Subject: MPI and DQS

From: "Matt Challacombe (T-12)" <[email-masked]>
Date: Wed, 30 Sep 1998 17:09:04 -0600

Hi,

I have the following DQS and MPI difficulties I hope ya'll
can help me with (Linux 2.0.35, MPICH 1.1.1, and DQS 3.2.3).

Firstly, I have 8 dual nodes. There are two clusters, a PARALLEL
cluster with queues that are superior to those in a SERIAL cluster.

Problem 1.  If I specify 4 processors, eg.

#$ -l qty.eq.4.and.PARALLEL

but tell mpirun to use 8 processors (to take advantage of the SMP)
as for example,

mpirun -nolocal -np 8 cpi > cpi.out

I find that the run has taken place on all 8 nodes!   Is there
a way to get the machines allocated by DQS, so that I can pass it
to mpirun as a machinefile?  Is there another fix?

Problem 2.  If there are SERIAL jobs running on each node, and I
run an MPI job using the queues in the PARALLEL cluster,  the node
acting as the MPI_HOST will suspend the SERIAL job on that node,
but the rest of the active PARALLEL queues do not suspend the
SERIAL jobs that are running.

Cheers, Matt

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Matt Challacombe
Los Alamos National Laboratory    http://www.t12.lanl.gov/~mchalla/
Theoretical Division              email: [email-masked]
Group T-12, Mail Stop B268        phone:   (505) 665-5905
Los Alamos, New Mexico  87545     fax:     (505) 665-3909
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