Hello,
I didn’t know the best place to post my question so I am posting to both lammps and openmpi.
I have downloaded and installed lammps on a system that does not have infiniband on any node meaning that no infiniband interfaces are physically present. There is a head node and 16 compute nodes and the system runs correctly except that I get the warning message shown below once per node when a job starts up. How can I eliminate the warning?
[compute20:06109] mca: base: component_find: unable to open /usr/lib64/openmpi/lib/openmpi/mca_btl_openib: perhaps a missing symbol, or compiled for a different version of Open MPI? (ignored)
Thank you.
Robert Diersing
Frank H. Dottterweich College of Engineering
Texas A&M University-Kingsville
Hello,
I didn't know the best place to post my question so I am posting to both
lammps and openmpi.
it is an openmpi question.
I have downloaded and installed lammps on a system that does not have
infiniband on any node meaning that no infiniband interfaces are physically
present. There is a head node and 16 compute nodes and the system runs
correctly except that I get the warning message shown below once per node
when a job starts up. How can I eliminate the warning?
mpirun --mca btl tcp,sm,self ...
should do the trick. more details are in the OpenMPI docs. this flag
can also be specified in a global configuration file for OpenMPI.
please note, that the parallel scaling for LAMMPS over TCP/IP is
probably not very good for typical systems, so you probably want to
use either hybrid MPI+OpenMP to reduce communication contention or
better yet, only run inside a single node and then --mca btl sm,self
is sufficient.
axel.