Backup
If you remove the ownCloud app or update it - a backup is created automatically.
The backup remains on the host system and can be restored.
It is stored in :
/var/lib/univention-appcenter/backups/
The file name is :
appcenter-backup-owncloud:date
In it, you find your data and conf folders.
Your database backup is in :
/var/lib/univention-appcenter/backups/data/backups