Exercise#
Exercise: Setting up and running your first case
Use the 4 CESM commands to create a new case. Do the setup, build and submit your job.
Use qstat
to check your job is running. This command will show all the jobs that
are running on the cluster by all users, so you can also use qstat -u <username>
to
just see your jobs.
Check that your run completes. Check the files are in the archive directory.
Click here for hints
Create a directory to keep your CESM cases
Decide on a location where you want to keep your CESM cases.
We’ll use a directory cases
within your home directory as an example e.g.,
cd
mkdir cases
In the commands above:
cd
brings you to your home directoryand
mkdir cases
makes the directorycases
Create a new case
To start, we will create a coupled simulation under 1850’s conditions using a 2 degree atmospheric resolution and the g17 ocean grid. We’ll call it case01
and put it in your cases
directory.
cd $CESMROOT/cime/scripts
./create_newcase --case ~/cases/case01 --compset B1850-tutorial --res f19_g17
NOTE: B1850-tutorial is not an available compset in CESM2. It is a compset that has been specially designed for this tutorial.
Setup, build and submit your run
Now go in to your cases directory. You should see a sub-directory case01
.
This is your case directory and contains all the scripts necessary to compile and run CESM.
From within your case directory, CESM can be set up, built and run, using the following three commands
cd ~/cases/case01
./case.setup ; #(sets up the case)
qcmd -- ./case.build ; #(builds the case)
./case.submit ; #(submits the case to the queue)
NOTE: The qcmd
command when running case.build
submits the build command to the queueing system.
Whether you need to add in the qcmd --
before ./case.build
will depend on your system.
Check the model is running
Once you have submitted the case, you can see its status in the queue with either of the following commands:
qstat -u <username>
or this also works:
squeue -u <username>
replacing <username>
with your username for the system.
You can also see CESM outputting data as the simulation progresses in the run directory, which for our purposes, is located at
~/scratch/case01/run
. This is where the data are output until the run is finished, at which point it is moved to the archive directory. For our purposes, the archive directory is located at ~/scratch/archive/case01
.
Check the files are in the archive directory
Once the run has finished, you can go into ~/scratch/archive/case01/atm/hist
and see the output CAM history files.
However, for this first run, the default length of the run is 5 days and only monthly averages are output, so that directory is empty at the moment.
But, if you go into ~/scratch/archive/case01/rest/
you’ll see a directory for the 6th January, year 1 that
contains the restart files that would be necessary to continue this run further.
Click here for the solution
A B1850-tutorial
case with the 2 degree atmosphere and g17 ocean grid and named case01
can
be set-up, built and submitted with the following commands:
cd $CESMROOT/cime/scripts
./create_newcase --case ~/cases/case01 --compset B1850-tutorial --res f19_g17
cd ~/cases/case01
./case.setup
qcmd -- ./case.build
./case.submit