I believe the btl must include self - can't just be openib. So you need -mca btl self,openib, otherwise the proc cannot talk to itself.
On Oct 12, 2011, at 12:46 PM, Bhargava Ramu Kavati wrote: > Hi, > I am using OpenMPI version 1.4.3 on CentOS5.4 machines (connected back to > back using Infiniband HW) > I am trying to run example apps in OpenMPI using the below command. > > "mpirun --prefix /usr/local/ -np 2 --mca btl openib --mca > btl_openib_cpc_include rdmacm -hostfile tmp_host_file ring_c" > > Here tmp_host_file contains IP addresses of two hosts. After running this > command, I see the error as > > "At least one pair of MPI processes are unable to reach each other for > MPI communications. This means that no Open MPI device has indicated > that it can be used to communicate between these processes. This is > an error; Open MPI requires that all MPI processes be able to reach > each other." > This clearly indicates that there is an option missing the command due to > which MPI processes are not able to reach each other. Can you please let me > know > 1) how do we resolve this > 2) IP is the only way for MPI processes to reach each other (i.e. it'll go > via IPoIB in infiniband case) ? > > Thanks & Regards, > Ramu > _______________________________________________ > devel mailing list > de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/devel
