I turned an old Mac into a NAS – here's why you should too

Tech enthusiasts know that finding ways to keep outdated hardware from ending up in landfills is good for the environment – even if your everyday Mac or PC needs an upgrade. However, that is easier said than done. I found a way to buy an old iMac for less than $100 and use it as an external monitor until disaster struck. In the midst of the chaos of my apartment move, I broke the display on the 2012 iMac, and that left me seriously confused as to what to do with it. I couldn't fix it because I could buy two more iMacs for the price of a replacement screen.

I'm sure you'll find yourself in the same situation at some point. You may have a drawer or shelf full of old or broken hardware – sometimes both – that stays off most or all of the time. I wasn't ready to finally shut down this aging iMac because other than the cracked glass, it works perfectly. So I decided to convert it into a NAS (Network Attached Storage) device. It was surprisingly easy, and it's something you should do if you've already upgraded to one of the best Macs and have an old one lying around.

The hardware I use

A 2012 iMac with a cracked screen and optional DAS

Apple bundles several features with macOS, from the latest macOS Sequoia to older versions of Mac OS X, that make setting up a Mac as a NAS a painless endeavor. I used a 21.5-inch iMac for this project that came out in late 2012, and these are relatively common machines. They were very popular in the corporate and educational sectors and also sold well as family computers. This iMac came with 8GB of DDR3 memory, a 2.7GHz quad-core Intel Core i5 processor, and an Nvidia GeForce GT 640M graphics card with 512MB of vRAM.

You don't need any additional hardware for a simple NAS setup. It is possible to connect this exact iMac to your network using only a wireless connection and the computer's internal storage. However, an Ethernet connection is strongly recommended for the best performance. Additionally, the “Fusion” hard drives on this and similar iMac model years have been running for over a decade. Since they are doomed to fail, I recommend swapping to an internal SSD or simply connecting to an external Mac SSD and storing all your important files there.

Redundancy is important, and you don't want to lose your valuable files if an outdated Mac takes over. That's why you should follow the 3-2-1 rule when it comes to NAS hardware and data redundancy. As a proof of concept, I connected a Direct Attached Storage (DAS) unit to this iMac, configured as a RAID array. This way, my iMac becomes the network-attached device in the chain, and the DAS is there for redundancy.

The setup process

All the features you need are built into macOS and Mac OS X

As you've probably learned by now, using an old Mac as a NAS can be as simple or as complicated as you want. In its simplest form, setting up macOS File Sharing for the first time only requires a few steps. After following the steps below, you'll be able to access your old Mac from another Mac or PC – just like a typical NAS.

1. Open System settings or System settingsdepending on what is available in your version of macOS
2. Click on Split tab, either in the sidebar or in the icon grid.

   

3. You will see a list of sharing options. Activate File sharing to use your Mac as a simple NAS file server. You can also flip the switch Media release to share things like your iTunes library.
4. Under the File Sharing tab.click + under Shared folders to select a folder/volume. If you activate File sharingone Public folder is automatically created for your system.
5. Now it's time to set permissions for each user or group. You'll need this to remotely access your Mac's files.
   • Read only: The user or group can view the content but cannot write data.
   • Write only (Dropbox): The user or group can write data but cannot see the contents of the folder.
   • Reading and writing: The user or group can both see and write data in the shared folder.
   • No access: The user or group cannot view the shared folder.

     

6. Check those Share files and folders via SMB Crate. This allows users on Windows and other platforms to access your Mac's files with an approved username and password.

   

After that, you can open Finder on any Mac connected to your network and click network Tab. Now you will see the name of your iMac – now configured as a NAS file server. You can remotely access the files as if they were stored directly on your Mac, or even remotely access and control your Mac's desktop. That's all you need to use your Mac's built-in hard drive or SSD as a NAS, and you can easily connect external storage or DAS to expand your storage space.

Should you use an iMac as a NAS?

It can be a great media and file server with limited maintenance requirements

It took me about 20 minutes to get this old iMac running as a NAS, and that's certainly the appeal of a project like this. You don't have to buy external hardware or spend a lot of time tinkering with special NAS software. Anyone, regardless of experience level, can use macOS File Sharing and set up their own NAS server in under an hour by following the steps above. However, this method is only a realistic option for people who want basic file hosting, media sharing, and remote access. If you dream of NAS projects and Docker containers, you want to build or buy dedicated NAS hardware.