2016 takes a leap…a leap second

As if 2016 weren’t bad enough…this year is going to be slightly longer than normal. New Year’s Eve will be one second longer in 2016 to adjust for the shifting rotation of the Earth.


leap second is a one-second adjustment that is sometimes applied to Coordinated Universal Time (UTC) in order to keep its time of day close to the mean solar time, or UT1.

This leap second has the potential to cause chaos for IT systems that cannot deal with a 61-second minute. Websites such as Reddit, Yelp, LinkedIn have previously experienced outages for a period of time due to the leap second in 2012.

Most VMware products are unaffected by this time change that will occur this weekend However, some products are affected. Please see KB 2147498 for more information.

For those VMware products affected, the common work-around is to enabled Slew Mode for NTP. For more information see KB 2121016.

Horizon Agent fails to install: “system must be rebooted” error

Nothing is more fun than walking into a client site on a Monday morning and something that’s supposed to be easy (installing Horizon Agent in base image) doesn’t work.

I logged into the Windows 7 virtual desktop image and tried to install the Horizon Agent, however, I received a message stating: “The system must be rebooted before installation can continue.” Seemed simple enough, so I restarted the machine, and tried again. Same error. #facedesk


Did some digging and found an old KB (1029288). The KB doesn’t say that it is applicable to Horizon View 7.0.x but it solved the issue I was having.

First I tried to uninstall and re-install VMware Tools. No luck.

I went through the registry keys suggested by the aforementioned KB but there weren’t any associated strings associated with the registry keys.

At the very end of the list, two registry keys were listed:

  • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce\
  • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnceEx\

There were values located in HKLM\Software\Microsoft\Windows\CurrentVersion\RunOnce, so I deleted all the values, rebooted the machine.

Voilà! I was finally able to get the Horizon Agent to install so I could proceed with my day. It appeared that there was a previously failed installation that was preventing the Horizon Agent from launching its own installer.

Horizon 7 Instant Clones – Folder Structure

When provisioning Horizon 7 Instant Clones, you may have noticed some new folders that were created in the VM and Template view in the vSphere Web Client.

Screen Shot 2016-12-19 at 9.37.17 AM.png

Each of these folders has a specific purpose for Instant Clones:

  • ClonePrepInternalTemplateFolder
    • cp-template-xxxx –  Virtual machine that is a template used to create Instant Clones; this is created from the master image.
  • ClonePrepParentVmFolder
    • cp-parent-xxxx – These virtual machines exist in a 1:1 relationship to the number of ESXi hosts in the cluster. I have a four node cluster, therefore I have 4 clone prep parent virtual machines. Each ESXi host has one of these powered on and in memory in order to provision the Instant Clone VMs.
  • ClonePrepReplicaVmFolder
    • cp-replica-xxxx – This virtual machine is used to create the clone prep parent virtual machines. It will be also used as necessary to provision additional clone prep parent virtual machines.
  • ClonePrepResyncVmFolder
    • If the Instant Clones are updated with a new image, a virtual machine will be created here for staging purposes.

Learning from Failure – My Path to VCDX (Part II)

ICYMI, you can find Part I here.

Second Attempt – Pass!

The important decision to make whether I should wait or reapply immediately. Brett and I talked a lot about this over the two days following our results. I decided that I would shore up the gaps in our design (primarily our DR plan and the capacity planning) and reapply for the November defense. The deadline for application was Aug 24…that meant I had slightly less than two weeks to edit the design and reapply. Brett decided to wait because he had a lot of work obligations for the second half of the year. Per policy, VCDX partners can defend separately (however, must apply at the same time) but must be within two defenses of each other.

In case you did not know, a second defense on the same design requires a change log to be created. Check out Lior Kamrat’s blog post here.

In hindsight, it was a crazy move to reapply so quickly. Between application and defense in November, I had VMworld US, two Europe trips, and VMworld EU…translating to not a lot of time to prepare. But I felt like I had a better idea of what I needed to do and what the panelists wanted to see.

I talked to many VCDX candidates and VCDXs while at VMworld US and VMworld EU. I listened to all their advice and how they prepared. I’m grateful for the time that so many spent with me.

This time I decided to prepare differently. I was going to do it my way. I went into a little bit of an isolation; I didn’t tweet about it. I didn’t work with as many people, I kept my group small. I just focused on working with my study group. I didn’t do as many mocks for myself (I think only two or three), but I participated in quite a few mocks as a “panelist” for others. I created flashcards for questions I thought panelists would ask. And I completely rebuilt my slide deck so that the intro (or main deck) would talk more to my requirements and constraints, as well as specifically highlight my design decisions.

I went up to Palo Alto a few days before my defense to do some mocks and study with a member of my study group. Unluckily, my defense was the morning after the US election so I stayed up later than I had planned. I went over my slide deck, slide-by-slide, with someone in my study group that night. I woke up early, flipped through my main deck one last time, and then headed to VMware’s campus. While I waited for my panel, I reviewed through my Quizlet sets one more time.

Honestly, I wasn’t sure how I did. I felt more comfortable in the design scenario because I did what I normally do with a client—I wasn’t so focused on following someone else’s template. In the defense section, I felt I did ok but I could tell I wasn’t doing well explaining my networking. I got a little ramble-y in that area. I think I may have made up for that in the scenario. Either way, I was convinced I’d failed again.

To VMware’s credit, they cranked out our results much quicker than in July. I defended on Wednesday and found out my results the following Tuesday. I passed! I’m officially #243.


