Sean Crookston

Setting vCenter Alarms with PowerCLI

Sean Crookston — Mon, 13 Feb 2012 13:00:00 +0000

vCenter as of version 5.0 defines 54 default alarms that can be configured for notification. What vCenter does not provide however is a way to automatically configure all those alarms to be sent to a single email address without having to manually go into each alarm. The below PowerShell script however will take care of that. After configuring the vCenter server connection information and changing the email address, this script will setup emails that are triggered by any change in alarm state. This is a one time email per state change, however you could use the –repeat option to set repeat emails for certain states if desired.

Note that in the Code you will not see anything to set the Yellow—>Red state. I could not find this documented anywhere but by default it appears this will be set. Including it in the code would result in errors.

http://www.seancrookston.com/set_alarms.ps1

I also managed to find someone who has written a much smaller set of code that will look for all existing alarms and set email notifications as well as another individual with a similar script for setting alarms.Check out these two posting for more details.

http://jpaul.me/?p=1999

http://www.van-lieshout.com/2012/01/powercli-automation-create-vcenter-notification-email-alarm-action/

If you would like to know more about the various PowerCLI commands for alarms be sure to check out this VMware posting:

http://blogs.vmware.com/vipowershell/2010/12/managing-vsphere-alarms-with-powercli.html

Forcing a Kernel Dump on a vSphere Host : The Purple Screen of Death

Sean Crookston — Mon, 09 Jan 2012 13:30:00 +0000

This is nothing new however I thought I’d share on how to force a PSOD on a vSphere host in case you were not aware. I had done this a while back but was unable to retrieve the information my self when searching. Thanks to @CianoKuraz & @lamw(http://www.virtuallyghetto.com) for their help on Twitter.

Eric Sloof (http://www.ntpro.nl) documented this quite some time ago on his website here. The process is quite easy and goes as follows:

Connect to the vSphere host via SSH.
Type vsish
Type set /reliability/crashMe/Panic

Alternatively you can send an NMI interrupt. This depends on your hardware and if you are interested in learning more about this check out VMware KB 1014767

Great VMware VCP 5 Resources Page

Sean Crookston — Wed, 28 Dec 2011 12:21:59 +0000

I’ll be needing to renew my VCP 5 and with some down time towards the end of the year I figured now is as good of a time as any to go through the blueprint and do some studying for the exam. Damian Karlson who previously took over the VCAP-DCA study guide for me also has a great resource page for the exam with links to a lot of great community resources. If you are also taking the xam I would highly recommend checking this page out.

http://damiankarlson.com/2011/11/01/vmware-vcp-5-resources/

Another Great VCAP-DCA Resource

Sean Crookston — Wed, 21 Dec 2011 16:04:02 +0000

Chad King over at http://virtualnoob.wordpress.com has posted a great resource for VCAP-DCA studying. Using a Mindmap he incorporated some of the great resources already out there and you can check this out at the URL below. Mindmaps are definitely a great way to break out a blueprint like those for the VCAP exams and should prove as a great resource for your studying.

http://virtualnoob.wordpress.com/2011/12/19/vcap-dca-uber-awesome-study-guide/

Chad also has a nice set of VCP resources up on his page.

VCDX Defense Preparation

Sean Crookston — Wed, 12 Oct 2011 12:54:00 +0000

I have officially decided that I will target defending for the VCDX in May of next year in Toronto. This may or may not also be the first opportunity to defend for the VCDX 5, however I find it highly unlikely being I haven’t even heard of a beta for the VCAP-DCA/VCAP-DCD5 to date. Incidentally at this time this is also going to be the last change to defend a vSphere 4 design.

While doing a little browsing in the VCDX forum I found an interesting fact. Since November of 2010 there have only been 5 people who have achieved the certification.

The limited growth shows two things:

One the number of individuals defending is obviously going to be limited based on requirements for a VCP/VCAP-DCA/VCAP-DCD and financial restrictions of defending including travel. There are only approximately 400 VCAP-DCA and VCAP-DCD certifications issued, with what I gather to be a high overlap of individuals having both. If I had to guess you are probably only looking at 550-600 people who would be eligible to submit a defense.
Secondly they aren’t just giving these things out to everyone that does defend.

I see the fact that only 5 have been issued in almost the past year not as a point of intimidation but rather a challenge. I currently have a design picked out that I will be using for the defense and will be working over time to put my submission together. Luckily I have until March where anything needs to be submitted.

