Just wondering if anybody has seen this issue and\or known of a resolution? I have a new 15" MacBook Pro with High Sierra Installed and I noticed that I am rapidly running out of space despite having a 512GB internal SSD and all of documents and photos (other than a small subset that have been imported to the photos app for sharing) living on an external SSD. On doing some investigation I found that About This Mac is showing a whopping 305GB classified as System, but it doesn't add up. It shows 392.53GB available of 499.31, but if you add up all of the used space it is about 377 used. Get info on the drive shows the "missing" space as Available\purgeable, but About This Mac and terminal do not. I can't create a boot camp partition bigger than 99GB which is how I discovered the problem. I have chatted with Apple support. First level was typical 1st level, sending me links to articles that I had already seen and tried. Second level was quite good and spent quite a bit of time looking at different things before getting me to reinitialise spotlight. The theory being that it would reclassify whatever it is taking up the extra space as purgeable, and free up the space, but it kind of felt like "oh, try this thing that will run for 2 days so that I can get off this call" Interestingly the disk space analysis tool he got me to install (Disk Inventory X) doesn't show what is consuming the space. It shows the space as used at the top level, but the analysis doesn't show it. I kinda feel like it just isn't releasing space from some deleted files. I had a fairly large Parallels vm that I moved to trash and then emptied the trash, but I can't prove that it is related. So I'm going to let spotlight do it's thing for a couple of days, but does anyone have any other ideas before I erase the drive and reinstall if this doesn't work?