TrueNAS vs OpenMediaVault vs Unraid

You Just Want to Store Some Linux ISOs

You’ve got a box under the desk. Maybe it’s an old PC, maybe it’s an actual rackmount you impulse-bought for $60 at an estate sale. You have drives. You have a vague notion that you want to stop copying files over USB like it’s 2004. You type “home NAS OS” into a search engine and immediately regret it because now there are six Reddit threads calling each other wrong and someone brought up their ZFS pool like it’s a first-born child.

Here’s the thing: TrueNAS Scale, OpenMediaVault, and Unraid are all good. They’re just good at different things, for different people, with different definitions of “I’ll deal with that on Saturday.”

This article won’t tell you one is objectively better. It’ll tell you which one is right for you — and more importantly, which one your future 2 AM panicking self will thank you for picking.

What a NAS OS Actually Does (vs. Doing It Yourself)

You could install Debian, slap ZFS on it, configure Samba, write your own systemd units, and maintain it indefinitely. Some people do this. They are not wrong. They are also the kind of people who enjoy debugging PAM configs at midnight.

A dedicated NAS OS wraps all of that into a web UI with:

• Storage management — disk pools, RAID/parity, filesystem creation
• Share management — SMB/NFS/iSCSI configured through a GUI
• App layer — Docker containers, VMs, or both, depending on the OS
• Monitoring — SMART data, temps, capacity graphs
• Permissions — users, groups, ACLs without touching /etc/passwd directly

The difference between the three isn’t “which one does NAS stuff.” They all do NAS stuff. The difference is how much they opinionated your life in doing it.

TrueNAS Scale — The ZFS Path

TrueNAS Scale is what you pick when data integrity is your religion and you are willing to tithe accordingly. It’s Linux-based (Debian underneath), maintained by iXsystems, and it treats ZFS not as a feature but as a core identity. There is no “but I want ext4” — you’re on ZFS, you’re going to like it, and honestly? You probably will.

What ZFS Gives You

ZFS is copy-on-write, self-healing, and snapshot-native. Every write is checksummed. Bit rot — the slow corruption of data over years that kills silently on ext4 — is something ZFS actively fights. You get snapshots that take milliseconds and can replicate to another TrueNAS box over SSH. You get datasets with quotas, compression, dedup (if you have RAM to burn).

It’s the kind of filesystem that makes you feel like your data is safe in a way that a RAID controller with no checksumming never quite achieves.

The Hardware Demands

Here’s where it gets spicy. ZFS wants RAM — the general rule of thumb is 1 GB per TB of storage, though that number was born in enterprise SAN land and is somewhat negotiable for home use. The ECC RAM debate is long and mostly settled: ECC is nice, not strictly required for home NAS, but if you’re running TrueNAS on a proper server with ECC slots, there’s no reason not to use it.

More practically: TrueNAS wants matched disks. ZFS pools are happiest with same-size drives. Expanding a pool by adding one bigger disk doesn’t work the way you want it to. You’re adding a new VDEV or replacing all disks and resilvering, not just slotting in a 16 TB next to your 4 TBs and calling it a day. This is a real friction point that trips up home labbers who accumulated drives over time.

The App Story

TrueNAS Scale ships with an app marketplace powered by Docker Compose (as of Electric Eel 24.10, which replaced the previous K3s/Helm-based catalog). It covers the popular stuff — Jellyfin, Nextcloud, Plex, etc. — via curated Compose stacks managed through the UI. If you want to break out of the app catalog and run arbitrary containers, you can — but you’re wading into ix-apps territory and the docs occasionally get thin.

TrueNAS Scale Strengths

• Best-in-class data integrity with ZFS
• Excellent snapshot + replication story (send/receive over SSH)
• Active open-source development, iXsystems backing
• Great for media servers, backup targets, anything where “I need to know this data is intact in five years”

TrueNAS Scale Weaknesses

• ZFS pool expansion is painful (matched-size-disk preference)
• App layer has rough edges compared to just running Docker Compose
• Heavier RAM footprint
• The UI is feature-rich in a way that can be intimidating at first

Target user: The person who has a 4-bay NAS, is buying matched drives, and says things like “my scrub schedule runs on Sunday nights.”

OpenMediaVault — The Debian Power-User Path

OMV is what you get when someone says “I like Debian, I just want a web UI for the boring parts.” Under the hood it’s stock Debian, which means if you know Linux, you can always fall back to the shell and do it the right way. The web UI wraps storage, shares, users, and services — but it doesn’t try to own your machine the way TrueNAS does.

