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Environment Modules
[http://modules.sourceforge.net|Environment Modules] are designed to manage custom package installations. Software in our department is all installed to a network filesystem mounted over NFS where each package available is installed to it's own directory. This allows us to manage a wide range of software across different Linux distributions without users having to deal with any configuration. We can include different versions of software, letting users choose which they want to use.
Using Modules
On any Linux system in our department, you can run module avail
from your shell to get a list of available software.
ktm5j@applecake ~ $ module avail ------------------------ /sw/centos/Modules/modulefiles ------------------------ altera_pro modelsim_ae php7 python3.6.2 cuda-toolkit-9.0 modelsim_ase php7.1.10 qsys emacs nios2eds python quartus matlab php python3
After deciding what software you want to use, load the package using
module load
. Now the software is ready to use.
ktm5j@applecake ~ $ module load python3 ktm5j@applecake ~ $ which python /sw/centos/python/3.6.2/bin/python
After loading several modules in your session,
module list
will show what modules have been loaded.
ktm5j@applecake ~ $ module load matlab ktm5j@applecake ~ $ module load php ktm5j@applecake ~ $ module list Currently Loaded Modulefiles: 1) matlab 2) python3 3) php
module display
will show specific information about the environment variables that will be modified by a module.
ktm5j@applecake ~ $ module display python ------------------------------------------------------------------- /sw/centos/Modules/modulefiles/python: module-whatis Python current prepend-path PATH /sw/centos/python/current/bin prepend-path LD_LIBRARY_PATH /sw/centos/python/current/lib prepend-path LD_INCLUDE_PATH /sw/centos/python/current/include prepend-path MANPATH /sw/centos/python/current/share/man ------------------------------------------------------------------- ktm5j@applecake ~ $ echo $LD_LIBRARY_PATH /sw/centos/python/3.6.2/lib
You can switch
, changing one version of software for another, or unload
modules when you are done or no longer want this software.
ktm5j@applecake ~ $ module switch python3 python2 ktm5j@applecake ~ $ module unload php
Things to keep in mind
Shell Scripting/Slurm Batch
If you write shell scripts or slurm batch files that make use of these software packages, remember that you must still load modules from inside of your script. For example, your script must contain the line module load python3
before you can use python from inside of your script.