HP XC System 2.x Software - Manual (Page 120)

8.9 Environment Variables
HP-MPI on HP XC provides the following additional environment variables:
8.9.1 MPIRUN_OPTIONS
MPIRUN_OPTIONS is a mechanism for specifying additional command line arguments to
mpirun . If this environment variable is set, then any mpirun command will behave as if the
arguments in MPIRUN_OPTIONS had been specified on the mpirun command line. For
example:
% export MPIRUN_OPTIONS="-v -prot"
% $MPI_ROOT/bin/mpirun -np 2 /path/to/program.x
The above commands are equivalent to the following:
% $MPI_ROOT/bin/mpirun -v -prot -np 2 /path/to/program.x
8.9.2 MPIRUN_SYSTEM_OPTIONS
The MPIRUN_SYSTEM_OPTIONS environment variable allows a system administrator
to preset options which will be inserted before MPIRUN_OPTIONS and any explicit
mpirun options on the command line. This is most useful for establishing a preferred IP
address/hostname for TCP communications in the situation where a user explicitly requests
TCP via the
-TCP option, or when default system interconnection selection chooses TCP.
This environment variable can be overridden.
8.9.3 MPI_IC_ORDER
The MPI_IC_ORDER environment variable, whose default contents are
"
elan:gm:itapi:TCP ", instructs HP-MPI to search in a specific order for the presence of a
system interconnect. Lowercase selections imply use if detected, otherwise keep searching.
An uppercase option demands that the system interconnect option be used, and if it cannot be
selected the application will terminate with an error. For example:
% export MPI_IC_ORDER="elan:TCP:gm:itapi"
% export MPIRUN_SYSTEM_OPTIONS="-subnet 192.168.1.1"
% 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 -subnet 192.168.1.1 -prot -srun -n4
./a.out
The system interconnect decision will look for the presence of Elan and use it if found.
Otherwise, TCP will be used and the communication path will be on the
subnet
192.168.1.1 .
The following is an example of using TCP over Gigabit Ethernet, assuming Gigabit Ethernet
is installed and
192.168.1.1 corresponds to the Ethernet interface with Gigabit Ethernet.
Note the implicit use of -subnet 192.168.1.1 is required to effectively get TCP over the
proper subnet.
% export MPI_IC_ORDER="elan:TCP:gm:itapi"
% export MPIRUN_SYSTEM_OPTIONS="-subnet 192.168.1.1"
% $MPI_ROOT/bin/mpirun -prot -TCP -srun -n4 ./a.out
8.9.4 MPI_PHYSICAL_MEMORY
MPI_PHYSICAL_MEMORY allows you to specify the amount of physical memory in kilobytes
available on the system. MPI normally attempts to determine the amount of physical memory
8-10 Using HP-MPI