Permanently disable ESXi coredump file

Products

• VMware vSphere ESXi

Issue/Introduction

This article provides steps to configure a network coredump collector and permanently disable coredump file.

Symptoms:
This procedure is useful for any of these symptoms:

• No supported storage is available to ESXi for core dump location (software iSCSI and software FCoE are not supported).
• A datastore fills up due to the automatic creation of core dump file. This happens when no suitable dump file or dump partition exists.
• Even after deletion of the core dump file, once the ESXi is rebooted, the file is recreated.

Environment

VMware vSphere ESXi 8.0
VMware vSphere ESXi 7.0
VMware vSphere ESXi 6.7
VMware vSphere ESXi 6.5
VMware vSphere ESXi 6.0

Cause

Any ESXi host since VMware vSphere ESXi 5.5 automatically creates a file to extend the core dump partition when no suitable dump file or dump partition exists. This core dump is created on a random VMFS datastore using a smart selection algorithm.

Resolution

Note: Please keep in mind that for troubleshooting purposes core dumps can be required. Therefore please make sure not to disable the local core dump file of any ESXi before first configuring network core dumps as in step 1 below:

1. Configure ESXi host to use a network core dump collector by running these commands:

   # esxcli system coredump network set --interface-name vmkX --server-ipv4 X.X.X.X --server-port 6500
   # esxcli system coredump network set --enable true

2. Disable and delete the currently configured coredump file:

   # esxcli system coredump file set --enable false
   # esxcli system coredump file remove --force

3. Disable autoCreateDumpFile:

   # esxcli system settings kernel set -s autoCreateDumpFile -v FALSE

4. You can check the setting with the following command:

   # esxcli system settings kernel list -o autoCreateDumpFile

5. Reboot the ESXi host.

Additional Information

For further information please refer to the following documentation sections:

Configure ESXi Dump Collector with ESXCLI
Set Up a File as Core Dump Location

Impact/Risks:
A core dump is the state of working memory in the event of host failure. It is needed in the investigation of an issue. If the core dump file is disabled, a network core dump collector should be configured.