ProxMox not booting after connecting 2nd GPU

[OkDaca]

Hi everyone, I am new to ProxMox and have encountered an issue:

-I have successfully set up GPU passthrough with one RTX 3090 that I use for one VM
-I wish to set up a second VM using a spare RX 470.
-As soon as I connect the second GPU my system will not boot and I am not able to connect to it

System specs:
MB: B550 Elite V2
CPU: Ryzen 7 5700x
Ram: 32gb kingston fury
2x 512gb WD NVMe SSD
GPU: Zotac RTX 3090 & XFX RX 470

My current grub setting:

GRUB_CMDLINE_LINUX_DEFAULT="amd_iommu=on iommu=pt vfio_iommu_type1 allow_unsafe_interrupts=1 pcie_acs_override=downstream,multifunction nofb nomodeset video=vesafbff initcall_blacklist=sysfb_init"

If someone has some advice I would appreciate it a lot!

 

[leesteken]

-As soon as I connect the second GPU my system will not boot and I am not able to connect to it

Does it really not boot or maybe it's just the network connection that is no longer working? Can you (temporarily) remove the passthrough so you can troubleshoot without a network connection issue?

The network devices have a name based on the PCI ID. Changing (or adding or removing or enabling/disabling on-board) PCI(e) devices can change the PCI ID of other PCI(e) devices. They "shift up or down by one or more" and this breaks the network configuration because the name of the device changes. Find out the new names of the network devices using ip a (usually the first number went up by 1) and adjust the network configuration in /etc/network/interfaces accordingly.
This network device name change can also happen due to a kernel update. You can also name the network devices yourself to prevent this. See here for example: https://pve.proxmox.com/wiki/Roadmap#Kernel:_Change_in_Network_Interface_Names

 

[OkDaca]

Does it really not boot or maybe it's just the network connection that is no longer working? Can you (temporarily) remove the passthrough so you can troubleshoot without a network connection issue?

The network devices have a name based on the PCI ID. Changing (or adding or removing or enabling/disabling on-board) PCI(e) devices can change the PCI ID of other PCI(e) devices. They "shift up or down by one or more" and this breaks the network configuration because the name of the device changes. Find out the new names of the network devices using ip a (usually the first number went up by 1) and adjust the network configuration in /etc/network/interfaces accordingly.
This network device name change can also happen due to a kernel update. You can also name the network devices yourself to prevent this. See here for example: https://pve.proxmox.com/wiki/Roadmap#Kernel:_Change_in_Network_Interface_Names

Thanks a bunch, the passthrough was the issue, completely forgot to disable it whilst setting up the second GPU, forgot I had to add the second GPU to the vfio.conf file, after disabling the passthrough of the 3090 and adding the iommu ID of the RX 470 the system boots up completely fine and I am now setting up the second VM and adding the passthrough, thanks!!!

Does it really not boot or maybe it's just the network connection that is no longer working? Can you (temporarily) remove the passthrough so you can troubleshoot without a network connection issue?

The network devices have a name based on the PCI ID. Changing (or adding or removing or enabling/disabling on-board) PCI(e) devices can change the PCI ID of other PCI(e) devices. They "shift up or down by one or more" and this breaks the network configuration because the name of the device changes. Find out the new names of the network devices using ip a (usually the first number went up by 1) and adjust the network configuration in /etc/network/interfaces accordingly.
This network device name change can also happen due to a kernel update. You can also name the network devices yourself to prevent this. See here for example: https://pve.proxmox.com/wiki/Roadmap#Kernel:_Change_in_Network_Interface_Names

However, now I have this issue on the second VM when I add passthrough, this is all my screen displays

Any ideas?