Example Slurm scripts¶

To submit a job script to SLURM, use the sbatch command followed by the name of your script:

sbatch my_script.sh

This page walks through several example scripts of increasing complexity, then covers how to submit and run them.

Creating a Script File¶

Before you can submit a job, you need to create a script file. You can use any text editor available on Easley. The three most common are:

nano — simplest, recommended for beginners:

nano my_script.sh

vi/vim — available on every Unix system:

vi my_script.sh

emacs — feature-rich editor:

emacs my_script.sh

Hello World¶

This example uses the Bash shell to print a simple "Hello World" message. The shell is specified by the shebang line at the top of the script (#!/bin/bash). If you do not specify a shell, your default shell will be used. Since this script uses only built-in Bash commands, no software modules are loaded — module usage is introduced in the next example.

Create a file called hello.sh and add the following:

#!/bin/bash
## Introduction for writing a Slurm script
## Requesting 1 node, 8 processors per node, and 2 hours of walltime.

#SBATCH --job-name=my_job
#SBATCH --nodes=1
#SBATCH --ntasks-per-node=8
#SBATCH --time=02:00:00
#SBATCH --partition=general
#SBATCH --mail-user=myemailaddress@unm.edu
#SBATCH --mail-type=BEGIN,END,FAIL

## Change to the directory the Slurm script was submitted from
cd $SLURM_SUBMIT_DIR

## Print a hello message indicating the host this is running on
export THIS_HOST=$(hostname)
echo "Hello World from host $THIS_HOST"

The number of tasks per node (--ntasks-per-node) must always be less than or equal to the number of physical CPU cores available on the node. On Easley, --ntasks-per-node should be <=64. We recommend always requesting the maximum number of processors per node to avoid multiple jobs on one node having to share memory. For more information see CARC systems information.

Multi-Processor Example¶

This example runs a command across multiple CPUs on a single node using MPI.

Create a file called multiprocessor.sh and add the following:

#!/bin/bash
## Multi-processor example
## The Center for Advanced Research Computing
## at The University of New Mexico

#SBATCH --job-name=my_job
#SBATCH --nodes=1
#SBATCH --ntasks-per-node=8
#SBATCH --time=02:00:00
#SBATCH --partition=general
#SBATCH --mail-user=myemailaddress@unm.edu
#SBATCH --mail-type=BEGIN,END,FAIL

# Load the OpenMPI module
module load openmpi

# Change to the directory where the Slurm script was submitted from
cd $SLURM_SUBMIT_DIR

# Run "hostname" on every CPU
# $SLURM_NTASKS is the total number of CPUs requested: 1 node x 8 CPUs = 8
mpirun -np $SLURM_NTASKS hostname

Multi-Node Example¶

This example spreads work across multiple nodes using MPI. When running across multiple nodes, use srun instead of mpirun — SLURM passes node information to srun automatically.

Create a file called multinode.sh and add the following:

#!/bin/bash
## Multi-node example
## The Center for Advanced Research Computing
## at The University of New Mexico

#SBATCH --job-name=my_job
#SBATCH --nodes=4
#SBATCH --ntasks-per-node=8
#SBATCH --time=02:00:00
#SBATCH --partition=general
#SBATCH --mail-user=myemailaddress@unm.edu
#SBATCH --mail-type=BEGIN,END,FAIL

# Change to the directory the Slurm script was submitted from
cd $SLURM_SUBMIT_DIR

# Load the OpenMPI module
module load openmpi

# Run "hostname" on every CPU across all nodes
# $SLURM_NTASKS is the total number of CPUs requested: 4 nodes x 8 CPUs = 32
srun hostname

Submitting Jobs¶

Batch Submission¶

To submit a script to the batch scheduler, use sbatch followed by the script name. SLURM returns a job ID when the job is successfully submitted, which you can use to check the status of your job.

sbatch hello.sh

Submitted batch job 156452

Check the status of your job with:

squeue --me

Once the job completes, the output will be written to a file named slurm-<jobid>.out in the directory you submitted from. View it with:

cat slurm-156452.out

Hello World from host easley004

For more information on available options type man sbatch.

Interactive Jobs¶

At times — such as when debugging — it can be useful to run a job interactively. Use salloc followed by your resource request, and SLURM will allocate a node and log you into it directly.

salloc --nodes=1 --ntasks=8 --time=00:05:00

salloc: Granted job allocation 156469
salloc: Nodes easley004 are ready for job

Once on the node, load your modules and run your script normally:

module load openmpi
bash helloworld_parallel.sh

Hello World from host easley004
Hello World from host easley004
Hello World from host easley004
Hello World from host easley004
Hello World from host easley004
Hello World from host easley004
Hello World from host easley004
Hello World from host easley004

When you are finished, type exit to release the node back to the pool.

Note: CARC recommends submitting jobs via sbatch wherever possible, as job submission will catch errors in resource requests before the job runs. Reserve interactive sessions for debugging and development.

This quickbyte was validated on 6/17/2026

Migrated from UNM-CARC QuickBytes (last source update 2026-06-17). Spotted a problem? Open an issue or pull request.