SLURM Basics

The ACE HPC Cluster uses SLURM (Simple Linux Utility for Resource Management) to manage job scheduling and resource allocation.

What is SLURM?

SLURM allows you to submit, monitor, and manage jobs on the cluster. It ensures efficient use of compute resources by queueing jobs and allocating them based on availability and policy.

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Key Commands

Action	Command	Description
Submit job	sbatch script.sh	Submits a job using a SLURM batch script
Check job queue	squeue -u $USER	Lists your active and queued jobs
Cancel job	scancel <job_id>	Cancels the specified job
Job details	scontrol show job <job_id>	Shows detailed info about a job
Job history	sacct -j <job_id>	Displays job accounting data
Node status	sinfo	Lists node states and partition info
Estimated start	squeue --start -u $USER	Predicts job start time

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Sample SLURM Script

#!/bin/bash
#SBATCH --job-name=myjob
#SBATCH --output=job_%j.out
#SBATCH --error=job_%j.err
#SBATCH --time=01:00:00
#SBATCH --nodes=1
#SBATCH --ntasks=4
#SBATCH --mem=8G


module load python/3.10
python my_script.py

Explanation

--job-name: Name of your job

--output: Standard output file (%j is job ID)

--error: Standard error file

--time: Max wall time (HH:MM:SS)

--nodes: Number of nodes to use

--ntasks: Total number of tasks/processes

--mem: Memory per node

Best Practices

• Test scripts on small inputs before scaling up.

• Use reasonable --time to avoid delays or early termination.

• Regularly monitor jobs with squeue and sacct.

• Cancel jobs you no longer need with scancel.