Steps on How to Submit Jobs

How to Submit Interactive jobs

There are different ways to submit interactive jobs.

Using qsub

qsub command is patched locally to handle the interactive jobs. So mostly you can use the qsub command as before:

[xwang@pitzer-login04 ~]$ qsub -I -l nodes=1 -A PZS0712
salloc: Pending job allocation 15387
salloc: job 15387 queued and waiting for resources
salloc: job 15387 has been allocated resources
salloc: Granted job allocation 15387
salloc: Waiting for resource configuration
salloc: Nodes p0601 are ready for job
...
[xwang@p0601 ~]$ 
# can now start executing commands interactively

Using sinteractive

You can use the custom tool sinteractive as:

[xwang@pitzer-login04 ~]$ sinteractive
salloc: Pending job allocation 14269
salloc: job 14269 queued and waiting for resources
salloc: job 14269 has been allocated resources
salloc: Granted job allocation 14269
salloc: Waiting for resource configuration
salloc: Nodes p0591 are ready for job
...
...
[xwang@p0593 ~] $
# can now start executing commands interactively

Using salloc

It is a little complicated if you use salloc . Below is a simple example:

[user@pitzer-login04 ~] $ salloc -t 00:30:00 --ntasks-per-node=3 srun --pty /bin/bash
salloc: Pending job allocation 2337639
salloc: job 2337639 queued and waiting for resources
salloc: job 2337639 has been allocated resources
salloc: Granted job allocation 2337639
salloc: Waiting for resource configuration
salloc: Nodes p0002 are ready for job

# normal login display
[user@p0002 ~]$
# can now start executing commands interactively

How to Submit Non-interactive jobs

Submit PBS job Script

Since we have the compatibility layer installed, your current PBS scripts may still work as they are, so you should test them and see if they submit and run successfully. Submit your PBS batch script as you did before to see whether it works or not. Below is a simple PBS job script pbs_job.txt that calls for a parallel run:

#PBS -l walltime=1:00:00
#PBS -l nodes=2:ppn=40
#PBS -N hello
#PBS -A PZS0712

cd $PBS_O_WORKDIR
module load intel
mpicc -O2 hello.c -o hello
mpiexec ./hello > hello_results

Submit this script on Pitzer using the command qsub pbs_job.txt , and this job is scheduled successfully as shown below:

[xwang@pitzer-login04 slurm]$ qsub pbs_job.txt 
14177

Check the Job

You can use the jobscript command to check the job information:

[xwang@pitzer-login04 slurm]$ jobscript 14177
-------------------- BEGIN jobid=14177 --------------------
#!/bin/bash
#PBS -l walltime=1:00:00
#PBS -l nodes=2:ppn=40
#PBS -N hello
#PBS -A PZS0712

cd $PBS_O_WORKDIR
module load intel
mpicc -O2 hello.c -o hello
mpiexec ./hello > hello_results

-------------------- END jobid=14177 --------------------
Please note that there is an extra line #!/bin/bash added at the beginning of the job script from the output. This line is added by Slurm's qsub compatibility script because Slurm job scripts must have #!<SHELL> as its first line.

You will get this message explicitly if you submit the script using the command sbatch pbs_job.txt

[xwang@pitzer-login04 slurm]$ sbatch pbs_job.txt 
sbatch: WARNING: Job script lacks first line beginning with #! shell. Injecting '#!/bin/bash' as first line of job script.
Submitted batch job 14180

Alternative Way: Convert PBS Script to Slurm Script

An alternative way is that we convert the PBS job script (pbs_job.txt) to Slurm script (slurm_job.txt) before submitting the job. The table below shows the comparisons between the two scripts (see this page for more information on the job submission options):

Explanations Torque Slurm
Line that specifies the shell No need 
#!/bin/bash
Resource specification

 

 
#PBS -l walltime=1:00:00
#PBS -l nodes=2:ppn=40
#PBS -N hello
#PBS -A PZS0712
 
#SBATCH --time=1:00:00
#SBATCH --nodes=2 --ntasks-per-node=40
#SBATCH --job-name=hello
#SBATCH --account=PZS0712
Variables, paths, and modules 
cd $PBS_O_WORKDIR
module load intel
 
cd $SLURM_SUBMIT_DIR 
module load intel
Launch and run application 
mpicc -O2 hello.c -o hello
mpiexec ./hello > hello_results
 
mpicc -O2 hello.c -o hello
srun ./hello > hello_results
In this example, the line cd $SLURM_SUBMIT_DIR can be omitted in the Slurm script because your Slurm job always starts in your submission directory, which is different from Torque/Moab environment where your job always starts in your home directory.

Once the script is ready, you submit the script using the command sbatch slurm_job.txt

[xwang@pitzer-login04 slurm]$ sbatch slurm_job.txt 
Submitted batch job 14215
Supercomputer: 
Owens
Pitzer