We don't seem to be closing on a theory that would solve my problem.
So far, RC seems to be saying - the space is there but you just can't see it. it's taken up by temporary files that will make room for more if needed. And it's not Time Machine because the files that show up in MobilBackups are simply links and don't take up significant space.
I have proven the problem by removing 10GB of Movies and watching the OTHER increase to show that I still have only 92GB of available space. In theory I could remove 50GB more and the OTHER might take up that space - this is the case for my sons MBP where OTHER is 350GB and he can only find 100GB.
And I have shown that I have about 130GB unaccounted for by showing my current SSD usage.
So there is approximately 130GB of OTHER not showing on this picture but showing up above as not available.
Should I believe that if I were to try to transfer 200GB of new files to my drive, it would magically free up the space? I haven't use a computer like that before - it would certainly be a surprise if it did that but I have my doubts of success.
Here is a summary of actions taken:
- I have rebuilt Spotlight
- I have run Cocktail and rebuilt or removed systems caches, logs, temp files, etc.
- I have mapped my drive using DiskWave, Grand Perspective, Omni Disk Sweeper, and Supaview
- I have removed iCloud from my Time Machine backup volumes - TM now ignores iCloud
- I have rebooted on the Recovery Internet and run disk utilities
- I have moved files to iCloud to test the impact on this issue
- I have looked into Activity Monitor and quit any processes like SystemStats that was using significant disk space
- I have restarted the MBP and done the equivalent of a ZAP PRAM operation
- I have disabled Contacts and Calendar - disconnected them from iCloud and deleted their storage folder contents
- I have removed all foreign language support
Any other theories or recommended actions are welcome (I may have forgotten a few that I took and not recorded on my list)
It would appear that my next move should be to start over and either re-install OSX or completely wipe my SSD and restore from time machine - I should do a clean install of OSX but I'm not sure I know how to do all of that yet so I'll need to read something.