Hi, I am a new Mac user, going great so far but have lots of questions. My new iMac Retina 5K has a 3 Tb fusion drive. I read that a backup Drive for time machine should be at least as large as the drive you are backing up. It will be years before I get anywhere near using the 3 Tb so do I need a drive that large i.e. Will it work with a smaller backup drive. I had also considered getting a larger drive and partitioning it, with one partition used to store Windows files. Would this work with Parallels or VM fusion? Thanks for your help.