Backup and erase without solution

Hello. Allow me to share a problem or two.

I am in charge of managing a Moodle with version Moodle 3.11.2 (Build: 20210729), with the Edumy theme.
Moodle currently has 125 gigs of space occupied out of 150 gigs. Therefore it approaches very close to the dangerous limit.

I want to back up some subjects. When I perform the backup as an administrator and request the backup with registered users, the copy takes a long time and stops at 96.2%
1. Any solution for this?

If you make a copy without registered users, the backup is carried out successfully.
2. Are user files guaranteed in this copy?


When I delete a course, I am left with a /course/delete.php page that shows nothing.
3. The problem besides this page not giving anything is that the space on the server increases.
That is, I don't delete the discipline and I increasingly run out of space on the server. My question is is there any other way to delete the subjects if I am forced to do so?


4. I'm thinking about doing a complete Moodle backup, as I need to restart a new project, I follow these steps, did I forget something?

1. Place Moodle on maintenance.
2. Back up the config.php file
3. Back up quick sqldatabase (zipped format)
5. Backup the www folder in TGZ format
6. Back up the moodledata folder

Thank you very much.