i have a early 2009 mac mini and I have noticed that I had been getting a swap file. I have 4 gigs of ram and I don't ever remember having a swap file. seems it started with parallels saying I was running another session when I was not. so it made a swap file well after rebooting that seems to have gone away but I noticed I always have a small swap file. even though i have over 2 gigs of free memory. well running the newest version of 64 bit handbrake leaving it running when I go to bed I have found twice all my free hard drive space has been used as a swap file. I get the message that I am out of hard drive space and every thing is paused or not responding. I have to reboot to get things back to normal. time may fix it but who knows? I don't have anything new running and parallels is not running in the background. so why do i have a swap file at all with 2 gigs of free memory? my wifes mac mini with only 2 gigs does not have a swap file.