A typical problem you may face with the ESXi host is the fatal PSOD error, as shown in the following screenshot:

This crash is a problem that can be related to CPU, RAM, modules, hardware, or a software bug. When you see this error through iDRAC or iLO, you should take a photo or screenshot to support VMware. You can also try checking the VMware KB to find a resolution. Did you experience PSOD after an ESXi upgrade? A possible quick solution to fix this error is to perform an ESXi downgrade. This problem may also occur when you change RAM or firmware in HBA. All of these situations can be potentially problematic for ESXi.

Another way to troubleshoot the problem is to gather maximum information from PSOD, such as the most recent changes in the environment, and restart the ESXi host to create the log bundle requested by the VMware support. The log bundle can be created with a GUI or a CLI with the vm-support command.

Does the PSOD occur only on one ESXi host or all ESXi hosts with Qlogic FC HBA? Is it a specific ESXi build that's affected by the problem? You must know this information because it can help you resolve the root problem.

The worst situation you can face is when the VMkernel is in the stopped status, and the ESXi host is not responding. When the VMkernel is busy and doesn't work correctly, as a possible solution, you can try to reboot the host. After rebooting the ESXi, it is very important to gather logs and performance statistics for the support.