Re: password-less public-key authenticated ssh

No problem. Attempting to get an MPI cluster working from scratch is going to be complicated, so you'll need to collect a lot of information to make it work.

The crossover cable looks just like a regular ethernet cable, but lets you directly connect 2 computers without putting a switch or router in between. Radio Shack will certainly have them.

The frontend node acts as a DCHP server, and passes out IP addresses to any computer that asks for one. That's the reason why it is important to isolate the cluster from other networks. Otherwise, the PelicanHPC DHCP server will pass out 10.11.1.x addresses to computers that don't want them, and your compute nodes may get their IPs from the other server, instead of from the PelicanHPC frontend node.

Don't worry about the worker nodes, just netboot them as described in the tutorial. As long as they are set to netboot (you might need to go into BIOS setup to enable that) things should be ok.

Good luck!