Hi guys,
I think i found a solution for the VT-D problem. If you add the boot option pci=nommconf to grub you can boot every OS including TrueNAS Scale.
I tried with TrueNAS, Ubuntu, Debian and Proxmox.
I was not sure if it is stable so I tested it for about 3 weeks now and i can report that so far everything works perfect.
I am now running proxmox with a TrueNAS vm on top. The NVMe’s are handed over to TrueNAS via PCIe passthrough (VT-D, iommu) so truenas has access to the whole disks and not just virtual disks. So also SMART checks are possible.
By the way this solution is not limitted to 4x m.2 nvme’s, I run it fully populated with 8.
This really opened the device for me to use it as a homeserver/nas as i planned for. I was even able to passthrough the GPU to Jellyfin, immich and nextcloud for transcoding and basic AI workloads.
It took me a long time to find the issue and solve it and I hope it helps some of you!