This time I’m going to try skipping the IOMMU aspect of this rebuild process because it was honestly such a nightmare the first time I built the server.
In that particular situation, I didn’t have everything built into the server from the get-go, and nothing in the network was depending on it’s presence yet. I added pfSense next, and that took a while to get it to the point where the config worked for me, and I had the main wireless router performing all of my DHCP. I didn’t “cut” everything over to pfSense and Pihole until months after I had installed them. But this time, I was under a little more pressure to restore things to the way that they were back when we had Proxmox and pfSense/Pihole/TrueNAS working for us. So just to simplify my life, I decided not to employ IOMMU this time around.
What is IOMMU you ask? It’s short for Input/Output Memory Management Unit, and is a hardware feature that sits between your system’s memory and I/O devices (like GPUs, NICs, or storage controllers), and it plays a crucial role in:
Memory Protection
• Prevents devices from accessing unauthorized memory regions
• Shields the system from faulty or malicious DMA (Direct Memory Access) operations
Address Translation
• Maps device-visible virtual addresses to physical memory addresses
• Enables devices to access non-contiguous memory as if it were contiguous (scatter/gather)
️ Virtualization Support
• Essential for PCI passthrough in Proxmox and other hypervisors
• Allows guest VMs to use real hardware securely and efficiently
I decided this time I was going to only rely on native Proxmox systems to get things up and working. Sadly, the use of IOMMU when I first provisioned the server were exceedingly difficult to find or research on the web, because it was the proverbial “wild-west”, and for every post I could document that said to do something using Method-A, I found at least 10 other posts that said Method-A was entirely wrong. So even with the best of tools at my disposal, it was for me a veritable nightmare. Mostly it’s about the fact that if you do select the wrong method, you could literally destroy your hardware.
So this time, going to take it nice and slow to try to keep my sanity. Let me know if you had similar problems employing IOMMU.