<html><head></head><body bgcolor='#FFFFFF' style='font-size:12px;background-color:#FFFFFF;font-family:Verdana, Arial, sans-serif;'>Hello mpich community,<br/>having survived the various open source parallelization aids (pvm, mpich1-2) with UNIX like OS(SCO, AIX, LINUX since kernel 0.99) with successful couplings of different computers, a few days ago I started working with mpich2-1.4 on LINUX (MANDRIVA, DEBIAN) to install the well-kown code mcnpx on small clusters (at work and at home).<br/>Parallel calculation on different CPUs on one computer works fine, but coupling of two machines fails up till now.<br/>After quite a lot of efforts to find hints in the internet the current situation now is that on my homecluster with MANDRIVA2010.1 on a desktop 64 bit dual-core system and MANDRIVA2010.2 on a notebook 32bit dual core system the basic testprogram "cpi" runs on both system using a hosts file with local computer defined. Trying on both systems to add the second one results in very similar error messages. Here the 32bit notebook case:<br/>[inr487@cblxnbmd2 mpich2-1.4]$ mpiexec -bootstrap ssh examples/cpi<br/>Process 2 of 4 is on cblxnbmd2<br/>Process 3 of 4 is on cblxnbmd2<br/>Process 1 of 4 is on cblxhome<br/>Process 0 of 4 is on cblxhome<br/>Fatal error in PMPI_Reduce: Other MPI error, error stack:<br/>PMPI_Reduce(1270)...............: MPI_Reduce(sbuf=0x7fff36062ab8, rbuf=0x7fff36062ab0, count=1, MPI_DOUBLE, MPI_SUM, root=0, MPI_COMM_WORLD) failed<br/>MPIR_Reduce_impl(1087)..........:<br/>MPIR_Reduce_intra(848)..........:<br/>MPIR_Reduce_impl(1087)..........:<br/>MPIR_Reduce_intra(895)..........:<br/>MPIR_Reduce_binomial(206).......: Failure during collective<br/>MPIR_Reduce_intra(828)..........:<br/>MPIR_Reduce_impl(1087)..........:<br/>MPIR_Reduce_intra(895)..........:<br/>MPIR_Reduce_binomial(144).......:<br/>MPIDI_CH3U_Recvq_FDU_or_AEP(380): Communication error with rank 2<br/><br/>The bootstrap part in the command line is the last trial from several suggested proposals.<br/>I tried various ssh configurations working fine without password on the command line of both systems, using the ~/.ssh/config mechanism.<br/>I would very strongly appreciate when somebody could give me hint how to couple two computer on a private net 192.168.2.xxx using the current new version of mpich2-1.4.<br/>Thank you very much in advance for any tip,<br/>C. Broeders<br/><br/>--<br/>C.H.M. Broeders, http://www.cornelis-broeders.eu</body></html>