What-If Analysis – Add/Remove ESXi Host Shows Lower available Capacity in Aria Operations

Products

• VCF Operations/Automation (formerly VMware Aria Suite)

Issue/Introduction

In Aria Operations, the What-If analysis for removing/adding ESXi host capacity may appear incorrect, showing a lower available capacity than the total cluster capacity.

Environment

Aria Operations 8.x

Cause

This behavior occurs because the host failover percentage is enabled in vCenter with vSphere High Availability (HA) Admission Control. Aria Operations bases What-If analysis on Usable Capacity rather than the cluster’s total capacity.

Resolution

This behavior is expected, as Usable Capacity is reduced by reservations configured for HA and other vSphere services, resulting in lower available values.

To align What-If analysis capacity values with total cluster capacity, disable the host failover percentage in vSphere HA. If Admission Control remains enabled, the current behavior will persist by design.

Note: Once the host failover percentage is disabled in vCenter, the Usable Capacity aligns with the Total Capacity.