How does PBS_NODEFILE work in pbs?

Question

For example, I have a file /home/user/nodes, which contains:

node1
node2
node3
node4
...

When I try to submit a job like:

qsub -v PBS_NODEFILE=/home/user/nodes -l nodes=2

Does it mean that pbs will select 2 nodes from /home/user/nodes list? I tried but it was not. It still chose the nodes from $PBS_HOME/server_priv/nodes, which is the default configuration.

I really want pbs could choose nodes from my own nodefile, is there a good way to do this?

Thanks.

Answer 1

With a queue system the idea is you let the system assign the nodes to your job when the job runs so you will never use your 'nodes' file. At run time, the variable PBS_NODEFILE is set to the location of a file that is created for your job that includes a list of the assigned nodes.