Over the next 7 months or so I will blog quite a bit about the process and in the end the result that follows.While I of course would like to see this process end in certification, I know that I will learn a great deal along the way regardless.

But don’t take that as a losing attitude, I am fully planning on passing the defense = )

Using VMware View for Server Linked Clone Desktops

Sean Crookston — Mon, 03 Oct 2011 12:34:00 +0000

While playing in my home lab I recently had the idea pop in my mind of if View would support linked cloning of server operating systems. And by support I mean allow as there is no way any of the following is supported by VMware.

There are a number of reason I can think of that would be a good use case. Firstly if there was a need to have a pool of test servers available for quick installation or functionality testing. Secondly for saving some space in lab setups where disk space is of particular concern. The limited space of SSDs become much less of a concern if so.

You may say well lab manager and vCloud Director exist for this. And I would agree with you there. My main concern is simplicity and being I already have View setup and running this would be a very simple solution. Now there does already exist several PowerShell scripts that will create linked clone desktops for you. They work very well but for me my lab becomes so disorganized that the idea of managing my clones through a GUI interface like VMware View is very appealing. Besides its cool.

While I did get View to somewhat work it wasn’t perfect. I still am unable to connect with the View client, which is not something I truly desire but would have been cool. For automatically assigning desktops to individuals this would have been necessary, but logging in via RDP or the vSphere client is more then enough for me. The agent to my surprise installed without issue so I was hopeful it would work but unfortunately it did not.I also found that the only way to get systems to automatically be named was through the use of a customization specification.

Below is what you’ll need to do. Note that I only tested this with vSphere 5 and View 5 and don’t know if it will work any more or less then it does with other configurations. If you’ve tried this before or gotten any further then I have I’d be eager to hear from you.

A requirement for View to even detect the system and snapshot when creating the pool is that it be a desktop operating system. So I also had to change my 2k3 machine to a windows xp hardware profile and my w2k8 server to a Windows 7 hardware profile.
As mentioned above the only way to get systems to be named according to any type of naming pattern was to use a customization spec.

VMware Autodeploy Using Cisco DHCP

Sean Crookston — Wed, 21 Sep 2011 15:12:58 +0000

I have been working in the lab trying to get some hands on time with all of the new features of vSphere 5. Currently on the block is Autodeploy. There are a lot of great resources out there for Autodeploy already and I’ll include some links below. The main purpose however of this entry is to expose an issue I found when using Cisco DHCP scopes. I’ll follow up with saying that most of my experience in DHCP is with Microsoft AD.

When trying to enable options 66 and 67 I could not connect to the PXE Server I received the DHCP address but could not get connected to the TFTP server. The message I received back was PXE-E32 TFTP Open Timeout.

I banged my head against a wall for a bit checking configs, making sure the tftp service was running and making sure I wasn’t missing anything obvious. In a last ditch effort something I read alluded to the below commands that could be used in lieu of option 66 and option 67. After configuring the below for the scope it worked immediately.

next-server 192.168.1.44

bootfile undionly.kpxe.vmw-hardwired

Autodeploy Links

https://www.vmware.com/files/pdf/products/vsphere/VMware-vSphere-Evaluation-Guide-4-Auto-Deploy.pdf

http://kendrickcoleman.com/index.php?/Tech-Blog/using-vmware-autodeploy-for-esxi.html

http://www.yellow-bricks.com/2011/08/25/using-vsphere-5-auto-deploy-in-your-home-lab/

http://www.gabesvirtualworld.com/vsphere-5-auto-deploy-pxe-booting-through-cisco-asa-firewall/

http://ntpro.nl/blog/archives/1819-vSphere-5-Auto-Deploy-Demo.html

vSphere 5 for the SMB

What Happens With VMFS3 LUNs Greater Then 2 TB

Sean Crookston — Mon, 19 Sep 2011 12:00:00 +0000

I had someone run into an issue earlier in the day that I couldn’t’ explain in regards to a datastore size. We found the LUN size itself was greater then 2 TB, which was acknowledged as not being supported but the amount of space that did become available did not make sense.

So we all know that there is a 2 TB-512 LUN size limit for VMFS3, but do you know what size LUN you will be presented with when you present a LUN bigger than this?

Lets say we add a new VMFS3 volume on a presented LUN that is 3,5 or 7 TB? One would expect that you would then receive a 2TB LUN at least, but in actuality you will end up with a 1 TB LUN. How about a 3.5,5.5, or 7.5 TB volume? You would end up with a 1.5 TB LUN in each of these cases.

I looked for a knowledgebase to back this but could only find one community posting which alluded to the LUN size being based on the remainder of what was presented after taking 2 TB chunks out at a time. This means you could end up with some really weird sizes you weren’t expecting.

*Note-Frank Denneman(http://frankdenneman.nl) made an important observation that this information only applies to VMFS3. This entry has been updated to reflect that this information applies to VMFS version 3. VMFS version 5 will support a 64TB LUN.

Gap Analysis VCAP-DCD to VCDX

Sean Crookston — Wed, 14 Sep 2011 12:00:00 +0000

After now passing the VCAP-DCD now have to consider preparing for the VCDX. As I’ve started to think about it I’ve realized I’m going to need basically do a gap analysis of where I’m at now versus what constitutes a successful VCDX submission and then defense.

So what is the difference between someone who is a VCAP-DCD and a VCDX? A few critical things come to mind for me initially, but lets start out with what VMware defines them as on their certification page.

VCAP-DCD

The VCAP-DCD is directed toward IT Architects and Consulting Architects who are capable of designing VMware solutions in a multi-site, large enterprise environment. They have a deep understanding both of VMware core components and their relation to storage and networking, and also of datacenter design methodologies. They also possess knowledge of applications and physical infrastructure, as well as their relationship to the virtual infrastructure.

VCDX

VMware Certified Design Expert (VCDX) is the highest level of VMware certification. This elite group is comprised of design architects highly-skilled in VMware enterprise deployments and the program is designed for veteran professionals who want to validate and demonstrate their expertise in VMware virtual infrastructure.

One main difference of note above is consulting architects vs design architects, however this probably has very little bearing on differentiating between the two. Most importantly what stands out is that the VCDX program is designed for veteran professionals who wish to validate and demonstrate their experience. There is a clear definition here that according to VMware, they are expecting VCDX candidates to be those that are not only experienced, but can demonstrate their experience. Something we probably already knew here.

Now some things that come to mind when I start thinking about where someone goes from being a VCAP-DCD to preparing for a VCDX. These may not apply to everyone of course and these are just my opinions in some cases.

Every VCDX I know of is regularly participating in design exercises as part of their daily job and likely is a customer facing engineer. This is not to say that someone who is not the prior does not have a chance of successfully defending, but it means someone like myself who is an implementation engineer is likely at a slight disadvantage just based on not going through the motions of presenting and defending designs on a day-to-day basis. Additionally as Brian Rice has pointed out in his article on defending a fictitious design, it is important to think like an architect so throughout the process and up to the defense it will be important to play the role, even if you are not presently one.

Those who are regularly presenting to customers and in turn the VCDX panel need to be able to articulate their thoughts. They don’t just know things like the maximum number of servers in an MSCS cluster on vSphere or that you can’t VMotion these machines. They know that these things are constraints to any design and may either be acceptable or not based on the functional requirements of the customer. Additionally it is your job to justify your choices, just because you tell a customer or panelist your decision doesn’t mean it will not be questioned. In terms of the defense I have heard from many about your journey to the answer and not the answer itself.

Design Architects also know that all the information to a design is not going to be given to them. It is their job to meet the customers requirements, and to question and interview to get those requirements. Without doing so vital information will be left out and the design can be deemed a failure by the business.

There is obviously much more to it then that, so please share your thoughts below.

VCAP-DCD Tips and Exam Experience

Sean Crookston — Tue, 13 Sep 2011 12:30:00 +0000

This morning I successfully completed the VCAP-DCD exam and although I read about 30 people’s reviews on the exam, I was definitely not prepared for the questions that were asked, or rather I should say they were a bit different then I was expecting. Additionally this morning I wasn’t quite as focused as I would have liked to have been.

Without going into things that violate NDA ,I will say that certain things people recommended to focus on or complained about related to the beta were not mentioned or barely relevant. Additionally the drag and drop questions and the thoroughness of each question is something to be aware of. For me the most difficult thing to swallow was that many questions are multiple selections, and the questions are very thorough so at times it was hard to know for certain if I completely comprehended the scenario and successfully chose the right answers.

The best thing you can do to prepare for the exam is follow the blueprint and have experience analyzing environments and doing designs. Many have said the Design Workshop was great preparation for the exam and while I feel that course was great, there is not a correlation to any of the content of the course and the exam itself.Overall this makes for a difficult, but worthwhile credential to achieve.

Overall if you think you are ready, book the exam and go take it. If you do not think you ready then you probably need some more time/experience before you attempt this one.

Now on to contemplating the VCDX…