Enabling vSAN OSA fails where vSAN ESA was previously enabled and storage pools still exist.

Products

• VMware vSAN 8.x
• VMware vSAN

Issue/Introduction

When attempting to enable vSAN OSA on a vSphere cluster, if the nodes were previously used in a vSAN ESA cluster and the storage pools were not removed prior to disabling vSAN/moving the node to new cluster. then enabling vSAN OSA will fail.

This will fail with Status 'General vSAN error. vSAN can not be enabled as there are storage pool disks on <hostname>' where each <hostname> listed is a node that still has storage pools configured.

Environment

ESXi 8.x

vSAN 8.x

Cause

vSAN OSA and vSAN ESA are not inter-compatible - if changing from vSAN ESA to OSA (or moving a node that was previously in a vSAN ESA cluster) then all storage pools should be evacuated and removed before doing so.

This also applies for changing from vSAN OSA to vSAN ESA.

Resolution

Ensure that there is no data required from the disks claimed for use as vSAN ESA storage pools, removing storage pools deletes any data that was stored on these disks and is irreversible.

Remove the storage pools on all nodes that have these configured.

This can be achieved by either:

1. Temporarily enabling vSAN ESA on the cluster then removing these via Cluster > Configure > vSAN > Disk Management > Select node > VIEW DISKS > Select disk > REMOVE DISK , then once all storage pools have been removed, disable vSAN (Cluster > Configure > vSAN > Services > TURN OFF VSAN) and enable vSAN OSA (deselect vvSAN ESA slider on initial Configure vSAN UI).

Or 

2. Identify all disks with storage pools enabled on them via SSH to each node:

# vdq -Hi

# esxcli vsan storagepool list

# esxcli vsan storagepool remove -d <device_id>

Proceed with enabling vSAN OSA.