How to compile and run a C/MPI program "tst.c" on the cluster p1 in batch mode?
First you should decide for your favorite MPI implementation. Available are:

• the MPICH implementation with ch_gm device. To compile the program use
  > /usr/local/clos/mpich/bin/mpicc tst.c -o tst -lm
  
• the MPICH implementation with ch_p4 device. To compile the program use
  > /usr/lib/mpich/bin/mpicc tst.c -o tst -lm
  remark:
  • the option -o tst specifies the filename "tst" of the executable (default is "a.out")
  • -lm is necessary if you use the math library
  • Note that programs using stdin (e.g. scanf(...)) do not work properly in batch mode. The stdin cannot easily be redirected.
• to submit the program on 5 processors, use
  > pbs_sub tst -np 5 myarg
  remark:
  • myarg is passed to the program as command line option
  • after submission you get the job-id, e.g. 526.master1
  • if your job needs more than the default value 3600 minutes (= 1hour) you should specify the required time explicitely. For example, to get two hours type
    > pbs_sub -l walltime=7200 -- tst -np 5 myarg
    
• to check the job queue, type
  > pbs_stat -v
  
• premature output of your job can be obtained with
  > pbs_output 526
• after completion, the output (stdout/stderr) can be found in the files tst.o526 and tst.e526

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