VCDX Preparation & Tips - Phase 1, Wake up

Posted on 22 Oct 2013 by Ray Heffer

Today I was delighted (for once) to be woken up by my children at 5am shaking me to get me out of bed. It’s a nasty habit, but it is the first thing I do when I wake up is check my phone for Tweets, Emails, Messages, and so on. Still in a semi-sleep state of consciousness I saw the email with my VCDX results. My hands were shaking, quite literally and it took me a good 20 seconds (which seemed like hours) to read the attachment and realise that I passed. I am VCDX #122.

Exactly one year ago I was in two minds whether to apply for the VCDX certification. Mainly because I had only one vSphere design under my belt, and I didn’t think it would be good enough. Working for VMware Professional Services as a Senior Consultant at the time gave me one HUGE advantage. I remember walking over to say hello to one of the engagement managers and she said “Oh by the way, we’ve got a design engagement for coming up which I’ve marked you for.”. It was then I decided that the effort I’d put into that design would have to exceed the customers expectations and deliver the quality the VCDX title demands.

I’m writing this blog post to help anyone that has the VCDX certification as a goal. Everyone has different reasons for wanting to achieve the title. For some it will help them with that next career move or promotion, whilst others simply see this as a personal accolade they wish to strive for. For me it was the latter but it soon became apparent, because I can’t keep quiet, that I put a lot on the line having told practically everyone in my team, people at VMworld, partners, and customers, that I was going to be defending in Barcelona. Suddenly Twitter was alive with my friends and colleagues wishing me luck. But what if I failed? After all this was my first attempt! To top it off, I have only just joined a new team at VMware so I felt that I needed to prove myself.

So what if you fail? It really doesn’t matter, believe me, it doesn’t. Whilst preparing for the VCDX defence I read various blog posts and articles from other VCDX’s that took multiple attempts at making the grade. This isn’t because their technical knowledge is lacking or their design is poor, but they may have missed or lacked clarity in one particular area. The blueprint lists five design qualities: Availability, Manageability, Performance, Recoverability, and Security. It’s not enough to just talk about these areas, but when questioned by the panel members you need to demonstrate that your design addresses each of these areas. You must be able to articulate how your design decisions meet these design qualities and answer some tough questions. There is more than one way to meet a particular design quality, so you’ll need to know your design in intricate detail as well as the other design choices you were faced with at the time.

Your design may have met or exceeded the customer expectations, but it must also address the requirements of the VCDX blueprint. Also, think about this… If you’re customer asked you to hold a design workshop in the local pub one afternoon, explaining the design in detail, without having the design document to hand, can you do that? If so, then you’re on your way to becoming a VCDX.

So what preparation is needed?

If you’re aiming for the VCDX then you’ve already proven your technical expertise by passing the two required VCAP exams. That’s a massive achievement in itself! Based on my experience, I spent the most part of a year working with the customer that my design was based on. I had many challenges by the customer, vendors, and peers on design decisions and technical considerations during this time. In the 12 months on that project I probably spent 480 hours on the design alone, if not more. You’ll often hear about the hundreds of hours that go into the design in preparation for the VCDX and I can certainly agree that this is a common trait with those that are successful.

Being in a position to spend that amount of time on a customer engagement may not be possible though, and you don’t necessarily have to be a consultant working full time on a design to achieve the VCDX. It might sound like I’m contradicting myself, but those hundreds of hours must come from somewhere… weekends. I was extremely lucky to be able to work directly with my customer for such as long period of time, and not everyone has that opportunity. That being the case then you’ll need to be prepared to spend many hours in your spare time, weekends and evenings, working on the design. If you’re not prepared to do this then perhaps the VCDX is not for you.

The Nitty Gritty

If the countless hours and intricate knowledge of your design hasn’t put you off then you’re already on the right path. Well done for getting this far into the blog post too! I cannot reiterate enough that you need to read the blueprint. Let me pick a two random topics from the blueprint and we’ll use that as a basis for the discussion.

Example 1: Virtual Machine Sizing

You need to make sure that your design addresses capacity planning and the sizing of your virtual machines. This affects vSphere HA configuration, storage performance and capacity, ESXi cluster sizing, which vSphere licensing you need, and memory management, just to name a few. Make sure you have not only included this in your design but you can confidently discuss how you made your calculations and what impact sizing has. For example, do you have any ‘monster’ VMs? If so then ask yourself how this changes your design decisions. Duncan Epping talked about HA admission control a few years back, but the technical considerations are still valid today: YellowBricks

Example 2: Monitoring

My design presented a few challenges in regards to monitoring. For one, the customer was going to implement vCenter Operations at a later date so it wasn’t part of the design. But I still needed to address this as it’s one of the blueprint areas. Also, one of the security requirements in my design was to implement ESXi Lockdown Mode. With this enabled it breaks the vMA which I was going to include in the design as an interim measure whilst they implement a Syslog server. This has since changed and I’m able to utilise the vSphere Syslog Collector even with Lockdown mode enabled. Can you see where this is going? To address monitoring I have to consider some of the security requirements. It’s all well and good recommending in the design that ESXTOP can be used, but not if they have no means of accessing it! Just by thinking about monitoring, I’ve exposed some issues that relate to Security and Manageability. This is the essence of the VCDX defence.

Practice Makes Perfect

So you’ve done your design, checked it against the blueprint and even had some colleagues and peers review it. You have had it reviewed haven’t you? In that case you need to be confident at presenting your design. You may need to do this with your customer, but I cannot stress enough how much you need to practice at this. Be confident in understanding the design and why you reached certain design decisions. If you don’t know the answer, then say “I don’t know” and how you would go about finding out before moving on. Remember, we’re all human, even the panelists! I had to work on the Sunday before my VCDX defense, so I missed out on the VCDX boot camp in Barcelona. However, I was presenting on the Sunday so that was still good practice for my presentation skills. In the months leading up to the defense I had also presented the design a good number of times to my customer with varying levels of technical ability. In fact some of the less technical audiences can often present some of the more unexpected and challenging questions!

Wrapping Up

Achieving the VCDX is a fantastic goal to work towards, and you’ll gain so much in knowledge and better soft skills by just going through the process. Remember the VCDX community is quite small but I’ve found each and every one to be very friendly and supportive. I would recommend getting involved in the community discussions, so I’ve listed a few places below to get started.