                                 MPICH2
                                 ------
                 Grid Engine Parallel Support for MPICH2
                 ---------------------------------------

Content
-------

1) Content of this directory hierarchy
2) mpich2.template
3) startmpich2.sh
4) stopmpich2.sh
5) 'mpich2.sh' job example
6) Copyright


1) Content of this directory hierarchy
--------------------------------------

This directory contains the following files and directories:

   README           this file 
   README.atm       desribes how to run MPI jobs over ATM
   startmpich2.sh   startup script for MPI
   stopmpich2.sh    shutdown script for MPI
   mpich2.template  a MPICH PE template configuration for Grid Engine
                    (tight integration)
   mpich2.sh        a sample MPI job
   hostname         a wrapper for the hostname command (see README.atm)
   rsh              a wrapper around the default rsh command to access
                    the SGE built-in qrsh instead

Please refer to the "Installation and Administration Guide" Chapter "Support
of Parallel Environments" for a general introduction to the Parallel
Environment Interface of Grid Engine.


2) mpich.template
-----------------

   Use this template as a starting point when establishing a parallel
   environment for MPICH2 with tight integration. You need to replace
   <the_number_of_slots> and <your_sge_root> with the appropriate information.

   Here is a list of problems for which tight integration provides solutions

   - resource limits are enforced also for tasks at slave hosts
   - resource consumption at slave hosts can be accounted
   - no need to write a customized terminate method to ensure
     that whole job is finished on qdel
 
   Here is a list of problems which are not solved by the tight integration

   - can't trigger job finish if application finishes partially

   There are two samples included. You should use these samples to verify
   that your integration of Grid Engine with MPI/MPICH works correctly.


3) startmpich2.sh
-----------------

   The starter script 'startmpich2.sh' needs some command line arguments, to 
   be configured by use of either qmon or qconf. The first one is the path
   to the "$pe_hostfile" that gets transformed by startmpich2.sh into a
   MPI machine file. On successful completion startmpich2.sh creates a
   machine file in $TMPDIR/machines to be passed to "mpirun" at job
   start.

   $TMPDIR is a temporary directory created and removed by the Grid Engine
   execution daemon.


4) stopmpich2.sh
----------------

   The stopper 'stopmpich2.sh' just removes $TMPDIR/machines.  


5) 'mpich2.sh' job example
-----------------------

   This sample script will execute the mpihello program without the use of
   daemons. So a connections by the SGE supplied qrsh is sufficient.


6) Copyright
------------

   (c) 2002 Sun Microsystems, Inc. Use is subject to license terms.