The Plugin Ecosystem

OMV ships lean. Out of the box you get SMB/NFS shares, basic disk management, and a serviceable but not glamorous UI. The real power comes from omv-extras — an unofficial but community-blessed plugin repository that adds:

• Docker/Portainer — full container management
• ZFS — yes, you can have ZFS on OMV (via a plugin), though it’s not as first-class as TrueNAS
• SnapRAID — software RAID with error correction that runs as a nightly job
• MergerFS — a FUSE filesystem that merges multiple disks into one logical pool

The SnapRAID + MergerFS combo is the OMV power move. MergerFS pools your drives into one mountpoint (/data looks like it’s one giant drive, it’s actually five). SnapRAID runs nightly parity calculations so if one disk dies, you can recover it. It’s not real-time RAID — there’s a window between parity syncs where you could lose recent writes — but for a media server with files you’re not actively writing to at 11 PM, it’s a pragmatic trade-off.

Filesystem Flexibility

OMV doesn’t care what filesystem you use. ext4, btrfs, ZFS (via plugin), XFS — format however you want. This makes it genuinely great for using existing drives without reformatting. Got a drive already full of stuff on ext4? OMV can import it.

The “You Maintain It” Reality

Here’s the honest part: OMV is Debian with a nice shirt. When something breaks, you are debugging it on a Linux system, because that’s what it is. This is good if you’re a Linux person. It’s a learning curve if you’re not. The UI is functional but not polished in the way Unraid’s is. There are occasional gaps where you’ll SSH in and wonder why the UI doesn’t expose a setting that clearly exists.

Also: plugin updates can occasionally require attention. It’s not set-and-forget in the way TrueNAS aspires to be.

OMV Strengths

• Full Debian under the hood — SSH in and do anything
• Filesystem agnostic
• SnapRAID + MergerFS = great media server foundation
• Docker/Portainer integration is excellent
• Free and open source
• Runs on very modest hardware

OMV Weaknesses

• Thinner polish than the others
• ZFS is a plugin, not native
• SnapRAID parity is not real-time (overnight sync gap)
• Plugin quality varies; some are community-maintained with variable attention

Target user: The home labber who already runs Linux servers, wants a GUI for the tedious parts but isn’t afraid of the shell, and has a pile of mixed-capacity drives they don’t want to reformat.

Unraid — The “I Have Weird Disks” Path

Unraid is the NAS OS for people who opened their parts bin and found a 4 TB, a 6 TB, an 8 TB, and a 2 TB, and thought “surely there’s a way to use all of these.” There is. It’s Unraid.

The Parity Architecture

Unraid doesn’t use RAID in the traditional sense. You designate one disk as your parity disk (it must be the largest, or tied for largest). Every other disk in the array is independent — no striping. A parity calculation covers the whole array, so if any one data disk fails, you can reconstruct it.

The upside is radical: mixed disk sizes work fine. Add a 10 TB next to your 2 TB without rebuilding anything. Replace the 2 TB with a 12 TB later. Each disk is just a disk with XFS or btrfs on it, mounted into the array. The array appears as one pool via a share system.

The Cache Pool

Raw array writes go through the parity disk, which means sequential write speeds are bounded by one disk (more on this in the tradeoffs section). The fix is the cache pool — a separate pool of fast drives (SSDs work great here) that acts as a write buffer. New data lands on the cache, then moves to the array on a schedule (the “mover”). Since Unraid 6.12+, the cache pool can run ZFS, which is a meaningful improvement.

Apps, Docker, and VMs

Unraid’s app store (“Community Applications”) is the best out-of-three for sheer usability. It’s a curated, searchable library of Docker containers. One-click deploy, sensible defaults, active templates maintained by the community. VMs work well too — Unraid was built partly around the idea of running a gaming VM while using the NAS side simultaneously.

The UI is polished. New users consistently find Unraid the easiest to get started with.

The License

Unraid is paid. $49 for Basic (up to 6 storage devices), $69 for Plus (12 devices), $129 for Pro (unlimited). One-time, not subscription. For a home lab, this is genuinely a non-issue — it’s less than a dinner out, and you get lifetime updates. Mention this in a forum and someone will tell you OMV is free. They’re right. It’s also a different product.

