I highly recommend that ssh be the only access method permissible for the root user across all nodes of the cluster. We want to install and use rshd and rsh nonetheless to get the best performance out of the cluster. We will make it nonusable for the root user though. Cluster jobs should be ran as a non-root user. If you need to increase their priority then you can do so as root using the renice(man renice) command.
To enable rsh to work transparently (no password required, and no prompts) for non-root users across all nodes of the cluster we need to install the packages of course, but also we need to ensure that the hostnames of each cluster node is listed in the /etc/hosts.equiv file for each cluster node. This step still needs to be automated by being handled in debut's bootstrap.sh.
For now .. or unless Peter has already fixed it, you have do a "for all" loop to copy this file over.