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Login Nodes

Opening an SSH connection to ULHPC systems results in a connection to an access node.

ssh iris-cluster

ssh aion-cluster

To be able to further run GUI applications within your [interactive] jobs: 

ssh -X iris-cluster   # OR on Mac OS: ssh -Y iris-cluster

To be able to further run GUI applications within your [interactive] jobs: 

ssh -X aion-cluster   # OR on Mac OS: ssh -Y aion-cluster

Important

Recall that you SHOULD NOT run any HPC application on the login nodes.

That's why the module command is NOT available on them.

Usage

On access nodes, typical user tasks include

  • Transferring and managing files
  • Editing files
  • Submitting jobs

Appropriate Use

Do not run compute- or memory-intensive applications on access nodes. These nodes are a shared resource. ULHPC admins may terminate processes which are having negative impacts on other users or the systems.

Avoid watch

If you must use the watch command, please use a much longer interval such as 5 minutes (=300 sec), e.g., watch -n 300 <your_command>.

Avoid Visual Studio Code

Avoid using Visual Studio Code to connect to the HPC, as it consumes a lot of resources in the login nodes. Heavy development shouldn't be done directly on the HPC. For most tasks using a terminal based editor should be enough like: Vim or Emacs. If you want to have some more advanced features try Neovim where you can add plugins to meet your specific needs.

Tips

ULHPC provides a wide variety of qos's

  • An interactive qos is available on Iris and Aion for compute- and memory-intensive interactive work. Please, use an interactive job for resource-intensive processes instead of running them on access nodes.

Tip

To help identify processes that make heavy use of resources, you can use:

  • top -u $USER
  • /usr/bin/time -v ./my_command

Running GUI Application over X11

If you intend to run GUI applications (MATLAB, Stata, ParaView etc.), you MUST connect by SSH to the login nodes with the -X (or -Y on Mac OS) option:

ssh -X iris-cluster   # OR on Mac OS: ssh -Y iris-cluster

ssh -X aion-cluster   # OR on Mac OS: ssh -Y aion-cluster

Install Neovim using Micormamba

Neovim is not installed by default on the HPC but you can install it using Micromamba.

micromamba create --name editor-env
micromamba install --name editor-env conda-forge::nvim
After installation you can create a alias in your .bashrc for easy access: 
alias nvim='micromamba run --name editor-env nvim'

Last update: July 25, 2024