Environment and Modules¶
After logging in, you may want to configure the environment. Write your preferred path definitions, aliases, functions and module loads in the .bashrc file
# ./bashrc # Source global definitions if [ -f /etc/bashrc ]; then . /etc/bashrc fi # User specific aliases and functions alias qs='qstat -a' module load intel/2015b # Display information to standard output - only in interactive ssh session if [ -n "$SSH_TTY" ] then module list # Display loaded modules fi
Do not run commands outputting to standard output (echo, module list, etc) in .bashrc for non-interactive SSH sessions. It breaks fundamental functionality (scp, PBS) of your account! Take care for SSH session interactivity for such commands as stated in the previous example.
In order to configure your shell for running particular application on Salomon we use Module package interface.
Application modules on Salomon cluster are built using EasyBuild. The modules are divided into the following structure:
base: Default module class bio: Bioinformatics, biology and biomedical cae: Computer Aided Engineering (incl. CFD) chem: Chemistry, Computational Chemistry and Quantum Chemistry compiler: Compilers data: Data management & processing tools debugger: Debuggers devel: Development tools geo: Earth Sciences ide: Integrated Development Environments (e.g. editors) lang: Languages and programming aids lib: General purpose libraries math: High-level mathematical software mpi: MPI stacks numlib: Numerical Libraries perf: Performance tools phys: Physics and physical systems simulations system: System utilities (e.g. highly depending on system OS and hardware) toolchain: EasyBuild toolchains tools: General purpose tools vis: Visualization, plotting, documentation and typesetting
The modules set up the application paths, library paths and environment variables for running particular application.
The modules may be loaded, unloaded and switched, according to momentary needs.
To check available modules use
$ module avail **or** ml av
To load a module, for example the Open MPI module use
$ module load OpenMPI **or** ml OpenMPI
loading the Open MPI module will set up paths and environment variables of your active shell such that you are ready to run the Open MPI software
To check loaded modules use
$ module list **or** ml
To unload a module, for example the Open MPI module use
$ module unload OpenMPI **or** ml -OpenMPI
Learn more on modules by reading the module man page
$ man module
As we wrote earlier, we are using EasyBuild for automatized software installation and module creation.
EasyBuild employs so-called compiler toolchains or, simply toolchains for short, which are a major concept in handling the build and installation processes.
A typical toolchain consists of one or more compilers, usually put together with some libraries for specific functionality, e.g., for using an MPI stack for distributed computing, or which provide optimized routines for commonly used math operations, e.g., the well-known BLAS/LAPACK APIs for linear algebra routines.
For each software package being built, the toolchain to be used must be specified in some way.
The EasyBuild framework prepares the build environment for the different toolchain components, by loading their respective modules and defining environment variables to specify compiler commands (e.g., via
$F90), compiler and linker options (e.g., via
$LDFLAGS), the list of library names to supply to the linker (via
$LIBS), etc. This enables making easyblocks largely toolchain-agnostic since they can simply rely on these environment variables; that is, unless they need to be aware of, for example, the particular compiler being used to determine the build configuration options.
Recent releases of EasyBuild include out-of-the-box toolchain support for:
- various compilers, including GCC, Intel, Clang, CUDA
- common MPI libraries, such as Intel MPI, MPICH, MVAPICH2, Open MPI
- various numerical libraries, including ATLAS, Intel MKL, OpenBLAS, ScaLAPACK, FFTW
On Salomon, we have currently following toolchains installed:
|ictce||icc, ifort, imkl, impi|
|intel||GCC, icc, ifort, imkl, impi|
|goolf||BLACS, FFTW, GCC, OpenBLAS, OpenMPI, ScaLAPACK|
|iompi||OpenMPI, icc, ifort|