Need TrueNAS and Windows... Which should be a VM in which?

I want a car that flies too

I can’t see a gaming machine coexisting with anything else to to resource demands. I’d say you’re looking at 2 machines. A dedicated VR gaming machine and then everything else.

Depending on your hardware, lookup proxmox with gpu passthrough.

If you go this route, use a pci-sata card dedicated for truenas, or else hdd-smart won’t work

Just my experience, I ignored everyone saying don’t virtualize TrueNAS. It ran fine, I lost no data but…. Random things would crash the truenas VM. I ended up putting it on bare metal and its been stable ever since.

I had TrueNAS virtualized with Proxmox.

Microsoft only supports hardware passthrough to Hyper-V VMs on server editions of Windows, not regular Windows 10/11. That means you won't be able to pass a HBA or SATA controller directly to TrueNAS if you're virtualising it on top of Windows.

You can do GPU passthrough to a VM runnong on top of TrueNAS Scale, but if I remember correctly NVIDIA goes out of their way to make it a pain. You might also have problems with anticheat in some games.

So I am converting an old system from purely a VR gaming machine to a TrueNAS machine that I also want to be able to do VR and Couch gaming on.

Can this be done? Maybe under Proxmox or another Hypervisor, sure

Should this be done? Heck no!

So, as others have hinted, running all of that under one box will require a BEEFY setup to handle the load of each. But, there's also the concern of stability and out right glitchiness of such a setup. You've likely gotten the idea from Linus Tech Tips, or some other YT vid, but let me say it's best on paper\video and less desirable as a daily driver.

I have had two friends attempt this. Each one, while they got it going, never had it going for long. There either was issues with hardware always working, the GPU operating without bugging out, or some other issue with lag\slowness even with available resources...

I highly suggest you just do those things under separate systems.

Run windows and vm scale for sure. If you planning on gaming on it at all the trunas vm won't cut it.

You can do this with ESX (and some of the other free solutions) - you virtualized TrueNAS with direct pass through your HBA to the VM. In another VM, you pass through your USB ports, graphics card, etc. to your Windows VM. And now you have a VM that is your main system (your keyboard and mouse plug into the pass through’d USB adapters)

I’ve done this, and still do this with TrueNAS. It’s never crashed because it was inside a VM.

The one issue I see here is your VR rig turned server likely won’t have ECC memory. I attribute the fact I’m running with great stability for many years to my ECC ram. But don’t let that stop you if you know and accept the risks.

I got this exactly running, 1 host pc running bare metal truenas scale with a windows 10 vm machine and gpu pass through it (gtx 1660 super) couch gaming using moonlight game streaming, best of both worlds (gaming and file storage)

The funny thing is that most people eventually disaggregate functions because everything is suboptimized, complicated, and difficult to maintain

I'd suggest keeping things the way that they are

If you aren't asking much of Plex, you can run it on TrueNAS, but it probably won't be a satisfying situation in the long run

Truenas on bare metal and windows in VM.

If you have a second video card you could pass it and the USB control though to windows. This would make the machine work like a windows native machine for the most part.

Windows Server will run in unactivated mode indefinitely. Don't use the trial version. Use the retail/OEM ISP. Yes it's breaks ToS but it won't be a problem otherwise.

Install TrueNAS in Hyper-V VM. You will need to pass through the physical disks and the storage won't be usable until the TrueNAS install is done and you get file sharing up and running. You can then put other VMs on the TrueNAS Storage.