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SCITAS 101#

This page provides a TL;DR introduction to getting started with SCITAS so that you can start working as quickly as possible.

Before You Start#

This page explains what to do after having successfully connected to one of the clusters.

Step-by-step guide#

Information

On our systems, we have compiled and installed software modules either with Intel Compiler and Intel MPI or GCC and OpenMPI and those are the only supported compiler/MPI combinations.

1. What is installed on the clusters#

To see the list of installed software (modules), load the compiler and the MPI implementation you intend to use and do

module spider

2. Getting the examples#

Once you have logged in to the machine, we suggest you download the examples with the git command:

git clone https://c4science.ch/diffusion/SCEXAMPLES/scitas-examples.git

3. Running the examples#

Enter the directory scitas-examples and choose the example to run by navigating the folders. We have three categories of examples: Basic (examples to get you started), Advanced (including hybrid jobs and job arrays), and Modules (specific examples of installed software).

To run an example, e.g. HPL-mpi of the Advanced category, on Jed cluster do:

sbatch --qos=debug hpl.run

or, if you do not wish to run on the debug QOS,

sbatch hpl.run

4. Running interactive jobs#

An interactive job allows you to connect directly to a compute node. Simply type the command Sinteract from the login node to start an interactive session with 1 core and 4GB of memory for 30 minutes.

You can use the following options to request more resources or more time:

Sinteract -h

    usage: Sinteract [-c cores] [-n tasks] [-t time] [-m memory] [-p partition] [-a account] [-q qos] [-g resource] [-r reservation]

    options:
     -c cores cores per task (default: 1)
     -n tasks number of tasks (default: 1)
     -t time as hh:mm:ss (default: 00:30:00)
     -m memory as #[K|M|G] (default: 4G)
     -p partition (default: parallel)
     -a account (default: phpc2017)
     -q qos as [normal|gpu|gpu_free|mic|...] (default: )
     -g resource as [gpu|mic][:count] (default is empty)
     -r reservation reservation name (default is empty)

e.g. to run an MPI job with 16 processes for one hour using 32 GB of memory on the debug QOS:

Sinteract -n 16 -t 01:00:00 -m 32G -q debug

Izar Cluster

On the Izar cluster, the -g option is necessary to request the desired number of GPUs. For example:

Sinteract -g gpu:1


Last update: November 28, 2023