HP XC System 4.x Software Using Mpich with Slurm Allocation, Using Mpich with LSF Allocation

respectively. These subsections are not full solutions for integrating MPICH with the HP XC System Software.

Figure 11-1 MPICH Wrapper Script

#!/bin/csh

srun csh -c 'echo `hostname`:2' sort uniq > machinelist set hostname = `head -1 machinelist awk -F: '{print $1}'`

ssh $hostname /opt/mpich/bin/mpirun options... -machinefile machinelist a.out

The wrapper script is based on the following assumptions:

•Each node in the HP XC system contains two CPUs.

•The current working directory is available on all nodes on which an MPICH job might run.

•You provide the mpirun options that are appropriate to your requirements.

•The executable file is named a.out.

•The wrapper script has the appropriate permissions.

You need to modify the wrapper script accordingly if these assumptions are not true.

11.7.1 Using MPICH with SLURM Allocation

The SLURM-based allocation method uses the srun command to spawn a shell; the remote job is run from within the shell, as shown here:

% srun		-Aoptions	1
%	./wrapper		2
%	exit		3

NOTE: This method assumes that the communication among nodes is performed using ssh and that passwords are not required.

1The srun -Acommand allocates the resources and spawns a new shell without starting a remote job. For more information on the -Aoption, see srun(1) .

IMPORTANT: Be sure that the number of nodes and processors in the srun command correspond to the numbers specified in the wrapper script.

2This command line executes the wrapper script to start the job on the allocated nodes.

3After the MPICH job specified by the wrapper completes, the exit command terminates the shell and releases the allocated nodes.

11.7.2Using MPICH with LSF Allocation

The LSF-based allocation method uses a single bsub command to create an allocation, as shown here:

%bsub -I options... wrapper

The bsub command launches the wrapper script.

IMPORTANT: Be sure that the number of nodes and processors in the bsub command corresponds to the number specified by the appropriate options in the wrapper script.

NOTE: This method assumes that the communication among nodes is performed using ssh and that passwords are not required.

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