A vSphere cluster with two ESXi hosts may see three vSphere Cluster Services (vCLS) virtual machines

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:
A vSphere DRS cluster containing two ESXi hosts may show three vCLS virtual machines instead of two per the product documentation .

This is reported in vCenter Server 7.0 Update 1 and later.

Environment

VMware vCenter Server 7.0.x

Cause

This is a known issue and harmless for the operational purposes of vSphere. vCLS is limited to three virtual machines per cluster and will not exceed this value.

Resolution

The issue is resolved in vCenter Server 7.0 Update 3 (build number 18700403)

Workaround:
The following workaround may be performed, however a third vCLS virtual machine may be deployed depending on operations performed in the future.

Disable vCLS on a Cluster via Retreat Mode

One operation that appears to cause this is if an ESXi host is disconnected/removed and then re-added to the vSphere Cluster. This could cause the slot calculation to change which may have EAM deploy a new vCLS virtual machine.

Additional Information

vSphere Cluster Services (vCLS) in vSphere 7.0 Update 1 and newer versions

Impact/Risks:
There is no risk to having an additional vCLS virtual machine in the cluster.