Hidden files after Big Sur downgrade

[andrevanrensburg]

I had to downgrade back to Catalina from Big Sur. I formatted my HD and installed Catalina from a bootable flash drive. After installation I only had about 20 GB of free space on my HD, more than 200 GB was taken up as hidden 'other' files. I tried formatting the HD again and installing Catalina again, same problem, only now I only have 9 GB left...I have tried all the usual ways to find/delete these hidden files to no avail, including scripts in Terminal, various disk sweeping apps, etc.

 

[Cory Cooper]

Hello and welcome.

Sounds like you may not have erased the whole disk, just one of the APFS containers. I assume you have a backup of your data, and want to completely erase the entire drive to start fresh?

- In Disk Utility, make sure you click View > Show All Devices in the menu bar.
-In the left sidebar in the Internal section, click the topmost icon (device), which will be name with brand of drive you have, and not a container or volume name.
-Then click erase and choose your format.
-You can then proceed to reinstall macOS Catalina.

See if that works for you.

C