I have an old MacBook running OS 10.7.5 that I periodically backed up. When I purchased my latest iMac, I transferred the MacBooks HD using a firewire or thunderbolt transfer to the new iMac, now running OS 11.1. I just went to back up the new Mac using the old back up from the MacBook. The name of the old backup automatically appears in the time machine window. Will time machine overwrite the old back up to the current HD from my new iMac?
iMac 21.5″ 4K, macOS 11.0
Ah' OK.
If the new iMac does not want to resume using the old TM backups, then use Disk Utility to erase the drive and start new backups on it.
It is not supposed to, but it could be a problem because you jumped all the way from macOS 10.7 to macOS 11.
If you have already transfered everything off the old MacBook and wanted to reuse the old backup drive, then it shouldn't really matter if Time Machine continues the old backup or starts new backups.
Personally if I wanted to keep the old backups in tack, then I would just get a new external drive to backup the new iMac.
I've transferred everything to the new Mac. The old back-ups name is listed in the time machine dialog box with zero space. I really don't need to back up the old MacBook because everything is on my new Mac, which I need to back up. I'm just trying to save some money by not having to purchase another external HD.
Using an Old backup
