. . . if I want to use it for backing up when I plug an external drive into my MBP or MB? For example, I use SuperDuper to make a complete backup of my harddrive every two weeks. Whenever I plug in the external drive, which has 3 partitions, Time Machine asks me 3 times if I want to use it for backups. I've also got another external drive for storing RAW imag files, and of course, the same thing happens. Time Machine is turned off, too. Anything I can do to avoid this minor annoyance? TIA.