Cannot configure vSAN on a cluster with previously enabled vSAN capacity reservation.

Products

• VMware vSAN

Issue/Introduction

The purpose of this article is to describe this issue and to provide a viable workaround.

Symptoms:

If vSAN is disabled on a cluster with a Host Reserve or Operational Reserve having previously been set, attempting to re-enable vSAN on the cluster will fail with the following warning:  

"Configuring fault domains on a vSAN cluster with capacity reservation enabled is not supported."

 

Environment

VMware vSAN 8.0.x

Cause

This issue is due to vCenter incorrectly parsing the cluster configuration when attempting to re-enable vSAN workflow.

Resolution

VMware Engineering are aware of this issue, a fix has been implemented and is due to be released as part of vSphere 8.0 U3.

Workaround:

In the Fault Domain section of the Configure vSAN workflow, create a Fault Domain for each node in the cluster. Each Fault Domain should include only one node.

 

This will allow the workflow error to be passed and vSAN enabled again. 

 

Once complete, the Fault Domains can be removed by simply navigating to the Fault Domain Configure section and dragging each Host from it's respective Fault Domain back to "Standalone Host" section.

Additional Information

Impact/Risks:

If Host Reserve or Operational Reserve have been configured on a cluster and vSAN is subsequently disabled, re-enabling will fail with an error message.