Some macOS users running macOS High Sierra (10.13) have reported a low disk space warnings/loss of disk space. If deleting files and emptying your Trash does not appear to return any disk space, you may be suffering from a bug with Apple’s Local Snapshots.
To remedy the issue do the following:
- Open Terminal from /Applications/Utilities.
- Run the below command, and enter your administrator password if prompted:
sudo tmutil thinLocalSnapshots / 10000000000 4
This will remove any Local Time Machine Snapshots on your Mac, hopefully freeing up disk space.