How to correctly monitor containers ram usage?

Hi, I’ve got a little problem monitoring containers (lxc and openvz)
sample output of free -m
total used free shared buffers cached
Mem: 512 49 462 969 0 23

In fact this containers memory usage is just 26MB, so how can i monitor this correct?

proxmox webinterface:


in fact this container got a constant ram usage of 20-30mb ram, so librenms graphs are false and i always get notifications…

We’re reporting back what the OS is telling us. I think this has been covered before so have a search around for more info.

Well but doesn’t htop do the same? Its reporting the correct ram usage, what is different for librenms?
And is there no way to adjust this?