I've looked up a few threads on the subject but found no definite answer... I'm wondering if using two separate external Firewire hard drives for backing up an iMac with the aid of Time Machine will work and be safe (not messing up things etc.)? One external drive is now attached to the iMac, backing things up every 3 hours (I found the default hourly backup a bit too much so I installed Time Machine editor in order to change this). It works just the way it should. But in case of theft, fire etc. it would be nice to have yet another backup drive as well. Naturally that drive would be stored in an off-site location and thus not backed up to that often, but at least I wouldn't lose absolutely all my files if my computer + regular backup drive was to be stolen or damaged in a fire, just the very latest files. So let's say I pull out that drive every 2 weeks or so, disconnect the regular Time Machine drive, attach the "off-site stored drive" and tell Time Machine to do a backup right away. Would my computer be able to tell the two drives apart (I'd give them different names of course), understanding that the "regular" backup drive should just continue backing up as it left off last time, or will it get confused? I like Time Machine because it's maintenance-free, so I'd rather not use some other, separate and complicated backup software for the "off-site" drive if I can avoid it. By the way: my backup drive is a 2.5" external Firewire drive which means that it takes its power from the Firewire 800 cable totally eliminating any additional power supply and cables. Just one cable and a small enclosure. Neat and tidy and very much recommended!