Yesterday, I took the VCAP4-DCD beta exam (VDCD410), like many others have done this week. There is a thread started already in the communities forum. Just like previous beta exams with VMware, I had to take the exam at a Pearson-owned facility. There are a few within an hour of me, so I didn’t need to fly anywhere. It’s funny, Jason Boche mentions that he couldn’t take coffee into the testing center. The person at the facility where I took the exam said no food, drink, candy, etc. The center where I usually take exams is more laid back and are OK with coffee as long as there is a lid. In fact, they offer to sell you bottled water to take in with you. VMware only requires a finger print scan and a photo with the two forms of ID. I noticed some people were getting their hand vein patterns recorded. Crazy.
Passing the VCAP4-DCD exam is one of the requirements for anyone, including a VCDX3, to achieve the VCDX4 certification. So passing this exam is very important to me.
The beta exam was 131 questions/tasks with four hours to complete. (There was a guy before me that was taking a test that lasts 630 minutes!) I would think that some of these may get cast off as improper, too easy or too hard. If all of the questions prove to be OK, then VMware has a nice, fair pool of design questions. I would also think that the “GA” exam will only be a portion of these questions.
There are three types of questions or tasks: The standard multiple guess questions, a few “match the object to a category” drag and drop tasks and a few diagramming tasks.
Exam Content – What You Need to Know!
I am under countless NDAs on this, so there will be no “scoops” here. I can say that the exam is true to the Blueprint. Rather than giving a direct link to the PDF, which could change, I will tell you to go to www.vmware.com/go/vcap. Click on the “Datacenter Design” tab. There is a link to the current blueprint there. It was just changed to fix an issue with broken hyperlinks. There are also links to a FAQ, the VCAP Communities landing page and a link to a demo of the diagramming tool.
Make sure you read and understand all of the documents and web pages that are linked in the blueprint. VMware leaves no stone unturned. I would not advise trying to memorize all of the content listed in the blueprint, your head would explode. Just comprehend what you read. Much of this is conceptual and revolves around the methodology and best practices GUIDANCE that VMware chooses to publish.
Make sure you take a look at the VCAP4-DCD Exam UI Demo. This is the exam version of a Visio tool. One of my complaints about the VI3 Design Exam was the quality of the diagramming tool. It is greatly improved in this exam. In the VCAP4-DCD beta exam, there were more than one diagramming task. I don’t think VMware is looking for the Mona Lisa. This is more of a “show your work” kind of thing. The diagramming tasks are not that complex and will only cover a few design criteria in each task.
Since this is a DESIGN exam, there are plenty of scenarios that involve capacity planning. Since you will not have any tools available to do your work, you will need to understand the math involved in capacity planning. There is a simple calculator available via a link at the top of the screen. You will also need to understand the math involved with calculating HA, DRS, reservations, shares and limits.
Finally, with the beta, there was a time constraint. I think I had about 10 or 15 minutes left when I was done. Make sure you manage your time. There was no “back” button and there was no way to mark questions or tasks for review in the beta exam. This may or may not hold true for the “GA” exam. Remember: If there is no “back” button or way to mark a question, make sure you are OK with your answer before clicking the “next” button. I clicked it a few times as I was thinking “Maybe I should read that again….”
My Soapbox Moment
I don’t want to “toot my own horn” or sound arrogant here, but I purposely did not “study” for this exam. I did read the blueprint and skim some of the documents. The hyperlinks were broken in the 1.2 version and I didn’t try to find them too hard. I didn’t study for the VCAP4-DCA exam either (I passed by the skin of my teeth!). In my (humble) opinion, the exams require that you have EXPERIENCE in the subject of the exam. I don’t think VMware intends to have “paper VCAPs” although I am sure there will eventually be some out there.
If you want to pass the VCAP4-DCA exam, you should have experience managing a vSphere environment. If you want to pass the VCAP4-DCD exam, you should have experience in designing at least one vSphere environment. You need to go through the thought processes involved in the ASSESS – DESIGN – IMPLEMENT – MANAGE cycle. I am sure that the design workshop will assist you in gaining the knowledge and some experience in designing a vSphere environment, but it won’t give you everything you need for passing this exam. Certainly, if you want to progress to the final step and submit and defend a design, you will need EXPERIENCE. This is why there is such a high fail rate for the design defense.
Since everyone else in the world is heralding the release of vSphere 4.1, I figured I would post some bad news. The stuff you may want to know BEFORE you jump into upgrading to vSphere 4.1. Before I start, I want to make it clear that vSphere 4.1 is a great product overall. And I have already been leaning to ESXi, so the announcement that this will be the last release with the “traditional” ESX has been expected. I will talk about ESXi and its improvements in a later post. I just want you to be aware of these rather significant Gotchas.
