I'm having a little trouble following this email thread, so forgive any misunderstanding.
If I understand this correctly, you are able to correctly run if you provide a -hostfile option. The issue is that mpirun does not appear to be picking up the PBS_NODEFILE automatically and using it - correct?
If that is true, then the problem is most likely that mpirun isn't finding the file. There should be an environmental variable $PBS_NODEFILE that contains the full path to the file. Also, that file (and the entire path to it) must be readable by the user.
Can you check that this is the case?
On Dec 1, 2009, at 4:08 PM, Belaid MOA wrote: