I recently purchased a 256GB MBA. I would like to set up a time machine backup with my 2TB external drive. However, I don't want to waste the entire drive backing up, plus I have 1TB or so of music and video that I would like to store on this same external. Is there any way to have both a time machine and other storage on the same external? How, do I format the external as 2 partitions? Can I do that in Disk Utility?