vSAN policy application fails after change to Host mirroring in 2-node cluster

Products

• VMware vSAN

Issue/Introduction

Customer unable to apply new storage policy; error indicates missing disk groups as indicated in the below screenshot.

Environment

ESXi 8.0.3 

Cause

The "Host mirroring - 2 node cluster" rule defines the number of additional failures that an object can tolerate after the number of failures defined by Failures to Tolerate (FTT) is reached. Because vSAN performs this secondary object mirroring at the disk group level, each data host must contain a minimum of three disk groups (or three disks in a storage pool for vSAN Express Storage Architecture). The error occurs because the underlying hosts lack the minimum requisite disk groups to satisfy the storage policy.

Resolution

        For a two-node cluster using Host Mirroring policy, ensure each host meets the following requirements:

• Minimum of three disk groups per host.
  
  
• Alternatively, three disks in a storage pool (if using vSAN Express Storage Architecture).

 

Additional Information

https://techdocs.broadcom.com/us/en/vmware-cis/vsan/vsan/7-0/vsan-adminstration/using-vsan-policies/about-vsan-policies.html