Update Apptainer info

content/submitting_jobs/creating_an_interactive_job.md

@@ -30,6 +30,14 @@ job.  You can provide options to the interactive job just as you would a
 regular SLURM job. The default job runtime is 1 hour, and can be
 increased by including the `--time` argument.
 
+### Interactive job for Apptainer
+
+Running Apptainer via an interactive job requires at least 4GBs of RAM:
+{{< highlight bash >}}
+$ srun --mem=4gb --nodes=1 --ntasks-per-node=4 --pty $SHELL
+{{< /highlight >}}
+If you get any memory-related errors, continue to increase the requested memory amount.
+
 ### Priority for short jobs
 
 To run short jobs for testing and development work, a job can specify a