[mpich-discuss] modifying the round-robin

[Benjamin Svetitsky]

Greetings,

I am running MPICH2 on a cluster of four quad-core machines under Linux. 
  If I run a job such as

mpiexec -l -n 4 hostname

then one process runs on each node, whereas I would prefer that all four 
run on the same node.  I tried modifying mpd.hosts to read:

nodeA:4
nodeB:4
nodeC:4
nodeD:4

but the result is not what I expected:

nodeC% mpiexec -l -n 4 hostname
0: nodeC
3: nodeB
2: nodeB
1: nodeB

How can I get the mpd to fill the hosts one by one reliably?

Incidentally, the :4 option is not documented in the Installation Guide. 
  I picked it up in the gutter.  If it doesn't do this, what DOES it do?

Thanks,
	Ben
-- 
Prof. Benjamin Svetitsky         Phone:            +972-3-640 8870
School of Physics and Astronomy  Fax:              +972-3-640 7932
Tel Aviv University              E-mail:      bqs at julian.tau.ac.il
69978 Tel Aviv, Israel           WWW: http://julian.tau.ac.il/~bqs