I have a pair of Mid-2007 MacBooks (one on 10.5.8 and one on 10.7.5), a pair of Mid-2006 Mac Pros (both running 10.7.5), a 2005 iBook G4 (10.5.8), and a 2004 PowerBook G4 (10.5.8) that won't backup to my Time Machine drive. These Macs will take forever to go through the "Indexing backup…" stage, but will fail each time. All 13 other Macs that I own will back up to this drive with no issues at all, and the oldest OS X version being used in this group is 10.11.
Is this just a thing that's been killed off, or am I not doing something right here? I've even tried to backup these machines to the drive first after formatting it on one of the affected Macs, no dice. Space remaining on the drive also shouldn't be an issue (~800GB of 4TB used).
Any help is greatly appreciated!