vSAN Skyline Health warning - vSAN Cluster Partition - vSAN Witness Appliance

Products

• VMware vSphere ESXi

Issue/Introduction

vCenter vSAN Skyline Health Alarm Network Health - vSAN Cluster Partition has triggered.

The alert shows that there is a duplicate entry for the vSAN witness host.

One entry shows the witness host as part of the vSAN cluster and the second entry in it's own partition separate from the vSAN cluster as seen in the below screenshot, essentially a split-brained scenario.

 

Environment

VMware vSAN (All Versions)

Cause

This was caused due to required vSAN port 2233 is blocked via a firewall not allowing proper communication between witness hosts and the data hosts.

 

Resolution

Engage your networking team and ensure all required vSAN ports are open bidirectionally so that ESXi data hosts and ESXi witness host are able to communicate properly.

See KB vSAN Witness appliance partitioned from the stretch cluster to help troubleshoot the network connectivity between the vSAN witness host and the data hosts.