I have a retina MBP with 16GB RAM. The majority of my HD is allocated to Boot Camp, so I have only about 6GB free on my OSX partition. (I plan to change this in the near future.) recently, I have been getting messages that my Startup Disk is almost full. This seems to happen regardless of what I have open, though it's usually standard stuff (Safari, Word, Preview, etc). When I run GrandPerspective to see what's taking up so much space, it looks like the Swap File. When I restart, the space is freed up again. is there a known reason for this? user error?