mpiexec makes a couiple of serial jobs on each node

["Masahiro TATSUMI (巽]

Hi!

I'm trying to replace mpirun with mpiexec  but I could not get parallel
job.  

When I try the following script, 

----------------------------------------------------
#!/bin/sh
#PBS -N cpi_mpiexec
#PBS -j oe
#PBS -l nodes=3
cmd_dir="/usr/local/bin"

cat $PBS_NODEFILE
${cmd_dir}/mpiexec /usr/local/mpi/examples/cpi
-----------------------------------------------------

I got the output that tells 3 serial jobs was executed on each node as
follows:

-----------------------------------------------------
anymede3
ganymede2
ganymede1
Process 0 on ganymede2
pi is approximately 3.1416009869231254, Error is 0.0000083333333323
wall clock time = 0.000086
Process 0 on ganymede1
pi is approximately 3.1416009869231254, Error is 0.0000083333333323
wall clock time = 0.000084
pi is approximately 3.1416009869231254, Error is 0.0000083333333323
wall clock time = 0.000082
Process 0 on ganymede3
-----------------------------------------------------

Using mpirun, a parallel job with 3 processors executed correctly:


-----------------------------------------------------
#!/bin/sh
#PBS -N cpi_mpirun
#PBS -j oe
#PBS -l nodes=3
n=`wc -l < $PBS_NODEFILE`
echo job running on $n processors
echo nodes:
cat $PBS_NODEFILE
mpirun -np $n -machinefile $PBS_NODEFILE /usr/local/mpi/examples/cpi
-----------------------------------------------------

-----------------------------------------------------
job running on 3 processors
nodes:
ganymede3
ganymede2
ganymede1
Process 0 on ganymede3
Process 1 on ganymede2
Process 2 on ganymede1
pi is approximately 3.1416009869231249, Error is 0.0000083333333318
wall clock time = 0.000311
-----------------------------------------------------


What is wrong with mpiexec ?


---
Masahiro TATSUMI, Ph.D.  <tatsumi at nfi.co.jp>   // Parallel, it works!
Fuel Engineering and Develpment Dpt.,  Nuclear Fuel Industries, Ltd.
950 Ohaza Noda, Kumatori-cho, Sennan-gun, Osaka 590-0481 JAPAN 
          Tel.: +81-724-52-8111   Fax: +81-724-52-8117