PAM Appliance virtual memory seems to be about 90% used according to SNMP data, but the status of the virtual appliance only displays about 50%. Why is this so ?

Products

• CA Privileged Access Manager - Cloakware Password Authority (PA)
• PAM SAFENET LUNA HSM
• CA Privileged Access Manager (PAM)

Issue/Introduction

In many cases, memory utilization for a given PAM appliance is obtained by using the snmp poll functionality. 

By means of the MIB results it is possible to determine how much memory is being used and trigger alerts if the memory is too low.

Sometimes it may happen that, even though the memory usage reported by PAM in its monitor is low (say 40%), the memory utilization reported through SNMP greatly differs from this figure and in fact reports about 90% usage.

Why may there be a discrepancy between computed memory through the SNMP MIB and the one shown in the control panel of the appliance ?

Environment

CA PAM, all versions

Resolution

The dashboard shows the physical memory usage (RAM usage, as the label says).

The SNMP status shows virtual memory and that is consistent with the virtual memory usage. 

Java always allocates a lot of virtual memory, that’s why it gives high numbers for the java (cspmsrv) process, and for virtual memory usage overall. 

Most of it is not used and the actually RAM usage is much lower. If RAM usage were very high it would suggest a resource problem on the appliance, but virtual memory usage in itself is not that problematic. 

The RAM usage shown on the dashboard comes from /proc/meminfo