Yellow Bricks

by Duncan Epping

Archives for 2009

New Sponsor: Train Signal

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Yellow-Bricks.com is proud to announce a brand new sponsor; Train Signal!

Train Signal is the leading provider of computer training software for IT Professionals covering Microsoft, Cisco, CompTIA and VMware.

Now I could write an article praising Train Signal but there’s no point. I don’t need to convince you guys Train Signal should. David Davis(one of Train Signal’s instructors) recently posted an 18 minute introduction on his blog(vmwarevideos.com) to the upcoming VMware vSphere video training course. Check it out:

Code Central

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I visit the VMTN Communities daily and recently noticed a new section called Code Central. I didn’t pay attention to it cause I thought it was a private section but apparently it is not. Nava Davuluri introduced this new section and his role within VMware recently in a blog article:

I’m Nava Davuluri, a new hire into Product Marketing. This is my third month at VMware and things are off to a great start! One of the highlight events at my job so far includes attending the new vSphere launch, where I got to see business leaders in computer technology talk about how VMware products are increasing efficiency(performance, power and hardware) control( security and service levels) and choice (hardware, OS and application architecture) for the next-generation of cloud computing. This has given me a perspective on how important these products are and also made me realize the importance of my role.

I was hired to manage the sample code arena for developers and system administrators that make up the majority of VMware developer community. My biggest goal here is to make your life easier. Yes!, by creating a community based sample code site where it will be easy to create, collect and share sample codes in one single straight forward page.

Some people have started adding scripts to this new section of the community already, take a look and contribute!

http://communities.vmware.com/community/developer/codecentral
http://blogs.vmware.com/codecentral/

VMFS/LUN size?

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A question that pops up on the VMTN Community once every day is what size VMFS datastore should I create? The answer always varies,  one says “500Gb” the other says “1TB”. Now the real answer should be, it depends.

Most companies can use a simple formula in my opinion. First you should answer these questions:

  • What’s the maximum amount of VMs you’ve set for a VMFS volume?
  • What’s the average size of a VM in your environment? (First remove the really large VM’s that typically get an RDM.)

If you don’t know what the maximum amount of VMs should be just use a safe number, anywhere between 10 and 15. Here’s the formula I always use:

round((maxVMs * avgSize) + 20% )

I usually use increments of 25GB. This is where the round comes in to play. If you end up with 380GB round it up to 400GB and if you end up with 321GB round it up to 325GB. Let’s assume your average VM size is 30GB and your max amount of VMs per VMFS volume is 10:

(10*30) + 60 =360
360 rounded up -> 375GB

New version of ESX Healthcheck script

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Long before people ever heard about the VI Toolkit the ESX Healthcheck ruled the earth. The ESX Healthcheck script used the esxcfg-* commands in the Service Console and dumped all the info into a html file.

Today a new version of ESX Healthcheck has been released(0.30) after two years of silence. It has taken them a long time but it’s worth it in my opinion. Anders is looking for people that want to help out developing the script, so if you are interested leave Anders a comment on his blog.

VCDX Defense, the blog article!

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As you know I did the final part of the VCDX certification in San Francisco during the VMware Technical Services vSummit. I wanted to share my experience with you so you know what to expect to a certain degree and more importantly get the word out in general.

The last part of the VCDX certification is the defense. In short: you will need to write a design, fill out the application and defend your design during a two to three hour session.

Although I can describe it in 30 words it is not as simple as it may sound. First of all your design needs to meet specific requirements. I can’t go in to the details unfortunately but when you receive an invitation you will receive all the prerequisites. Like me, most of you done numerous designs, but keep in mind it needs to be in English and so will your defense need to be. This is an extra barrier for many of the non- native speakers; I know it was for me.

The defense part:
75 minutes – executive overview and an in-depth design defense
30 minutes – design workshop
15 minutes – problem analysis

For the first 15 minutes, the executive overview, you can use a couple of slides. Like I said it’s an executive overview and its only 15 minutes so don’t go into the technical details, there’s no need for that share your experience and maybe tell about political issues for instance. These 15 minutes gave me the opportunity to get rid of my nerves.

The in depth design defense is self-explanatory I think. Just be prepared to get questions on every single aspect of your design, know it inside out and not only “what” and “how”, but especially “why”.

Next two are role-play based. The panel is the customer and you are the architect. By asking questions, white boarding, discussions you will need to solve an issue or come to a specific solution for the customer. This is something you can not really prepare. Although you may think you will have more than enough time, you will not have time enough. Time flies when the pressure is on. Keep in mind that it’s not the end result that counts for these scenarios, it’s your thought process!

I’ve read comments on the written exams; some thought they were too easy. I can promise you this will not be easy this is not a test you can study for and pass if you crammed all the details. You will need specific soft skills and a wealth of knowledge.

Good luck and enjoy the ride,