vSAN Capacity utilization alarm does not show full cluster capacity

Products

• VMware vSAN

Issue/Introduction

• vCenter reports a Disk Space warning on vSAN cluster under vSAN Skyline Health "What if the most consumed host fails"
  
  
• This Capacity utilization alarm shows Disk Space utilization of x where x is less than the full cluster capacity.

Environment

VMware ESXi 7.x
VMware ESXi 8.x

Cause

The "What if the most consumed host fails" check is a predictive simulation that evaluates cluster resource usage after a potential ESXi host failure. It focuses on the host with the highest resource consumption to ensure the cluster can sustain a worst-case scenario failure.

The cluster capacity that it displayed is the predicted capacity after the most consumed host has failed and not the full cluster capacity.

Please refer to vSAN capacity utilization alarm 'What if the most consumed host fails'

Resolution

This alarm is primarily informational and intended for capacity planning.

To monitor the vsan capacity utilization please refer to vSAN Health Service - Capacity utilization - Storage space