How to build your own NAS (and more) from an old PC

How to build your own NAS (and more) from an old PC

If you’d like a bit more say in the construction of your NAS, or want more space and functionality without having to pay for a commercial device, deciding to build your own NAS system from re-purposed hardware could be the solution for you.

Unlike creating a NAS from a router and an external storage device, this approach involves working with hardware as well as software, so a working knowledge of which bits go where inside a computer will certainly come in handy. Having said that, it’s not too hard to learn, and there are plenty of resources available – such as GFCFree’s guide to Computer Basics, which can help you get your head around the basics of computer hardware, and Brian Moses’ DIY NAS: 2016 Edition – an accessible and comprehensive explanation of how to buy and build your own NAS system.


Plenty of storage space

The biggest advantage of using old parts to create a new device is that you can add as many external drives as you have ports on your motherboard (and space for in your enclosure). This will give you a much greater storage capacity than if you’re using a simple router and external drive.

Create a RAID array

Having more space for storage devices also means that you’ve got the tools to create a RAID array – a means of using additional disks to keep mirrored copies of the data on your primary hard disk drive(s). This is an excellent way of keeping your data safe, and restoring files should an HDD fail.

The steps you’ll need to follow to setup RAID on your NAS system will depend on which OS software you are using. Take a look at your chosen provider’s website for more details!

High end performance for a low price

It’s easy to get ahold of previous generation computer parts these days – whether you buy them online through sites like Craigslist or eBay, get them at thrift stores and garage sales, or simply make use of an old computer lying around at home.

As older processors, motherboards, and other essential NAS components are replaced with newer versions, the outdated tech doesn’t lose its value for basic tasks like data storage – and it gets a lot cheaper.  For example, an Intel Pentium E5500 CPU, released in 2010, can be snapped up on Amazon for just $35, while its 2015 successor the Intel Pentium G4400 will cost at least double. While differences in technology between the two models might be significant to those looking to build a top of the range PC, for the purposes of creating a NAS, they’re very much the same product.

For an excellent overview of hardware prices, check out PCPartPicker and browse by individual parts. Compiling prices from reputable vendors across the internet, the site gives a very good idea of how much (and how little) you can get your NAS components for.

What’s even better is that these inexpensive components can be brought together to create a NAS system which, if it was shop-bought, could easily set you back thousands of dollars. Of course, you can choose to use more expensive parts for a more streamlined and efficient build but, crucially, that’s entirely up to you.

Very customizable

Both with hardware and software, taking the the from-scratch approach when you build your own NAS will let you create a device that meets your exact specifications. Not only can you decide how many drives you want to use, and how your NAS interacts with other network devices, but being able to choose from multiple operating systems (Amahi, FreeNAS, or NAS4Free to name just a few) lets you decide exactly what your NAS will do, and how it will do it.

Limit your power consumption

Commercial NAS devices can leave you with a fairly hefty electricity bill, on top of your initial outlay for the box itself. By building your own, you can choose a CPU that treads very lightly when it comes to energy consumption – it’ll cost more to buy in the first place, but the savings over time will certainly pile up.

Raspberry Pi

Another option if you’re looking to conserve power is to build your own NAS using a Raspberry Pi. You won’t be able to add more than a couple of external drives, so RAID options are limited, but it’s certainly an eco-friendly option, and cheap too – all you’ll need is the Raspberry Pi itself (around $35), and a couple of hard disk drives, which should set you back between $50 and $100 each. Check out How-To Geek’s excellent tutorial if you’re interested in giving it a try.


You’ll need some technical know-how

Although of course it’s never too late to learn, if you’re not confident figuring out some technical jargon, this might not be the best solution for you. Even experts make mistakes, so it’ll help if you’re ready to roll with the punches and know how to salvage things if something goes a bit wrong. On the plus side, it’s nowhere near as hard as it looks – you just need a little faith!

If building your own NAS still doesn’t sound too appealing, check out our guide to setting up a NAS system using DD-WRT for a cheap and relatively simple DIY NAS solution, or head over to our Commercial NAS Devices page to find out what pre-made NAS boxes have to offer.

It takes time

While commercial NAS systems by companies like QNAP and Synology can be set up in about 20 minutes, building one from scratch is going to take much longer. Sourcing the parts, getting them delivered, putting aside time for construction, installing and familiarizing yourself with an OS… will all take a while. So if you’re looking for a quick fix, you may be better off taking a different approach.

So what do you need to build your own NAS?

A NAS enclosure

A NAS enclosure is, essentially, the box that your motherboard and drives will sit inside. Technically, you can make it from pretty much anything you like, so long as it protects the tech – but an old computer casing is probably the quickest and easiest way to go – and will cost you next to nothing.

If money isn’t an issue, then you might also want to consider a Micro-ATX or Mini-ITX case, for something a bit more high-end. You can find them on Amazon, of course, as well as on computer parts sites like Newegg and PCPartPicker.

A motherboard

A motherboard is one of the most crucial components of any DIY NAS, so it’s worth spending some time to make sure that you find one that works for you. You won’t need anything fancy, but you will want to ensure that it a) fits comfortably within your chosen NAS enclosure, and b) is compatible with all of your other components, or you’ll be making a lot of extra work for yourself further down the line!

