I have a running standalone ISPConfig server with Apache, and need to run a separate NginX ISPConfig server. Is it possoble to turn the first standalone server into multiserver setup? This way when I install the NginX server I just join it to the first ISPCofig server.
Thats possible. Each standalone server can be used as the master for a multiserver setup without any modifications.
So when installing the second server in expert mode I just enter the root user info for first server and that's it?
In expert mode, you first enter the local mysql root details, the installer then asks you if you want to join another server and then you enter the root login details of the master server. ensure that you added a mysql root user on the master first that is able to connect from hostname and ip of the slave. see multiserver tutorial for details.