Woke up this morning, turned on my computer and checked my e-mail and then went off to shower. Came back to a message that said your start-up disk is close to being full, which was news to me since I thought I had over 200gb still free. I checked and it said I had zero KB available... Went into time machine to check my last back-up from the night before, and it said I had last night I had over 200gb free... Little about my computer: 2009 Mac Pro running 10.5.8 4 Internal Drives: 2 300gb WD velociraptors (one for OS X boot and one is my windows drive) and then 2 1tb WD black drives for storage. The OS X boot drive has an external for time machine, while each 1tb has its own external with ccc doing backups. Now my first question is does anyone have any idea what could have caused this, or is there some information they think might help me find what did it? My first instinct was to go to the root of my boot drive and look for huge files. After not finding any I turned on hidden files and checked those as well, again nada. I am really mystified as to WHERE the space went... even if I don't find out what caused it I'd still take any ideas on finding the memory sink. Second question is should a clean install and time machine restore fix it? I am guessing I would get back the space, but unless I can figure out what caused it do you guys think it is worth it? Last question is a little off topic, but since I may be doing a clean install anyways should I just go ahead and upgrade to snow leapord? I have my home folder on one of the 1tb drives, would there be any issue to using a "leapord home folder" with snow leapord? I know I'd lose my apps, but I was thinking about doing a clean install anyways. Thanks for any ideas on this guys, really has me mystified.