Windows Diego Cells on vSphere Intermittently Crash or display 'Bluescreen'

Products

• VMware Tanzu Application Service for VMs

Issue/Introduction

Symptoms:

Windows Diego Cells intermittently crash, restart, or display a blue screen error.

Error Message: Checking the 'Event Viewer' on the Windows Cell shows a 'Warning' entry relating to a driver:

A TDI filter (\Driver\vnetflt) was detected. This filter has not been certified by Microsoft and may cause system instability.

 

Environment

Cause

The issue is caused by a memory corruption when TCP connections are not handled correctly in the vShield Endpoint TDI Manager driver, 'vnetflt.sys'.

Resolution

The driver is installed, it needs to be uninstalled with VMware Tools to prevent the crashing of cells. This may require a new Windows Stemcell to be created with VMware Tools reinstalled without the problem driver.

This driver is not installed by default in VMware Tools; for example, when installing on the Windows Stemcell, the driver is only installed in one of two ways:

1. Choosing the 'Complete' installation option when installing VMware Tools
2. Choosing the 'Custom' installation option and manually selecting the driver for install.

In order to avoid the driver being installed, ensure the 'Typical' installation option is chosen when installing VMware Tools, or if the 'Custom' option is necessary, ensure the driver 'vnetflt.sys' is not selected for install.