Sorry for not replying earlier. Yes, you hit on a solution.
Note, too, that the MTLs are only used by the "cm" PML, and the BTLs are only used by the "ob1" PML. So if you're using the openib BTL for IB support (vs. the MXM MTL), you can effectively choose one or the other by setting OMPI_MCA_pml=ob1 or OMPI_MCA_pml=cm Which will force the use of ob1 or cm, and therefore force the use of the BTLs or MTLs, respectively. More importantly, forcing the use of ob1/BTLs means that the MTLs will *not* be opened (i.e., so you won't see the MX MTL complain about the lack of myriexpress). Make sense? You probably figured out that you can set these values either in the environments of these machines or in machine-specific config files in the Open MPI installation tree. Environment is usually easier, especially if you have Open MPI installed in a single, common location on a networked filesystem that is available on all servers. Hope that helps! > On Feb 11, 2015, at 8:07 PM, Avalon Johnson <avalo...@usc.edu> wrote: > > > > Hi all > > I have figured this out. For anyone who needs to at run time disable a single > item default MCA value, the solution is to set. > > OMPI_MCA_mtl=^mx > OMPI_MCA_btl=self,sm,openib,tcp > > > as mentioned > > OMPI_MCA_mtl="" > > will not do the job. > > Avalon Johnson > ITS HPCC > USC > > "It takes a village ..." > > On Wed, 11 Feb 2015, Avalon Johnson wrote: > >> >> >> We have a cluster which is a combination of Myrinet and Infiniband nodes. >> >> We are using a common openmpi 1.8.4 software tree accessible to both set of >> nodes. >> >> Our Infiniband nodes do NOT have the libmyriexpress.so library installed >> (since it is not needed). >> Likewise the Myrinet nodes do not have the OFED libraries installed. >> >> >> When running an MPI program on the Infiniband node, openmpi in trying to >> determine what transport methods are available, tries to load the >> libmyriexpress.so, and then complains that it is not found. >> >> >> I would like to disable this behavior. I had hoped to use the OMPI_MCA_mtl >> environment variable to do this. >> But I unable to come up with a setting that accomplishes this. That is have >> OMPI_MCA_btl set to 'self,sm,openib,tcp' and no MCA mtl checked or used. >> >> >> For the equivalent problem on our Myrinet cluster I set OMPI_MCA_btl, to >> 'self,sm,tcp' and OMPI_MCA_mtl to 'mx' >> >> Does anyone know how to disable the MCA mtl at run time, since it's not >> needed on the Infiniband nodes? >> >> >> Thanks in advance. >> >> My apologies if this has been addressed before, I did not find it when >> searching the list. >> >> >> Avalon Johnson ITS HPCC >> USC >> >> "It takes a village ..." >> _______________________________________________ >> 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/2015/02/26315.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/2015/02/26317.php -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
