You can start with one server
KLYRN VM can run its controller and its first compute node on the same server, so you can try it with a single machine.
You do not need two servers to try KLYRN VM. The controller and the first compute node can share one.
How to do it
Install the controller, then run klyrn-vm admin node add-local on the same server. In our test that took 12 seconds on Ubuntu.
What is ready
The server gets a private network, a storage pool and a catalogue of images. You can create your first machine straight away.
When you need more room, add a second server from the panel. Your first compute node stays free, and each one after it is $5 a month.