vSAN Skyline Health: Network diagnostic mode (Warning)

Today, I saw the above warning in vSAN Skyline Health, and I would like to share the solution with you.

The following information can be found under Details:

Network diagnostic mode is enabled more than 24 hours (94 hours). The network diagnostic mode is only used for troubleshooting, if the troubleshooting is done, please disable it.

No sooner said than done, we switch to the Configure level, there to vSAN Services and under Performance Service we see that the Network Diagnostic Mode is enabled.

As soon as we click on EDIT, we already see a warning:

The network diagnostic mode will collect the network metrics every 1 second for the last 30 minutes to help with troubleshooting. When enabled, the network data within 30 minutes will not be displayed. Check back the network performance metrics after 30 minutes. This mode is only for troubleshooting. It should not be enabled for a long time because it will consume extra CPU and memory resources to do the troubleshooting work. Please turn off the network diagnostics mode when the troubleshooting is done.

To be honest, I don’t even know why I switched on Network Diagnostics Mode – Normally, VMware Support will ask you to activate this mode. So we disable it, a quick update to our vSAN configuration occurs, and the warning in vSAN Skyline Health disappears.

Here you can find a KB article about Network diagnostic mode: https://knowledge.broadcom.com/external/article/326418/vsan-health-service-performance-service.html#:~:text=Network%20diagnostic%20mode%20allows%20the,as%20directed%20by%20VMware%20Support.

And that’s it for this short, snappy blog article, if you have any questions, please use the comment section below. 🙂