OK, I made all the suggested steps and everything went well.
The problem is that now, trying to reach Owncloud from the browser I’m back to this topic: https://dietpi.com/forum/t/solved-owncloud-doesnt-found-ocdata-file-after-have-change-the-drive/6062/7 where the page tells me it can find the .ocdata file in the data root…
I’m not sure if, following the steps suggested in the topic, I’ll solve the problem.
also because when I arrive at this command chown www-data:www-data /mnt/ownclouddrive/
it says me: chown: cannot access ‘/mnt/ownclouddrive/’: No such file or directory
What do you think?