I moved a number of files from my hard drive to iCloud Drive, the files disappeared from my hard drive immediately and they started populating in iCloud as expected. However since then, my free local storage went from 40GB to 1.5GB and getting worse every few mins. The only solution I've found is to restart the computer which releases a few GB but not long after that it goes down to 1.5-2GB free. Never seen anything like this before, but my gut feeling is that Yosemite is keeping a copies of the 40GB somewhere hidden in the local system for quick access. Any clues on how to fix it? I've run CleanMyMac a few times but I only manage to delete a few MBs.