I keep seeing people virtualizing TrueNAS on top of Proxmox, and honestly, I don’t get it.
TrueNAS is a dedicated storage OS — it’s designed to be the base layer, managing your disks, ZFS, shares, snapshots, and all that. So why would you then put it inside a VM, pass through entire HBAs or disks, and add a whole layer of complexity just to run it under Proxmox?
If you’re trusting TrueNAS to manage your storage, why not run it on bare metal like it was intended?
It feels like a strange hybrid where people:
• Don’t want to use TrueNAS for running VMs (understandable — bhyve and jails aren’t for everyone),
• But also don’t want to take the time to learn how to set up a basic Samba or NFS server on Debian/Ubuntu/whatever,
• So they end up with this Frankenstein setup that’s harder to troubleshoot, maintain, and secure.
What’s the real benefit here, aside from “I want a nice GUI” or “I saw it on YouTube”?
Does anyone actually gain something from this that offsets the added complexity and risk?
Genuinely curious if I’m missing something — open to being convinced otherwise.
I can see a use for this in a home lab especially when for testing or learning about TrueNAS. Many also getting into the homelab space want to run only one server for everything so have to make a choice. As you stated, running VMs and containers has been more difficult in TrueNAS than in Proxmox, which is the darling VM platform for YouTube creators so has many more tutorials available.
The changes we are seeing in TrueNAS scale vs core may make running VMs/containers easier and change this calculation for some in the future.
I did exactly this when I first had to set up a NAS at my small business and the reasons were financial. At the time, FreeNAS greatly simplified many pieces of the puzzle. It was robust, provided good UI tools for managing, backing up, and sharing files with my users and it saved the headache of jumping into the deep end of samba, nfs, afp, and whatever else I was using at the time. I didn’t know what I was doing and the UI really helped get up to speed. Installing it as a VM was the only good option I could see. I had other services I needed to provide and I didn’t have a ton of extra hardware.
Virtualizing FreeNAS back then worked really well for me. These days I have separate hardware for a TrueNAS Core file server (that will probably become vanilla FreeBSD in the near future) and a small cluster of PVE servers. I still think virtualizing TrueNAS makes sense in some circumstances. I think the problems arise when people expect any virtualized NAS to provide production-level service while using the host machine as a playground.
Because it places all of your rollback / snapshot / etc functionality under a single pane of glass, rather than splitting it between two wildly different interfaces and platforms. Is it the best idea, technically, or performance-wise? Absolutely not.
But, for reference, I have frequently virtualized XigmaNAS beneath Linux KVM for clients who want full service SMB networking but don’t want to put money in Microsoft’s pocket. The key thing is, when I do it that way, XigmaNAS actually runs on UFS2–not ZFS–because, again, I’m reserving the ZFS layer and the snapshotting and replication and everything else all the way up top, at the host level, rather than nesting it.
Don’t get me wrong, nesting ZFS beneath ZFS does work. It’s not really unsafe data-wise. But it can cause some really ugly performance complications if you aren’t capable of expert-level tuning!
I agree with you, @mercenary_sysadmin — that’s exactly my point. If you’re already committed to running Proxmox and just need a NAS, then why use TrueNAS at all?
Solutions like MS Server, XigmaNAS, or even a basic Ubuntu LXC container can provide SMB/NFS shares and integrate much more cleanly into the Proxmox ecosystem — especially when you want to take advantage of ZFS at the hypervisor level, as you mentioned.
What really puzzles me is the sheer number of people going for this setup where they pass entire disks or HBAs through to a TrueNAS VM. That kills Proxmox’s ability to manage storage directly and often leads to performance bottlenecks or loss of flexibility.
Sure, the “single pane of glass” argument makes sense if it truly simplifies things — but let’s be honest, in most of these setups, the same sysadmin is managing both Proxmox and TrueNAS anyway
Even in environments with separation of duties, I’d argue this architecture adds more complexity than it solves. From a design perspective, it doesn’t really hold up, and it should be strongly discouraged.
If someone wants the full TrueNAS experience with ZFS, snapshots, replication, etc., then just run it on bare metal — it’s excellent for that.
If you’re going with Proxmox, keep your storage strategy aligned with it. There are better-suited, more efficient options than shoehorning TrueNAS into a VM.
