If I move my home folder to an external SSD, what happens to the system data?

I am just moving over to a new MacMini and I am going to use an external SSD for my home folder. I have just done a big clean-out of my files but I have discovered that I still have more than 200GB of "System Data" in my hard drive. I have done a massive spring clean using CleanMy Mac but it is still there. Will that System Data be transferred over to my external drive or will it be stored on the internal hard drive of my new MacMini? If it is, I will run out of space before I start!

Mac mini (M4)

Posted on Mar 14, 2025 05:24 PM

Reply
Question marked as Top-ranking reply

Posted on Mar 14, 2025 07:27 PM

rogercorke wrote:
I am just moving over to a new MacMini and I am going to use an external SSD for my home folder.

Moving your user home folder to an external drive is not a good idea. The system expects your home folder to be on the internal (system) drive especially if it's the only user account, which is also your main admin account. There is a lot of stuff in the hidden Library folder in your home folder that the system and apps depend upon.


If your goal is to keep most of your user data on the external drive, you can achieve that without moving your user home folder. None of this *needs* to be in your user home folder.

  • Music, TV & Photos libraries can easily be relocated to an external drive. Instructions are available in each of those apps' user guides and people here can also tell you how to do it.
  • iMovie, Final Cut, Lightroom, CaptureOne and other app libraries/catalogs can can be created and/or relocated to an external drive.
  • Lightroom, CaptureOne, Bridge and other image catalogs can be saved to an external drive.
  • Browser preferences can be set to save downloads to a folder on an external drive
  • And finally, nearly all apps can save to any disk or folder you specify including an external drive.


Here's what I do. On my external drive I duplicate the folder structure of a basic user home folder. I then point the appropriate apps to those folders. With apps like Word, Excel and other apps that don't have libraries, when I need to save a file I simply direct it to save to a location on the external drive.

  • Documents
  • Downloads (for browser downloads)
  • Pictures (for Photos library)
  • Music (for Music library)
  • TV (for TV library)
  • plus other folders that are unique to my needs
    • Movies - for iMovie libraries
    • Family History - for genealogy database & files
    • Catalogs - for LR & CaptureOne catalogs
    • etc.



18 replies

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

If I move my home folder to an external SSD, what happens to the system data?

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.