Hi Ali

I have seen this reported twice now – I think from two different sources, but I could be incorrect. Unfortunately, we don’t have access to an AIX cluster to investigate the problem. We don’t see it on any other platform at this time.

Could you tell me something more about your cluster? In particular, it would help to know your launch environment (e.g., rsh/ssh, SLURM, TM, etc.). The noted behavior of using —debug-daemons to resolve the problem has me puzzled as that flag only causes the daemons to keep their stdio ports open – it has nothing to do with the application processes nor the I/O forwarding subsystem.

I can suggest a couple of options in the interim, though I don’t know that they will solve the problem:

  1. You could upgrade to the 1.2 beta release. The runtime underwent some significant changes that might help here; or
  2. You could try configuring Open MPI with “--disable-pty-support”. The I/O forwarding system is currently based upon pty’s. We have seen a problem on one other platform where the pty support wasn’t quite what Open MPI expects – disabling it solved the problem. You should first check if the 1.1.2 release supports this configuration option (I honestly can’t remember – it has been too long) - you may need to upgrade to 1.2 to do this.

I hope that provides some help. If/when we get access to an AIX cluster, we’ll try to dig deeper into this issue.


On 12/22/06 7:44 AM, "Ali Eghlima" <Ali_Eghlima@raytheon.com> wrote:


We have Open MPI 1.1.2 installed on IBM AIX 5.3 cluster. It looks like
terminal output is broken. There are a few entry in the archive for this problem,
with no suggested solution or real work around.

I am putting this posting with hope to get some advise for a work around or solution.

#mpirun -np 1  hostname   

       No out put, piping the command to "cat" or "more" generate no out put as well.
       The only way to get an output from this command is to add --debug-daemons

#mpirun -np 1 --debug-daemons  hostname

Even this debug option is not working for a real application which generate several output.

Looking forward for any comments.



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