HP-MPI User's Guide (11th Edition)

Understanding HP-MPI
MPI options
Chapter 3 149
TOTALVIEW When you use the TotalView debugger, HP-MPI uses your
PATH variable to find TotalView. You can also set the absolute path and
TotalView specific options in the TOTALVIEW environment variable. This
environment variable is used by mpirun.
% setenv TOTALVIEW /opt/totalview/bin/totalview
Interconnect selection environment variables
MPI_IC_ORDER MPI_IC_ORDER is an environment variable whose
default contents are "ibv:vapi:udapl:psm:mx:gm:elan:itapi:TCP" and
instructs HP-MPI to search in a specific order for the presence of an
interconnect. Lowercase selections imply use if detected, otherwise keep
searching. An uppercase option demands that the interconnect option be
used, and if it cannot be selected the application will terminate with an
error. For example:
% export MPI_IC_ORDER="ibv:vapi:udapl:psm:mx:gm:elan: \
itapi:TCP"
% export MPIRUN_OPTIONS="-prot"
% $MPI_ROOT/bin/mpirun -srun -n4 ./a.out
The command line for the above will appear to mpirun as
$MPI_ROOT/bin/mpirun -prot -srun -n4 ./a.out and the
interconnect decision will look for the presence of Elan and use it if
found. Otherwise, interconnects will be tried in the order specified by
MPI_IC_ORDER.
The following is an example of using TCP over GigE, assuming GigE is
installed and 192.168.1.1 corresponds to the ethernet interface with
GigE. Note the implicit use of -netaddr 192.168.1.1 is required to
effectively get TCP over the proper subnet.
% export MPI_IC_ORDER="ibv:vapi:udapl:psm:mx:gm:elan: \
itapi:TCP"
% export MPIRUN_SYSTEM_OPTIONS="-netaddr 192.168.1.1"
% $MPI_ROOT/bin/mpirun -prot -TCP -srun -n4 ./a.out
On an XC system, the cluster installation will define the MPI
interconnect search order based on what is present on the system.