Thanks. That fixed it. I had earlier tried to disable Spotlight by adding the backup drive to the Spotlight Privacy list. When I tried that I got a message that said that Spotlight understood that the drive was a Time Machine drive and it would disable indexing of everything EXCEPT for Time Machine Backups. Next I tried to disable Spotlight all together using
sudo mdutil -a -i off
After doing this and checking the status of indexing with
sudo mdutil -a -s
I saw that indexing was disabled for
/Volumes/My Book
which is the mount point for the Time Machine backup drive but when I backup was running I saw that indexing WAS STILL ENABLED for
/Volumes/My Book/Backups.backup
and I couldn't figure out how to turn it off until I saw the "sudo launchctl unload" command in that link. Thanks. I don't use Spotlight so for me it's no big deal. Thanks again.