1 2 3 Previous Next 127 Replies Latest reply on Mar 22, 2017 1:16 AM by rdelaflorvalls

    Help Create Some New DCD Study material / New Material

    JPM300 Expert

      Hello all,


      So after just missing my first attempt at my DCD I figured I would take what I learned from that experience and help build some new practice material for those who are attempting the VCAP-DCD5.1/5.5 exam.  During my studies I found a lot of good material out there around the items on the blue print but didn't find a lot of material to help me get into the mind set / exam mode per say.  A good example of this is Joshua's Test Track for the DCA.  He has created some really good practice questions with a lab to boot to really get you in the right mind set for the DCA.  What I would like to do is build something simular for the DCD.


      With that in mind, here is the project:

      I would like to build a interactive webpage that will simulate what the design questions and drag-n-drop questions are like on the exam with some practice questions created by myself and other people of the community.  How I'm going to try and make it, I'm going to try and use jsPlumb or maybe other simular drag-n-drop java libraries with html 5 to help create an enviroment.  Here is a link to the jsPlumb so you can kind of get an idea of how it will work:



      jsPlumb 1.6.4 demo - home (Vanilla)


      Other Java libraries to try




      This is what it will look like:






      Once the frame work is in place we can create test questions and have an interactive testing system to also help grade peoples awnsers to help prep people for the DCD exam prior to writing.


      Milstones of the project:


      1.)  Create Photoshop and site layout - I have already completed this and continueing to work on it to get more scenario's, I will post the photoshop .psd shortly incase anyone wants to use them to create there own for the time being

      2.)  Collect Good test questions with photoshop with an awnser page for the time being until the javascript is written -  this partialy done.  I currently only have two questions created

      3.)  Put it all together and post it.  I'm in the process of registering a blog so once I get that done and everything is together I can post the interactive page there and link it in the forums

      4.)  Shed less tears over failed DCD attempts


      Here are the first two questions I have created:









      DCD-Q1-A1 - One possible design choice to suit all the requirements, there is many others.  I will also build on this design and put a section for NIOC for those who want to add in 10GB NICS


      Now for a quick explanation to my awnser to the design.  For this one I put in an additional 2xQuad Port nics in the available PCI slots.  This allows for 2 nics for mgmt, 2nics for iSCSI, 2nics for backup, 2 nics for FT, 2 nics for DMZ for isolation, and 4 nics for the VMware Network as one of the requirement was it needed 2.43Mbps throughput.  Since you never truely get 100% on network transfer speeds I typically build out to 80%, which is 800Mbps for a 1GB nic.  So to meet the 2.43Mbps you would need a minium of 3 1GB NIC's, however this leaves a single point of failure as if one nic fails the VM Network can only push 2Mbps of traffic till that NIC is back online.  Thus I bumped the VMnetwork to 4 1GB NIC's so there was no single pont of failure.  If anyone else has better ways or other ways please feel free to post on it or work through the question.





      A quick Explantion of the design layout





      Special thanks to lbourque for running this past the VMware Certification team so fast and getting the green light


      If anyone wants to create some questions please post them here as I've told lbourque I'd post them here so they can be looked over incase there is any issues with them.


      Current questinos / designs i'm working on:

      vApp desing question

      Storage design question

      Calculation questions IE. what is the min amount of hosts you need to run X number of servers with X cpu, X memory, X networking

      Multiple choice questions to hammer on the blue print topics like RPO, RTO, ect.


      Thanks again, and I hope to get enough free time in the next few weeks to make some good progress on this.


      Also please excuse any spelling mistakes / type-o's, I put this together pretty quickly and haven't had a great deal of time to look it over


      Cheers everyone and good luck!

        • 1. Re: Help Create Some New DCD Study material / New Material
          JPM300 Expert

          I will be posting an update hopefully later today with some other questions / photoshop stuff.  Till then I wanted to dig these articles up as I haven't seen them posted elsewhere in the DCD study resources but I think they are good resources on Logical Network Designs and RPO,RTO, WRT, MTD


          Logical Network Design

          VMware vSphere 5 Host NIC Network Design Layout and vSwitch Configuration [Major Update] | Tech Blog | Blog


          RPO, PTO, WRT, MTD explained very well:

          RPO, RTO, WRT, MTD…WTH?! - Default Reasoning


          Also some multiple choice question are coming as well.

          • 2. Re: Help Create Some New DCD Study material / New Material
            JPM300 Expert

            Another thing to keep in mind for the 5.1 DCD is according to the brownbag video's that was linked in the other study resource material the points for questions was loosely broken down as such:


            Multiple Choice: 1pt per question

            Drag-n-Drop - 10pt per question

            Design Question - 25-50 points


            I know for the 5.5 this changed a bit with the reduction in multiple choice questions and the master design question.  However just something to keep in mind when creating your time mangement strategy.

            • 3. Re: Help Create Some New DCD Study material / New Material
              ShadyMalatawey Hot Shot

              Hi JPM

              Good work and wish you better luck next time
              Wanna post a link to the site so I can take a look ..?!
              Contact Paul McSharry (Author of Official Certification Guide of VCAP-DCD) he has some design scenarios that can be uploaded on your website
              Follow @Pmcsharry

              • 4. Re: Help Create Some New DCD Study material / New Material
                JPM300 Expert

                Hey ShadyMalatawey,


                Sure thing i'll post the site as soon as I got something up, I'm just in the process of registering the domain still   works got a VDI project going on thats keeping me busy, so i'll get the site up on this forums asap.  Also I'd like to have the framework in place so people could play with the drag n drop features prior to posting, but we'll see.  The javascript part takes me a bit as I'm not a developer by nature


                Thanks, I will deffiently try and get in touch with Paul McSharry and see what he can share with us, thanks for the heads up!


