Hard Drive Storage

Hi Jeffer,

You might have erased your Mac improperly. Let me explain.

In macOS Catalina and later, your Mac uses two important volumes, bundled together into a volume group:

• The System volume, Macintosh HD, contains the vast majority of macOS.

• The Data volume (Macintosh HD - Data) contains everything else, including all of your files, apps, and settings.

When you erase Macintosh HD or Macintosh HD - Data in Disk Utility, it may give you the option to erase either the individual volume, or the volume group. The correct option is to erase the volume group - that will delete the Data volume entirely, and erase the system volume.

Based on your screenshot, it appears that only the system volume was erased, and the previous Data volume was left alone. When you reinstalled macOS onto Macintosh HD, a new Data volume was created, and the orphaned Data volume from the previous installation is still sticking around.

To fix this issue, follow these steps:

1. Start up in macOS (normally), and log in to your user account.
2. Open Disk Utility, located in Applications -> Utilities.
3. There should be two entries for Macintosh HD - Data. Determine which one of them is orphaned:
   1. The legitimate Data volume uses the mountpoint "/System/Volumes/Data", and its erase button is greyed out.
   2. The orphaned Data volume uses a different mountpoint and it can be erased.
4. Select the orphaned Data volume, then click the (-) button. Click Delete to confirm.
5. Your Mac should now be completely fresh.