The following are all Unix commands (Linux or MacOS).

If you are a Windows user, please share your tips on what tools work best for you.

1. Remember to connect to the VPN before trying to log onto Orion:

   https://na.nmbu.no/

   ssh inf205-2024-<your two digits>@login.orion.nmbu.no

2. On Orion, you have a folder called $SCRATCH that should be used for temporary content.
   For example, let us copy the spheres code with domain decomposition to that folder.
   
   On Orion:
   
   echo $SCRATCH
   
   This gives you the name of the folder, probably /mnt/SCRATCH/inf205-2024-<your two digits>

   Now from the local system:
   
   scp -r sphere-config-par inf205-2024-<your two digits>@login.orion.nmbu.no:/mnt/SCRATCH/inf205-2024-<your two digits>/
   
3. On Orion, check the list of available modules:

   module avail

   It is a very long list.
   For example, there is as of now a module "OpenMPI/4.1.5-GCC-12.3.0" which is the default for "OpenMPI".

4. Load the modules you would like to activate, for example:

   module load OpenMPI

5. You can always check the list of currently loaded modules using:

   module list
   
6. Compile the parallel code, for example, in case of sphere-config-par:

   cd $SCRATCH/sphere-config-par
   make eval-par

7. We normally want to have the executable files outside the scratch folder, in the permanent storage, for example:

   mkdir ~/bin
   cp $SCRATCH/sphere-config-par/eval-par ~/bin/

8. Create a folder in scratch for your job, for example:

   mkdir $SCRATCH/sphere-test-job
   cp $SCRATCH/sphere-config-par/32768-particles.dat $SCRATCH/sphere-test-job/

9. You need to create a bash script file to submit to the job scheduler Slurm.
   Details on this are found in the Orion documentation, and also in the documentation for Slurm.
   
   Here, let us use the shared file "sphere-test-job.qsub".
   Copy it via scp, or copy-pased its content using vim, which may be simpler.

   Edit the user-dependent entries in the bash script.
   
10. Now you can submit the job using "qsub" and check the queue status using "qstat":   

    qsub ./sphere-test-job.qsub
    qstat
    
11. Once the job is done, you will find its output in the scratch folder from which it was executed.

12. You will often want to copy the results back to your local system for further analysis.
    Recall that this needs to be done from your machine, not from Orion, for example as follows:
    
    scp -r inf205-2024-<your two digits>@login.orion.nmbu.no:/mnt/SCRATCH/inf205-2024-<your two digits>/sphere-test-job .