Good morning, We have a small cluster in an isolated environment. Our lead has spearheaded a reinstall to get away from Bright Cluster Manager and CentOS. This is the first time our project has done anything like this, and we have hit a snag that we believe is MPI-related. As root: * Job runs as expected (verified with 2 nodes) * mpirun with host file, same result As user account: * Single node works * 2 nodes, job hangs with no error output that we can find To us, and our colleagues at our main Computing Center, it seems related to permissions/authentication. But everything we know to check has been checked several times (i.e. user can ssh to nodes 001-002 where root was successful, user was not; permissions on mpi directory 755, even tried 777 just to rule it out). Details I believe may be asked: * RHEL9 * Mpich4.2.3 was compiled with gcc11.5.0 * Consistent results with scheduler and mpirun * Tested HPL and our primary application, both built against the same mpich version Hoping we can get some suggestions. Thanks in advance! Respectfully, Tanner Nelson