work/life/career must-read books

These are the books I’ve read or want to read. I can really recommend to go deep into the subject of personal development. Most of what I’ve read can easily be applied in everyday life :). Or sets into motion subconscious changes.

John Somnez (

Credits: book suggestions from Martin Koel.



Book: team geek


If you were to ask me to summarize the book ‘Team Geek‘ into one key point, it would be this:

“Great software is build by teams”.

Therefore modern workplaces are hubs where developers collaborate and build upon each others’ knowledge.

Functioning in a team boils down to having ‘HRT’ (hearth):

  • Humility
  • Respect
  • Trust
HRT. Source:

And to be an effective engineer, communication is vital.


big leap in personal development

Recently I started with a job flirt at work. It is a funky name for ‘experiencing what it is like to work for another team’. Next up there is more on my ‘big leap in personal development’.

I started at the TUX-team. I wanted to experience the engineering spirit within that team, and to get feedback on my soft skills.

The end?

After two sprints (four weeks) it was time to go back to my original squad. I enjoyed the job flirt. I exceeded others’ expectations of my soft skills. How did I do this?


Well, I’ve been meditating. Through meditation, I learned to be more patient and relaxed. And when I’m relaxed, that benefits others too. I’m easier to get along with, easier to approach and to collaborate with.

I started meditating on a daily basis eight months ago. I’m using Headspace guide meditations. Andy has done a great job by offering a Westernized approach to meditation.


Other credits go to the book ‘verbinding door avontuur’. Floor Vullings and Floris Muller have published this long awaited book about the ‘buitendoor‘ approach to team building and collaboration. It was refreshing to read and I could directly apply the material at the job flirt.


Website :
ISBN        : 9789082823400

Troubleshooting virtualbox VM’s not starting

On my Linux Mint 17.1 machine I regularly face an error starting a VM. This error occurs after every kernel update. It says that the VirtualBox kernel driver was not loaded.

This can be solved by reinstalling the virtualbox-dkms package:

sudo apt-get --reinstall install virtualbox-dkms

And then the VirtualBox kernel drivers are loaded.

This workaround turned out fine for me, so I thought I could share it. Remark; updating the Addons can also help. Go to: File – Check for updates.



Ordina DevOps: puppetmaster configuratie in GIT

In deze tutorial leg ik uit hoe grote bedrijven hun puppet omgeving hebben ingericht. De puppetmaster configuratie wordt opgeslagen in een GIT repository, zodat wijzigingen op een centrale plaats kunnen worden gedaan. De ingebruikzijnde puppet modules worden ook centraal beheerd. Deze uitleg is gebaseerd op een puppettraining. Het is een globale uitleg van de werking, en geen stap voor stap handleiding.

Continue reading Ordina DevOps: puppetmaster configuratie in GIT

simultaneous tasks in bash

Function that calculates the sha1 hash of 1. the backup partition and 2. the backup image simultaneously.

[ecp code=”simultaneous_tasks_in_bash”]

sha1sum backup partition &
sha1sum backup image &
wait $(jobs -p)


The & creates a background task, which can be viewed using jobs or top.