I'm not having any trouble getting it to start, and it's definitely using the openib btl. I was just wondering how it decided whether the openib btl was appropriate before going down the btl list to tcp when all mpirun gets is a hostname and no other information about connectivity on the remote end. For instance, is this determined before or after orted runs on the remote end?
On 12/23/14, 2:18 PM, Howard Pritchard wrote:
Hello Gary, It depends on how the Open MPI was built, and on mca parameters passed to the job either via settings in an mca params conf file or the mpirun command line or env. variables. If you have mxm (MLNX) or psm (qlogic/intel) installed on the system where your open mpi was built, you may actually be using one of those via the MTL path. Try mpirun -np 2 -H hosta,hostb -mca btl self,vader,openib ./your_favorite_test That should force open mpi to try using openib between the pair of hosts. Note you don't need "vader" on the command line if you are running only one mpi rank/node. Howard 2014-12-23 11:48 GMT-07:00 Gary Jackson <ga...@cs.umd.edu <mailto:ga...@cs.umd.edu>>: How does OpenMPI decide whether to use the IB BTL between a given pair of hosts, assuming there is an IB interface available? -- Gary _________________________________________________ users mailing list us...@open-mpi.org <mailto:us...@open-mpi.org> Subscription: http://www.open-mpi.org/__mailman/listinfo.cgi/users <http://www.open-mpi.org/mailman/listinfo.cgi/users> Link to this post: http://www.open-mpi.org/__community/lists/users/2014/12/__26063.php <http://www.open-mpi.org/community/lists/users/2014/12/26063.php> _______________________________________________ users mailing list us...@open-mpi.org Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/users Link to this post: http://www.open-mpi.org/community/lists/users/2014/12/26064.php
-- Gary
