Starting with vSphere 7.0 Update 2, you may have noticed a new "Enable monitoring events" setting when configuring time for your ESXi hosts, whether that is using the classic Network Time Protocol (NTP) or the newly introduced Precision Time Protocol (PTP).
What exactly does this enabling this setting do? This was a recent question that I had answered internally and figured I would share the detail as the description may not be super clear. Simply put, this enables the publishing of different NTP and/or PTP operations as vCenter Server Events, which can then be used to audit time skews in your environment for compliance to troubleshooting or debugging.
Below is a screenshot of the vSphere UI under the Events view for an ESXi host after enabling the monitoring events setting. We can now see new NTP events for when there is clock skew that has been corrected to synchriapzation to upstream time source.
As of this blog post, there are currently a total of 13 possible NTP and/or PTP events that can be be emitted from vCenter Server. For the complete list of NTP/PTP operations, please refer to this resource and search for the keyword "esx.problem.clock" for different event types and description. In addition to viewing these events within the vSphere UI, customers can also configure alarms and notification (Slack, Microsoft Teams, etc.) for specific NTP/PTP events using the VMware Event Broker Appliance (VEBA) solution which nicely compliments this new feature in vCenter Server.
David Bass says
How does one enable monitoring events on a host that was upgraded to 7U2 or later? It isn't obviously in the ntp settings or the advanced settings.
William Lam says
This feature is part of vCenter Server and configured when selecting desired ESXi host and under Configure->System->Time Configuration