I know how to fix this problem, I was just wondering if anyone knows WHY it happens. I have a network drive that I use on my iMac and every time it's nearly full, my WHOLE machine becomes unusably slow. I mean, even opening a finder window can take up to a minute. Just deleting a couple of files off the network drive will fix the problem. Unfortunately, it can take up to an hour just to delete a file because everything is so slow, including the actually deleting of the file. I don't have an system files on the drive, just a bunch of video files and personal documents. I was just curious why the network drive being slow would impact the whole system? It just seems weird to me.