryzen 7 3700X 8-Core @ 3.6 GHz
GPU1: XFX Radeon RX 580 8 GB (Graphics: [1002:67df] 29:00.0 / Sound: [1002:aaf0] 29:00.1)
GPU2: SAPPHIRE Radeon RX 550 DirectX 12 100414P4GL 4GB (Graphics: [1002:699f] 25:00.0 / Sound: [1002:aae0] 25:00.1)
In order to get GPU1 to work I had to include the GPU’s vfio-pci.ids into the syslinux configuration.
vfio-pci.ids=1002:67df,1002:aaf0,1002:699f,1002:aae0
When I added the GPU2 vfio-pci.ids (1002:699f,1002:aae0) to the syslinux configuration, unRAID won’t boot in the PCIe ACS override of downstream: pcie_acs_override=downstream. So I am running ‘both’: pcie_acs_override=downstream,multifunction.
Below are a list of settings I tried. Each resulted in disabling my ability to write to the ‘domains’ share.
- Changed domains to reside on disk1
- Changed VMS machine to Q35 per spaceinvader one (https://www.youtube.com/watch?v=QlTVANDndpM&t=509s). Initial trials were with machine i440fx.
- Added the ‘Graphics ROM BIOS’ for GPU2
- In VM XML file added multifunction=’on’ per spaceinvader one (https://www.youtube.com/watch?v=QlTVANDndpM&t=509s).
- Updated to unRAID 6.9.0-beta25
I have not tried the following
- Changed the ‘Server boot mode’ to Legacy. I cannot get the system to boot in legacy.
- Swap GPU location on the motherboard
- Tried another GPU
- Update bios
Each trail had varying levels of success, but eventually resulted in similar outcomes. The setup that resulted in the system working for the longest period had the following settings and the diagnostic file name:
- Machine: Q35-4.2
- vbios: NA
- Multifunction: on
- unRAID OS: 6.8.3
- Diagnostic file: batcave-diagnostics-20200721-2302.zip
Here is my latest trial, which didn’t get far.
- Machine: Q35-5.0
- vbios: NA
- Multifunction: on
- unRAID OS: 6.9.0-beta25
- Diagnostic file: batcave-diagnostics-20200723-0918.zip
Here are some forums that indicate similar issues.
Seems like this person has a similar issue, but no resolution shared.
https://forums.unraid.net/topic/86519-unraid-680-1660-gtx-gpu-passthrough/
This person was able to fix it with a bios update (not unRAID).
https://www.reddit.com/r/VFIO/comments/g5hi4k/going_mad_help_needed_with_gpu_passthrough/
This person got it to work by changing their GPU.
https://forums.unraid.net/topic/79134-ryzen-internal-graphics-passthrough/
batcave-diagnostics-20200721-2302.zip batcave-diagnostics-20200723-0918.zip