Using an external drive (WD) as Time Machine backups, but at the same time as another disk to store most of my multimedia files. I've read that SuperDuper is good at acting as a boot-drive. So now, I would like to backup my data using SuperDuper on my current external disk. The problem is that I'm afraid such action might completely erase my data on the ext-disk and, well, erase everything on it. Please, anyone who went thru this, please advise how to proceed.