vPivot

Scott Drummonds on Virtualization

Alternative to DRS

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Now that I am six months removed from VMware, I will admit that we executed poorly in the space of performance management.  I know that there is intense work going on right now in acquisitions, unification of performance management tools, and vCenter improvement through folding in vscsiStats and esxtop data.  But in the area of performance reporting and visualization, VMware’s success has been minimal.  VMware hopes its acquisition of AliveVM will plug part of this gap but today it is safe to say the field is wide open for VMware’s partners.

This morning one such partner, VMTurbo, gave me a demonstration of their offering in this field.  Their product provides an obvious improvement on vSphere’s performance visualization capabilities.  But given the state of VMware’s visualization capabilities virtually any graphical front-end provides an improvement.  But what really set off my imagination were two features I had not seen before:

  • A third-party alternative to DRS.
  • Cross-cluster resource optimization.

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Storage Consolidation (or: How Many VMDKs Per Volume?)

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Part of the performance best practices talk I co-presented at VMworld in San Francisco and Copenhagen focused on answering the question, “How many virtual machines can be placed on a single VMFS volume?”  There are a lot of theories as to a best answer.  It will not surprise you to learn that no single consolidation ratio works in every environment.  Your workloads will influence the maximum consolidation.  But we know enough about how ESX virtualizes storage to provide guidance as to the right storage consolidation ratios.

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Performance Troubleshooting Made Simple

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I have struggled for years to give VMware’s customers a framework for diagnosing performance problems. People want a simple system to troubleshoot the unknown sources of poorly performing applications. The best attempt at documenting such a flow is Hal Rosenberg’s document on vSphere performance troubleshooting. Elegant as it may be, Hal’s document remains complex for the novice VI administrator.  And it is because that document is so complex that performance people maintain their job security. 🙂 But in an effort to further obviate my own job, I will try and generalize the troubleshooting flow to add more clarity to the process.

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How Many Virtual CPUs Per VM?

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Virtual machine sizing is a tricky issue for many VMware administrators. It is important to find the right number of virtual CPUs to maximize application performance and minimize wasted CPU cycles. The optimal number of vCPUs can never be easily identified. But I can offer a few suggestions to help get this number right.

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Processor Utilization Calculations

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A little Friday esxtop trivia for the performance massive: did you ever notice your Hyper-Threaded systems have three rows showing CPU utilization in the CPU panel header?  They are labeled “PCPU USED(%)”, “PCPU UTIL(%)”, and “CORE UTIL(%)”.  Here is a screen shot to jog your memory:

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esxplot 1.0 Released

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I am pleased to announce that Geoff White has completed the first official release of esxplot, version 1.0.  In an earlier blog article we discussed a beta version of this product and the response from VMware’s customers has been fantastic.  Those of you that have played with esxplot know its value in assisting with esxtop-based analysis.  I urge everyone to download the new version and give it a try.

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Optimizing Memory Utilization

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My recent series of blog articles have discussed ESX memory management the the performance specter of host swapping. My last article attempts to correct the misconception that VMware recommends against over-commit memory.  In that article I suggested that memory over-commit is requirement in optimizing memory utilization. Today I want to provide a specific example to show why this is true.   I am have also included tips for identifying host swapping in your environments.
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Solid State Disks and Host Swapping

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Recently I have been thinking, talking, and writing about ESX host memory swapping a lot.  ESX swaps memory under the same conditions that traditional operating systems do; the application(s) is using more memory than available on the physical hardware.  Host swapping is an unavoidable consequence of this condition, whether virtualization is present or not.

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esxtop Analysis With esxplot

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esxtop remains a popular performance troubleshooting tool because of its fine granularity, expansive counter list, and support for interactive and off-line analysis. The biggest problem with esxtop is the huge CSV files generated in batch mode.  The output is so large that Excel is unable to open the file and Perfmon can take hours to do so. But now we have a better way to manage esxtop batch files.

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Micro-bursting and Storage Performance

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I have been reading Chad Sakac’s article on IO queues and micro-bursting for months now.  Chad is wicked technical for a manager type and after reading this post a dozen times I think I finally have it internalized.   Let me put my own spin on this tome, embedded in which are several jewels of wisdom.

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