Originally Posted By: ganbustein
Originally Posted By: Virtual1
I have a flash drive here I'd like to include in my time machine backup
You don't want to have TM back up a drive that will sometimes be unmounted. If TM runs while the drive is unmounted, it will record in its snapshot that the volume was not present. The next time TM runs after you mount the drive, it'll notice that the volume is new, and will back up the whole thing. Unmount it, let TM run, mount it again, and let TM run again, and TM will again decide that the entire volume is new and copy all files all over again. All this copying not only consumes time but also chews up precious space on your backup volume.



I would expect time machine to identify the volume based on its UUID, and be able to tell that it's the same volume, but I will take a look at it and see if it can tell the difference.

If it does indeed see it as a unique structure, it should show up numerous times in my /Volumes folder when I browse time machine, once for each copy it has made. If it does, I'd call it a whopper of a TM bug. But I'll take a look and report back.

I work for the Department of Redundancy Department