To be clear: this is a common misconception. Open MPI does not determine which network to use for MPI communication by the hostname(s) you use to launch your application. Specifically: the hostnames that you list in the hostfile, command line, or whatever your resource manager provides are *not* used to determine which networks to use for MPI communication.
Open MPI only uses hostnames to identify unique servers (so that we can launch processeson them). We use different controls -- outlined by Ralph -- to determine which network(s) to use for MPI communication. Hope that helps. On Feb 2, 2013, at 6:43 AM, Ralph Castain <r...@open-mpi.org> wrote: > I'm afraid this doesn't make much sense to me. LSF has dispatched node1 and > node2 - correct? It sounds like you have also given those names aliases that > refer to their IB ports - generally a very bad practice, but let's set that > aside for now. > > If they are the same physical nodes, then the node name makes no difference - > OMPI will see both TCP and IB on the node and use them. You can control which > interfaces get used by simply telling OMPI on its command line: > > mpirun -mca btl tcp,sm,self ... will use shared memory and TCP > > mpirun -mca openib,sm,self ... will use IB and shared memory > > Using host names to try and control which network gets used isn't going to > work - the software is too smart to be fooled that way. > > > On Feb 2, 2013, at 6:33 AM, HM Li <li...@163.com> wrote: > >> Can you help me? >> >> The bnode1.bnode2 and node1,node2 are the hostnames of the same nodes >> corresponding to the InfiniBand and ethernet network respectively. >> The node1,node2 are the nodes declarated in lsf.cluster.name >> In order to use the IB network, I have modified the lsf mpijob script, and >> modified the HOSTFILE containing the nodes which LSF dispatched from node to >> bnode. >> Then use "mpiexec -machinefile $HOSTFILE $COMMANDLINE" to run my jobs. >> But the job exits and shows: >> ------------------------------------------------------------- >> A hostfile was provided that contains at least one node not >> present in the allocation: >> >> hostfile: /home/nic/hmli/.lsbatch/bhost23263.node1 >> node: bnode2 >> >> If you are operating in a resource-managed environment, then only >> nodes that are in the allocation can be used in the hostfile. You >> may find relative node syntax to be a useful alternative to >> specifying absolute node names see the orte_hosts man page for >> further information. >> ------------------------------------------------------------- >> >> I don't want to change the hostname from node to bnode in lsf.cluster.name. >> >> Thank you very much. >> >> >> _______________________________________________ >> users mailing list >> us...@open-mpi.org >> http://www.open-mpi.org/mailman/listinfo.cgi/users > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
