Using the local debugger to review logs after an ESXi host fails with a purple diagnostic screen

Products

• VMware vSphere ESXi

Issue/Introduction

When an ESXi host encounters a critical error and halts with a purple diagnostic screen, it attempts to dump diagnostic information to disk or via the network. If these attempts are unsuccessful due to configuration errors or critical failures, not much troubleshooting information is available.

The purple diagnostic screen contains messages similar to:

• "Escape" for local debugger.
• Press Escape to enter local debugger.
  

In such cases, you can use the ESXi local debugger to review the VMkernel logs to determine the cause of outage.

Notes:

• The same information is also available via the serial port. For more information, Enabling serial-line logging for an ESX or ESXi host (1003900).
• Interpretation of the VMkernel log messages obtained using this method is outside the scope of this article.

Symptoms:

Environment

VMware ESXi 4.1.x Embedded
VMware ESXi 4.0.x Installable
VMware ESXi 3.5.x Installable
VMware vSphere ESXi 5.0
VMware ESXi 4.0.x Embedded
VMware ESXi 3.5.x Embedded
VMware vSphere ESXi 5.5
VMware vSphere ESXi 5.1
VMware ESXi 4.1.x Installable

Resolution

The vSphere ESXi local debugger can be used to review logs following a critical failure and purple diagnostic screen.

To review logs using the ESXi local debugger:

1. At the purple diagnostic screen on the ESXi host, press the Escape key on your keyboard. The console switches to a black screen titled vmkernel debugger (h for help).
2. Type l and press Enter on your keyboard to display the VMkernel log.
3. Use the PgUp, PgDn, and arrow keys on your keyboard to scroll through the VMkernel log.
4. Take screenshots or notes of key information from the VMkernel logs preceding the purple diagnostic screen.
5. Press the Escape or q key on your keyboard to exit the log viewer.
6. Search for log messages or review Interpreting an ESX host purple diagnostic screen (1004250) to interpret available information.

The vSphere ESXi local debugger can be used to soft-reboot the ESXi host after a critical failure and purple diagnostic screen.

To soft-reboot the host using the ESXi local debugger:

1. At the purple diagnostic screen on the ESXi host, press the Escape key on your keyboard. The console switches to a black screen entitled vmkernel debugger (h for help).
2. Type r or reboot and press Enter on your keyboard to reboot the host.

Additional Information

Enabling serial-line logging for an ESXi/ESXi host
Interpreting an ESX/ESXi host purple diagnostic screen