You want to check the PacketShaper's memory utilization as a percentage. Although there is no Command Line Interface (CLI) command to check the PacketShaper's memory utilization as a percentage, there is an SNMP OID.
You can poll the MIB value with the following SNMP OID:
OID: 1.3.6.1.4.1.2334.2.1.5.29
Object Name: psAlarmMemoryAvailablePct
To track memory errors, you can create a memory allocation adaptive response agent. See the following topic in the PacketGuide:
https://origin-symwisedownload.symantec.com/resources/webguides/packetguide/current/info/goals3.htm#memory