Hope some of you old pro's can help me out here. I will be upgrading to Mavericks in the next few days but want to make sure I do it right. Currently running ML on a late 2012 iMac. Have my machine backed up by Time Machine. Should I create a bootable version of ML before I upgrade just incase? If so I have a copy of CCC installed which I assume I would use. How big a thumb drive would I need to do that (if necessary)? Which files do I need to back up to create a bootable drive? Other than taking an extra back up on another external drive for my Pictures, Music and documents anything else I need to do or worry about?