In Monterey, I'm backing up, via Time Machine, an external drive ("SOURCE") to another external drive ("TARGET"). Is it possible to change out the SOURCE without Time Machine starting over?
iMac 21.5″, macOS 12.3
That won't work since each new source will bear a unique UUID. TM will keep them separate from one another.
Are you certain that you know what TM does? If you need to retain old backups from the "old" source, what you propose will accomplish that. If you are expecting TM to act as an archival system, that's not what it does. If you were to "merge" the two, backups from the "old" source that do not exist on the "new" source eventually get deleted. You have zero control over that.
You don't have to do anything. What you describe is correct; the new source will be added to Time Machine. The other source volume will forever remain separate. If you no longer wish to retain it, erase the entire Time Machine backup disk.
Obviously it would be best to start a new set of backups on a new disk before you do that, otherwise you will be left with no backups for a short period of time.
Time Machine will add that additional source to the existing backup.
But how do I set up the new SOURCE for that to happen? The new SOURCE contains the data from my previous source disk (which is too small -- so I have a new source disk). I read that if you simply swap in a new source disk, as I'm describing, Time Machine will start from scratch, and not build on its previous backups.
I'm trying to see if there is any way to get around the new source being added, as a new volume. That's because the new source volume simply contains what was on the old source volume -- I just moved the data from the old to the new volume. So it would be good if the backups could also continue, as they would if I still had the old volume. Perhaps Time Machine could be tricked into just continuing its backups, if I give the new volume the same name as the old volume?
Thanks, that's helpful -- I guess I was hoping that Time Machine used volume names rather than UUIDs, but evidently not.
In Monterey, I'm backing up, via Time Machine, an external drive ("SOURCE") to another external drive ("TARGET"). Is it possible to change out the SOURCE without Time Machine starting over?
