Performance Troubleshooting for VMware vSphere 4 and ESX 4.0

Performance Troubleshooting for VMware vSphere 4 and ESX 4.0

Performance problems can arise in any computing environment. Complex application behaviors, changing demands, and shared infrastructure can lead to problems arising in previously stable environments. Troubleshooting performance problems requires an understanding of the interactions between the software and hardware components of a computing environment. Moving to a virtualized computing environment adds new software layers and new types of interactions that must be considered when troubleshooting performance problems.

The attached document is the first installment in a guide covering performance troubleshooting in a vSphere environment. It uses a guided approach to lead the reader through the observable manifestations of complex hardware/software interactions in order to identify specific performance problems. For each problem covered, it includes a discussion of the possible root-causes and solutions. Topics covered include performance problems arising from issues in the CPU, memory, storage, and network subsystems, as well as in the VM and ESX host configuration. Guidance is given on relevant performance metrics to observe using the vSphere Client and esxtop in order to isolate specific performance issues.

This first installment of Performance Troubleshooting for VMware vSphere 4 covers performance troubleshooting on a single VMware ESX 4.0 host. It focuses on the most common performance problems which affect an ESX host. Future updates will add more detailed performance information, including troubleshooting information for more advanced problems and multi-host vSphere deployments.

This is a living document. Reader comments, questions, and suggestions are encouraged.


Thanks for writing such a good document !

Kind Regards,


This is a must read! Very good. My suggestion for a future version of this document is evaluate how vCenter AppSpeed fits into the picture. When is it helpful? When is it optional?


Thank you from Singapore.

Great doc ... it lays out the fundamentals in a clear concise manner.

In my organization I have lots of server engineers who are not necessarily VM experts but do have to troubleshoot performance issues with server (VM or physical). I've been looking to create docs to help guide their efforts and direct them in understanding how the virtualization layer may be contributing to potential problems.

I'd love to see this document (or a version thereof) put up as a sort of troubleshooting workflow 'wizard' ... I work in a large org where lots of folks may do troubleshooting. They may not all be able (or willing) to read the entire doc, but a question-drive tool of sorts that could guide their troubleshooting workflow would be very very cool.

Very good document for someone new to troubleshooting performance in a virtualized environment.

Looking forward to seeing information that includes DRS enabled clusters.

There are several references to "... average above 75%" or "... peaks ... above 90%". For those interesting in setting up monitoring or reporting for these utilization metrics what time period is recommended for calculating "average" and "peak"?


This should be required reading for every Sys admin setting up ESX Systems. It would save alot of pain and suffering...


I've created a presentation, this presentation has cost me a lot of time to prepare but it was a joy to build it. I’ve been working on it for two months. Besides delivering training on a daily basis, I’ve spent every free minute on doing research, gathering screenshots and creating awesome graphics. Two valued virtualization colleagues have reviewed the presentation so I want to thank Rawlinson Rivera and Harold Schoofs for their great feedback. vSphere  Advanced Troubleshooting has been presented during my VMware training courses for five times, so from this place many thanks to all my students for their great feedback in the past weeks. I’ve uploaded the presentation to SlideShare but you can also get a copy here: AdvancedTroubleshooting.pdf - 50 slides of awesomeness from start to end, I hope you enjoy it.

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‎07-13-2009 07:03 AM
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