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 troubleshooting guide covers 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.
In particular, the troubleshooting guide covers performance troubleshooting on a VMware vSphere 4.1 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.
http://blogs.vmware.com/performance/2011/02/perf-troubleshooting-41.html
