Backup users but skip user files

Hi,

Is there a way to backup courses and the participants of each course including messages in forums, activities, files submitted and grades. But avoid including user private files.

Because i'm trying to backup a small course, with few resources but 1000+ students. And I'm getting a 150MB-backup file.

I think this backup file shouldn't be bigger than 1MB.

Thanks!

Version: 2.6.2+