Time Machine and Spotlight (Sierra)
Hello.
So my situation is as follows. I use an external USB SSD for Time Machine backups. Usually after erasing the drive Time Machine works as expected for some time. Then the backup starts to fail on each attempt with 'Time Machine could not complete backup'. I've noticed that sometimes it's impossible to eject the drive also.
I've then checked what might be holding the drive (lsof) and found out that's mds process, which stands for Spotlight indexer as far as I get.
If I add mentioned drive to 'Privacy' list in Spotlight preferences, each reboot it disappears from this list.
If I disable indexing (launchctl unload -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist), scheduled or manually triggered Time Machine backup goes just fine each time.
Now the backup runs each hour and keeping indexing on means facing the same issue quite often. I don't use indexing and therefore consider having it disabled OK.
All this doesn't look sound in 2017. I'd like to know if there is any other good solution to this issue.
iMac, macOS Sierra (10.12.6)