[Beowulf] mpirun and batch systems

[daniel.kidger at quadrics.com]

Erik,
> I have a question about how various batch systems run MPI jobs.
> 
> Say I have a head node and 16 compute nodes. I submit a job
> that requires 8 nodes, and the batch system allocates me
> nodes 4,5,6,7,8,9,10,11. 
> 
> Where does my 'mpirun' get executed from? On the head node? Or on
> node 4? 

This can depend upon the batch system and how it is configured. What is common is for the 'first' (not necessarily the lowest numbered) of the list of nodes assigned to a job is the one where the batch scripts executes.
  The most common alternative is that batch script gets executed on what is classed as a 'login node'. 


Yours,
Daniel.

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Dr. Dan Kidger, Quadrics Ltd.      daniel.kidger at quadrics.com
One Bridewell St., Bristol, BS1 2AA, UK         0117 915 5505
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