Memory usage not matching free command on host

I setup Librenms to monitor a KVM host and 4 guests but I’m finding that the Memory Usage graph does not match what the servers show. They are all Ubuntu 16.04, host and guests.

Here is a screenshot of LIbrenms and running free -m on the server

librenms memory usagefree

I see I was missing the second line in Librenms’s output.

2nd line

The problem is that the graph is built from the total used and that will always show pretty much 100% because of disk caching not?

Can we get the graph built from the second line of numbers? I’m new at Librenms so still trying to find my way around.

I have same problem, on one proxmox host that has scheduled backups to nfs storage same issue occurs as yours, htop och free -m contrair to librenms memory usage shows full but actually its not.

[email protected]:~# free -m
total used free shared buff/cache available
Mem: 128924 20222 680 522 108021 111143
Swap: 8191 116 8075