vSAN Witness Appliance fails to deploy after encountering a host hardware issue while applying upgraded licenses.

Products

• VMware vSAN
• VMware vSAN 8.x

Issue/Introduction

Symptoms:

• You had a hardware issue while applying the upgraded licenses to a 2 node stretched cluster while performing an upgrade from vSAN 7.x to 8.x.
• After correcting the hardware issue and applying the licenses, you deploy the updated (8.x)  witness appliance, but it is failing with error: "Failed to add witness host to stretched cluster":

• When you view the vSAN cluster members in the esxcli vsan cluster get, you see that the witness is part of the cluster despite the failed task.
• The cluster is functional, but it is showing as a single site in the Fault Domains (Cluster -> Configuration -> vSAN -> Fault Domains).

Environment

• VMware vSAN 8.x

Cause

• The vSAN cluster object in vCenter is out of sync with the hosts, so is in a "half-configured" state due to interruption during the initial replacement attempt.
• Examples of events that could lead to such a result are hardware failure, network failure, power issues, etc.

Resolution

• You will need to create a new cluster in the vCenter, then migrate the vSAN nodes to the new cluster.
• Please follow the steps in the following KB article to migrate the vSAN nodes to the new cluster:

Moving a vSAN Cluster from one vCenter Server to another (= Migrating )