[torqueusers] Nodes dual and quad core
prakash.velayutham at cchmc.org
Mon Feb 11 05:49:47 MST 2008
On Feb 11, 2008, at 6:04 AM, Albino Aveleda wrote:
> I have a cluster with dual and quad core processors. Some nodes have
> two dual cores per processors and others have two quad cores per
> processors. How could I submit a job selecting number the cores?
> For example, the user want run the mpi program with 16 cores, if I use
> “#PBS -l nodes=2:ppn=8” only the quad cores will be use, but in this
> example I have 4 nodes with two dual cores free that they could run
> this job.
> How do I write the job for chose cores and not processors?
> Best regards,
Which scheduler are you using? (Torque native / Maui / Moab).
I am not sure if this is completely supported in Torque, but in Maui/
Moab, there is a property called JOBNODEMATCHPOLICY which can be set
Also, in Moab, you can request something like "qsub -lnodes=4" and
this will only look for 4 cores.
And If you would want to get 4 cores from the same node, then you
would use "qsub -lnodes=4,tpn=4".
Or, if you want 2 nodes with 4 cores each, you would use "qsub -
lnodes=8,tpn=4" (here the total cores is 8, and the tasks per node is
4, which means a total of 2 nodes). The regular syntax of "qsub -
lnodes=2:ppn=4" would not work in Maui/Moab as in Torque.
Hope that helps.
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