Description
This article describes the different OIDs available to monitor memory consumption on FortiGates.
Scope
FortiGate.
Solution
It is possible to use the below 2 OIDs to monitor the current memory usage on FortiGate.
- fgSysMemUsage (.1.3.6.1.4.1.12356.101.4.1.4.0): shows the amount of used memory, as displayed in the command 'get system performance status'.
- fgHaStatsMemUsage (.1.3.6.1.4.1.12356.101.13.2.1.1.4): shows the amount of used memory in a HA cluster, as displayed in the command 'get sys ha stat'.
Note that both SNMP OIDS and CLI commands will show different outputs.
The SNMP OID 'fgSysMemUsage' and the CLU command 'get system performance status' will show the used memory.
While the SNMP OID 'fgHaStatsMemUsage' and the corresponding CLI command 'get sys ha stat' will display the used + freeable memory usage.
Examples of the CLI outputs:
get sys perf stat
CPU states: 0% user 0% system 0% nice 100% idle 0% iowait 0% irq 0% softirq
CPU0 states: 0% user 0% system 0% nice 100% idle 0% iowait 0% irq 0% softirq
Memory: 2040300k total, 899456k used (44.1%), 753980k free (37.0%), 386864k freeable (18.9%)
get sys ha status
...
sessions=15539, average-cpu-user/nice/system/idle=0%/0%/0%/100%, memory=30%
Below is an example of the CLI outputs and the SNMP OIDs at the same time:
CLI:
get sys perf status | grep Memory
Memory: 2055932k total, 1076464k used (52.4%), 676012k free (32.9%), 303456k freeable (14.7%)
get sys ha status | grep memory
sessions=21, average-cpu-user/nice/system/idle=1%/0%/0%/99%, memory=52%
SNMP OID:
Name/OID: fgSysMemUsage.0; Value (Gauge): 52 <--- used (52.4%).
Name/OID: fgHaStatsMemUsage.1; Value (Gauge): 67 <--- used (52.4%) + freeable (14.7%).
FortiGate can send an SNMP trap if the memory usage is higher than 80% (default). This value can be modified using the configuration below.
config system snmp sysinfo
set status enable
set trap-low-memory-threshold 85
end
Related article:
Technical Tip: How to Configure FortiGate SNMP Agent for Monitoring
