WilliamLam.com

  • About
    • About
    • Privacy
  • VMware Cloud
  • Tanzu
    • Application Modernization
    • Tanzu services
    • Tanzu Community Edition
    • Tanzu Kubernetes Grid
    • vSphere with Tanzu
  • Home Lab
  • Nested Virtualization
  • Apple

VM serial logging to the rescue for capturing Nested ESXi PSOD

03.21.2016 by William Lam // Leave a Comment

I frequently deploy pre-releases of our software to help test and provide early feedback to our Engineering teams. One piece of software that I deploy some what frequently is our ESXi Hypervisor and the best way to deploy it, is of course inside of a Virtual Machine or commonly referred to as Nested ESXi.

Most recently while testing a new ESXi build in my lab (screenshot below is for demo purposes, not the actual PSOD image), I encountered an ESXi purple screen of death (PSOD) during the bootup of the ESXi Installer itself. Since ESXi had not been installed, there was no place for ESXi to actually store the core dumps which made it challenging when filing a bug with Engineering as screenshots may not always contain all the necessary details.

Screen Shot 2016-03-21 at 9.26.08 AM
Luckily, because we are running in a VM, a really neat feature that VMware has supported for quite some time now is configuring a virtual serial port for logging purposes. In fact, one of the neatest feature from a troubleshooting standpoint was the introduction of the Virtual Serial Port Concentrator (vSPC) feature in vSphere 5.0 which allowed a VM to log directly to a serial console server just like you would for physical servers. You of course had few other options of either logging directly to the serial port of the physical ESXi, named pipe or simply to a file that lived on a vSphere Datastore.

Given this was a home lab setup, the easiest method was to simply output to a file. To add a virtual serial port, you can either use the vSphere Web/C# Client or the vSphere APIs. Since this is not something I need to do often, I just used the UI. Below is a screenshot using the vSphere Web Client and once you have added the virtual serial port, you need to specify the filename and where to the store the output file by clicking on the "Browse" button.

vm-serial-logging
If the GuestOS which includes ESXi has been configured to output to a serial port, the next time there is an issue and you can easily captured the output to a file instead of just relying on a screenshot. One additional tip which might be useful is by default, vSphere will prompt whether you want to replace or append to the configured output file. If you wish to always replace, you can add the following VM Advanced Setting and you will not get prompted in the UI.

answer.msg.serial.file.open = "Replace"

Virtual serial ports are supported on both vSphere (vCenter Server + ESXi) as well as our hosted products VMware Fusion and Workstation.

Share this...
  • Twitter
  • Facebook
  • Linkedin
  • Reddit
  • Pinterest

Categories // ESXi, Fusion, Nested Virtualization, Workstation Tags // esxi, fusion, nested, nested virtualization, psod, serial logging, vSphere, workstation

Search

Author

William Lam is a Senior Staff Solution Architect working in the VMware Cloud team within the Cloud Infrastructure Business Group (CIBG) at VMware. He focuses on Cloud Native technologies, Automation, Integration and Operation for the VMware Cloud based Software Defined Datacenters (SDDC)

Privacy & Cookies: This site uses cookies. By continuing to use this website, you agree to their use.
To find out more, including how to control cookies, see here: Cookie Policy

Connect

  • Email
  • GitHub
  • LinkedIn
  • RSS
  • Twitter
  • Vimeo

Support

Recent

  • Quick Tip - Adding a vTPM (Virtual Trusted Platform Module) to a Nested ESXi VM 05/13/2022
  • vSphere Event-Driven Automation using VMware Event Router on VMware Cloud on AWS with Knative or AWS EventBridge 05/10/2022
  • Integrating VMware Event Broker Appliance (VEBA) with Zapier 04/28/2022
  • Using Terraform to activate Tanzu Kubernetes Grid Service on VMware Cloud on AWS 04/27/2022
  • DFI GHF51 - Worlds smallest AMD Ryzen SBC 04/19/2022

Advertisment

Copyright WilliamLam.com © 2022

 

Loading Comments...