Unraid: Mix drive sizes with parity and a big app store
Unraid boots from a USB stick, or from an internal SSD or NVMe drive since version 7.3, and lets you add drives of any size over time, protected by parity rather than striped RAID. Self-hosted apps install as Docker containers from Community Apps, and VMs with GPU passthrough are built in. It is paid software, licensed per server: Starter ($49, up to 6 drives) and Unleashed ($109) include a year of updates, Lifetime ($249) includes them for good.
Is Unraid right for you?
Choose Unraid if: You have mismatched drive sizes and want to add drives one at a time, protected by parity.
Pros
- Mix drives of any size and grow the pool over time
- Docker apps from Community Apps and VMs with GPU passthrough
- Boots from USB, SSD or NVMe
Cons
- Paid licence, per server
- Proprietary software
- No ARM support
Compare with other NAS OS
See how Unraid differs on storage, licensing and what it runs on.
| Spec | Unraid | TrueNAS | HexOS | ZimaOS | openmediavault | FygoOS | MOS |
|---|---|---|---|---|---|---|---|
| Price | From $49 | Free | $199 lifetime | Free, $29 Plus | Free | Free, $199 lifetime | Free |
| Licence | Proprietary | GPL-3.0 / LGPL-3.0 | Proprietary | Proprietary | GPL-3.0 | Proprietary | AGPL-3.0 |
| Based on | Slackware | Debian | TrueNAS | Buildroot | Debian | Linux | Devuan |
| Boots from | USB / SSD / NVMe | SSD / NVMe | SSD / NVMe | SSD / NVMe | USB / SSD / NVMe | SSD / NVMe | USB / SSD / NVMe |
| Storage | Parity array or ZFS | ZFS | ZFS | RAID, ZFS or JBOD | RAID, mergerfs, SnapRAID | ext4, Btrfs or ZFS | XFS, Btrfs, mergerfs, SnapRAID, parity array |
| Mixed drive sizes | Yes | Each vdev uses its smallest drive | 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 | Community Apps (Docker) | TrueNAS 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 | 4 GB | 8 GB | 8 GB | 4 GB | 1 GB | 2 GB | 4 GB |
| Best for | Growing a pool from mismatched drives | Data integrity, snapshots and replication | 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 |