I am on 10.15.2. I did not upgrade/update (I seldom do, and when I do it is after much deliberation). My new Air came with Catalina on it and, in view of a Sierra install (or any OSX install any more compared to the good old days) being far from straightforward, I just went with Catalina.
I am following up from my earlier question:
What I did was to move some subdirs/folders I don't really need on my SSD to an external drive that usually stays connected via USB. Doing so increased free space to about 25 GB, so that should have done it. Except it didn't.
It is worth mentioning that I do not log out or shut down or even reboot much. Since the days of PowerBook G4s and Puma all I do is shut the lid.
Now, since I cleared up about 25 GB on the SSD about two months back, the max space I have used is about 2 GB; impossible that I would have used up more than 4 GB. But the free disk space I have now is only about 11 GB. No such thing ever happened on various OSX versions up to and including Sierra (from which I made this big, sudden, and awful jump to Catalina).
So where did the 14 GB disappear? The only think I can think of is memory leaks through VM taking up blocks and blocks of disk space and never releasing them. If this is correct, is there a way to trace the rogue application(s)? And what is this problem with Catalina making disk space mysteriously disappear?
Thanks for any help.