Free and Open Source NAS Operating Systems

On this page you will find information about free, open-source network attached storage operating systems. Once you have have built your home server, it won’t be able to do anything, unless you install an operating system that turns your server in to a NAS server.

One could say that any operating system could server files and media over a network, which is true, but the systems below are optimised to serve your files and media. And, the good thing, they’re all free.

A list of proprietary NAS operating systems can be found here, but they’re not the main focus of this blog. We’ll focus on the following instead:

  • Amahi
  • EON ZFS Storage
  • FreeNAS
  • Napp-it
  • NexentaStor
  • OpenFiler
  • OpenMediaVault
  • NAS4Free


  • CryptoNAS
  • PulsarOS
  • aStor



Amahi is a free and open-source Home Server built on Fedora Linux that provides:

  • Media streaming
  • Shared Storage (disk pooling technology is handled by Greyhole)
  • Automated backups
  • File Sharing
  • Disk Monitoring
  • One-click apps
  • Secure VPN
  • Shared applications like calendar and wiki.

Amahi Linux Home Server makes your home networking simple and manages basically the networking and backup of all the computers, game consoles and other devices in your network, and provides secure access to your network from the internet. Amahi’s

The core functionality available in the base Amahi HDA install includes:

  • Protect Your Computers – Backup all your networked PCs simply and easily on your home network. If one of your PCs “dies” you can easily restore it!
  • Organize Your Files – Access, share and search your files from any machine on your network, making it easy to share and find your photos, music and videos.
  • Internet Wide Access – Automatically setup your own VPN so you can access your network from anywhere: safely and securely.
  • Private Internet Applications – Shared applications like calendaring, private wiki and more to come, will help you manage your home and your family!



EON ZFS Storage

EON stands for Embedded Operating system/Networking. It is the first embedded Solaris ZFS (Zettabyte File System) Network Attached Storage distribution based on Opensolaris.

EON ZFS Storage is a RAM-based ZFS storage appliance running live from CCD/DVD, USB, CF or other devices, optimized to give you an embedded NAS storage appliance feeling. The appliance image provides a high performance 32 or 64-bit storage solution built on ZFS, using regular disks which eliminates the use of expensive RAID arrays, controllers and volume management software.

EON focuses on using a small memory footprint so it can run from RAM while maximizing the remaining free memory for ZFS performance. Running from RAM adds the advantage of being one hard disk greener in power consumption and removes the OS install disk as a point of failure. And if your hardware fails, no costly measures are needed to recover your precious data. Simply attach the disks to another machine with a ZFS capable operating system or EON.

EON, based on Solaris Express Community Edition (SXCE) OS (code named “Nevada”) offers rock solid, reliable, enterprise featured storage, with unlimited file system snapshots (version-ing or rollback points), transparent file system compression and de-duplication(duplicate elimination).



FreeNAS is a free and open-source software providing network-attached storage (NAS). This storage platform supports sharing files and media across Windows, Apple, UNIX-like systems and various virtualisation hosts such as XenServer, VirtualBox and VMware.

FreeNAS comese with support for a number of network protocols (CIFS, AFP, NFS, iSCSI, SSH, rsync and FTP/TFTP), full-disk encryption, a plugin architecture for third-party extensions and, probably most importantly, it includes the ZFS filesystem (high storage capacities integrating file systems and volume management into a single piece of software),

FreeNAS is based on FreeBSD’s NanoBSD embedded build system, the Python programming language, the Django CMS and the dōjō toolkit JavaScript toolkit.comes with a dedicated management web interface

FreeNAS is developed by iXsystems, which also sells TrueNAS, a FreeNAS based OS that comes with propriety tweaks and optimisations, as well as full support.



NexentaStor is an easy to use storage appliance, that harnesses the power of the ZFS filesystem. It provides enterprise class experience, with an easy to use web based interface to administer your file server. It features iSCSI support, unlimited incremental backups or ‘snapshots’, snapshot mirroring (replication), block level mirroring (CDP), integrated search within ZFS snapshots and a custom API.



OpenFiler is a full-fledged, NAS/SAN operating system, based on the rPath Linux distribution and released under the open source GPLv2 license. OpenFiler can be installed on PCs and servers, or can be alternatively be run as a virtual machine. Unlike FreeNAS, Openfiler requires ‘decent’ server hardware with minimum specs of 1GHz CPU, 2GB RAM, 10GB disk space and an Ethernet adapter.

Openfiler supports the SMB/CIFS, NFS, HTTP/WebDAV and FTP network protocols. Network directories supported by Openfiler include NIS, LDAP, Active Directory, and Hesiod. Openfiler also offers extensive sharing management features, such as multi-group based access control. Protocol settings and many other settings can be managed by a web interface.

OpenFiler can act as a simple file server, or if you want you can configure it as an iSCSI, or even a Fibre channel SAN. Not only that, but what sets it apart from other free NAS operating systems like FreeNAS is that you can actually configure Openfiler in a high Availability (HA), Active/Passive cluster for redundancy.

