Nova OnDemand

Overview

Nova OnDemand enables users to access the Nova cluster from a web browser.   The user can either get a Linux shell on the head node, or a full graphical Linux desktop for running graphical applications.

Topics

Connect Your Browser to https://nova-ondemand.its.iastate.edu

You will be prompted for your Iowa State login credentials, if you haven't connected to an ISU site yet.  (NOTE:  The site is only accessible if you are on campus or connected over the VPN).  

Also, if this is the first time you've ever logged in to Nova, you will receive an email from the Nova cluster with instructions for adding your Nova multi-factor authentication (MFA) key.   Those instructions are specifically for users who will log in to the Nova cluster using an SSH client, not from the web browser.

The Nova OnDemand Dashboard 

After you login, you will see the Nova OnDemand dashboard shown below.  There are several functions available from the main menu:

  • Files allows you to navigate the /home,  /work, /ptmp, and /lustre/hdd directory trees.  You can upload/download files here, but larger file transfers should be done with the Nova Data Transfer Node (DTN).
  • Jobs lists the status any running or pending jobs you have submitted to the job queue
  • Clusters provides a quick shell access on the head node, as well as a way to recover your MFA key.
  • Interactive Apps - provides a list of interactive applications, in particular the Nova Desktop graphical interface.
     
Nova OnDemand Dashboard

To Get a Shell on the Nova Head Node

Under the Clusters dashboard menu you will see a selection for >_Nova Shell Access.  Select that to get a shell window on the head node.

 

The shell interface will be more or less identical to logging in on the head node with an SSH client, as seen below:

 

Use salloc to Get a Shell on a Compute Node

From the screen above, you can see that the Nova Shell Access option gives the user a shell on the Nova head.  Keep in mind that you don't really want to do a lot of heavy work on the head node.  It is always a good idea to use the salloc command to open a shell on a compute node.   The following salloc command requests an interactive session on a compute node with 8 core cores, 10GB of memory, for 4 hours:
 

$ salloc -N 1 -n 8 --mem=10G -t 4:00:00

The Nova Desktop Session

From the Nova OnDemand dashboard, you can also select a full graphical desktop session known as the Nova Desktop. Under the Interactive Apps menu, select the Nova Desktop option.  Next, you will use the form shown below to specify the resources you want for the session.  Note that Nova Desktop sessions can request CPUs, GPUs, memory, as well as other job specifics.

 

Fill Out the Interactive Session Details in the Form

You will need to enter details for the graphical session.  Note that, aside from Screen Resolution, the options on the form are exactly the same options you can provide for requesting batch or interactive options on the cluster.  The Optional Slurm Arguments field can be used to provide less common job options.

Available Software on Nova Desktop

There are many useful tools and major applications available via Nova Desktop:

  •  File Browser: A file browser is available under the Files menu view and modify your files on the cluster.  You can also upload files to and download files from the cluster.  Note, file uploads through OnDemand are limited to files 20 MB or less.
  • Job Viewer: A viewer to see your active cluster jobs is available under the Jobs->Active Jobs menu.
  • Terminal: The terminal on the cluster is available under the Clusters->Nova Shell Access menu.
  • Linux Desktop: A Linux desktop environment is available under both the Interactive Apps->Desktop and Interactive Apps->Engineering Desktop menus.  In addition to the typical desktop software, the following software is also installed within these desktops:
    • Ansys Fluent
    • Ansys Mechanical
    • Matlab
    • ParaView
    • STAR-CCM+
    • Tecplot
  • QGIS: QGIS is available as a stand-alone graphical user interface under the Interactive Apps->QGIS menu.
  • STAR-CCM+: STAR-CCM+ is available as a stand-alone graphical user interface under the Interactive Apps->STAR-CCM+ menu.
  • Tecplot: Tecplot is available as a stand-alone graphical user interface under the Interactive Apps->Tecplot menu.
  • Jupyter: Jupyter is available as a stand-alone graphical user interface under the Interactive Apps->Jupyter menu.  Both Jupyter Notebooks and Jupyter Labs are available.  Jupyter Labs is generally recommended as it is more feature rich.
  • R-Studio: R-Studio is available as a stand-alone graphical user interface under the Interactive Apps->RStudio Server menu.
  • Visual Studio Code: Visual Studio Code is available as a stand-alone graphical user interface under the Interactive Apps->VS Code Server menu.