postgresql.service: The name org.freedesktop.PolicyKit1 was not provided by any .service files

When i restart postgresql, i get following error

postgres@vmi465483:~$ systemctl restart postgresql.service
Failed to restart postgresql.service: The name org.freedesktop.PolicyKit1 was not provided by any .service files
See system logs and 'systemctl status postgresql.service' for details.
postgres@vmi465483:~$ 

This is because you are running the command as user postres.

Login as user “root”, you will be able to restart postgres with command

systemctl restart postgresql

See PostgreSQL