My ramblings about all things technical


VMware vSphere: Manage for Performance Course Experience

Last week I was fortunate enough to be able to attend the VMware vSphere: Manage For Performance course. I did the lab related to this course at VMworld Europe last year and in my now increasing preparations for the VCAP-DCA exam I knew I needed to strengthen my troubleshooting skills and more importantly fine tuning my ESXTOP/RESXTOP skills. Quite a few people commented that they really liked my VMware vSphere: Manage and Design for Security Course Experience posting so I thought i would try do the same for this one for anyone interested or thinking about booking the course.

  1. Day one covered the first three and a half modules Course Introduction, Performance in a Virtualized Environment, Virtual Machine Monitor and part of CPU Performance. It introduced you to all the monitoring tools you can use with an introduction to the performance graphs in Virtual Centre and ESXTOP,how to utilise these tools to work out possible problems and what to look for that may be good indicators of problems. Probably the thing I enjoyed the most about this course was that there was loads of labs for you to learn how to do it all yourself rather than learning it off a PowerPoint sheet or your course guide. If you are a regular reader of this blog then you’ll know I’ve been trying to perfect my knowledge of ESXTOP/RESXTOP and wrote a blog about it too “Understanding and using ESXTOP/RESXTOP”. This learning of it was a great stepping stone for the skills they covered in the course and for a few parts the links and resources in my blog gave me an even deeper knowledge of ESXTOP. For the virtual machine monitor module it covered Software and hardware virtualisation techniques which i knew fairly well from my studying for my VCP exams and the labs for it were really great in covering how the usage of these varying techniques can really help with the performance of your virtual machines/environment. Next we got into a bit of the CPU Performance module which introduced the CPU scheduler, CPU Cache contention and the NUMA. As with the hardware/software virtualisation techniques i had a good bit of knowledge about the CPU scheduler and NUMA from my VCP studies but it was a great refresher on the NUMA particularly and allowed me to better understand how it works and how the misallocation of resources can impact your virtual machines due to NUMA. Frank Denneman has done two brilliant postings all about the sizing of VM’s and NUMA Nodes and ESX 4.1 NUMA Scheduling which covers pretty much everything you need to know about this feature and how to use it correctly in your environment.
  2. Day 2 we finished off CPU Performance by learning how to use ESXTOP and the performance metrics in vCentre to find and recognise possible cpu problems and how to fix them. Next we covered Memory Performance which was fairly straight forward in my opinion but did give great recommendations on how to utilise your memory effectively and how ballooning and memory swapping works and what the increase of these values means to the performance of your environment. Yet again Frank Denneman has covered these topics brilliantly in two blog postings Memory reclamation, when and how? and Disable ballooning? which I’ll personally be rereading through myself so as to better my understanding of how it can help/impact my virtual machines. Next we did the Network Performance module which covered all the varying network card options you can select,what each allows you to do,what additional features each one gives and how these features work. This was also a refresher for me due to my VCP studies but it did seem to alert a lot of the people on the course with me to the benefits of upgrading all your virtual machines to hardware version 7 and changing their network cards to VMXNET3. VMware have a great KB article on this Choosing a network adapter for your virtual machine. For the rest of the module it was yet again teaching you how to find and troubleshoot possible network problems using the performance charts and ESXTOP.
  3. Day 3 finished off the last three modules Storage Performance,Virtual Machine Performance and Application Performance. Storage performance was good and was very interesting to hear how many people don’t use thin provisioning due to their belief that it impacts performance in certain ways. I’m not going to get into it on here and I agree it does in certain instances but like I said to the people on the course with me I would recommend reading  the VMware white paper on it first and make your own decisions from there. There are also loads of top blog postings on the subject so I would also recommend reading a few of those (Duncan Epping’s and Eric Gray’s in particular). For the last two modules of Virtual Machine Performance and Application performance these were essentially just applying what you learn for cpu,memory and network to your virtual machines and what to consider for the virtualising of differing applications.

Funnily enough whilst on the course the latest release of the vSphere performance troubleshooting guide for 4.1 came out which is perfect post course reading material for me. Duncan Epping’s posting alerted me to the release so only right to point to his posting here.

Well that’s a high level review of what I learnt/was covered in the course. As with any course though what you get out of the course is very dependant on your knowledge of the product/s and even though I have a fairly good amount of knowledge on the product and features I did still learn a fair amount and it was a really great refresher on certain features in preparation for my VCAP: DCA exam sitting.



Understanding and using ESXTOP/RESXTOP

Lately I’ve noticed more and more people referring to stats and figures they have collected on their environments via ESXTOP/RESXTOP. I learnt about esxtop for my vcp exams but I have to be honest I haven’t really used it in my environment and recently I felt that I was surely denying myself and thereby the possible performance advantages for my environments by not using this tool to try find and fix any performance problems my vm’s/hosts may be experiencing.

I thought I would try write up a blog posting detailing everything  I had learnt but as is normally the case  some of the top bloggers out there have already beaten me to it and done such amazing jobs of it there’s no real reason for me to to do it. So instead I have collated all the information I have used to strengthen my knowledge on this tool and how it can help every virtual infrastructure administrator and or user to get the most out of their virtual machines and servers, especially with the imminent removal of the COS.

First is the ultimate resource for reference and learning what is possible with esxtop(I’m still amazed how much this tool can do and with update 2 there’s even more functionality). This VMware communities document has everything you could ever want to learn and know for esxtop and is staggeringly detailed whilst still being updated to include new functionalities and options. I’ve only managed to absorb some of the information off this document so far as it’s so much to learn and take in.

Next is a brilliant posting by Duncan Epping of Yellow Bricks fame all about the usage of ESXTOP and how he has utilised it with perfmon to retrieve all the desired data he needs for troubleshooting problems.

Jason Boche has also done a posting all about the capabilities of drilling down through the performance metrics to get very specific results.

Forbes Guthrie has done a brilliant vReference card for all the performance metrics you will see in your performance troubleshooting and monitoring. A very helpful “print out” capable card for quick reference as the same implies 🙂

Simon Long of The SLOG fame has done a very interesting posting all about using ESXTOP with VMware ESXi and is a very interesting look and example of how to do this monitoring once the COS is gone and ESXi is the only dominant host type. This kind of example is one of the main reasons I knew I needed to brush up my ESXTOP skills.

Kedrick Coleman pointed me to a very nice tool by VMware labs called ESXPlot which “is a GUI based tool that lets you explore the data collected by esxtop in batch mode”. I am yet to test this out but it looks like a very helpful tool in getting your performance data into once easy to monitor and even better to show to the boss/upper management the performance statistics of your environments/specific machines

Lastly if you were fortunate enough to attend or have a subsciption to the VMworld 2010 sessions then I would HIGHLY recommend the Troubleshooting using ESXTOP for Advanced Users session

Hopefully some of the resources help people strengthen their knowledge of ESXTOP/RESXTOP.

Gregg Robertson