Resource Allocation¶

Before you submit a job, first estimate its CPU, memory, wall-time needs, then express those requirements explicitly in the job resource list so the scheduler can allocate the right resources and enforce sensible limits.

Warning

Your job can only use the resources you request. If it tries to use more CPU cores or memory than allowed, it will be limited or even stopped by the system if memory overcommitted. To avoid issues, always request the right amount of resources for your job.

Note

If you submit a job without a resource list, the scheduler will apply its site defaults 1 CPU core and 1 GB of memory. If your job requires more, it may run slowly or be terminated for exceeding these limits.

Resource List¶

You can list all available node resources using pbsnodes -a command.

Resource	Description
`select`	Number of chunks for parallel jobs
`ncpus`	Number of CPUs per node
`mem`	Amount of memory per node
`walltime`	Maximum runtime

Example¶

#!/bin/bash
#PBS -l select=1:ncpus=4:mem=8gb
#PBS -l walltime=02:00:00

module load mysoftware      # Load any necessary modules
./my_program                # Run your application

In this example, the job requests 4 CPU cores and 8 GB of memory on a single node, with a maximum runtime of 2 hours.