Subject: Re: [OMPI users] Some Newbie questions
From: jody (jody.xha_at_[hidden])
Date: 2009-06-29 02:08:32


Hi Umanga

Yes, ssh (or rsh) should be configured on every machine, and it must
be configured
in such a way that no passwords are needed to make a connection. For example,
for passwordless connection using ssh i place every node's public key into
the file ~/.ssh/authorized_keys of every node.

And, yes, 1.2.7 is a rather old version - the current one is 1.3.2. It
would be good
if you could update your version to a newer one.

Jody

On Mon, Jun 29, 2009 at 7:00 AM, Ashika Umanga
Umagiliya<aumanga_at_[hidden]> wrote:
> Hi Vipin ,
> Thanks alot for the reply.
> I went through the FAQ and it also answered some of my questions.
>
> But my problem is, since I am using TCP/Ethernet  I guess that MPI uses
> SSH/RSH to communicate between peers.
> And for that, each peer should have the copy of the application right?
>
> I use 1.2.7rc2 (from Debian/Lenny repo) , and I didn't see the option
> "--preload-binary" , is it because the lower version?
>
> Bets regards,
> umanga.
>
>
>
> vipin kumar wrote:
>
> Hi,
> I am not expert, I am user like you but I think I can help you,
>
> Q. After installing OpenMPI on each machine ,do i need to run a
> service/daemon on each machine?
> Ans. No, not at all, Open MPI takes care of that for you.
>
> Q. How does peers in MPI environment communicate ?
> Ans. Using Communicator(name of the group of processes to whom it belongs,
> technically handle) and rank of the process in that Communicator.
>
> Q. After implementing parallel program , do I have to install the
> application on every machine ?
> Ans. Not necessary. Use "--preload-binary" option while launching the
> application through mpirun or mpiexec.
>
> Useful links:
> 1. http://www.open-mpi.org/faq/?category=running#simple-spmd-run
> 2. http://www.open-mpi.org/faq/
> 3. man page for mpirun
>
> Regards,
> Vipin K.
>
> On Mon, Jun 29, 2009 at 8:21 AM, Ashika Umanga Umagiliya
> <aumanga_at_[hidden]> wrote:
>>
>> Greeting all,
>>
>> I am new to Open MPI and I have some newbie questions. I have given 4
>> machines at our laboratory to set up Open MPI.Our net work is simply
>> TCP/Ethernet running Debian Linux.
>>
>> 1) After installing OpenMPI on each machine ,do i need to run a
>> service/daemon on each machine? (How does peers in MPI environment
>> communicate ?)
>>
>> 2) After implementing parallel program , do I have to install the
>> application on every machine ? (I thought the program automatically
>> propagated to other peers , like in RMI applications? )
>>
>>
>>
>> Thanks in advance,
>> Umanga
>>
>>
>> _______________________________________________
>> users mailing list
>> users_at_[hidden]
>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>
>
>
> --
> Vipin K.
> Research Engineer,
> C-Dot, Bangalore, India
>
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