TrueNAS vs Unraid vs OpenMediaVault: Which NAS OS Should You Actually Run?
A practical comparison of TrueNAS, Unraid, and OpenMediaVault for a budget homelab NAS: cost, drive redundancy, hardware requirements, and which one fits your build.
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The NAS vs DAS decision is about whether you need a separate storage box at all. This one assumes you already answered yes. You’ve got a spare PC, a purpose-built NAS chassis, or a pile of drives and a plan, and now you need an operating system to run on it. Three names come up every time: TrueNAS, Unraid, and OpenMediaVault.
They get lumped together because they all do the same basic job (turn a bunch of drives into one manageable pool with some protection against a drive dying), but the way each one gets there is genuinely different. Picking the wrong one for your hardware or your patience level is a common homelab regret. Here’s how they actually differ.
The three, in one sentence each
- TrueNAS (Scale or Core): ZFS-based storage, free and open source, built by a company that also sells enterprise hardware, and it wants RAM and full disks more than the other two.
- Unraid: a paid, Linux-based array system built around mixed drive sizes and easy Docker/VM support, with a genuinely different redundancy model than RAID.
- OpenMediaVault (OMV): a free, Debian-based NAS OS with a plugin system, the lightest of the three, and the least opinionated about how you set things up.
If you remember nothing else: TrueNAS wants you to buy matched drives and give it real resources. Unraid wants you to throw whatever drives you already own at it. OMV wants to get out of your way and let you build whatever you want on top of plain Debian.
Feature comparison
| TrueNAS | Unraid | OpenMediaVault | |
|---|---|---|---|
| Cost | Free | $49-$149 one-time (by pool size) | Free |
| Redundancy model | ZFS RAIDZ (parity across the whole pool) | Single/dual parity drives (mixed sizes OK) | mdadm RAID or SnapRAID plugin |
| Mixed drive sizes | No (ZFS wants matched vdevs) | Yes, this is its whole pitch | Yes with SnapRAID; no with mdadm RAID |
| RAM requirements | Higher (ZFS ARC cache wants 8GB+) | Lower (4-8GB is workable) | Lowest (2-4GB is fine) |
| Docker support | Yes (Scale), good | Yes, very good, first-class UI | Yes via plugin, more manual |
| VM support | Yes (Scale) | Yes, well integrated | Limited, third-party plugins |
| Boot drive | USB or SSD, dedicated | USB stick (unusual but standard) | Any drive, standard install |
| Best for | Data integrity purists, ZFS fans | People with a drawer of mismatched drives | People who want a plain Linux box with a storage UI on top |
Redundancy: this is where they really diverge
TrueNAS uses ZFS, and ZFS pools want same-size (or same-shape) drives grouped into vdevs. Add a drive later and you’re often adding a whole new vdev, not just growing the pool. In exchange, you get checksumming on every block, snapshots that don’t lie, and a filesystem that’s genuinely excellent at catching silent data corruption before it becomes a real problem. This is the correct answer if data integrity is your priority and you’re willing to buy drives in matched sets.
Unraid flips the model. Your array can be a 4TB drive, an 8TB drive, and a 2TB drive from three different upgrade cycles, and it still works. One or two of your largest drives become dedicated parity drives, and Unraid rebuilds a failed data drive from parity plus the surviving drives. You don’t get ZFS-level checksumming by default (though Unraid does support ZFS pools alongside its array now), but you get to use every drive you already own without buying a matched set. This is why it’s the go-to for people who accumulated drives over several years rather than buying a NAS all at once.
OpenMediaVault doesn’t pick a side. It’s Debian with a management UI, so you choose your own redundancy: standard Linux mdadm RAID (wants matched drives, similar tradeoffs to ZFS), or the SnapRAID plugin (parity-based, mixed drive sizes, similar spirit to Unraid but snapshot-based rather than real-time, meaning a drive can fail between SnapRAID syncs and you lose whatever changed since the last sync). More flexible, more manual, more your responsibility to configure correctly.
Cost: the one real dealbreaker for some people
TrueNAS and OpenMediaVault are both free and open source. Unraid is not. Licensing is a one-time purchase based on how many storage devices you attach: a Starter tier caps at 6 devices for about $49, Unraid Plus goes up to 12 for around $109, and Unraid Pro removes the device cap entirely for about $149. There’s no subscription, and licenses transfer to new hardware if you’re not running the same USB boot key.
