The market for network-attached storage units has expanded significantly over the last few years. The rapid growth in public cloud storage (Dropbox, OneDrive, Google Drive and the like) has tempered the expansion a bit amongst consumers who are not very tech-savvy. However, the benefits provided by a NAS in the local network are undeniable, particularly when complemented with public cloud services. Enterprise users obviously need NAS units with different performance and feature requirements. Our previous NAS reviews have focused more on the performance aspect. With feature set and ease of use becoming important across all market segments, we believe that a qualitative evaluation of the different commercial NAS operating systems is needed to educate consumers on the options available.


Commercial off-the-shelf (COTS) NAS operating systems are popular across a wide range of market segments - business and enterprise users (including those with dedicated IT staff) prefer to have plug-and-play storage units that don't need much babysitting, while the average consumer often wants a media-centric unit without the hassle of re-purposing an old PC or building a file server from scratch. This regularly-updated piece will take a look at the features and usability of the currently popular COTS NAS operating systems.

The following NAS vendors / operating systems are currently covered in this article:

  1. Asustor [ ADM 2.6.5R9N1 ]
  2. Netgear [ ReadyNAS OS 6.6.0 ]
  3. QNAP [ QTS 4.2.2 ]
  4. Synology [ DSM 6.0.2-8451 Update 3 ]
  5. Western Digital [ My Cloud OS 2.21.19 ]
  6. ZyXEL [ FW v5.20(AATB.0) ]

Different vendors cater to different market segments - both in terms of hardware and software features. For example, Asustor, Netgear, QNAP and Synology have units ranging from 2-bay desktop models targeting the average home consumer to 12-bay rackmounts targeting SMBs and SMEs. Western Digital has only desktop units- 1- and 2-bay models targeting entry level users, and multiple 2- and 4-bay models targeting experts, professionals and business users. ZyXEL, on the other hand, focuses on only one market segment - the average home consumer. Every vendor other than ZyXEL in the list above carries both ARM- and x86-based solutions. ZyXEL has only ARM-based solutions in their lineup. The choice between ARM and x86 has to be made by the end-user depending on the requirements (number of users, transcoding support etc.). This piece is not meant to provide inputs on the hardware choice, though we will briefly touch upon how the OS features might vary based on the platform. The hardware currently used to test out the various OS features are tabulated at the end of this section.

Security has turned out to be a very important concern for equipment connected to the network, particularly those exposed to the Internet. Therefore, frequent updates are needed even in the NAS firmwares to handle vulnerabilities that get exposed from time to time. The release date of the latest firmware is also a measure of the commitment of the NAS vendor to their consumers.

Most COTS NAS operating systems are based on Linux, and utilize software RAID (mdadm) with the stable ext4 file system. Recently, btrfs has also become popular in this space. ZFS, due to its resource-hungry nature, has been restricted to units targeting enterprise users. DIY consumers can also get a taste of it using open-source BSD-based operating systems such as FreeNAS.

The following table provides the essential information discussed above in a easy to compare manner.

NAS Operating Systems Evaluation - Comparison Details
Firmware Version ADM 2.6.5R9N1 ReadyNAS OS 6.6.0
Firmware Release Date October 3, 2016 September 29, 2016
OS Kernel Linux 4.1.0 Linux 4.1.30
File System ext4 btrfs (Customized)
Evaluated Hardware 10-bay AS6210T 4-bay ReadyNAS RN214

This piece focuses on the core user-facing aspects of COTS NAS systems. These include the setup process and the quality of the user interface. Storage management and configurable services are the next topic. An overview of user management is followed by discussion of the networking features available in each OS.

Most NAS operating systems have feature parity in terms of core features. However, as we shall see at the end of this piece, there is a difference in ease of use which make some vendors stand out of the crowd. These vendors also try to differentiate with value-added services such as media servers, surveillance (IP camera) support, cloud features and other such features. They will be covered in detail in a follow-on article.

Setup Process and User Interface
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  • DominionSeraph - Monday, November 14, 2016 - link

    Or you could save yourself $900 by pulling a $100 desktop off craigslist. Windows is better for this, anyway. Homegroup + Teamviewer for management is just too easy.
  • wumpus - Monday, November 14, 2016 - link

    Quick check of the local craigslist implies that the buyer should indeed beware. Most "~$100 desktops" were Dells without support for more than 2 sata ports. Couldn't find any example of what the $100 server was, but strongly suspect it could handle 4 sata ports. Since most of these are Dells, check before assuming that you can simply cram a PCI-e card in to add ports (not to mention physically adding the drive).

