Hi, First up, sorry if this has been asked before, I have searched the forum but can't find the specific answer. I do a fair bit of photography and run a rMBP with only 128GB storage. I keep the most recent photos on the laptop, and eventually move across and store all on an external HDD (along with my iTunes library). And as this is my only copy, I want to back it up. I have read that TM can backup an external, and this is what I've done on to a second hard drive, but I notice that if I open TM with the backup drive attached but without the media drive attached, TM doesn't appear to show the media drive that I thought it backed up. I was assuming that if the media drive failed, I could just plug in the backup drive and get a copy of the media drive via TM. Maybe I am going about this wrong? At first I thought I could just copy and paste the photos etc on to the backup drive, but thought TM would be better as it would only save the updates each time after the first backup. Maybe just copy and pasting the files would be best? Advice appreciated. Thanks House.