home.md

@@ -27,12 +27,13 @@
 ## How to connect to the login node / hpc cluster
 
 ### From a Linux workstation
-You are free to choose your Linux version, but we recommend the following distributions:
+You are free to choose your Linux distribution, but we recommend the following distributions:
 - [Ubuntu Desktop 18.04 or 19.10](https://ubuntu.com/)
 - [Fedora 31 workstation](https://getfedora.org/)
 
 Other distributions:
 - [CentOS 8](https://www.centos.org/)
+- [Debian 10.2.0](https://www.debian.org/CD/)
 - [Red Hat 8](https://www.redhat.com/en/technologies/linux-platforms/enterprise-linux) Commercial license required
 - [Arch Linux](https://www.archlinux.org/download/) Rolling distribution
 
@@ -228,6 +229,10 @@ The setup is already described with the Linux client.
 
 ## Module environment
 
+When you will be working on the cluster, you probably the to load the correct the module, which will set the correct environment for you library, compiler or program.
+
+Here below are some useful commands and examples:
+
 - List all available modules
 
 ```
@@ -321,10 +326,10 @@ hello1.c:2:10: fatal error: mpi.h: No such file or directory
 compilation terminated.
 ```
 
-So we need to load the correct module:
+So we need to load the correct module and use the correct compiler
 
 ```
-$ module add pmi/openpmix/4.0.0/gcc-8.2.1
+$ module add mpi/openmpi/4.0.2/gcc-8.2.1
 ```
 
 - mpicc hello.c -o hello
@@ -341,6 +346,9 @@ Handy reference:
 Hello world from process 000 out of 001, processor name res-hpc-lo01.researchlumc.nl
 ```
 
+Here you can see that we ran the program only on 1 core of the cpu.
+To make use of the MPI capabilitues of the program, we have to run the program with the "mpirun" which comes with the loaded module mpi/openmpi/4.0.2/gcc-8.2.1
+
 - mpirun ./hello
 
 ```
@@ -361,6 +369,7 @@ Hello world from process 008 out of 016, processor name res-hpc-lo01.researchlum
 Hello world from process 009 out of 016, processor name res-hpc-lo01.researchlumc.nl 
 Hello world from process 014 out of 016, processor name res-hpc-lo01.researchlumc.nl
 ```
+Here you can see that it is using all the cores of the local machine.
 
 ## Submitting jobs