My computer is a late 2011 MacBookPro with an original 128 SSD running MacOs 10.13.6. For some years now the total of the used disk space plus the available disk space has been slowly shrinking. In particular, the available space keeps (slowly) decreasing, even if I do not use additional storage space.
Right now the free space is 11.5 GB out of a total capacity of 128 GB. Looking at "About This Mac > Storage" I see the following ("Documents" is 31.77 GB, blue is "Apps" with 6.69 GB, dashed is "Other Volumes in Container" with 3.88 GB)
Using OmniDiskSweeper v1.11 I get this instead
that sums up to roughly 67 GB used in total.
My question is: what is eating up disk space behind the curtains? Is this a software related problem or an hardware related problem? (since my SSD is one decade old, is there some mechanism that marks SSD sectors as unavailable when they break or become unreliable?)
Additional information:
- Time machine is enabled, I did the latest backup yesterday on an external hard disk, but available space did not change, even after a restart.
- About three months ago I made an accurate clean up of my hard disk using "Clean my Mac" to detect junk and manually deleted the actually useless files (caches, old files, unused apps, ...) reaching 25 GB of free space. Yet, after a few months, space slowly shrank to 11.5 GB.
- I found lots of other similar questions here and on the internet, but no answer seems to make sense in my case.
UPDATE (22/12/2022)
I scanned my ssd using Daisy Disk and got the following result. Any suggestions on how to get rid of those 41 GB of hidden space? (Daisy diary requires to buy the full version to display further details and I would like to avoid it).
tmutil listlocalsnapshots /
in terminal. Check the age of the snapshots to see if any are hanging around.$ tmutil listlocalsnapshots /
com.apple.TimeMachine.2022-10-13-220203 (dataless)
com.apple.TimeMachine.2022-12-22-175223