Open NAS Software: Choosing Open-Source NAS Software

This guide compares three open-source NAS software options: TrueNAS Community Edition, openmediavault, and Rockstor. For most home and small-office storage, the choice between them comes down to the filesystem you want. TrueNAS Community Edition is built on ZFS. openmediavault is a Debian-based system that formats disks with common Linux filesystems such as ext4, XFS, and Btrfs. Rockstor is built on Btrfs. Decide how you want your disks pooled and protected, check that your hardware suits that system, and then look at the apps you plan to run on top.

All three are free to download. The facts below come from each project's own website and code repository, checked on October 13, 2026.

What NAS software does

A NAS (network-attached storage) system turns a computer full of disks into shared storage for your network. The NAS software installs as the operating system on that machine. It pools the disks, protects data against a failed drive, shares folders over the network, and gives you a web interface to manage all of it. Most options also run extra apps, such as file sync or photo backup, on the same box.

The open-source options

TrueNAS Community Edition

TrueNAS Community Edition is the free version of TrueNAS, the storage system iXsystems also sells to businesses. Its website lists Linux kernel 6.6 and Debian 12 as the foundation and ZFS as the filesystem. TrueNAS describes the edition as "open core," so not every part of the commercial product is open.

Choose it if ZFS is the reason you are building a NAS: pooled storage with built-in checksums, snapshots, and replication between machines. Plan your disk layout before you start, because changing a ZFS pool layout later is harder than adding a folder.

openmediavault

openmediavault describes itself as "a free, open-source network attached storage (NAS) solution based on Debian Linux," released under the GNU General Public License v3. Its site lists file sharing, snapshot support for shared folders, updates through Debian package management, and plugins that add features.

Choose it if you already know Debian or Ubuntu and want a NAS that behaves like a familiar Linux server. Because it sits on Debian, the general Debian knowledge you have still applies when something needs fixing.

Rockstor

Rockstor describes itself as an "Open Source multi-arch NAS Built on OpenSUSE," powered by Linux and Btrfs. Its core code repository on GitHub is licensed GPL-3.0. The installers are free, but its FAQ says the curated Stable update channel requires a subscription fee; the Testing and Edge channels are free.

Choose it if you want Btrfs features, such as snapshots and mixing disks of different sizes, on an openSUSE base. Check its documentation and forum activity for the hardware you plan to use.

Where Unraid fits

Unraid is a popular NAS operating system, but it is not open source: its license agreement forbids copying the software beyond backups and forbids reverse engineering it. It is sold as a one-time license. On October 13, 2026, its pricing page listed Starter at $49 for up to 6 storage devices with one year of updates, Unleashed at $109 for unlimited devices with one year of updates, and Lifetime at $249 for unlimited devices with lifetime updates. If you specifically want open-source software, use one of the three options above.

How to choose

1. Pick the filesystem first. ZFS points to TrueNAS Community Edition, and Btrfs points to Rockstor. If you want a common Linux filesystem such as ext4 or XFS and have no strong preference, openmediavault fits.
2. Check your hardware against the project's own requirements page, including the number of drive bays, memory, and network speed. Each project publishes its own minimums, and they differ.
3. Decide how much Linux you want to touch. openmediavault rewards Debian experience, because it runs on Debian and updates through Debian package management.
4. List the apps you want to run on the NAS and confirm each one works there before you migrate data.
5. Test a restore before you trust the system. A backup you have never restored from is a guess.

Apps to run on your NAS

The NAS software stores and shares files. The apps on top are what most people actually use day to day:

• Nextcloud (AGPL-3.0) for file sync, sharing, and calendars, often used as a self-hosted Google Drive alternative.
• Immich (AGPL-3.0) for photo and video backup from your phone.
• Copyparty (MIT) as a lightweight file server you can open from any browser.

You can browse more options in our file storage category and our list of open-source Dropbox alternatives.