NC mariaDB with \data\ synchronizing

My files are outsourced on USB extern hd.
After crash of SD I have new installed debian and /apache/mariaDB/nc.
Now, calling URL I can not see any files which are physically on my extern HD.
Data folder is correct put in nc config.
Is there any possibility to synchron database and existing files from extern HD ?

Any help would be welcome!


you have to run the occ files:scan command on your server
sudo -u www-data php occ -v files:scan --all

from you nextcloud directory