                I will hopefully have 2-3 more photoshop questions up by the end of the weekend so stay tuned for that!


                I also sent Paul and email so hopefully he will jump in and help us out


                Got in touch with Paul and he said he would be glad to help, so hopefully we will see some better questions soon

                • 5. Re: Help Create Some New DCD Study material / New Material
                  JPM300 Expert


                  vAPP Question



                  • 6. Re: Help Create Some New DCD Study material / New Material
                    JPM300 Expert


                    Here is one possible answer to the question.  By making sure each VM stays on a separate host it will be less likely to see contention due to the high usage % of each host in the cluster currently.



                    I like this answer a little better as it is less restrictive with DRS rules as to where each VM can live.  This would help get the DRS % down while still meeting the requirements.


                    Feel free to add any feedback. 

                    • 7. Re: Help Create Some New DCD Study material / New Material
                      JPM300 Expert


                      Create Logical Storage Design


                      • 8. Re: Help Create Some New DCD Study material / New Material
                        JPM300 Expert




                        Now this one will need some discussion and if anyone has any input feel free to jump in as I work with iSCSI more often then Fibre.  With that said lets get down to this design.  First off I decided to put a second Silver LUN in as we are assigning each LUN or Datastore to a Service Processor in the storage.  This way the silver storage is more load balanced between the two storage processors as most VM's will probably land in Silver.  With that said we could of easily put one Silver LUN on either storage processor and connected it.


                        Moving on I connected two Fibre connections from each storage processor to the SAN Switches as the questions didn't state how many connections the service processors have as its a logical design I put two to eliminate any single point of failure.  Moving forward I decided to put two dual port HBA adapters in.  The question doesn't state there is a need for the through put or pathing of a dual HBA so we could of gotten away with two 1 port fibre HBA's but I look at 1 port HBA's as a minor single point of failure.  This is because if that 1 port on the HBA fails, your loose an entire path, effectively dropping your throughput to your SP's in half.  However if you put in two dual port HBA's in and you loose a port on 1 of the dual port HBA's then you have only lost 1/4 of your paths.  This is a matter of preference unless the question states there is pathing, throughput, or budget concerns.  In which case some of those constraints could alter our design decisions, so look out for those on the exam.


                        If anyone has any comments please feel free


                        I forgot to bring my template for the drag-n-drop stuff from work so I will have to work on some of the drag-n-drop stuff I had planned for the weekend on Monday.

                        • 9. Re: Help Create Some New DCD Study material / New Material
                          JPM300 Expert

                          Also just wanted to say thanks to: Maish Saidel-Keesing.




                          I am using a few of his Visio Stencils from his packages which have come in really handy

                          • 10. Re: Help Create Some New DCD Study material / New Material
                            ShadyMalatawey Hot Shot

                            I think you have to connect both Storage Processors to all of LUNs to eliminate Single Points of Failure, i.e. single processor dead and you lose two of your LUNs.
                            For Silver LUN, I think it depends and the exam reviewer If he wanted two LUNs (not mentioned to load-balance Silver Tier).

                            For HBAs and SAN Fabrics, Use 2 single-port HBAs, to eliminate Single Points of Failure also.
                            Wanna review this...?
                            Really, good work..
                            I wish I can help in that .. waiting on fire for the launching

                            • 11. Re: Help Create Some New DCD Study material / New Material
                              JPM300 Expert

                              Hey thanks for the advice, I can alter the answer design,


                              Quick questions:


                              1.)  When it comes to the LUNS and the connections to the Service Processors, typically most active active SP I've worked with if one fails the other service processor will take over the LUNS of the failed SP.  However in the logical design I'm guessing they wouldn't be assumed and you would have to draw the connectors?


                              2.)  Oh whoops LOL I meant to put in two dual port HBA's that way there would be 8 paths which would help if just a port failed.  Good catch,

                              Any thoughts on weather to put in 2 dual port or 2 single port?  Unless there is path, throughput or budget concerns?

                              • 12. Re: Help Create Some New DCD Study material / New Material
                                JPM300 Expert

                                In regards to this:



                                When I have worked with Fiber the storage teams typically keep each side to its own, for instance, Odds / Even and just let the multipathing take care of any switch failures.  However I guess this would be better as it would eliminate the loss of a SP if a SAN switch fails.

                                Odd's/even example




                                Let me know your thoughts and I can adjust the diagram a little later.

                                Thanks again,

                                • 13. Re: Help Create Some New DCD Study material / New Material
                                  ShadyMalatawey Hot Shot

                                  1) I think they would clearly state that or you just have to draw it as active-active.. best solution for redundancy. .

                                  2) I think min cost is recommended unless else is stated about hw constraints or throughput constraint..

                                  3) for fiber san i think that even you left even/odd configuration seperated, you should have to cross connect san switches to all SPs, i.e. both switches connected to all SPs.. in your original solution if odd or even switch fails, entire luns are down..

                                  im not storage expert..but I think that even my configuration can be done too..in the end, just the same 4 single-initiator zones are configured

                                  • 14. Re: Help Create Some New DCD Study material / New Material
                                    JPM300 Expert

                                    K, I think I have resolved it with the updated design.  Let me know what you think.



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