TrueNAS: ZFS-first NAS OS with snapshots and replication
TrueNAS Community Edition (formerly SCALE) puts ZFS at the centre: checksummed pools, cheap snapshots and replication to another box. Apps run as Docker containers. Each vdev is sized to its smallest drive, so drives within a vdev should match, and it needs at least 8 GB of RAM.
Is TrueNAS right for you?
Choose TrueNAS if: You want ZFS data integrity, snapshots and replication, and your drives are the same size.
Pros
- Free and open source
- Checksummed ZFS pools with cheap snapshots and replication
- Docker apps and VMs built in
Cons
- Drives within a vdev should match in size
- Needs at least 8 GB of RAM
- Must boot from an SSD or NVMe drive
Compare with other NAS OS
See how TrueNAS differs on storage, licensing and what it runs on.
| Spec | TrueNAS | Unraid | HexOS | ZimaOS | openmediavault | FygoOS | MOS |
|---|---|---|---|---|---|---|---|
| Price | Free | From $49 | $199 lifetime | Free, $29 Plus | Free | Free, $199 lifetime | Free |
| Licence | GPL-3.0 / LGPL-3.0 | Proprietary | Proprietary | Proprietary | GPL-3.0 | Proprietary | AGPL-3.0 |
| Based on | Debian | Slackware | TrueNAS | Buildroot | Debian | Linux | Devuan |
| Boots from | SSD / NVMe | USB / SSD / NVMe | SSD / NVMe | SSD / NVMe | USB / SSD / NVMe | SSD / NVMe | USB / SSD / NVMe |
| Storage | ZFS | Parity array or ZFS | ZFS | RAID, ZFS or JBOD | RAID, mergerfs, SnapRAID | ext4, Btrfs or ZFS | XFS, Btrfs, mergerfs, SnapRAID, parity array |
| Mixed drive sizes | Each vdev uses its smallest drive | Yes | Each vdev uses its smallest drive | Via JBOD, without redundancy | With mergerfs | Not documented | Yes |
| Virtual machines | Yes | Yes | Yes | Yes (ZVM) | Via plugin (KVM) | Yes (best on x86) | Yes (QEMU/KVM) |
| Apps | TrueNAS Apps (Docker) | Community Apps (Docker) | Curated one-click apps | One-click store (Docker) | Docker Compose plugin | App Center and Docker | MOS Hub (Docker templates), LXC |
| Architecture | x86 only | x86 only | x86 only | x86 only | x86 and ARM | x86 and ARM | x86 and ARM |
| Min RAM | 8 GB | 4 GB | 8 GB | 4 GB | 1 GB | 2 GB | 4 GB |
| Best for | Data integrity, snapshots and replication | Growing a pool from mismatched drives | TrueNAS without the learning curve | Simple app hosting with little setup | Low-power ARM boards and old PCs | Photo backup and file sharing with little setup | Unraid-style storage without a licence fee |