macOS High Sierra use almost all the hard drive space each time it's upgraded I have a 1T drive, and it normally uses 400 GB space. After the system upgrade from 10.13.5 to 10.13.6, the system now tells me the disk is almost full:



The system uses 870GB, almost the double what it used to.

Maybe there are some backup files in here, because sometimes disk space will be the correct size. I think a backup file is deleted at that time.

So what can I do to stop this from happening?
After contacting Apple's manual customer service, they told me to rebuilt the index of Spotlight, just add the Whole Macintosh HD to the exclude and then remove it, this solved the problem !