NCAR Supercomputer

NCAR Supercomputer#

Once you have an account and the necessary software, you can log in and run jobs on the NCAR supercomputer. The NCAR supercomputer is also referenced to the NCAR High Performance Computing (HPC).

Logging in on an NCAR system#

To log in, start your terminal or Secure Shell client and run an ssh command as shown here:

ssh -XY username@derecho.hpc.ucar.edu

OR

ssh -XY username@casper.hpc.ucar.edu

When you log in to the NCAR HPC machines, we recommend you use X11 forwarding. X11 forwarding is an SSH protocol that enables users to run graphical applications on a remote server and interact with them using their local display and I/O devices. It is frequently used by CESM developers for securely interacting with NCAR HPC remote machines.

You can do this by adding the -XY option when logging into the machines with SSH. More information about logging into the NCAR HPC follows below.

CISL Documentation on Using X11

Running on derecho#

This tutorial material is designed for use with the derecho HPC system. All of your CESM experiment builds and jobs will be run on derecho.

Please see the link below for more information about the derecho system, including a quick start guide with information about logging into derecho from a terminal, setting up your environment, submitting jobs, etc.

CISL Documentation on Using derecho HPC

Using Casper#

The Casper cluster is a system of specialized data analysis and visualization resources. Casper is not used for building or running CESM, but it is used for CESM data analysis. We will use Casper for the diagnostics section of the lab activities. To utilize the additional analysis tools described in the analysis tools section you will also want to use Casper.

CISL Documentation on Using Casper Cluster

Using JupyterHub#

The diagnostics section of this tutorial will use JupyterHub to run Jupyter Notebooks. You will need to login to the NCAR JupyterHub system to run the notebooks successfully. We will use Open OnDemand to launch JupyterHub.

Step 1. Access and bookmark the NSF NCAR Open OnDemand portal at: ondemand.hpc.ucar.edu

Step 2. Upon visiting the NSF NCAR Open OnDemand web portal, you will need to login and authenticate with your CIT credentials

Step 3. Navigate to Jupyter under Interactive Apps

Open OnDemand Landing Page

Figure: Open OnDemand Landing Page.

Step 4. Select the appropriate resources for your job

Entering options for server on JupyterHub

Figure: Entering options for server on JupyterHub.

Select the “Casper PBS Batch” option in the drop down menu. After, you will need to make other choices to select the right resources: 3 hours wall time to ensure your server is active for the entire hands-on activity session and Project Account UESM0016. Now launch the server.

Step 5. Connect to Jupyter

Launching Jupyter

Figure: Launching Jupyter.

Wait until your job transitions from Queued to Running, and then connect to Jupyter.

NOTE: To run a Jupyter cell

  • Type your command into the cell

  • To execute the command:

    • Press shift+return

    OR
    - Select the cell then click the 'play' button at the top of the window

To learn more about JupyterHub, please follow the link below.

CISL Documentation about JupyterHub

Contents