I backup to a NAS and to an external USB drive. I replaced my NAS and so am also re-working my backup structure. I'd like to keep another backup, but I don't really want to have Time Machine manage this third drive for me. Largely because of the local snapshot issue. My plan was to just copy the Time Machine backup from the USB drive to another MacOS formatted drive, which I can then store off site. I guess really I should just try this out and see if it works, but I'm hoping someone has done this before and can provide some feedback as to how well this worked? Time Machine -> NAS as normal. Time Machine -> external USB as normal. And then my third drive would just be a data copy of the above external USB drive to another USB drive which I would then store off site. Any significant alarm bells you guys can think of?