I purchased the Cloudmin addon, and I am playing around with it. Do I have to purchase two licenses so I can have it installed on two servers so I can create xen instances on both servers?
Cloudmin licensing permits you to install it on the machine that will be the management server and then you license the number of guests you wish to manage. For instance if you bought the 10 instance license then you can manage 10 guests with your management server.
You only need to install Cloudmin on 1 server.