After installing the nfs server it does not run. After manually sztarting the rpcbind and nfs-kernel-server service everything works fine, but after a reboot it is again not running.
After evaluating tons of answers and threads about this topic I found a quite simple solution.
The problem is that the rpcbind service is not started. This can be achieved just by adding the correct dependencies for the
Add an approipriate drop-in for this service. For example
[Unit] Requires=rpcbind.service After=rpcbind.service
Now reboot works fine without any strange sleep commands in service scripts.