Memory Exhaustion alarm triggered on vCenter Server despite no high memory usage processes found in ps command

Products

• VMware vCenter Server

Issue/Introduction

• The following alarm is triggered on the vCenter Server:
  
  Memory Exhaustion on <vCenter Name>
  
  
  
• Under VAMI > Monitor > CPU & Memory, memory utilization exceeds 85%.
  
  
• Executing the ps command reveals no processes with high %MEM values.
  
  # ps aux --sort=-%mem | head
  
  
  
• The overall sum of %MEM of ps command remains low.

Cause

These symptoms occur when memory ballooning is active on the vCenter Server virtual machine.

Memory ballooning can be confirmed via the following methods:

• Connect to the vCenter Server via SSH and execute the following command in the bash shell:
  
  

  # vmware-toolbox-cmd stat balloon
  Output Example)
  5106 MB

 

• Review the "Ballooned memory (vmmemctl)" metric within the vCenter Server virtual machine performance charts.

Resolution

Adjust host or cluster resources or configure reservation for the vCenter Server virtual machine to ensure sufficient memory is allocated to the vCenter Server virtual machine.