Using Environment Modules on HPC Clusters¶

Environment Modules is a package that allows you to dynamically modify a Linux user's environment through the use of modulefiles. These files contain information needed to configure the environment, making software packages accessible on demand. They are especially helpful in managing different versions of software packages.

This guide will help you understand the basics of using Environment Modules on our HPC clusters, including how to load, unload, and search for modules.

Introduction to Environment Modules¶

On HPC systems like OGBON, Environment Modules are used to modify the Linux environment variables, such as PATH, MANPATH, and LD_LIBRARY_PATH. These variables help the system locate and configure software packages.

Modules can be loaded and unloaded dynamically to manage multiple versions of software packages or associate them with specific versions of compilers or libraries.

Basic Commands¶

Checking Available Modules¶

To see a list of available modules, run:

module avail

Loading a Module¶

To load a module, use the following command:

module load <module name>

Unloading a Module¶

To unload a module, enter:

module unload <module name>

Unloading All Modules¶

To unload all modules at once, run:

module purge

Listing Loaded Modules¶

To see a list of currently loaded modules, use:

module list

Working with Modules¶

In this section, you'll learn how to find, load, and unload modules.

Find Modules¶

Listing All Available Modules¶

To list all available modules, run:

module avail

Searching for Modules¶

To search for specific modules or extensions, use avail. For example, to find and list all Python version 3 modules, run:

module avail python/3

Getting Module Help¶

To access a brief description of a module, enter:

module help <module name>/version

If you can't find a required software package, contact us with a software installation request or consult our installation guides to install it yourself.

Loading and Unloading Modules¶

Loading Modules¶

To load a module and its dependencies, use the module load command. For batch jobs, add the module load command(s) to your submission script.

For example, to load CMake version 3.22.1 and GCC version 11.2.0, run:

module load cmake/3.22.1 gcc/11.2.0

To see the loaded modules, run module list.

Unloading Modules¶

To unload a specific module that you've previously loaded:

module unload gcc/11.2.0

Or unload all modules at once with:

module purge

Further Reading¶

For more information on using Environment Modules, consult the documentation on the cluster by running:

man module

Best Practices and Troubleshooting¶

Here are some best practices and troubleshooting tips to help you effectively work with Environment Modules:

• Always use the appropriate version of a module, as different versions may have different dependencies and features.

• Make sure to unload conflicting modules before loading new ones. For example, unload an older version of a compiler before loading a newer one.

• If you encounter issues when loading a module, check the module's help documentation using module help <module name> for guidance on proper usage.

• In case of errors or conflicts, unload all modules using module purge and start again by loading the necessary modules in the correct order.