As soon as the new beta of macOS is out, I want to install it and use it as much as possible. But I also want my Sonoma installation to remain intact with my data – as a fallback, and because we will probably be unable to submit Mac apps from the beta to App Store Connect.

It took me some time to determine how to set this up. I ended up doing this:

  1. Create a new APFS volume.
  2. Download the Sonoma installer from the Mac App Store.
  3. Install Sonoma on the new volume.
  4. Boot into the new volume, and use Migration Assistant to copy my data from the other volume.

I now have a “Sonoma” volume and a “macos2024” volume.