Unraid Strengths

• Mixed-size disk support is unmatched
• Best app store / container management UX
• VM support is solid
• Great for junk-drawer hardware builds
• Polish and ease of use lead the pack

Unraid Weaknesses

• Paid (though affordable)
• Parity write bottleneck on array disks (cache pool mitigates this)
• Not fully open source (the community apps ecosystem is, the core isn’t)
• ZFS on cache pool only (array disks stay btrfs/XFS)

Target user: The person who wants the easiest path to a working NAS with whatever drives they have, values the app ecosystem, and is fine paying $49 once rather than maintaining a Linux system.

Comparison Table

A Docker Compose Starting Point

All three can run a basic media stack. Here’s a Jellyfin + Jellyseer combo you can drop in anywhere — the only difference is where you manage it.

services:
  jellyfin:
    image: jellyfin/jellyfin:latest
    container_name: jellyfin
    network_mode: host
    volumes:
      - /mnt/data/media:/media:ro
      - /opt/jellyfin/config:/config
      - /opt/jellyfin/cache:/cache
    restart: unless-stopped

  jellyseerr:
    image: fallenbagel/jellyseerr:latest
    container_name: jellyseerr
    environment:
      - LOG_LEVEL=info
    ports:
      - "5055:5055"
    volumes:
      - /opt/jellyseerr/config:/app/config
    restart: unless-stopped

• TrueNAS Scale: Deploy via the app catalog, or drop this in a Custom App. Your media path would be a dataset mountpoint, e.g., /mnt/tank/media.
• OMV: Run through Portainer (installed via omv-extras). Media path is wherever MergerFS merged your pool.
• Unraid: Community Applications has one-click templates for both. Set your media share path under /mnt/user/media.

Honest Tradeoffs

TrueNAS ZFS Pool Expansion Is Annoying

ZFS VDEVs are immutable. You can’t add a single disk to an existing mirror or RAIDZ and have it grow cleanly. Your options are: add a whole new VDEV (adds capacity in a new stripe), replace all disks in a VDEV with larger ones and resilver sequentially (slow and stressful), or wait for ZFS RAIDZ expansion (now in OpenZFS 2.2+ but TrueNAS support is catching up). If you’re starting fresh with matched drives this is fine. If you’re expanding ad hoc, it’ll make you want to throw a keyboard.

Unraid Parity Write Penalty

Every write to the array goes through a read-modify-write on the parity disk. At scale, this caps sequential array writes at roughly single-disk speed. If you’re writing large files constantly, you’ll notice. The cache pool is the fix — but you need fast cache drives, and you need to size the cache to absorb your write bursts before the mover runs. Most home NAS workloads (adding new media, backups on a schedule) don’t hit this hard. If you’re running a database on the array, you shouldn’t be doing that anyway.

OMV: You Maintain It

OMV is a UI on top of Debian. OMV updates don’t always align with Debian updates perfectly. Plugin quality varies. Occasionally a kernel update breaks something, or an omv-extras plugin lags behind a dependency change. None of this is catastrophic — it’s just Linux admin work. If you’re comfortable with that on a server, OMV is liberating. If you wanted appliance-style “set it and forget it,” it’ll occasionally remind you that it’s a power tool.

Pick the One That Matches Your Saturday

Here’s the real filter:

Pick TrueNAS Scale if: You’re buying new matched drives, ZFS data integrity matters to you, you want a proper snapshot/replication story, and you’re okay accepting that you’re in the ZFS world now with all its constraints. You want your data to still be intact in five years and you’re willing to plan your storage ahead of time.

Pick OpenMediaVault if: You’re a Linux person who wants a UI for the boring parts but expects to SSH in regularly. You have mixed drives you don’t want to reformat, you want to run Docker the way you want to run Docker, and you’re comfortable maintaining a Debian system long-term. The SnapRAID + MergerFS combo is genuinely great for media hoarding.

Pick Unraid if: You have a junk drawer of drives and want them working by Sunday afternoon. You want the best out-of-box container app experience. You’re not afraid to pay $49 for something that just works and has a great community. You also want to run VMs alongside your NAS without fighting the OS about it.

Your 2 AM self — the one who gets an alert that a drive is throwing errors — will appreciate whichever one you picked consistently and actually understand. The worst NAS OS is the one you’re half-familiar with because you kept second-guessing the choice.

Pick one. Set up your pools. Go store those Linux ISOs. They won’t store themselves.

Related Reading

• TrueNAS Apps vs Docker on TrueNAS Scale
• ZFS Send/Receive Over WireGuard for Off-Site Replication
• Backblaze B2 + rclone: Tiered Backup at Real-World Costs
• Backup Workflow Patterns That Work
• Bcachefs in 2026: Ready or Not