This article explains the Data Protection Health - vSAN data protection service health check in the vSAN Health Service and provides details about why it might report an error.
VMware vSAN 9.0 and higher
It checks the data protection service health and its connection status with vCenter server when vSAN data protection is enabled on at least one of the clusters in vCenter server.
Either the vSAN data protection service is down or communication issue is detected with the vCenter Server. Appliance health data is like a heartbeat sent to vSAN health service every 30 seconds indicating that vSAN data protection service is alive and kicking. If vSAN data protection service fails to send the heartbeat in regular intervals the last heartbeat must expire after 1 min and vSAN health service must indicate that the vSAN data protection service down event to vSAN Health.
To fix the error state from this health check, you should diagnose and address the root cause of why the vSAN Data Protection service is down or why there is a communication issue between the vCenter Server and the vSAN Data Protection service.
There could be several reasons why the communication is lost. Follow the steps to diagnose issue.
The overview card as error state:
The details table shows the overview status of data protection service and some guides to diagnose the issues: