Sep 172015
 

Seems a rather vague question right?

It can depend on any number of variables:

  • Weather
  • Speed
  • Tyre type
  • Tyre condition
  • Age of the driver
  • etc

I know starting a tech blog post off by talking about the stopping distance of a car is odd but I wanted to make a point as this is relates to a question I was asked by a customer recently.

A fairly snr figure in my customer organisation asked me in a public forum “How long does it take to power on a Vblock”. With the benefit of hindsight (isn’t that a wonderful thing), I should not have even entertained trying to answer his question in that forum. But of course I tried, with both parties dissatisfied of the quality of my answer.

As I tend not to give disappointing answers to questions this has troubled me for a few weeks now. Analysing my response over and over didnt seem to resolve my issues with my answer so I have come to the following conclusion

Fundamentally the question was floored!

For example is he referring to how long it takes to boot up the individual components after power outage? Is he referring to getting the base level virtual infrastructure back up (likes of vSphere etc)? Or is he (as i suspect) referring to how long it takes the application to be back to a state where they can run their services?

Each view point has a plethora of facets that need to be factored in to the SLA variables, like below just to mention a few:

  • MTTR – Mean Time To Recovery
  • RTO – Recovery Time Objective
  • RPO – Recovery Point Objective

In a mixed workload environment (which this is) it is common to see different workloads having different SLAs within the same system, and depending on the logical setup around each of those workloads (cluster settings, SRM, Stretched DC clusters etc) each SLA can vary wildly.

Thus, “How long does it take to Power on a Vblock” is not only an impossible question to answer (without a multitude of variables to support the questions) but its fundamentally the wrong question as each application will take differing levels of time to restore fully.

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Mar 232012
 

Happy to say I passed the VCP-510 today.

I have to say the VCP exam has become harder since the VI3 days. The VI3 was the last time I took the VCP as skipped the vSphere 4.x as it wasn’t something I needed at the time.

The broadness of the technical content that the VCP 5.x can choose to ask questions on and the level at which you need to know that contact is considerable. Since my VI3 qualification we have seen a plethora of features like vDS, storage vMotion, Storage Profiles etc, etc, etc. For the VI3 I honestly thing you could do the course read a few whitepapers and pass the exam. The VCP5 is definitely a step up, if you have little or no hands on they you will struggle to pass this exam. I have been in a more presales role for a while now so I struggled to get up to speed.

Although this is a hard exam, its a good thing it is. Far to many early VCPs back in 2008ish were claiming to be something they were not and along with the VCAPs I think its clearer now who knows their stuff.

What did I use to get up to speed:

  • vSphere 5 ICM course
    • This covered off the basics but did not cover things like ESXTOP, Auto Deploy, vDS, VASA etc etc. All of the excluded things are featured in the exam so either do the ‘Whats New’ course aswel or take the ‘Fast Track’ course. But no matter what you will be lucky to pass the exam with just attending a course. (exam prerequisites)
  • Trainsignals VMware vSphere 5 Training.
    • If you don’t get an opportunity to do the course or even if you do they this is CBT is highly recommended. The Demos alone are a fantastic way to learn especially if you don’t have access to a lab. I am doing a full write up on this CBT so ill link to it here once I’ve completed it.
  • Blog posts and link:

I’m not going to link everything I used as the above links already have some good resources in them to look at and some links to other useful pages.

WHATS NEXT: VCAP DCA or DCD I think. Would love to be among the first bunch to attempt a VCDX 5 defence but that’s just aspirational at the moment.

If you read this far down any you have your VCP-510 soon then I wish you the best of luck.

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