VM Memory Usage % Discrepancy between Aria Operations (formerly vRealize Operations) and Guest OS Task Manager

Products

• VMware Aria Suite

Issue/Introduction

The VM Memory Usage % displayed in Aria Operations is higher than the value shown in the VM Guest OS Task Manager

Environment

Aria Operations 8.x

Cause

The observed discrepancy between the VM Memory Usage % displayed in Aria Operations and the value shown in the VM Guest OS Task Manager is due to the different data collection methods employed by each tool

Resolution

The displayed VM Memory Usage % in Aria Operations is accurate and reflects the correct memory utilization of the virtual machine. The difference in values between Aria Operations and the Task Manager is not a cause for concern.

The Virtual Machine Memory Usage (%) metric is calculated using the following formula: VM Memory|Usage (%) = Guest|Needed Memory (KB) / Memory|Total Capacity (KB) * 100

Note: the Memory Usage metric seen in vSphere is different and corresponds with the "Memory|Consumed (%)" and "Memory|Balloon (KB)" in Aria Operations.

 

Example:

• Consider below example where VM Memory Usage % displayed in Aria Operations is 72.628% and VM Guest OS Task Manager is 68% :
• The VM Memory Usage % in Aria Operations is calculated using the following formula:
• In the provided example:
  • VM Memory|Usage (%) = 48740224 KB / 67108864 KB * 100 = 72.628%
• This indicates that the guest OS is using 72.628% of its allocated memory, even though the Task Manager shows 68% value due to temporary fluctuations or memory optimization techniques employed by the guest OS
• The observed discrepancy is inherent in the data collection methods and does not affect the overall functionality or performance of Aria Operations

 

Note: For a combined memory metric that includes both Guest OS, vSphere and ESXi memory configuration please refer to the "Memory|Utilization (KB)" metric which combines:

• VMware Tools (Running):  Memory|Utilization (KB) = Guest|Needed Memory (KB) + ( Guest|Page In Rate per second * Guest|Page Size (KB) ) + Memory|Total Capacity (KB) – Guest|Physically
• VMware Tools (Not running): Memory|Utilization (KB) = Memory|Consumed (KB) Memory|Usage (%) will prefer Memory|Non Zero Active (KB)

Additional Information

• It is recommended to maintain the default collection cycle of 5 minutes for Aria Operations metrics to balance data accuracy with performance considerations
• Decreasing the collection interval may lead to excessive data collection, potentially impacting vRops storage and performance
• The observed difference in memory usage values is a result of the varying data sources and collection mechanisms used
• The discrepancy is within the expected range and does not indicate any underlying issues