It seems that old files is not being deleted from moodledata/trashdir even after 24 hours (as Ken mentioned it should be).
Last week everyday I checked moodledata/trashdir size, so on tuesday, wednesday, friday it was 37-39GB.
Then automated course backups started on saturday 4AM and finished on ~11AM. I checked moodledata/trashdir on saturday and it was 290GB.
So as I mentioned weekly backups is around 240-280GB, so this is the number we get. On friday it was ~40GB + ~250GB after automated backups on sutarday and we have 290GB in moodledata/trashdir.
I checked on Sunday, on Monday and there was same 290GB used in moodledata/trashdir. So somehow oldest backups which are moved to trashdir is not being deleted even after 48 hours.
Server has access to moodledata folder, it's set to 777, so it's not permission issue.
Also I believe something has changed in Moodle backups process because now backups are made "randomly".
Can someone check in their Moodle and confirm that you have the same process?
Before update to 3.9.1 automated backups was made from the first course (id=1) to the last course (id=xxxx).
So using filezilla I could short mbz files by time created and all course were ordered by increasing id.
And now after update to 3.9.1 automated backups are being done "randomly". For example first automated backup done on Saturday 4:00AM was ID=1614, next was id=857, etc. It was done 2930 automated backups.
Screenshot below: