[mpich-discuss] mpiexec and -n option

[Jain, Rohit]

I can! I am just trying to understand the need for it. Do I always need to use it?

Documents are not clear about this usage. It looked like specifying host:<n> in host file might have worked here.

So far, it looks like I always need to use '-n 1' option, when using 'exec : exec : exec' style launch, irrespective of binding methods, or host file specification. Is that correct?

Regards,
Rohit


-----Original Message-----
From: Pavan Balaji [mailto:balaji at mcs.anl.gov] 
Sent: Tuesday, August 16, 2011 12:51 PM
To: Jain, Rohit
Cc: mpich-discuss at mcs.anl.gov
Subject: Re: [mpich-discuss] mpiexec and -n option


Is there a reason you don't want to use the "-n" option?

% mpiexec -f host_file -n 1 a1.out : -n 1 a2.out : -n 1 a3.out

  -- Pavan

On 08/16/2011 02:48 PM, Jain, Rohit wrote:
> Hi Pavan,
>
> Another question on running with host file.
> I want to run 3 processes on 3 different machines:
>
> I run:
> 	mpiexec -f host_file a1.out : a2.out : a3.out
>
> host_file:
> mach1
> mach2
> mach3
>
> or
>
> mach1:1
> mach2:1
> mach3:1
>
> It starts 3 processes on all 3 machines:
>
> #     Proxy information:
> #     *********************
> #       [1] proxy: mach1 (1 cores)
> #       Exec list: a1.out (1 processes); a2.out (1 processes); a3.out (1 processes);
> #
> #       [2] proxy: mach2 (1 cores)
> #       Exec list: a1.out (1 processes); a2.out (1 processes); a3.out (1 processes);
> #
> #       [3] proxy: mach3 (1 cores)
> #       Exec list: a1.out (1 processes); a2.out (1 processes); a3.out (1 processes);
>
> What am I doing wrong?
>
> Regards,
> Rohit
>
>
>

-- 
Pavan Balaji
http://www.mcs.anl.gov/~balaji