I got it working now.
But also only the dirty way with cifs as described here:
I had the same issue (symlinks it seems).
I tried the mfsymlink parameter trying to connect with the virtualbox functions but it crashed my startup completely and i had to undo it in recovery:
/etc/fstab looks like:
openhabian /media/share vboxsf uid=1000,gid=1000 0 0
this shows me the files and i am able to write but amanda-setup is not completing. only the folder is created. probably the symlink problem.
your code goes here
when i try to add mfsymlinks like that:
openhabian /media/share vboxsf mfsymlinks,uid=1000,gid=1000 0 0
it crashed my startup completely.
the working solution is:
//192.168.1.80/Backup/openhabian /media/share cifs vers=3.0,mfsymlinks,noauto,x-systemd.automount,_netdev,credentials=/root/.smbcredentials,dir_mode=0777,file_mode=0777 0 0