High Memory Utilization on PAM VM persists after temporary ESX server memory shortage

Products

• CA Privileged Access Manager (PAM)

Issue/Introduction

One of our PAM appliances has high, sustained RAM utilization at over 90%. This is abnormal for our environment. We found out that it started when the ESX server the VM is running on was low on memory and claimed some of the memory assigned to the PAM VM via its balloon driver for use by other VMs that were running out of memory. This condition no longer exists, but PAM continues to show very high memory usage.

Environment

Release : 3.4

Component : PRIVILEGED ACCESS MANAGEMENT

Cause

The VM memory usage showed that over half of the memory was balloon memory. Since PAM services kept running fine with previously allocated memory, there was no need for the OS running the PAM appliance to take this memory back. PAM does not control this but lets the OS its running on (Debian Linux) handle it.

Resolution

To avoid the possibility of the ESX server claiming much of the allocated memory of the PAM VM, edit the VM settings and increase the memory reservation. The balloon driver can claim at most (configured memory - reserved memory). To quickly recover RAM usage, reboot the VM once the total memory usage on the ESX server has gone down such that there is no need for memory ballooning.