My Thoughts  

  • Make sure your friends and family realize how much time you’ll be dedicating to VCDX.
  • No (wo)man is an island. Surround yourself with a community of others doing the same.
  • Join a study group. Gregg Robertson runs a great one on Google+ and Slack. Join it! But then find a smaller group who are preparing to defend around the same time as you.
  • Have someone (or multiple people) review your design as you are writing it.
  • Review your design and have someone else review your design once submitted. There will be gaps and errors—-find them! Figure out how to address them in your defense.
  • Do mocks! Do more mocks!!
  • Create backup slides in your PPT for reference, but do not be afraid to whiteboard in your defense.
  • Be familiar with your slide deck. You don’t want to waste time fumbling around looking for a slide in the defense. Work out those kinks in mocks.

But you should do what feels right to you. Don’t focus on the techniques that helped others. Don’t feel the need to follow someone else’s template. Achieve VCDX your own way. Grant Orchard (#233) just wrote a brilliant post along the same lines, read it here.

Obligatory Thank You(s) 

First and foremost, I would like to thank my VCDX partner, Brett Guarino, and his wife, Leann, for putting up with us working weekends and late nights and letting me stay all of those weeks in their home in Raleigh while we worked. Thank you to Brett’s managers at VMware for letting him dedicate time to this project. I can’t wait until he gets his number.

And a massive thank you to:

Lastly, Chris Williams, thank you so much for being the only person who responded with notes when we sent our design out for review. Your time reading our design is greatly appreciated and your notes were invaluable.

Learning from Failure – My Path to VCDX (Part I)

I’m excited to announce that I have been awarded the title of VMware Certified Design Expert (VCDX) #243. If you are unfamiliar with the VCDX program, you can find more information here.

My journey towards VCDX began a little over three years ago. I had successfully passed the VCAP5-DCA (May 2013) and VCAP5-DCD (Sept 2013) exams and was trying to figure out what was next for me.

I talked to my friend and former business partner, Brett Guarino, about it several times throughout the next few weeks. Together, we decided to partner up, write a design, and chase this certification together. In October 2013, I wrote an article titled “Why I am Pursuing the VCDX” for VMware Press, publicly announcing my pursuit (that way I could be held accountable). I had no idea what a long road this would be.


Writing the Design

This part took us forever. I think we underestimated the length of time it would take and it became increasingly difficult to prioritize VCDX time over work. This is primarily because Brett and I were both self-employed when we set out on this endeavor. So for me, taking time off to work on VCDX meant no money coming in for that given time period.

We kicked around a few different designs we worked on, considered doing something completely fictional, but ultimately we landed on a lab infrastructure design we had worked on together. Brett and I selected this design because it was very unique (leverages nested virtualization) but was still fairly simple.

By December 2014 we had put together our first draft of a design document and had created a plethora of diagrams and tables. But…around that time Brett accepted a position with VMware and was trying to settle into this new role. I was still self-employed and had landed a few gigs that were keeping me traveling overseas regularly. Our VCDX design was put on back burner…and it sat there for about a year.

Around Christmas 2015, Brett and I had a frank conversation regarding our pursuit of VCDX. When I had time to work, he was busy; when he was free, I was busy or out of the country. We tried to divide up the sections and conquer them separately but when we weren’t together we found that it was easy to prioritize something else over our design. It was time for us to ‘shit or get off the pot.’ Either we would both dedicate time working on this or we needed to pursue VCDX individually. We decided to give it one more shot together.

I had looked at the VCDX schedule and found that there was a submission deadline in May 2016 to defend in Palo Alto in July 2016. We created a schedule and got to work. We both took off for much of April to sit down and hammer out the rest of the design document together. Within about 2 weeks we had the design document finished and sent to a reviewer. From there, we split up the remaining work of completing the supplementary documentation (installation guide, implementation guide, testing and validation guide, and standard operating procedures). I think we underestimated the amount of time that the supplemental documentation would take.

With the deadline fast approaching, I found myself on a plane to Tel Aviv the day before the submission deadline. I was furiously making last minute adjustments to our documents, re-reading, editing, and trying to finish filling out the application.

We submitted our applications, and then had a drink to celebrate. Idiotically we thought the hard part was finished…we were wrong. Turns out preparing for the defense is far more stressful than writing the design.

First Attempt – Fail!

Once our applications were submitted, it came time to work on our PPT and start to participate in mocks. We should have started immediately after submitting our applications but we didn’t because we both had vacation plans for the end of May. And honestly, we really didn’t think we’d get accepted. We did. I took a week off in June and together we worked on our PPT and did some mocks for the design scenario portion of the design defense.

We both took off work for the two weeks leading up to our defense, crammed, and worked on perfecting our PPT. Through mocks we found quite a few gaps in our design and slide deck and we worked furiously to make more supplemental content (backup slides).

I defended on July 25 and Brett defended on July 26. I must say that I didn’t feel like I had bombed the defense, but didn’t walk out feeling like I’d given an A+ performance. I felt the outcome was 50/50. There were a few things I was hit on for which I was not properly prepared. I didn’t feel great about my design scenario —I think I had read too much about how it should approached by different VCDX bloggers and I tried to follow their approach and it just didn’t feel natural to me when I was in the room.

But I had a lot of time to replay my defense in my head because I didn’t find out my results until Aug 9…slightly over two weeks! I failed (sadly, Brett had failed as well). I’d thought a lot about my defense and I realized that I was completely “defensive” rather than “offensive,” I wasn’t guiding the conversation. I spent too much time in the technical details and not enough time explaining why I made that decision in the first place. Additionally I didn’t feel like I did the best job tying design decisions back to requirements. I was determined to learn from my mistakes.