vBrownBag – VCAP6-DCV Design Objective 2.2

vBrownBag EMEA is in the midst of recording sessions that cover the VCAP6-DCV Deploy (3V0-622) exam. If you are interested in presenting one of the exam objective, see the Call for Presenters post here.

Objective 2.2 – Map Service Dependencies

Skills and Abilities

  • Evaluate dependencies for infrastructure and application services that will be included in a vSphere design.
  • Create Entity Relationship Diagrams that map service relationships and dependencies.
  • Analyze interfaces to be used with new and existing business processes.
  • Determine service dependencies for logical components.
  • Include service dependencies in a vSphere 6.x Logical Design.
  • Analyze services to identify upstream and downstream service dependencies.
  • Navigate logical components and their interdependencies and make decisions based upon all service relationships.

Additional Resources

  • Graham’s blog post on Objective 2.2.
  • Don Ward’s post called “VMware Application Dependencies and Entity Relationship Diagrams”

Without further ado, the podcast recording can be found here:

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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.

giphy-2

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.

VCAP6-DCV Deploy (Beta)

I had the opportunity to take the VCAP6-DCV Deploy (Beta) exam last week.

The beta is still ongoing and costs $100 (regularly $400). A few notes:

It’s HOL based (HTML5 rather than RDP) so performance has improved quite a bit. But as expected, the vSphere Web Client is still quite laggy. The vSphere Client is still available, though some tasks must be completed through the vSphere Web Client.

Another improvement is that you can see the lab console and the instructions at the same time. But this posed a major issue with the screen resolution, in particular being able to see all of the vSphere Web Client.

CTRL and ALT are disabled, which you are warned about at the beginning of the exam. However, the exam does not warn you that the backspace key is also disabled. This irked me to no end throughout the test and slowed me down quite a bit when I was doing command line. (I don’t normally use the arrow key and then delete)

Copy and Paste does not work in the vSphere Web Client (another thing you are not warned about), only in the vSphere Client, PuTTY and Notepad++.

There are 27 questions, and the exam is 4 hours long. Ensure to pace yourself. If you get up to use the restroom mid-exam, the time will keep ticking down.

The content was decent, it stayed on track with the exam blueprint. I didn’t feel as rushed for time as with previous versions of the VCAP-DCA exam.

Here are a few other blogs that discuss the beta exam experience:

http://davidstamen.com/certification/my-vcap6-dcv-deploy-beta-experience/

https://sites.google.com/site/arielsanchezmora/home/study-guides/vcap6-dcv-deploy-beta

http://www.thomgreene.com/blog/2016/6/25/strategy-going-into-the-vcap6-dcv-deploy

Book Review – “Mastering VMware vSphere Storage”

For a book titled “Master VMware vSphere Storage,” about 1/3 of the book is spent discussing other topics. Storage does not get directly discussed until 88 pages in and begins by discussing storage APIs. I can understand giving a brief overview of vSphere but a majority of the review should be focused on the storage protocols and storage architecture rather than beginning with storage APIs and storage profiles. Once the book finally delves into configuring, optimizing, and troubleshooting storage, it does a good job covering the topics…though out of order at times (i.e. discusses optimizing before how to configure storage). Many great screenshots and diagrams demonstrating the points of discussion. However, for a book written for vSphere 5.1 / 5.5, there are quite a few screenshots from the vSphere Client rather than the vSphere Web Client. Overall 3/5.

 

You can find the book here.

Standard vSwitch Port Scale

Reading through the documentation for vSphere 5.5 something caught my eye…thought I’d share:

“For hosts running ESXi 5.1 and earlier, you can configure the number of ports that are available on a standard switch as the requirements of your environment change. Each virtual switch on hosts running ESXi 5.1 and earlier provides a finite number of ports through which virtual machines and network services can reach one or more networks. You have to increase or decrease the number of ports manually according to your deployment requirements.

NOTE Increasing the port number of a switch leads to reserving and consuming more resources on the host.If some ports are not occupied, host resources that might be necessary for other operations remain locked and unused.

To ensure efficient use of host resources on hosts running ESXi 5.5, the ports of virtual switches are dynamically scaled up and down. A switch on such a host can expand up to the maximum number of ports supported on the host. The port limit is determined based on the maximum number of virtual machines that the host can handle.”

I learn something new every day!!

Transparent Page Sharing (TPS) Changes

Quick review of TPS: Transparent Page Sharing allows pages that are identical to be stored in same place. When there is idle CPU time, vSphere looks for pages located across virtual machines that can be matched with one another and shared in physical RAM.  This is basically a deduplication method applied to RAM rather than storage. It allows vSphere to use just a single copy of these shared bits even though the bits are shared across two virtual machines.  This may provide may provide substantial memory savings.

Historically this has been enabled by default. But this is about to change.

Transparent Page Sharing will be disabled by default at the next major version release as well as the future updates to vSphere 5.x.

See Kbs 2080735 and 2091682 for more information.