Well, you could wait until March 3 to see what happens.
If it doesn't straighten out the you might have to do what I had to do once to help another Moodle admin person out.
There are three tables concerning backups that actually track backups.
mysql> show tables like '%backup%';
+-------------------------------+
| Tables_in_moodle31 (%backup%) |
+-------------------------------+
| mdl_backup_controllers |
| mdl_backup_courses |
| mdl_backup_logs |
+-------------------------------+
I had to trun off automated backups so no new one would kick in, kill off any process related to backups, clean out moodledata/temp/backups/ so that it contained nothing, then truncate all 3 of the tables above - leave the tables, just remove all the data in them .... 0 rows.
Go back into setup of automated backups and set the schedule. Then waited until the next day to see how it went.
It did complete in the allotted time ... no errors ... and nothing left in moodledata/temp/backup/ related and the reports showed things should work in future. I did come back to that server in a week and checked. And then again in another week and checked.
In your case, however, with 600 courses, it might take longer than over night. Just how large are courses? Now large here doesn't necessarily mean size ... could mean processing large ... like a course with 1000 quizzes - that one will take some time ... processing time.
There is an addon/plugin that you could add to your site called 'course sizes'. It will attempt to calculate the backup size of the courses.
One better than tha, however, is command line moosh. It has a a course-info option that provides more accurate data, me thinks.
Got any course in the 90Gig range? Yep, that's right. That one course could kill off automated backups for sure.
Too bad the automated backup doesn't give you an option to choose which courses to exclude. :\
On that server that has the 90+Gig course (also has a few others in 60+,50+, and 20+'s GIG ranges ... I have to use three scheduled cron jobs outside of Moodle and the /admin/cli/backup.php script that loops through course ID's to get a backup of all courses in a week. The largest course slated for beginning late Sat. night and will run until Sun some time.
Just hope you are not in the same boat! ;)
'spirit of sharing', Ken
