Possible Temporary Workaround?
I stumbled on something that stopped (for the time being) the excessive backups.
A quick review, my problem was that my disk space was being rapidly consumed. The root cause was traced to the fact that a recent code change created an infinite loop where the act of performing a backup was counted as a "change" to the course so that the course would get backed up repeatedly even when there weren't any actual changes made to the courses.
I accidentally prevented the scheduled backups from running for a week, after I resumed the backups the cycle seemed to have been broken so that only actual changes to the courses caused backups. I suspect that the situation still exists and that although there are currently far fewer courses being backed-up, that they will continue to be backed up forever and the number of courses involved will slowly grow until the situation becomes critical again.
How did I interrupt the backups? I meant to install an update for a plugin on my test system but accidentally began the process on my Production system. I didn't realize my mistake until I got to the step where the system asks if you want to update the database and I stopped. After I had installed and tested the update on my test system (about 1 week later), I updated the database on the Production system.
I still think that this is a coding problem that should be fixed but at least for me, it is not as urgent.
Natassia