Undersize/oversize metrics data missing or incorrectly calculated in Aria Operations.

Products

• VCF Operations/Automation (formerly VMware Aria Suite)
• Aria Operations for Applications
• VMware Aria Operations (formerly vRealize Operations) 8.x
• VMware Aria Operations 8.x

Issue/Introduction

• Undersize & oversize metrics are missing in Aria Operations for 10% or more vCenter VM's.
• "Oversized Virtual Machines" View has incorrect rightsizing data.
  Example: In the following image, "Reclaimable Memory" is equivalent to "Configured Memory", therefore reclaiming 100% of resources.

Environment

Aria Operations 8.17.x

Aria Operations 8.18

Aria Operations 8.18.1

Cause

After Aria Operations 8.17 the logic used to calculate rightsizing metrics changed.

The new logic for calculating rightsizing metrics is as follows:

1. When the VM is reclaimable, the rightsizing metrics are being reset to 0 and are continuously published as 0 while it is considered reclaimable.
2. When the VM is not reclaimable, then the rightsizing calculation takes place
   1. if there is a rightsizing recommendation based on these calculations, then the metrics will be published accordingly
   2. if the VM needs no rightsizing (according to calculations), then the rightsizing metrics will not be published at that time.

if no exceptions or errors are seen in the logs regarding the rightsizing calculations and metric publishing then rightsizing metrics will not be displayed. 

Resolution

Issue is fixed in Aria operations 8.18.2.

Additional Information

Release notes 8.18.2: Some Rightsizing Metrics Not Being Published