If you are interested in setting up a Message Passing Interface (MPI) cluster, you can also use Peak Two Cloud. First, launch a number of instances (nodes in your clusters) that you are going to use. Below is an example setup with four nodes, one of which is the head node.

Take note of the instance name and flavor used. The next step is to configure the cluster. Follow the steps here , changing the IP addresses and host names based on the launched instances. Once you are done, connect to the head node and begin running MPI programs on your cluster.

To enable password authentication on the machines (not require a public key file when you ssh to the machines), edit /etc/ssh/sshd_config and set PasswordAuthentication to yes. Restart the SSH daemon by running /etc/init.d/ssh restart.