A bug was discovered that caused an ESX PSOD on a host if you try to upgrade it to vSphere 4.0 Update 1 AND you have third-party management agents installed on the host. The details are in the VMware knowledge base KB1016070 article.
This bug offers two reminders of practices that should be followed when possible.
- Don’t update your ESX hosts right away when a new update number is released. Give it 3-6 months and follow the community for serious bug information.
- Try to keep third-party agents out of your Service Console. Some will say that they are there to alert the administrator of “failures.” However, that does absolutely no good if they cause the failures themselves.