    The common inclusion of "windows 7 ultimate" on boxes that were absolutely cut rate to begin with doesn't inspire me with confidence either. Of course, I'd be going the Linux (or BSD if I really wanted that ZFS goodness), but I'd check the fine print before building a windows server (not that windows isn't amazing at serving local desktops/notebooks.)

    Once you've carefully checked all the specs on your "$100 craigslist special", moving up to ZFS is what, $50 for 8G RAM (don't expect many of them to have open DIMM ports, hopefully all of them take DDR3). I suspect the real cost of all this is your time first, power consumed second, and finally the cost of the system (adding the cost of a simple server to your newegg hard drive order might be well over $200, I can't imagine the time issues making up the difference with the reviewed units. You can probably keep the power consumption down and make sure all your specs fit without dealing with clueless craigslist sellers. Of course, at this point windows has to justify its expense, but if you are only familiar with windows it is likely a no-brainer (you really don't want your first experience with Linux to be managing all your data, start with something a little less critical).
  • BenJeremy - Monday, November 14, 2016 - link

    Not sure I'd go with a $100 Dell special off CL or eBay, but a more generic system would work well enough...

    I bought a 8-port RAID SAS/SATA controller for $25 off of eBay (sold as "used" but the card was spotless). The only issue is case/power supply support at that point.
    Running your own Linux box, you can also run a LAMP stack and any software you might use personally, such as software to fetch files for you off of Usenet, for example.

    You could also add another network card, add in external storage as needed... I manage my server with WebMin and keep it in my basement (I have to make Linux feel at home).
  • darwinosx - Monday, April 3, 2017 - link

    There are many of us here who could do that and setup configure and maintain but why should we when a NAS does it much easier and far less maintenance. Especially with an OS like Synolgoys that has many easy to install and configure packages.
  • rtho782 - Monday, November 14, 2016 - link

    HP microservers are often down to about £170 new, given that we pay VAT and our currency is now worthless, I imagine they are about the same in $.

    One of those and either Windows or Linux seems a much better bet.

    Linux gives you zfs, and Windows will do tiered storage spaces (although you need to do the config on a Windows Server trial, it then works on consumer OSes, and ReFS is pretty good.)
  • wumpus - Monday, November 14, 2016 - link

    ZFS on Linux is a lawsuit waiting to happen. Oracle's law department (otherwise known as 99% of Oracle) is waiting for the best time to strike (probably when Red Hat includes it, which they won't do because of lawsuits. So it isn't as bad as it looks). In practice, this almost certainly means that your support disappears, not your data. But do you really want to copy all your data when this happens?

    But if Oracle wanted it part of Linux they would GPL ZFS. ZFS+BSD is legally Solaris, so no problem. But this is the same company spent billions to fight google over the Java API, so don't expect them to go down without a fight.
  • buxe2quec - Tuesday, November 15, 2016 - link

    Oracle released ZFS as CDDL. They cannot take it back, it has been developed further on the basis of that CDDL code. However no need to wait for linux/Redhat, since FreeBSD or OmniOS are already mature systems that have performant implementations of ZFS (technically, on illumos it's native).
  • coder111 - Tuesday, November 15, 2016 - link

    Yes, and CDDL is incompatible with GPL, it was explicitly designed to be so.

    So ZFS is fine for your personal use as you are not distributing software, you are just using it. Copyright law only applies to software distribution.

    But if any Linux distribution were to ship Linux+ZFS, THAT is a lawsuit waiting to happen, as they DO distribute software.
  • TheWrongChristian - Tuesday, November 15, 2016 - link

    But it'll be the Linux side doing the suing, not the ZFS/Oracle side. Including ZFS in Ubuntu isn't against the ZFS CDDL (IINAL, not legal advice etc.) Do you realistically see Linus (or others) suing Canonical?
  • tuxRoller - Thursday, November 17, 2016 - link

    What, WHY would the Linux side do the suing?
    The reason people say oracle might sue is because they (or sun) designed cddl to be incompatible with gpl (in a very particular way which relates to the idea of "copyright holders"), and, given that, and Oracle being somewhat litigious, there is a very understandable reluctance to properly include zfs into the kernel (as something other than a module, btw, since this has its own problems when it comes to system integration).

    Gpl is all about DERIVED works and that's how it propagates, and that is how companies can get around the vital nature of it---they write their proprietary modules then very thin shims which they gpl. ZFS, in particular, has long included a fairly big abstraction called the Solaris Porting Layer which is what allows it to run across different kernels but in a very non-ideal way.

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