503 Service Unavailable Owncloud after disk full


Last weekend the disk space of my Univention server was full. Result was that the Owncloud server stops working (normal behavior). I have already enlarged the disk two times before and with no problems at all. I use How to extend ownCloud storage - #4 by knebb to do this and it works.

Only now my Owncloud is not responding normal. I only get a 503 Service Unavailable page.

What I have check / done already:

After reboot the Univention server I stop the Owncloud docker with docker stop <docker ID>
When I start my docker with docker start -a <docker ID> I get the next error

Doctrine\DBAL\DBALException: Failed to connect to the database: An exception occurred in driver: SQLSTATE[HY000] [1045] Access denied for user 'owncloud'@'' (using password: YES) in /var/www/owncloud/lib/private/DB/Connection.php:62

When I remove the owncloud app and reinstall it, the data is gone but everything is working.

I’m running 5.0-1 errata287 with Owncloud 10.8

I think that the only problem is, is that owncloud in not able to connect to the database. So what are the best steps to resolve this problem?