Let's explore how to use the Slurm Batch System to the ATOS HPCF or ECS.

Basic Job submission

Access the default login node of the ATOS HPCF or ECS.

1. Create a directory for this tutorial so all the exercises and outputs are contained inside:

   mkdir ~/batch_tutorial cd ~/batch_tutorial

   
   

2. Create and submit a job called simplest.sh with just default settings that runs the command hostname. Can you find the output and inspect it? Where did your job run?

   Using your favourite editor, create a file called simplest.sh with the following content #!/bin/bash hostname You can submit it with: sbatch simplest.sh The job should be run shortly. When finished, a new file called slurm-<jobid>.out should appear in the same directory. You can check the output with: $ cat $(ls -r1 slurm-*.out | head -n1) ab6-202.bullx [ECMWF-INFO -ecepilog] ---------------------------------------------------------------------------------------------------- [ECMWF-INFO -ecepilog] This is the ECMWF job Epilogue [ECMWF-INFO -ecepilog] +++ Please report issues using the Support portal +++ [ECMWF-INFO -ecepilog] +++ https://support.ecmwf.int +++ [ECMWF-INFO -ecepilog] ---------------------------------------------------------------------------------------------------- [ECMWF-INFO -ecepilog] Run at 2023-10-25T11:31:53 on ecs [ECMWF-INFO -ecepilog] JobName : simplest.sh [ECMWF-INFO -ecepilog] JobID : 64273363 [ECMWF-INFO -ecepilog] Submit : 2023-10-25T11:31:36 [ECMWF-INFO -ecepilog] Start : 2023-10-25T11:31:51 [ECMWF-INFO -ecepilog] End : 2023-10-25T11:31:53 [ECMWF-INFO -ecepilog] QueuedTime : 15.0 [ECMWF-INFO -ecepilog] ElapsedRaw : 2 [ECMWF-INFO -ecepilog] ExitCode : 0:0 [ECMWF-INFO -ecepilog] DerivedExitCode : 0:0 [ECMWF-INFO -ecepilog] State : COMPLETED [ECMWF-INFO -ecepilog] Account : myaccount [ECMWF-INFO -ecepilog] QOS : ef [ECMWF-INFO -ecepilog] User : user [ECMWF-INFO -ecepilog] StdOut : /etc/ecmwf/nfs/dh1_home_a/user/slurm-64273363.out [ECMWF-INFO -ecepilog] StdErr : /etc/ecmwf/nfs/dh1_home_a/user/slurm-64273363.out [ECMWF-INFO -ecepilog] NNodes : 1 [ECMWF-INFO -ecepilog] NCPUS : 2 [ECMWF-INFO -ecepilog] SBU : 0.011 [ECMWF-INFO -ecepilog] ----------------------------------------------------------------------------------------------------

   
   

3. Configure your simplest.sh job to direct the output to simplest-<jobid>.out, the error to simplest-<jobid>.err both in the same directory, and the job name to just "simplest". Note you will need to use a special placeholder for the -<jobid>.

   Using your favourite editor, open the simplest.sh job script and add the relevant #SBATCH directives: #!/bin/bash #SBATCH --job-name=simplest #SBATCH --output=simplest-%j.out #SBATCH --output=simplest-%j.err hostname You can submit it again with: sbatch simplest.sh After a few moments, you should see the new files appear in your directory (job id will be different than the one displayed here): $ ls simplest-*.* simplest-64274497.err simplest-64274497.out You can check that the job name was also changed in the end of job report: $ grep -i jobname $(ls -r1 simplest-*.err | head -n1) [ECMWF-INFO -ecepilog] JobName : simplest