vSAN Health Test 'Site latency health' status changed from 'green' to 'yellow'

Products

• VMware vSAN

Issue/Introduction

vSAN Health Test 'Site latency health' status changed from 'green' to 'yellow'.

Environment

• vSAN 7.X
  vSAN 8.X

Cause

This event could be triggered if at least one of three conditions is met.

1. Latency between the Witness Node and any ESXi host in the Primary Site exceeds 200 ms.
2. Latency between the Witness Node and any ESXi host in the Secondary Site exceeds 200 ms.
3. Latency between any ESXi host in the Primary Site and any ESXi host in the Secondary Site exceeds 5 ms.

This can be caused by faulty or overloaded network infrastructure (switches and routers), or host connected components such as NICs, cables, or ports.

Resolution

Check the network path for where the delay is introduced and address with the customer hardware or network teams.

Additional Information

Networking Requirements for vSAN

・Maximum of 1 ms RTT for single site (non-stretched) vSAN clusters between all hosts in the cluster
・Maximum of 5 ms RTT between the two main sites for vSAN stretched clusters
・Maximum of 200 ms RTT from a main site to the vSAN witness host