[RegCNET] Multiprocess

[Torma Csaba]

Dear RegCM Users!

Instead of reporting problems, this time I send this message to let you
know that we succesfully compiled and run RegCM3 in a
SUN E10000 multiprocessor system with 48 processors.
Please find below the Makefile that we use.
Prior to compiling we asked our system administrator to install Sun HPC
ClusterTools 7 in the system:
http://www.sun.com/software/products/clustertools/ct7.html
This package contains openMPI, so that tha PATH setting in the Makefile
refers to the path of the ClusterTools installation
(this is machine dependent).
We tried to use MPICH (v1 and also v2) but we failed with the linker, so
finally we gave up trying with MPICH (we reported
our unresolved linker error in the mailing list in January).


Here is a list of modifications that were necessary for us to run RegCM3
in the SUN E10000.

1. PreProc/Terrain:

Makefile_SUN worked well for us as the Makefile.
In the last line of domain.param (NPROC) we set the number of processors
that we wanted to use (NPROC=48 in our case).
In the same file jx (number of grid points in x direction) must be
divisible with NPROC, and should be at least two times
NPROC. So in our case we set jx=96


2. ICBC

No modifications made, we simply used Makefile_SUN as Makefile
Note that terrain.x and icbc.x runs in single processor mode.


3. Model run

In RegCM/Main directory we adjusted MAKECODE so it pointed to
./0options/0_DIAG_PARALLEL_CODE
In the same directory we deleted mpif.h and then copied mpif.h from the
include directory of the Cluster tools
(/opt/SUNWhpc/HPC7.0/include/mpif.h) to RegCM/Main

In the directory that we used to run the model we adjusted regcm.x so that
the last line looked like this:
mpiexec -n 48 ./regcm<./regcm.in
Again, 48 refers to the number of processors that we use.

Finally we submitted the job, and that's all.
I hope it will be useful for someone.

Kind regards,

Csaba