ohhhhh that was my fault. Somehow the command got mixed. Corrected now. pls try again using the new command above.
root@DietPi:~# ls -la /mnt/dietpi_userdata/nextcloud_data/
total 164280
drwxrwx--- 6 www-data www-data 4096 Oct 7 09:13 .
drwxrwxr-x 8 dietpi dietpi 4096 Nov 2 2022 ..
-rw-r--r-- 1 www-data www-data 542 Nov 19 2022 .htaccess
-rw-r--r-- 1 www-data www-data 0 Nov 19 2022 .ocdata
drwxr-xr-x 7 www-data www-data 4096 Sep 18 16:10 admin
drwxr-xr-x 9 www-data www-data 4096 Sep 23 16:04 appdata_ock2gwc8lm4h
-rw-r--r-- 1 root root 23851766 Oct 7 09:13 dietpi-nextcloud-database-backup.sql
drwxr-xr-x 2 www-data www-data 4096 Nov 19 2022 files_external
-rw-r--r-- 1 www-data www-data 0 Nov 19 2022 index.html
-rw-r----- 1 www-data www-data 39424761 Oct 7 09:10 nextcloud.log
-rw-r----- 1 www-data www-data 104869848 Sep 26 23:11 nextcloud.log.1
drwxr-xr-x 4 www-data www-data 4096 Nov 19 2022 updater-ock2gwc8lm4h
-rw-r--r-- 1 www-data www-data 15470 Nov 19 2022 updater.log
ok the backup file has been created
let’s try to remove database server, reboot and reinstall
apt remove mariadb-server
reboot
apt install mariadb-server
No change. reinstalled but didn’t help.
hmm, what we could do, is to create a backup of your DietPi system and try to remove Nextcloud + components and do a reinstall. The DB backup created should be restored automatically on new install. But this would be quite a drastic step.
It’s probably the only option. but it’s strange that it went wrong on its own.