Question: Will my time machine backup from Sierra work on high Sierra?
I'm about to upgrade from Sierra to High Sierra. I have Time Machine backups on an external drive and I also have a SuperDuper bootable backup on another external drive, both of which are formatted as HFS drives. When I upgrade to High Sierra and my internal drive is changed to APFS, will these backups still be useful?
Should I disconnect the external drives when I do the upgrade?
Should I upgrade and then reformat the external drives to APFS? Would that happen automatically if I leave the drives connected when I am upgrading?
Mac mini, macOS Sierra (10.12.5)