Can you add -v to your mpiexec command? It will enable verbose output and hopefully give some clues to where things are getting stuck. Ken From: Tanner L. Nelson via discuss <[email protected]> Date: Monday, February 17, 2025 at 11:43 AM To: [email protected] <[email protected]> Cc: Tanner L. Nelson <[email protected]> Subject: Re: [mpich-discuss] Only Run as root 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 ZjQcmQRYFpfptBannerStart This Message Is From an External Sender This message came from outside your organization. ZjQcmQRYFpfptBannerEnd 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