VCDX Preparation: Q & A

Since I am currently undertaking the VCDX Certification process, many people ask me questions regarding preparing for the Defense. Yes, I capitalize ‘Defense’ because it’s a big deal to me right now. I have the benefit (?) of having gone through an unsuccessful Defense attempt at PEX in February ’13. Hopefully I can pass along a few things I’ve learned the hard way to other prospective VCDX candidates.

What was the biggest misconception you had going into the process?

My biggest misconception was that the defense would be all about the overall design. The VCDX is really about the ‘Design Process’, not the actual design. They don’t care if you have 10, 20, or 100 hosts in your overall design. They are really interested in what approach you took to gathering the project requirements and constraints, what assumptions you have taken, and if you have appropriately identified the risks involved with the design. Then, how did you determine the various components of your design, why you made decisions within that design, and how those decisions impact the overall design. What are the implications of changing any of the parameters, and how would you alter your design based on those changes? Why did you make this choice? What if you didn’t have Constraint-A, or Requirement-B? Where is the documentation to support that choice?

What size environments are you typically designing, what do you think the “minimum” would be?

This one is easy. “Size matters not.” Actually, the size of the design is not really as important as the process involved in determining the size of the environment. Personally, mine is 10 hosts, but was technically challenging due to several strict constraints. It was accepted for a Defense… twice. As I mentioned above, the VCDX Application is more about process and procedure, methodology, and the approach you took to the design. Your design needs to be big enough for you to show competency in the process and methods of designing a vSphere environment. I am assuming that if you’ve gotten to this point in the VCDX certification process, you know your vSphere down cold. You need to be technically sound and very good at what you do. You don’t necessarily need to show the panel that you can design a 250 host multi-site infrastructure, but instead show the process involved in getting to the point. Why did you need 250 hosts? How did you come to those conclusions? Where did you place them, and why?

How long did it take you to write your first VCDX design? How has that changed for subsequent designs?

My design is a partially fictitious one, based on a real customer, but adding a few pieces from other customers to fill it out into a ‘holistic’ design. I had all of the pieces, but had trouble with the documentation and template forms. Over 6-9 months, I wrote and re-wrote it several times. Finally, I settled on a template I was happy with and got down to writing. I spent about 45 hours writing before I finally missed the deadline for submission at Barcelona’12 last year. I took a few months off, then revised my design for PEX’13 and only needed another 35 or so hours to wrap that one up. Bear in mind, I already had the ‘real’ design in place and just needed to write up the Defense design. This time, I used a different template/form, borrowing from the SET for some inspiration. This re-work of my design only took about 24 hours to clean up and revise before submission. Overall, I spent about 100 or so hours over 14 months preparing two VCDX Applications.

How do you write up a design for submission? What sort of format are they asking for?

This is the most difficult piece of the design, because nobody gives you a template to follow. By the time you decide to attempt the VCDX, you should be well onto the path of doing designs for customers and such. The ability to design an infrastructure shouldn’t be the hard part. What drove me crazy for almost 9 months was the format/template of the design documentation. I started, stopped, and re-wrote my design about 5 different times before I settled on a form that I was happy with for my PEX ’13 defense. Since then, I took a look at the Plan and Design template that can be found in the SET (Solution Enablement Toolkits) on VMware’s Partner Central site. I used my original design layout, complemented it with what I found in the P&D, and created something that flowed much better for my VMworldUS’13 Defense.

Short answer: Get the SET documents and use them as a guideline. Your design should contain more than what is shown in the Plan and Design template, but it is a good starting point for the layout.


Once you are invited to defend, what’s next?

Prior to my first defense, I was extremely busy with work and didn’t focus as much as I intended originally. I didn’t do any mock panels, nor did I let anybody look at my design for comments. I intended to do both, but never got around to it. Life and work just got in the way of my plans. Upon arrival at PEX, I got together with @kennyga (defending) and we both did a mock defense in front of friends. My lack of preparation showed, and I spent that night reworking my presentation and memorizing everything in sight. Obviously, it wasn’t enough and I failed to gain my VCDX.

Take the time to do a few Mock defenses. The discussions that come up can do nothing but help you prepare for something you never thought of. If a panelist sees a problem that you overlooked, it can be disastrous. However, if it was uncovered in a Mock, you can prepare for that contingency. Also, don’t be too shy about asking friends or associates (current VCDX holders?) to review your design and offer comments. While not as ‘real’ as a Mock, they also help prepare you for other contingencies. Forewarned is forearmed.


What’s it like in the Defense?

Unfortunately, there is a huge NDA regarding what goes on in the Defense. I like to say that the VCDX Defense is like “Fight Club”… The first rule about the Defense is ‘You don’t talk about the Defense’. We can’t really say much other than our impressions. Fortunately, the VCDX Bootcamp lets us all have insight into the process and procedures. If you are interested in attempting a VCDX defense, I strongly encourage you to attend one of the Bootcamps. They are invaluable and accurately portray how things are handled in the room.

‘Pearls of Wisdom’ regarding the VCDX Defense:

  • It was one of the most difficult and emotionally draining experiences I have gone through.
  • All of the anxiety was self-inflicted, as I became intimidated by the reputations of my panelists.
  • Don’t try to ‘bullshit’ your way out of a corner. There’s a reason the panelists are there: They are VCDX’s and know their shit.
  • Stick to your guns and don’t ‘waffle’. If you made a decision based on a constraint or requirement, justify it.
  • Don’t let yourself get psyched out by preconceived notions of the Defense Panel. They’re not there to ‘screw you over’, but instead to make sure that you know what it takes to be a VCDX.
  • Everybody on the panel has had to go through the same thing you are doing right now.
  • They all know you are nervous, and want to see how you react under pressure and scrutiny.
  • To quote Frank Herbert, “Fear is the mind killer…”
  • The defense is not about determining how good your design is. If your design wasn’t correct, it never would have made it to the Defense. It is about your choices in the design, how you came to those conclusions, and why you made those choices. In short, the Defense is about YOU, not about the validity of your design.



As of right now, I am still pursuing my VCDX. I will make my second Defense appearance in a few weeks at VMworldUS’13, hopefully with better results than last time. If this information helps somebody else in their VCDX journey, it was well worth the effort. Good luck!

About timantz

I am a Solutions Architect at SimpliVity, helping people around the country with their virtualization, storage, backup and recovery projects.
This entry was posted in certification, VCDX, vmware, vSphere and tagged , , , . Bookmark the permalink.

4 Responses to VCDX Preparation: Q & A

  1. Well written Tim. I would reinforce your guidance on mocks. Mocks were key for me to understand how to deal with the unexpected, and focus on succinct delivery of an answer. Good luck at your VMworld Defense, you are going to do great.

    • timantz says:

      Thanks, James, and I agree with you. Mocks not only a chance for live interaction, but also a different perspective to your design. Another set of eyes, seeing the same thing, will perceive it in a different way. It never hurts to get another opinion, and could save you in the real Defense if it comes up from a panelist.

  2. Pingback: VCDX Preparation index - VirtualizeTips | VirtualizeTips

  3. Pingback: VCDX Architecture Links | nxgcloud

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