Open Stack

> I would recommend always building an All-In-One deployment in a virtual 
> machine
> so that you have a reference to compare against when moving away from 
> the 'stock config'.
> Documentation for the AIO can be found here 
> https://docs.openstack.org/openstack-ansible/ussuri/user/aio/quickstart.html

I gradually decreased the complexity of my test system towards the
'stock config' to find out what caused the error but it kept showing up.
Finally, it vanished when I rebooted the server and my original
configuration also completed successfully afterwards. 🤦‍♂️

Thank you for your help and the insights to OSA!

Kind regards,
Oliver