What Is NAS and Why Should You Use It?
NAS (Network Attached Storage) is a storage device connected to a network, allowing multiple users to access, share, and back up data from one centralized location. Instead of using portable drives for each computer, a NAS helps you:
- Access data anytime, anywhere via LAN or the Internet
- Automatically back up your computers and mobile devices
- Share photos, videos, and files among family or work teams
- Host services like web, mail, or media streaming
- Build a home lab for testing or virtualization
The best part? You don’t need to buy expensive hardware from Synology or QNAP — you can build your own NAS for free using open-source operating systems.
Top Free NAS Operating Systems in 2025
1. TrueNAS CORE
Base: FreeBSD
Highlights:
TrueNAS CORE is one of the most reliable and trusted NAS operating systems in the IT community. It uses the ZFS filesystem, known for its excellent data integrity, snapshots, and replication features. The web GUI is intuitive, allowing easy disk management, SMB/NFS/iSCSI sharing, and scheduled backups.
Best for: Small businesses and users who value stability and reliability.
2. TrueNAS SCALE
Base: Debian (Linux)
Highlights:
Developed by the same team as TrueNAS CORE but built on Linux, TrueNAS SCALE adds support for Docker, KVM, and Kubernetes. It enables you to turn your NAS into an application and virtualization server. SCALE is designed for hybrid and scale-out environments.
Best for: Advanced users and home lab enthusiasts who want NAS + container + VM in one system.
3. OpenMediaVault (OMV)
Base: Debian
Highlights:
OpenMediaVault is one of the most beginner-friendly NAS operating systems. It installs quickly, runs efficiently on older hardware, and supports a wide range of plugins such as Nextcloud, Plex, FTP, SMB, and more. Its lightweight web interface makes it ideal for DIY NAS setups or Raspberry Pi users.
Best for: Home users and NAS beginners.
4. Rockstor
Base: openSUSE (Btrfs)
Highlights:
Rockstor leverages the Btrfs filesystem, offering snapshots, cloning, and volume management. It features a modern web UI, efficient user management, and regular updates. The Personal Edition is free and suitable for small setups or home use.
Best for: Personal NAS, developers, and IT professionals who want a modern interface.
5. XigmaNAS
Base: FreeBSD
Highlights:
XigmaNAS (formerly NAS4Free) is lightweight, stable, and perfect for older machines. It can boot from USB, HDD, or even RAM. While its interface looks classic, it supports SMB, NFS, FTP, and iSCSI, making it extremely versatile.
Best for: Reusing old PCs, low-power servers, and lightweight NAS builds.
6. UnRAID (Free Trial)
Base: Linux
Highlights:
UnRAID is known for its flexible disk management — you can mix drives of different sizes without losing capacity. It also supports Docker containers and virtual machines. Although not fully free, the trial version allows full feature testing.
Best for: Power users, home lab setups, and personal cloud servers.
7. Openfiler
Base: rPath Linux
Highlights:
Openfiler is one of the earliest open-source NAS projects. It supports iSCSI, NFS, SMB, LDAP, and RAID, and offers an easy web interface for setup. While it’s less active today, it’s still useful for learning and lab environments.
Best for: Students, network engineers, and training labs.
Summary Table
| Operating System | Base Platform | Key Features | Best For |
|---|---|---|---|
| TrueNAS CORE | FreeBSD | ZFS stability, advanced GUI | Small business, professionals |
| TrueNAS SCALE | Debian | Docker/KVM/Kubernetes support | Advanced users, hybrid lab |
| OpenMediaVault | Debian | Lightweight, many plugins | Beginners, home NAS |
| Rockstor | openSUSE | Btrfs snapshots, modern UI | Developers, small projects |
| XigmaNAS | FreeBSD | Runs on old hardware, minimal | Lightweight NAS, old PCs |
| UnRAID | Linux | Flexible storage, Docker & VM | Power users, home labs |
| Openfiler | rPath Linux | iSCSI, NFS, RAID, LDAP | Lab testing, study use |
Recommended Hardware Configuration
- CPU: Intel or AMD with virtualization (VT-x / AMD-V)
- RAM: Minimum 8 GB (16 GB recommended for ZFS)
- Storage: At least 2 drives (for RAID or mirroring)
- Network: Gigabit Ethernet (2.5G+ preferred)
- Power Supply: Stable, since NAS runs 24/7
Conclusion
Building your own NAS is a great way to save money and gain a deeper understanding of network storage systems. Whether you choose the rock-solid TrueNAS CORE, the flexible TrueNAS SCALE, or the user-friendly OpenMediaVault, these free operating systems can transform your old PC into a powerful file server.
If you’re an experimenter or home lab builder, TrueNAS SCALE and UnRAID will let you explore virtualization, containers, and cloud-like functionality — all from your home network. 🚀
Read more
- How to Install Windows Server 2025 on Hyper-V (Step-by-Step Tutorial)
- How to Install Android on Hyper-V using BlissOS on Windows
- Proxmox VE – A Comprehensive Open-Source Virtualization Solution
- Top Free NAS OS to Build Your Own NAS Server
- TrueNAS Core vs TrueNAS Scale – Which NAS OS Is Right for You?