Configuring an ESXi host to capture a VMkernel coredump from a purple diagnostic screen

Products

• VMware vSphere ESXi

Issue/Introduction

This article provides an overview of configuring VMware ESXi with a location for storing diagnostic information during a purple diagnostic screen and host failure.

Environment

6.x
7.x

Resolution

During a host failure with a purple diagnostic screen, VMware ESXi attempts to save diagnostic information to one or more pre-configured locations. The available target locations and the methods to configure the host differ between versions of ESXi.

If the host is configured with a location for saving a coredump, but does not successfully record a coredump during a purple diagnostic screen, there are issues with either the storage medium or the connection to the storage medium. Configure an alternate target for saving the coredump to successfully capture diagnostic information from a subsequent outage.
 

Host Configuration

• Network Dump Collection
  
  ESXi hosts dump diagnostic information to a Network Dump Collector service through the network. For more information, see:
   
  • Configuring the Network Dump Collector service in vSphere(2002954)

• Disk Dump Collection
  
  ESXi 6.0-8.0 hosts dump diagnostic information to a partition on disk, including local or remote block devices. For more information, see:
   
  • Configuring a diagnostic coredump partition on an ESXi host (2004299).
  • Coredump to file. ESXi 5.5 and later hosts can be configured to generate a coredump to a file located on a VMFS datastore. For more information, see Configuring ESXi coredump to file instead of partition (2077516).
  
  Notes:
  • ESXi 5.5 introduces dump to file. For more information, see Configuring ESXi coredump to file instead of partition (2077516). This feature is introduced to remove the 100MB limitation which most of the time causes the dump to be truncated. Using the automatic sizing is the recommended way to configure dump to file and never results in a truncated dump.
  • ESXi 7.0 introduces a VMFS-L based ESX-OSData system volume which provides storage for coredumps to file, logs, and system configuration. During install and upgrades, a coredump to file is configured automatically to save dumps on this volume.