Zabbix reporting memory incorrectly?

[theWoosh]

Hi I have recently installed Zabbix 2.0-1 running on an Ubuntu 14.04LTS server running Plesk 12 (after spending days trying to configure Icinga2 and getting nowhere fast!).

I am concerned that using the supplied OS Linux template, the memory usage graph doesn't report what free or top report: for instance at the moment free -m says:
total used free shared buffers cached
Mem: 3952 3674 277 155 243 982
-/+ buffers/cache: 2448 1504
Swap: 1021 1019 2

while the Zabbix chart says I have 1.5g out of 4g free...

Any idea what is going on?

NB Also is there any way to show this chart as memory remaining at the top of the chart rather than at the bottom? i.e mapping used memory rather than available memory... it's counter-intuitive (at least to me)
Thanks for your time :-)

[evertonco]

It is a Linux info.

Look bold number on your output:

total used free shared buffers cached
Mem: 3952 3674 277 155 243 982
-/+ buffers/cache: 2448 1504
Swap: 1021 1019 2


This is info that zabbix is collecting. The item of OS Linux template is vm.memory.size[available]. Available memory on linux is: available = inactive + cached + free memory.

The info that you looking is vm.memory.size[free]. It is not in OS Linux Template.

Look this link: vm.memory.size_params

[theWoosh]

Thanks - I get this.
I need to monitor RAM usage so I can judge whether I need to increase RAM. Is it possible to monitor vm.memory.size[free]? I would like ideally to see it on the same chart as the figure including cache...
Sorry I'm new to Zabbix and on a learning curve here...

[Alwaysin]

http://www.linuxatemyram.com/

Zabbix is reporting the correct value of RAM.

Base on the right numbers to decide of increasing RAM or not, not the wrong

[theWoosh]

ahhh - whoops I misunderstood. Doh! I realise I was blinded to reality because the Plesk 'Server Health' panel is showing me the wrong value and left me thinking that I was short on RAM - I didn't understand why the Zabbix figure showed me I have plenty RAM.
I'm glad I installed Zabbix!
Thanks for your patience...

[evertonco]

You can edit os linux template changing available word to free or clone this item.

[theWoosh]

Thanks I'll try that anyway...