Issue: Why does my job run on only 1 node?
Example:
Resource_List.nodes = 10:ppn=1
The job then runs on only 1 node and not 10 different nodes. Here is an example of echoing out each thread on the host that my mpi job ran under.
n8
n8
n8
n8
n8
n8
n8
n8
n8
n8
I would have expected 10 different nodes
n8
n9
n10
n11
n12
n13
n14
n15
n16
n17
n18
Solution:
By default Moab will stack as many threads on a node as possible. You can change this behavior with:
At submission time:
NMATCHPOLICY | |
---|---|
Format | One of the valid settings for the parameter JOBNODEMATCHPOLICY |
Description | Specifies how node resources should be selected and allocated to the job. |
Example |
> qsub -l nodes=2 -W x=nmatchpolicy:exactnode bw.cmd Job should use theEXACTNODEJOBNODEMATCHPOLICY. |
Cluster wide policy:
Docs: NodeMatchPolicy
Tags: mpi, NMATCHPOLICY, same node