To troubleshoot your implementation of vSphere, identify the symptoms of the problem, determine which of the components are affected, and test possible solutions.

Identifying Symptoms
A number of potential causes might lead to the under-performance or nonperformance of your implementation. The first step in efficient troubleshooting is to identify exactly what is going wrong.
Defining the Problem Space
After you have isolated the symptoms of the problem, you must define the problem space. Identify the software or hardware components that are affected and might be causing the problem and those components that are not involved.
Testing Possible Solutions
When you know what the symptoms of the problem are and which components are involved, test the solutions systematically until the problem is resolved.

How Do You Identify the Symptoms

Before you attempt to resolve a problem in your vSphere implementation, you must identify precisely how it is failing.

The first step in the troubleshooting process is to gather information that defines the specific symptoms of what is happening. You might ask these questions when gathering this information:

  • What is the task or expected behavior that is not occurring?
  • Can the affected task be divided into subtasks that you can evaluate separately?
  • Is the task ending in an error? Is an error message associated with it?
  • Is the task completing but in an unacceptably long time?
  • Is the failure consistent or sporadic?
  • What has changed recently in the software or hardware that might be related to the failure?

How Do You Define the Problem Space

After you identify the symptoms of the problem in your vSphere implementation, determine which components in your setup are affected, which components might be causing the problem, and which components are not involved.

To define the problem space in an implementation of vSphere, be aware of the components present. In addition to VMware software, consider third-party software in use and which hardware is being used with the VMware virtual hardware.

Recognizing the characteristics of the software and hardware elements and how they can impact the problem, you can explore general problems that might be causing the symptoms.

  • Misconfiguration of software settings
  • Failure of physical hardware
  • Incompatibility of components

Break down the process and consider each piece and the likelihood of its involvement separately. For example, a case that is related to a virtual disk on local storage is probably unrelated to third-party router configuration. However, a local disk controller setting might be contributing to the problem. If a component is unrelated to the specific symptoms, you can probably eliminate it as a candidate for solution testing.

Think about what changed in the configuration recently before the problems started. Look for what is common in the problem. If several problems started at the same time, you can probably trace all the problems to the same cause.

How Do You Test Possible Solutions

After you know the symptoms of the problem in your vSphere implementation and which software or hardware components are most likely involved, you can systematically test solutions until you resolve the problem.

With the information that you have gained about the symptoms and affected components, you can design tests for pinpointing and resolving the problem. These tips might make this process more effective.

  • Generate ideas for as many potential solutions as you can.
  • Verify that each solution determines unequivocally whether the problem is fixed. Test each potential solution but move on promptly if the fix does not resolve the problem.
  • Develop and pursue a hierarchy of potential solutions based on likelihood. Systematically eliminate each potential problem from the most likely to the least likely until the symptoms disappear.
  • When testing potential solutions, change only one thing at a time. If your setup works after many things are changed at once, you might not be able to discern which of those things made a difference.
  • If the changes that you made for a solution do not help resolve the problem, return the implementation to its previous status. If you do not return the implementation to its previous status, new errors might be introduced.
  • Find a similar implementation that is working and test it in parallel with the implementation that is not working properly. Make changes on both systems at the same time until few differences or only one difference remains between them.