If you've spent any time in a homelab Discord or subreddit, you've seen the question pop up at least once a week: should I run Proxmox VE or TrueNAS Scale? Usually it comes from someone who just bought a used Dell R720 or built a mini PC with a couple of spare drives, and now they're staring at two download pages wondering which ISO to burn.
Here's the thing that trips people up: these aren't really competing for the same job. One is a hypervisor that happens to do storage well. The other is a storage operating system that happens to do virtualization too. Once you see it that way, the decision gets a lot easier.
This guide walks through what each one actually is, where they overlap, where they don't, and how to test both without committing your only pool of drives to a decision you might regret.
What You Will Learn
By the end of this article you'll know what Proxmox VE and TrueNAS Scale are built to do, how their storage and virtualization models differ under the hood, and which one fits your actual use case rather than the one with the louder fanbase.
- What each platform is designed for, in plain terms
- How ZFS works in both, and why that matters more than people think
- A safe way to test-drive both before you touch your real data
- The mistakes that send people down the wrong path
What Is This Feature?
Proxmox VE is a free, open-source hypervisor built on Debian. It runs full virtual machines through KVM and lightweight Linux containers through LXC. Storage is one of many things it handles — you can back VMs with ZFS, LVM, Ceph, or plain directories, but storage isn't the point of the product. Virtualization is.
TrueNAS Scale is the opposite starting point. It's a NAS operating system built around ZFS, the copy-on-write filesystem that made TrueNAS (and its predecessor FreeNAS) famous for data integrity. Scale added Linux underneath, a Docker-based Apps catalog for things like Plex or Nextcloud, and a Virtualization tab that runs KVM machines directly on the host. It used to run those apps on a lightweight Kubernetes setup, but more recent releases moved to plain Docker, which starts faster and is a lot easier to debug when something goes wrong.
So both platforms can technically do "storage and VMs." The difference is which one is the main course and which one is the side dish.
Why Would You Use It?
You'd lean toward TrueNAS Scale if your server's real job is being a NAS — storing photos, media, backups, documents — and you only want a VM or two on the side, maybe a Windows box for a specific app, or a Home Assistant instance. ZFS management in Scale is genuinely excellent. Creating a pool, setting up snapshots, configuring replication to a second box — all of that has a polished GUI built specifically for exactly that job.
You'd lean toward Proxmox VE if you're running more than a couple of VMs, if you want proper resource isolation between workloads, if you might build a cluster someday, or if you want LXC containers for lightweight services instead of spinning up a full VM for every little thing. Proxmox's ZFS support is also excellent — it's not a downgrade — but the interface is built around the VM inventory first and the storage config second.
Here's a comparison that usually settles the debate faster than a forum thread:
| Question | Proxmox VE | TrueNAS Scale |
|---|---|---|
| Primary job | Hypervisor (VMs and containers) | NAS (file storage) |
| ZFS support | Full, but you configure it yourself | Full, with a dedicated GUI built around it |
| Running 10+ VMs | Comfortable, designed for this | Possible, but not the intended workload |
| Clustering | Yes, built-in (Corosync) | No, single-node only |
| Docker/Apps | Via LXC or a VM you set up yourself | Built-in Apps catalog, Docker-based |
| SMB/NFS shares | Possible, but you're the one configuring Samba | Native, with a proper GUI |
| Snapshots and replication GUI | Yes, per-VM | Yes, per-dataset, more granular |
Notice neither column is "bad." They're just optimized for different afternoons.
Prerequisites
Before you install either one, a few things need to be in place. Neither of these operating systems is picky about exotic hardware, but they do have opinions about drives and memory.
- A machine with a 64-bit CPU that supports virtualization (Intel VT-x or AMD-V) — check this in your BIOS if VM creation later fails with a vague error
- At least 8 GB of RAM to test comfortably; 16 GB or more if you plan to run several VMs alongside a ZFS pool
- ECC RAM if you can get it, though it is not required — ZFS does not need ECC to function, despite what you'll read in old forum threads, but it does reduce the (already low) risk of memory errors corrupting data in flight
- A USB drive, 8 GB or larger, for the installer
- Separate drives for your data pool if you're testing TrueNAS Scale — never point it at your only boot drive
- A dedicated HBA card flashed to IT mode if you're passing physical disks through to a TrueNAS VM inside Proxmox — consumer SATA controllers in passthrough mode are a common source of grief
Step-by-Step Tutorial: How to Test Both Before You Commit Your Drives
You don't need two physical machines to compare these properly. The cleanest way to test both is to install Proxmox VE on the bare metal first, then run TrueNAS Scale as a virtual machine inside it. This lets you feel out the TrueNAS interface without wiping your host, and if you decide Proxmox alone suits you better, you just delete the VM.
- Download the Proxmox VE ISO from the official site and write it to a USB drive with a tool like Rufus (Windows) or
dd(Linux/macOS). - Boot from the USB drive and run through the installer. Pick ZFS as the root filesystem if your boot drive is an SSD or NVMe — this gives you snapshots of the host itself for free.
- Once installed, log into the web interface at
https://your-server-ip:8006. - Create a new VM. Give it at least 4 GB of RAM and 2 CPU cores for a comfortable TrueNAS Scale test — it runs fine on less, but the GUI feels sluggish under 4 GB.
- For the boot disk, set the type to SATA rather than VirtIO SCSI. TrueNAS Scale's installer doesn't always ship with the VirtIO driver preloaded, and a SATA disk avoids that headache entirely for the install step.
- If you have spare physical drives to test with, pass them through as raw disks rather than creating a virtual disk for the data pool. This gets you a realistic feel for how TrueNAS handles real hardware.
- Attach the TrueNAS Scale ISO, boot the VM, and run through its installer the same way you would on bare metal.
