Software Modules

Click here to download a printable, 1-page "Getting Started" tutorial for Software Modules.

CCV uses the Modules system for managing the software environment on OSCAR. The advantage of the modules approach is that it allows multiple versions of the same software to be installed at the same time. With the modules approach, you can "load'' and "unload'' modules to dynamically control your environment. You can also customize the default environment that is loaded when you login. Simply put the appropriate module commands in the .modules file in your home directory. For instance, if you edited your .modules file to contain

module load matlab

then the default module for Matlab will be available every time you log in.

Module commands

module list

Lists all modules that are currently loaded in your software environment:

$ module list

Currently Loaded Modulefiles:

  1) gcc/4.5.1           4) scipy/0.8.0         7) suitesparse/3.4.0

  2) python/2.6.6        5) gotoblas2/1.13      8) fftw/3.2.2

  3) numpy/1.5.0         6) lapack/3.2.2

module avail

Lists all available modules on the system. Note that a module can multiple version numbers: this allows us to maintain legacy versions of software or to try out beta or preview versions without disrupting the stable versions.

$ module avail
-------------------------- /gpfs/runtime/modulefiles ---------------------------

R/2.11.1               lapack/3.2.2           python/2.6.6

fftw/3.2.2             matlab/R2008b          scipy/0.8.0

gcc/4.5.1              matlab/R2009b(default) suitesparse/3.4.0

gotoblas2/1.13         metis/4.0.1

hdf5/1.8.5             numpy/1.5.0

module help modulefile

Prints additional information about a module:

$ module help numpy
----------- Module Specific Help for 'numpy/1.5.0' ----------------

	NumPy - Scientific Computing Tools for Python
	Version 1.5.0

	For more information, visit: http://numpy.scipy.org/

	Dependencies (auto-loaded):
	python/2.6.6

module display modulefile

Shows exactly what a given modulefile will do to your environment, such as what will be added to the PATH, MANPATH, etc. environment variables:

$ module display numpy

-------------------------------------------------------------------

/gpfs/runtime/modulefiles/numpy/1.5.0:

module-whatis     NumPy - Scientific Computing Tools for Python 

module         load python/2.6.6 

setenv         NUMPY_DIR /gpfs/runtime/opt/numpy/1.5.0 

prepend-path     PATH /gpfs/runtime/opt/numpy/1.5.0/bin 

prepend-path     LD_LIBRARY_PATH /gpfs/runtime/opt/numpy/1.5.0/lib 

prepend-path     PYTHONPATH /gpfs/runtime/opt/numpy/1.5.0/lib/python2.6/site-packages 

-------------------------------------------------------------------

module load modulefile

Adds a module to your current environment. It does so silently, unless there is a problem with the modulefile (in which case you should notify support). If you load the generic name of a module, you will get the default version. To load a specific version, load the module using its full name with the version:

$ module load gcc/4.5.1

module unload modulefile

Removes a module from your current environment:

$ module unload gcc

module switch modulefile_old modulefile_new

Different versions of entire software packages can be swapped with a single module command:

$ module switch gcc/4.4.1 gcc/4.5.1