You might want to ask that on the Beowulf mailing lists - I suspect it has something to do with the mount procedure, but honestly have no real idea how to resolve it.
On Jan 10, 2012, at 8:45 PM, Shaandar Nyamtulga wrote:
Hi I built Beuwolf cluster using OpenMPI reading the following link. http://techtinkering.com/2009/12/02/setting-up-a-beowulf-cluster-using-open-mpi-on-linux/ I can do ssh to my slave nodes without the slave mpiuser's password before mounting my slaves. But when I mount my slaves and do ssh, the slaves ask again their passwords. Master and slaves' ssh directory and authorized_keys have permission 700, 600 respectively and they owned only by owner mpiuser through chown.RSA has no passphrase.