vSAN node disk group shows unhealthy after re-installing ESXi on it

Products

• VMware vSAN

Issue/Introduction

Symptoms:

After re-installing the OS on the vSAN nodes, the disk groups are showing as unhealthy.

By navigating to vSAN cluster > Configure > vSAN > Disk Management, we see the disk group status as below:

Environment

VMware vSAN (All Versions)

Cause

This can happen if the hosts are not part of the vSAN cluster.

The same can be verified by running the below command:

[root@hostname:~] esxcli vsan cluster get

vSAN Clustering is not enabled on this host

Resolution

Add these hosts to the existing vSAN cluster by using the below command:

esxcli vsan cluster join -u sub_cluster_UUID

Refer below kb article for more information on how to add a host to vSAN cluster:

How to add a host back to a vSAN cluster after an ESXi host rebuild/reimage