Monitor Free Memory in Linux via SNMP

[mgajjar]

I am new to Zabbix. I want to monitor my Linux Server's memory utilization via SNMP.

In the Template "Template Module HOST-RESOURCES-MIB SNMPv2", the default item "Memory Utilization" in the item prototype calculates the free memory.

But I know that Linux defines free memory without including buffer/cache.

Is there a way that I can say that calculate memory that is free + buffer/cache?

I have to do this using SNMP. I can't use Zabbix agent.

[markfree]

What version of Zabbix Server are you using?

Are you refering to this calculated key "vm.memory.util[snmp]"?

I supose you could change the calculation to fit your system.

The following keys are all data read from SNMP agent and available within "Linux memory SNMP" template. So, you can play with them.

vm.memory.cached[memCached.0]
vm.memory.buffers[memBuffer.0]
vm.memory.free[memAvailReal.0]
vm.memory.total[memTotalReal.0]

[mgajjar]

The Zabbix version is 5.0

This is my item prototype configuration. This is default.

But I actually dont know hot keys works.

Because when I try modifying this item and then create a graph based on this. I simply don't get any data.

With the used one I can see data in the graph.

[markfree]

According to the Zabbix Git for version 5.0, this template uses the following formula:

last("vm.memory.used[hrStorageUsed.{#SNMPINDEX}]")/last("vm.memory.total[hrStorageSize.{#SNMPINDEX}]")*100

You might wanna check if keys "vm.memory.used" and "vm.memory.total" are giving you correct results as well.
Have you upgraded your server to 5.0 from an older version?

[mgajjar]

Yes I Upgraded from older version

[markfree]

Upgrading to the latest Zabbix version will not automatically upgrade the templates used.

Template changes [Zabbix Documentation 5.4]

This might explain the difference in template formula.