Gotcha #1 – Read Only Role allows members to add VMKernel NICs
From the release notes (You actually READ these, right?):
- Newly added users with read-only role can add VMkernel NICs to ESX/ESXi hosts
Newly added users with a read-only role cannot make changes to the ESX/ESXi host setup with the exception of adding VMkernel NICs, which is currently possible.Workaround: None. Do not rely on this behavior because read-only users will not be able to add VMkernel NICs in the future.
This is a fairly big security issue. I just LOVE the workaround notes. To be fair, I have found only one installation in my experience that uses the Read-Only Role. In my opinion, if they don’t have access to the physical data center, they don’t need any access to vCenter. But this is just something that should have been corrected before release.
Gotcha #2 – ESX/ESXi installations on HP systems require the HP NMI driver
- ESX installations on HP systems require the HP NMI driver
ESX 4.1 instances on HP systems require the HP NMI driver to ensure proper handling of non-maskable interrupts (NMIs). The NMI driver ensures that NMIs are properly detected and logged. Without this driver, NMIs, which signal hardware faults, are ignored on HP systems with ESX.CAUTION: Failure to install this driver might result in silent data corruption.Workaround: Download and install the NMI driver. The driver is available as an offline bundle from the HP Web site. Also, see KB 1021609.
It seems that every time HP releases a new set of SIM agents for ESX, something breaks. Is this VMware’s way of putting it on HP? Or was this an “OOPS”? If you search for “HP VMware NMI Driver” you come up with nothing. No download. It was no where to be found on Monday, but I did find it today on the HP support site.
Gotcha #3 – VMware View Composer 2.0.x is not supported in a vSphere vCenter Server 4.1 managed environment
The basic issue here is that vCenter 4.1 only works on a 64-bit system. View Composer only works on a 32-bit system. From the KB Article:“VMware View Composer 2.0.x is not supported in a vSphere vCenter Server 4.1 managed environment as vSphere vCenter Server 4.1 requires a 64 bit operating system and VMware View Composer does not support 64 bit operating systems.“VMware View 4.0.x customers who use View Composer should not upgrade to vSphere vCenter Server 4.1 at this time. Our upcoming VMware View 4.5 will be supported on VMware vSphere 4.1.”
Don’t these guys talk to each other? Didn’t they learn their lesson with the PCoIP issues? And why can’t you just admit it in the release notes instead of putting a link to the KB article? I completely missed this Monday morning.
Gotcha #4 – vCenter Installer SILENTLY Changes SQL Server Settings to Allow Named Pipes
- vCenter Server installation or upgrade silently changes Microsoft SQL Server settings to enable named pipes
When you install vCenter Server 4.1 or upgrade vCenter Server 4.0.x to vCenter Server 4.1 on a host that uses Microsoft SQL Server with a setting of “Using TCP/IP only,” the installer changes that setting to “Using TCP/IP and named pipes” and does not present a notification of the change.Workaround: The change in setting to “Using TCP/IP and named pipes” does not interfere with the correct operation of vCenter Server. However, you can use the following steps to restore the setting to the default of “Using TCP/IP only.”
- Select Start > Programs > Microsoft SQL Server 2005 > Configuration Tools > SQL Server Surface Area Configuration.
- Select Surface Area Configuration for Services and Connections.
- Under the SQL Server instance you are using for vCenter Server, select Remote Connections.
- Change the option under Local and Remote Connections and click Apply.
Can you hear the DBAs pissing and moaning?
Gotcha #4a – SQL Database is changed to Bulk Recovery Model (updated 10/27)
This on is funny. I just found out about it on 10/27/2010. When is comes to SQL for the vCenter database, VMware recommends using a simple recovery model. So, with their attention to detail, the upgrade process changes the database to a bulk recovery model. Inn this model, the logs keep growing until a backup purges it. No good.
Transaction log for vCenter Server database grows large after upgrading to vCenter Server 4.1 – http://kb.vmware.com/kb/1026430
Again vSphere 4.1 brings some great improvements and some welcome changes. As the product matures and more vendors work with the APIs, we will see some nice features that will help you in your journey to the private cloud. The Gotchas listed above may not exist if quality assurance is tightened. I think I would rather hear that a release is delayed because of pending bug fixes. How long will we need to wait to fix these? In any case, if the Read-Only Role or the View Composer gotchas don’t apply, then jump right in and install or upgrade to vSphere 4.1. Just make sure you install the NMI drivers and fix the SQL settings.
I got a tweet from William Lam last night. It looks like versions are hard-coded in Capacity-IQ making it incompatible with vSphere 4.1. Will also explains two ways to make it work.