by Emma Richardson.
You might double check that you have permissions set correctly on the folder allowing the apache user (linux) to delete...I have noticed that sometimes if you set the auto delete number after the fact, it will not always delete previously made backups but should work from then on - i.e. You have seven backups already and set it to 2. Moodle will allow two new backups (totally nine) and then start deleting but the original seven are not always deleted....I think anyway....