For maximum options when it comes to data redundancy and storage capacity, we’d recommend choosing a motherboard with at least 6 SATA ports, to ensure that you won’t run out of ports to connect your hard drives to. Important features like the ability to boot from USB can be found in most modern versions, although older models might not offer them – so check the manufacturer’s website for more details before handing over your money.

For more info on picking a motherboard, check out this great guide from PCWorld.


A CPU (also referred to as a processor) doesn’t need to be the latest model, and you’ll save a lot of money by using a previous generation model. Sticking with entry-level Intel or AMD models should set you up just fine, as you won’t need a lot of processing power to run your NAS system. You’ll also need to purchase a cooling system to prevent your CPU from overheating.


Once again, you don’t need to worry about getting anything top of the range when it comes to RAM. As a rule of thumb, NAS OS provider FreeNAS recommends purchasing 1GB of RAM for every TB of raw storage space you’re planning to use – although you shouldn’t encounter too many problems if you fall a little short. For a home setup, 2GB is usually a good place to start.

Hard Disk Drives

When you build your own NAS device, there are two different ways of approaching the search for hard-disk drives (HDDs) – buying one or two drives with the biggest storage capacity you can afford, or buying multiple, smaller drives to use in a redundant array.

For example, while buying a single 12TB hard disk might give you more space for less money, it means that all of your data will be stored in one place – leaving it entirely vulnerable and much more difficult to retrieve should that hard disk fail.

Alternatively, spreading your data across eg. one 4GB and four 2TB HDDs will mean that you’re not constantly relying on the performance of one disk. It also gives you space to set up a RAID array for redundant copies of your data that you can draw upon should your primary sources of storage be compromised – an essential part of keeping your stored files secure.

Extra stuff

You’ll need a few extra parts to get things up and running when you start to build your own NAS – namely a power supply and a few extra SATA cables. Although some enclosures come with power supplies included, many don’t, so it’s well worth checking in advance. You won’t need a lot of power to run your network storage device (it’s unlikely to ever have a draw of over 100 watts), but it’s worth choosing a make, like Seasonic or Antec, that you know will be reliable.

Similarly, many motherboards will only be sold with a few SATA cables – leaving you short if you want to include several drives in your NAS build. Buying some extras in advance won’t break the bank, and should save you some trouble when you start building your NAS system.

An operating system

In order to give your DIY NAS a functional operating system, you’ll need to download a program to do the legwork for you. There are several different software providers that you can use to do this – some of the most widely-used being FreeNAS, Amahi, and NAS4Free.


Amahi’s Home Server is ideal for home NAS users, as it gives your network storage device all of the functionality of an entry-level commercial system – apps and all. As well as allowing you to backup and share files from the devices in your local network, this open-source OS also offers features including an integrated and pre-configured OpenVPN server, a dynamic DNS name and disk monitoring.

On top of this, you can also choose to download apps for media streaming, torrenting, MySQL management, business administration, website management, and more. It’s not as easy to alter advanced settings as it is with FreeNAS and NAS4Free, but it’s an excellent solution if you’re building a home NAS and aren’t too concerned with techy extras.

Take a look at this LifeHacker article to find out how to install and make the most from Amahi.


Somewhat more complex than Amahi, FreeNAS is perhaps the best known NAS OS available, and has been running since 2005. As well as letting you perform basic NAS tasks like device backups, remote access, and file sharing, you’ll also be able to make use of more advanced features such as snapshot backups, replication, data encryption, and an extensive range of data integrity measures. There’s also a gallery of plugins available, including bittorrent, plexmediaserver and CrashPlan and ownbackup for creating additional online backups of your stored files.

You can also use FreeNAS to manage your redundancy settings, as the system incorporates ZFS – a file system volume manager and RAID controller designed to manage your RAID setup. One of the most respected NAS software solutions currently available, FreeNAS is accessible, with a great interface and a range of features to meet both home and business needs.

Check out Engadget’s tutorial for a step-by-step guide to setting up your home file server using FreeNAS.


NAS4Free takes a further step into techy territory, adding to standard backup and file sharing functions by acting as a BitTorrent client, RRD tool, webserver, DAAP server and more. Ideal for business and enterprise users, NAS4Free lets users get much more hands-on with advanced features – making it a little less accessible, but also giving you more control. Like its competitors, NAS4Free is also open source and free to use, with active forums providing customer support.

The NAS4Free wiki has plenty of info on how to setup and run the OS on your device.


Building your own DIY NAS from an old PC is an excellent way to get advanced features and plenty of storage space without paying out for a brand name. It’s also the best way to create precisely the NAS system you want, without compromising on detail.

Of course, this also means that there’s a lot that you can do with a NAS – the specifics of which we haven’t gone into in this introductory guide. For more detailed advice on selecting hardware and using your chosen software, check out CodeProject’s Build Your Own NAS Device, Brian Moses’ Diy NAS: 2016 Edition, and ARS Technica’s Ins and Outs of Planning and Building your Own Home NAS.


Build your own NAS with an external hard drive and DD-WRT router


NAS Comparison

Published on: June 29,2018.

Related Coverage

2 responses to “How to build your own NAS (and more) from an old PC

  1. Hello,

    I have an old PC plus 3 external hard drives. Can’t I just plug them all into a compatible wi-fi router and then set the specific hardware and software parts for the NAS purpose instead of picking up part from part?


  2. Great guide, lots of great resources linked in this post! Some people are even setting up their ownClouds these days!

Leave a Reply

Your email address will not be published. Required fields are marked *