[video=youtube_share;BVtQNK_ZUJg]http://youtu.be/BVtQNK_ZUJg[/video] Ok, so I don't have an explosive device primed with a proximity switch to deal with but the mess that is my back-up system is a computing disaster waiting to happen and demands a similar way of think to Bruce and Samuel in Die Hard 3. Over the last couple of years I've let my Mac based digital asset management lapse somewhat and now I'm in the position of having to do something about it before it's too late. I have: 1TB hard-drive 2TB external drive - main drive for archived photos and also has a back-up of my hard drive on it. Only 5GB free! 1TB external drive - back up photos on my 2TB archived drive. 630GB free. 1TB external drive - some back up for the 1TB hard drive and other files - only 22GB free! 1TB external drive - some back up for the 1TB hard drive and other files which are different to the other files on the 1TB drive above - only 6GB free! Ideally, I'd like to have: Hard-drive backed up on 2 separate external drives 2TB external drive for photos only (should be less than 1TB) backed up on two separate drives. I want to use this drive as the archive as it has Firewire connectivity. For safety's sake, I'm presuming that each drive may have some files on that are not on any other drive. What's the minimum number and size of drives will I need to buy in order to create a back up of everything and how do I go about it?