[torquedev] PPN/Node state bug?

Chris Samuel csamuel at vpac.org
Thu Sep 17 06:33:08 MDT 2009

----- "Simon Toth" <SimonT at mail.muni.cz> wrote:

> > I'm still not sure what this is meant to do!
> Well, by default, all requests for nodes are exclusive (confirmed by
> reading the server code). This should mean (according to Torque
> documentation), that when you allocate a node to a job, you can't run
> anything else on that node until the job finishes.

Umm, but the server doesn't decide that, that's a scheduler
decision IMHO.  Certainly with Maui/Moab that is controlled
by the policies you specify in the them.  It's the scheduler
that decides which vnodes get assigned to which jobs, not
the pbs_server.

> I also have PBS pro documentation here and it actually supports a
> separate flag for this: "#excl" (not sure what is default).

Never used PBSPro so no idea.

> If you don't need exclusive allocation, you have to specify "#shared"
> (for example if you just need to calculate something, then you don't
> really care that there are other jobs on other CPU's of the machine).

Never heard of that before, sorry!

Torque has cpuset support to avoid some of those issues anyway.

Christopher Samuel - (03) 9925 4751 - Systems Manager
 The Victorian Partnership for Advanced Computing
 P.O. Box 201, Carlton South, VIC 3053, Australia
VPAC is a not-for-profit Registered Research Agency

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