Ralph. I will be building from the Master branch at github.com for testing purposes. We are not 'supporting' Singularity container creation, but we do hope to be able to offer some guidance, so I think we can finesse the PMIx version, yes?
That is good to know about the verbs headers being the only thing needed; thanks for that detail. Sometimes the library also needs to be present. Also very good to know that the host mpirun will start processes, as we are using cgroups, and if the processes get started by a non-tm-supporting MPI, they will be outside the proper cgroup. So, just to recap, if I install from the current master at http://github.com/open-mpi/ompi.git on the host system and within the container, I copy the verbs headers into the container, then configure and build OMPI within the container and ignore TM support, I should be able to copy the container to the cluster and run it with verbs and the system OMPI using tm. If a user were to build without the verbs support, it would still run, but it would fall back to non-verbs communication, so it would just be commensurately slower. Let me know if I've garbled things. Otherwise, wish me luck, and have a good weekend! Thanks, -- bennet On Fri, Feb 17, 2017 at 7:24 PM, r...@open-mpi.org <r...@open-mpi.org> wrote: > The embedded Singularity support hasn’t made it into the OMPI 2.x release > series yet, though OMPI will still work within a Singularity container anyway. > > Compatibility across the container boundary is always a problem, as your > examples illustrate. If the system is using one OMPI version and the > container is using another, then the only concern is compatibility across the > container boundary of the process-to-ORTE daemon communication. In the OMPI > 2.x series and beyond, this is done with PMIx. OMPI v2.0 is based on PMIx > v1.x, and so will OMPI v2.1. Thus, there is no compatibility issue there. > However, that statement is _not_ true for OMPI v1.10 and earlier series. > > Future OMPI versions will utilize PMIx v2 and above, which include a > cross-version compatibility layer. Thus, you shouldn’t have any issues mixing > and matching OMPI versions from this regard. > > However, your second example is a perfect illustration of where > containerization can break down. If you build your container on a system that > doesn’t have (for example) tm and verbs installed on it, then those OMPI > components will not be built. The tm component won’t matter as the system > version of mpirun will be executing, and it presumably knows how to interact > with Torque. > > However, if you run that container on a system that has verbs, your > application won’t be able to utilize the verbs support because those > components were never compiled. Note that the converse is not true: if you > build your container on a system that has verbs installed, you can then run > it on a system that doesn’t have verbs support and those components will > dynamically disqualify themselves. > > Remember, you only need the verbs headers to be installed - you don’t have to > build on a machine that actually has a verbs-supporting NIC installed (this > is how the distributions get around the problem). Thus, it isn’t hard to > avoid this portability problem - you just need to think ahead a bit. > > HTH > Ralph > >> On Feb 17, 2017, at 3:49 PM, Bennet Fauber <ben...@umich.edu> wrote: >> >> I am wishing to follow the instructions on the Singularity web site, >> >> http://singularity.lbl.gov/docs-hpc >> >> to test Singularity and OMPI on our cluster. My previously normal >> configure for the 1.x series looked like this. >> >> ./configure --prefix=/usr/local \ >> --mandir=${PREFIX}/share/man \ >> --with-tm --with-verbs \ >> --disable-dlopen --enable-shared >> CC=gcc CXX=g++ FC=gfortran >> >> I have a couple of wonderments. >> >> First, I presume it will be best to have the same version of OMPI >> inside the container as out, but how sensitive will it be to minor >> versions? All 2.1.x version should be fine, but not mix 2.1.x outside >> with 2.2.x inside or vice-versa (might be backward compatible but not >> forward)? >> >> Second, if someone builds OMPI inside their container on an external >> system, without tm and verbs, then brings the container to our system, >> will the tm and verbs be handled by the calling mpirun from the host >> system, and the OMPI inside the container won't care? Will not having >> those inside the container cause them to be suppressed outside? >> >> Thanks in advance, -- bennet >> _______________________________________________ >> users mailing list >> users@lists.open-mpi.org >> https://rfd.newmexicoconsortium.org/mailman/listinfo/users > > _______________________________________________ > users mailing list > users@lists.open-mpi.org > https://rfd.newmexicoconsortium.org/mailman/listinfo/users _______________________________________________ users mailing list users@lists.open-mpi.org https://rfd.newmexicoconsortium.org/mailman/listinfo/users