- Once it's up, log into the TrueNAS web UI, create a pool, set up an SMB share, and copy some files to it. This ten-minute exercise tells you more about whether you like the Scale storage workflow than any spec sheet will.
If, after poking around, you decide TrueNAS Scale should be the main event instead of a guest, install it directly on the bare metal and skip Proxmox entirely for that box. There's no shame in running two dedicated machines either, if you have the hardware for it — a lot of homelabbers eventually land there.
Commands Explained
A few commands come up constantly once you're living day-to-day in either platform. Here's what they actually do.
| Command | Where | What it does |
|---|---|---|
zpool status | Both (via shell) | Shows the health of your ZFS pool — degraded drives, resilvering progress, errors |
zfs list | Both (via shell) | Lists datasets and how much space each one is using |
qm list | Proxmox VE | Lists every VM on the node with its ID and current status |
pct list | Proxmox VE | Same idea, but for LXC containers instead of VMs |
zpool scrub poolname | Both (via shell) | Manually triggers a scrub, which reads every block and checks it against its checksum |
midclt call app.query | TrueNAS Scale | Lists installed apps from the command line, useful when the GUI won't load |
You'll rarely need the shell in TrueNAS Scale day-to-day — that's kind of the point of it. In Proxmox, dropping into the shell is more routine, especially once you start managing LXC containers directly.
Common Errors
A handful of issues show up over and over for people switching between these platforms or trying both for the first time.
"Pool import failed" after moving drives into a TrueNAS VM. This almost always means the drives were passed through as a new virtual disk instead of a raw physical disk, so ZFS sees different hardware and refuses to assume it's the same pool. Re-check your VM's disk passthrough method.
VirtIO network adapter not detected during TrueNAS Scale install. Switch the VM's network device to E1000 temporarily for the install, then switch back to VirtIO afterward and install the guest drivers from within Scale.
"Task failed" when starting a VM on TrueNAS Scale after a Proxmox migration. The two platforms don't share VM definitions — you can migrate the underlying disk image, but you have to recreate the VM configuration by hand on the other side.
ZFS pool shows as degraded after import in Proxmox. Check dmesg for drive errors first. It's usually a loose SATA cable or a drive that was disconnected uncleanly, not actual data loss.
Troubleshooting
If a TrueNAS Scale VM inside Proxmox feels slow, check three things in order: whether the CPU type is set to host instead of the default (this exposes your real CPU features instead of a generic one), whether the disk controller is VirtIO SCSI with the VirtIO drivers actually installed inside the guest, and whether you gave it enough RAM for ZFS's ARC cache to do its job — 4 GB is the floor, not a comfortable amount.
If Proxmox itself feels unstable after adding a lot of storage, check free -h for memory pressure. ZFS's ARC will happily eat most of your free RAM by design, which looks alarming the first time you see it but is completely normal — it releases memory back when something else needs it.
If SMB shares from TrueNAS Scale are slow over the network, the usual suspects are jumbo frames not being enabled consistently across your switch and NIC, or a spinning-disk pool without a dedicated write cache trying to keep up with sequential writes from multiple clients at once.
Best Practices
Don't run TrueNAS Scale as a VM on top of Proxmox and then pass through the exact same disks Proxmox's own boot pool lives on. Keep the host's boot drive completely separate from any pool you hand to a guest.
Snapshot before you experiment. Both platforms make this nearly free with ZFS, so there's no excuse for testing a risky change without one first.
If you do run TrueNAS Scale virtualized, set up a Proxmox backup job for that VM's configuration in addition to whatever backup strategy you have for the data itself. Losing the VM definition after a host rebuild is an annoying, avoidable delay.
Resist the urge to run your primary NAS pool as a virtual disk file. Physical disk passthrough exists specifically so ZFS can see real drive health data (SMART attributes, real serials) instead of a layer of virtual abstraction that hides it.
I'd also skip mixing drive sizes in the same vdev if you can help it — ZFS will let you, but you'll waste capacity on the bigger drives and complicate a future upgrade.
Frequently Asked Questions
Can TrueNAS Scale replace Proxmox VE entirely?
For a single-purpose NAS with a couple of side VMs, yes. For a homelab running many VMs, containers, or a cluster, no — that's outside what Scale is built for.
Can Proxmox VE replace TrueNAS Scale entirely?
Mostly, if you're comfortable configuring Samba and NFS shares yourself on a ZFS dataset. You'll lose the polished snapshot and replication GUI that Scale provides out of the box.
Is ZFS on Proxmox VE as reliable as ZFS on TrueNAS Scale?
Yes. It's the same OpenZFS codebase underneath both. The reliability is identical; only the management interface differs.
Does TrueNAS Scale support GPU passthrough for apps?
Yes, for supported cards, both for its Apps catalog (useful for Plex hardware transcoding) and for VMs through its Virtualization tab.
Which one is easier for a first-time NAS build?
TrueNAS Scale, by a clear margin. The storage-specific GUI removes a lot of the manual Linux administration Proxmox expects you to handle yourself.
Can I run both at once on separate machines and connect them?
Very common setup. Proxmox mounts an NFS or SMB share from a separate TrueNAS Scale box as backup or bulk storage, while each machine does the job it's actually built for.
Conclusion
Neither platform is the "beginner" one and neither is the "advanced" one — they're built for different jobs, and the right pick depends on what your server is actually going to spend most of its time doing. If storage is the whole point, start with TrueNAS Scale. If VMs and containers are the whole point and storage is just a means to that end, start with Proxmox VE.
And if you genuinely can't decide, that's fine too. Install Proxmox on the bare metal, spin up a TrueNAS Scale VM inside it with passthrough disks, and live with it for a couple of weeks. Most people know within a weekend which side of this they actually fall on.