Thanks to commercial support, support for iSCSI, integration into LDAP and Active Directory, and other basic features for businesses, makes OpenFiler a much opted storage operating system  within enterprises.


The open network attached storage solution – Built to give your data a home.

OpenMediaVault (OMV) is a next generation network attached storage (NAS) solution based on Debian Linux. Though not released yet, OMV utilises the many strong points of FreeNAS, but instead of using FreeBSD as its base, it uses Debian

OMV aims to be a simple NAS solution for home environments which means that OMV is no router, firewall or storage solution for hundred of users. OMV has a modular design so it can be easily extended with plugins and other contributions from the community.

OMV contains services like SSH, (S)FTP, SMB/CIFS, AFP, UPnP media server, DAAP media server, RSync, DDNS, BitTorrent client and many more.

In summary: OpenMediaVault is primarily designed to be used in home environments or small home offices, but is not limited to those scenarios. It is a simple and easy to use out-of-the-box solution that will allow everyone to install and administrate a Network Attached Storage without deeper knowledge.




NAS4Free is an embedded open source storage NAS (Network-Attached Storage) distribution based on FreeBSD, and is a continuation of the original FreeNAS code which was developed between 2005 and late 2011. It was first released under the new NAS4Free name on 22nd March 2012 and based on FreeNAS 7.

NAS4Free supports file sharing across Windows, Apple, and UNIX-like systems. It includes ZFS v5000, software RAID (0,1,5), disk encryption, S.M.A.R.T and report emailing functionality. NAS4Free also supports the following protocols: CIFS (samba), FTP, NFS, TFTP, AFP, RSYNC, Unison, iSCSI (initiator and target), HAST, CARP, Bridge, UPnP, and Bittorent, which are all configurable through the web interface.

NAS4Free can be installed on Compact Flash/USB/SSD media, hard drive or booted from a LiveCD with a small USB pen drive to store configuration settings.


Discontinued NAS systems


CryptoNAS is a NAS project that concentrates on disk encryption for NAS servers. CryptoNAS, formerly known as CryptoBox, is a Linux-based LiveCD that incorporates encryption with a NAS server.

CryptoNAS aims to make NAS file encryption as easy and straight-forward as possible. It provides two packages:

  1. The CryptoNAS-Server package is targeted at network administrators and adds hard disk encryption to a file server (running Samba, NFS, DAV, etc.) and a user-friendly, web-based frontend for harddisk encryption to an existing fileserver.
  2. The CryptoNAS-CD is targeted at home users who want to set up an encrypting file server without bothering about complicated administration issues. CryptoNAS-CD allows for easy NAS device encryption and browsing through a web interface.

The CryptoNAS-Server can be installed on an existing Linux system with a minimum kernel 2.6, cryptsetup with LUKS support, kernel support for the crypt target of the device mapper, and Python 2.4. It runs on pretty much any Linux distribution, but the CryptoNAS developers only provide packages for Ubuntu and other Debian distributions.

Once an encrypted volume has been activated through the CryptoNAS web front-end, the server can be accessed on the local network via a SMB/CIFS share. The encrypted disk partitions are LUKS (Linux Unified Key Setup) volumes, which can be opened from any PC on the network by using FreeOTFE in Windows to decrypt and access the files, or directly with modern Linux systems.

The minimum requirements to run the CryptoNAS-CD is a 200MHz CPU with 64 MB RAM, a CD-ROM, a network connection, and a storage disk. The storage disk can be any drive supported by the Linux kernel (2.6.20), such as IDE, SCSI, USB, FireWire, SATA, and RAID.

It is important to remember, that if you switch off the computer on which CryptoNAS is running, that the encrypted hard drives on your NAS will shut down and it will be inaccessible until you reopen it again entering the correct passphrase. You must remember that as long as CryptoNAS is running with the disks mounted the data is unencrypted and the encryption key held on RAM memory, only if someone disconnects your NAS device (i.e. NAS device gets stolen) or you turn it off encryption will secure your data.



pulsar os nas solution

PulsarOS ( | SourceForge) is a Linux-based Network-Attached Storage (NAS) distribution geared for home use, featuring a modular build and very small footprint.

PulsarOS aims to keep everything simple; it somes with a clean and simple front end, and keeps evertything under the hood simple too. It loads completely into RAM (only 20Mb required) and uses 15Mb of disk space. These minimal storage requirements make it a perfect distribution for Intel’s Atom or VIA’s mini-itx processors and other low-powered devices. Combined with an IDE-CF adapter or small flash module it is silent, working away without noise, and “green”, using hardly any power. The plugin system makes PulsarOS highly extensible whilst keeping the distribution simple.
The project has gone quiet and seems abandoned as there haven’t been any updates since 2009.



aStor is developed by eTegro Technologies and is based on Debian GNU/Linux distribution and uses Einarc (Einarc is not a RAID CLI), a universal storage RAID command line interface and an API that provides management for various hardware/software RAID devices, uniting them all in a single paradigm.

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