Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

Subject: Re: [OMPI users] Problem: openmpi using lam
From: Reuti (reuti_at_[hidden])
Date: 2008-03-08 10:40:05

Am 08.03.2008 um 12:26 schrieb Justus Schwabedal:

> I thought LAM/MPI is being merged into openmpi. I think, Im not
> sure how the implementations are related. I think lam is just a
> runtime for which now openmpi delivers some support. If not so, I
> dont understand. However orte is another runtime right? I thought I
> can switch between those using something like mpi-selector-menu. I
> think Im lost. How can I use openmpi to run a distributed system
> efficiently? I dont want to fall back on old LAM/MPI since I want
> to be modern :o)
> Yours, J

You can't mix different MPI implementations. If you compiled your
program with LAM/MPI, you must use their mpirun. There is no binary
interface defined for MPI, so that you could change the to be used
MPI implementation just on the fly from one run to the next. If you
want to change to Open MPI, you have to recompile your program and
use Open MPI's mpirun.

To your test-run: you specified to use two processes, but not where
to start them. Hence you must provide something like a machine file.
In LAM/MPI you could try:

mpirun C hello.x

(again: this only works in LAM/MPI).

In a distributed environment it's must common to use a queuing sytem
to select free nodes most efficiently for you. E.g. SGE ( http:// ) or Torque ( http:// )
and to start the jobs under their supervision.

-- Reuti

> -------- Original-Nachricht --------
>> Datum: Fri, 7 Mar 2008 13:19:16 -0500
>> Von: Jeff Squyres <jsquyres_at_[hidden]>
>> An: Open MPI Users <users_at_[hidden]>
>> Betreff: Re: [OMPI users] Problem: openmpi using lam
>> On Mar 7, 2008, at 11:31 AM, Justus Schwabedal wrote:
>>> I need advise to get openmpi to work using lam.
>> I think you're slightly confused -- LAM/MPI and Open MPI are two
>> different software projects that implement the same standard (MPI).
>> This list is for supporting Open MPI. Another list
>> (
>> ) is available for supporting LAM/MPI. You might want to refer to
>> the
>> "Getting Help" page on the LAM/MPI site
>> (
>> ). I suspect that your problem has to do with your hostfile, and you
>> should check the LAM/MPI user's guide for the answer.
>> But be aware that LAM/MPI is in maintenance mode -- it is being
>> deprecated in favor of Open MPI. See the announcement at the top of
>> LAM/MPI's home page.
>> Good luck.
>>> For testing I installed it on two machines running opensuse10.3
>>> (both atholon 64) connected via ethernet. I then try to run a test
>>> script "hello.x" with the following commands:
>>> jus_at_cusp:~/Code/Spielwiese/Mpi> make hello
>>> mpicc hello.c -o hello.x
>>> jus_at_cusp:~/Code/Spielwiese/Mpi> lamboot mfile
>>> LAM 7.1.4/MPI 2 C++/ROMIO - Indiana University
>>> Enter passphrase for key '/cusp/jus/.ssh/id_rsa':
>>> Enter passphrase for key '/cusp/jus/.ssh/id_rsa':
>>> jus_at_cusp:~/Code/Spielwiese/Mpi> lamnodes
>>> n0 cusp:1:origin,this_node
>>> n1
>>> jus_at_cusp:~/Code/Spielwiese/Mpi> mpirun -np 2 hello.x
>>> Process 0 on cusp out of 2
>>> Process 1 on cusp out of 2
>>> The jobs are thus wrapped only on the node "cusp", not on both. I
>>> have no clue why this is.
>>> Thanks, Justus
>>> --
>>> Psst! Geheimtipp: Online Games kostenlos spielen bei den GMX Free
>>> Games!
>>> _______________________________________________
>>> users mailing list
>>> users_at_[hidden]
>> --
>> Jeff Squyres
>> Cisco Systems
>> _______________________________________________
>> users mailing list
>> users_at_[hidden]
> --
> Psssst! Schon vom neuen GMX MultiMessenger gehört?
> Der kann`s mit allen:
> _______________________________________________
> users mailing list
> users_at_[hidden]