For a small build (under 6 drives), $49 one-time is a reasonable price for the ease of use and Docker integration you get in return. For a big media server with a dozen drives, the free options start looking a lot more attractive on cost alone.
Hardware requirements
None of these need enterprise hardware, but they don’t want the same thing from a budget box.
TrueNAS is the most demanding. ZFS caches aggressively in RAM (the ARC), so 8GB is a bare minimum and 16GB+ is where it stops feeling cramped. ECC RAM is recommended by the TrueNAS team for maximum data integrity, though plenty of home users run it fine on non-ECC hardware. If you’re repurposing an old PC into a dedicated NAS, this is the one where more RAM actually buys you something.
Unraid is lighter on RAM (4-8GB is genuinely workable for a storage-only array) but appreciates more RAM if you’re also running several Docker containers or VMs on the same box, which is the whole point of running Unraid instead of a dumber NAS OS.
OpenMediaVault is the least demanding of the three. It’s plain Debian, so anything that runs Debian comfortably runs OMV comfortably. An old PC with 4GB of RAM and a couple of drives is a perfectly fine OMV box.
For the actual drives, a plain 2TB or 4TB drive like the Seagate BarraCuda works across all three, since drive choice is mostly independent of which OS you pick. If you want a separate cache or app drive so your Docker containers aren’t fighting your spinning storage for I/O, a 2TB NVMe like the Crucial P3 Plus works as a TrueNAS special-purpose vdev, an Unraid cache pool drive, or an OMV app-data drive.
Docker and VM support
This is the category that pulls a lot of homelab users toward Unraid specifically. Its Docker management is a first-class citizen in the UI, not an afterthought, with a template system (Community Applications) that makes installing containers close to a one-click experience. VM support through its built-in KVM manager is similarly polished.
TrueNAS Scale added solid Docker and VM support in recent versions and has closed most of the gap, though the UI still feels more storage-first with apps layered on top rather than built in from day one.
OpenMediaVault can run Docker through the community compose plugin, but it’s the least integrated of the three. You’re closer to running plain Docker on Debian with OMV handling the storage underneath, which is fine if you’re comfortable with the command line but not the “click to install Jellyfin” experience Unraid sells.
The decision matrix
| Your situation | Pick |
|---|---|
| You have mismatched drives from years of upgrades | Unraid |
| You want the best Docker/VM experience on a NAS OS | Unraid |
| You care most about data integrity and are buying matched drives | TrueNAS |
| You want it free and don’t mind ZFS’s drive-matching requirements | TrueNAS |
| You want a plain, lightweight Linux box with a storage UI on top | OpenMediaVault |
| You’re repurposing genuinely old, low-RAM hardware | OpenMediaVault |
| Budget for licensing is a hard no | TrueNAS or OpenMediaVault |
What I’d actually recommend for a first NAS build
If you’re starting from a pile of drives you already own, in different sizes, and you want Docker apps running alongside your storage, Unraid earns its license fee. The one-time cost is small compared to what a bad redundancy experience costs you in lost weekends.
If you’re buying drives fresh and can commit to a matched set, TrueNAS Scale gives you real ZFS integrity for zero dollars, and that’s hard to argue with on a budget site. The RAM requirement is the one place I’d tell you not to cheap out. An 8GB box running TrueNAS is a worse experience than a 16GB box running TrueNAS, in a way that isn’t true for the other two.
If you’re just repurposing an old machine you already have sitting around and don’t want to think about it much, OpenMediaVault is the path of least resistance. It won’t hold your hand, but it also won’t ask anything of your hardware that plain Debian wouldn’t.
Whatever you pick, the OS doesn’t replace a backup plan. RAID and parity protect you from a drive failing, not from ransomware, accidental deletion, or the box itself dying. The homelab backup strategy guide covers the layer that actually protects your data, and it applies the same way regardless of which of these three you’re running. If you’re still deciding between building a dedicated NAS at all versus keeping drives in your main server, homelab storage options is the article to read first. And if the box running any of this is going to be new hardware rather than something you already own, the best mini PCs for a homelab roundup covers what’s worth buying in 2026.