I had to change the openvpn configuration automatically and realized that the service was starting without any configuration. I assume that the openvpn service daemon was starting all configurations listed present in the /etc/openvpn directory.
After renaming the active configuration the new one I created did not run until I added it to the file /etc/default/openvpn. The point is the default one which was running before and whose configuration file I renamed was not in /etc/default/openvpn so I assuming that the previous one was configured somewhere else.
Are there any places where openvpn is configured besides /etc/default/openvpn?
