Category Archives: VMware

VCDX: Days before the defense

After hundreds of hours of preparations (or at least a few) the defense day is finally near.

During the preparation there are several activities that are mentally taxing:

  • First Skill Sessions.
    • Sessions where you get to know how little you know and how much you still need to learn. Think of it as a Total Perspective Vortex, only for skill levels in IT specific technology stacks. 🙂
  • Full Mock Defenses.
    • Here you get a sense of how the actual defense could go. The first ones always shows some weaknesses either in communication skills, presentation slides or not knowing answers to questions.
  • Troubleshooting Mock Scenarios.
    • The first one usually leaves you with a sense of panic. It tends to be hard to change ones troubleshooting methods to accommodate a more verbal method. Also it seems strange to approach a problem from a couple of notes on slide point of view. Hard to know where to start etc.
  • Design Mock Scenarios.
    • Same goes for this as the troubleshooting scenario. It’s hard to know how to approach the problem and where to start. The first ones are usually not very good.
  • Skill Updates.
    • The amount of data that need to be processed sometimes can be hard. I must admit some of the detailed HA stuff I’ve already forgotten, but extensive cramming is not a good solution.

All these items will get easier with practice, so after a few sessions of each type, you get comfortable (enough) not to be stressed about the actual session in the defense.

As for the skill update, I recommend entering the vortex early in the process to actually know how much need to be learned and plan accordingly.

But it would be a shame if all the preparation and hard work put into the project would go to waste because of stress. So I recommend that the last days before defense are not spent frantically studying a specific topic or doing 14 hour days.

For me I spent them in London, doing a mock defense with some of the guys also going for the VCDX at that time. I can not recommend it enough to do real life mocks before the defense if possible because it showed be a couple of items that I needed to fix and focus on. A major change of the slide deck is not a good thing but perhaps a new deepdive slide to better explain topic.
Other than that I spent about 4 hours the day before just practicing the presentation, over and over. Watched TV the rest of the day.

Then the day comes and you need to travel to the VMware offices. No need to panic. Don’t panic.

VCDX: Defense Preparation Timelime

The VCDX defense preparation phase includes both slide deck creation and common tasks such as skill updates, potential question creation, alternatives, deep dives, skill transfers, mock defenses and study group meetings.

When is it best to start? Depending on your mental state at the time of design document submission, right away. I took 7 days off until I started creating my presentation and working on all the other items.

Never mind if you don’t know if the design was accepted. Just start. Worse case scenario is that you spent some hours on a presentation that you will use the next time you submit the design.

It will get really hard if you know 3 weeks before the defense that you are going to defend and the presentation is still a New button in PowerPoint.

As for which item to address first I focused on the presentation first and got a good template and the layout just right while getting feedback from my mentor and the study group.

Then I addressed my weakest skills, added to my presentation and did further study group sessions, including design mocks and troubleshooting/design scenarios.

As for a specific timeline of each item, I actually went and did the thing my brain allowed me to do. Some nights I just couldn’t do a single slide in the deck. Then I logged into Pluralsight and just watched some network videos. It was all about change of pace (and learning method; Read-Interact-Listen-Watch).

The time I spent for my defense preparation were about 216-260 hours. Why the gap? Cause I only noted 216 hours and those number did not include all the time I spent going over Quizlet and reading books.

Here is a graph of the time spent on preparations:


And here is a graph of the time spent each day on preparations:


Why did I use time to account for the time I spent on the project? Cause I could. And I’m a data junkie. I just really love looking at graphs with lots of connected piece of information. Don’t judge. 🙂

This time did not include the time I spent each day learning my Quizlet cards (during transit to and from work and also whenever I could) and reading various books for skill update. That would add about 40 hours to the total number.

At the start of the journey I scheduled how much time I would spend on the project. The following graph shows the difference between these two:


I planned for 270 hours, but was only about 20 hours short if the off-screen hours were taken into account.

So do start as soon as you can preparing because every hour you can put in will help in the defense itself.

VCDX: Design Scenario

The 75 minutes for the defense section just finished, now a short break while the panelist gets the next part ready, The Design Scenario, where you get to show how you would approach a specific set of business and technical requirements. Fast.

The 45 minutes (Extended from 30 min to 45 min in 2016) alloted to this part go by quick. Quick really isn’t fast enough to begin to describe it. But there is no need to have fully functional environment ready for deployment either.

As far as I know the goal of the defense scenario is not to see how fast you can design, its more about how you approach the design requirements and how you verbalize your thought process. But then again you can cover more ground if you can do it really quick 🙂

The VCDX design scenario will give you access to 1-3 slides containing a set of requirements and constraints, both business and technical. Also you might get access to number for an existing environment that need to be accounted for in the design. Your role is to ask additional questions for more information about the problem that the fictional customer is facing, additional business requirements or even a set of constraints.

The VCDX blueprint explains this section like this:
Respond interactively to a presentation of requirements and constraints to show the ability to produce a design which satisfies a customer’s needs.

Real world design sessions take hours, even tens of hours of different meetings with a different people to be able to fully understand the requirements for a complex environment. This is usually done with a set of specific guidelines in place, what should be asked, who to ask and who will approve the final conceptual design. The design scenario is somewhat that process but only in 30-45 minutes and with less emphasis on a fully designed solution in the end. Process is key here and to be able to cover as much as possible the guidelines need to be become more streamlined as well.

Rene Van Den Bedems blog post about the design scenario is a great resource that has a lot of good recommendations to do just that, and I used them as the basis to create a whiteboard layout to be able to show the process as fast as I possibly could.

Here is a picture of the layout:


On the left there are specific notes and recommendations and below that is the process itself. So the plan was to be able to go through that process as fast possible.

On the right are potential questions to ask regarding a specific technology stack to be able to fulfill any requirements.

The whiteboard layout has several sections:

  • On the left there is the conceptual list with possible design goals, success factors, requirements/constraints/assumptions(if any)/risks. This does not mean that these topics will be on the slides themselves as you might need to ask around for them.
  • Next to that is the design characteristics part where the plan was to use specific markings to be able to mark each design decision taken with a specific characteristic.
  • Below those two were the design decisions themselves and those were supposed to be classified based on blueprint sections. I never even got close to be able to categorize them. Still the logic around it seemed to make sense at the time.
  • The rest of the whiteboard contains a logical design diagram with specific room for storage and network and additional room for management layers. Design choices were located near the corresponding stack.

I practiced drawing the layout on different sizes of whiteboards just to be ready, and so that I could draw it as fast as possible and knew what should go where.

The plan was to have something remotely similar to that during the scenario itself. Due to the nature of the design scenario I got I never got close to being able create it though. But I had a plan in regards for the process and the layout I wanted to use to show my design skills and I think that made a difference.

Practice a design scenario mock with the study group at least 3-4 times before the defense day. Once with the process in front of you, the other time with nothing but a whiteboard. Always a whiteboard. And coffee. Always coffee.

Some additional pointers:

  • Plan for dual site designs as well. Space becomes scarce when drawing everything twice.
  • Not all designs are just about the infrastructure, the workloads are important to.
  • If you have access to two whiteboards please do use them both.
  • Talk, talk, talk. Tell the panelist what you are thinking, and why. Requirement->Design decision with justification and an alternative if applicable. Short explanations, no technology deep dives explaining a specific feature in vSphere.

And finally here are some other helpful resources for the design scenario:

And also many of the VCDX’s post their recommendations and experiences about the design scenario in their “experience post”, so you can find a detailed list of such posts over at Gregg Robertsons blog: