Web monitor Summary shows almost zero RAM usage for guests, while guest OS shows several GB

[Divergence]

I have several nodes running Ubuntu 18 or 20 as guest OS. They have 32 GB allocated memory, but show on the web monitor summary as using less than
one of percent of allocated RAM.
The Memory usage shows pale green 32 Gi, but reports RAM usage (dark green ) about 140 MiB.

On the guest OS I get:

free -h
total used free shared buff/cache available
Mem: 31Gi 5.0Gi 4.6Gi 62Mi 21Gi 25Gi
Swap: 7.2Gi 8.0Mi 7.2Gi

I'm running some fairly memory-heavy programs on the guest OS so I'm sure it will not run on 140 MB of RAM.

One guest is running Arch Linux and it is showing almost full RAM usage.

So what's going on here?
And what is this pale green memory (memory usage) and dark green (RAM usage) supposed to indicate in the Summary window?

 

[UdoB]

The view from the inside is massively different from the view from the outside.

From inside: Ram used buffers and caches are counted as free/available.

From the outside: that very Ram is used! It can not be shown as free, because it isn't.


Also: https://www.linuxatemyram.com/

 

[Divergence]

The view from the inside is massively different from the view from the outside.

From inside: Ram used buffers and caches are counted as free/available.

From the outside: that very Ram is used! It can not be shown as free, because it isn't.


Also: https://www.linuxatemyram.com/

Thanks for the reply, but my problem is the opposite: Inside it shows the RAM used. but outside it is shown not used.
I did find tons of discussion on the issue you mention here, but I could not really figure out how it would apply to my
case.

 

[UdoB]

Thanks for the reply, but my problem is the opposite:

Ooops...

I re-read your first post: are we talking about a VM or a Container? My answer aimed at a VM.

For a Container the Host knows which processes, buffers, caches etc. are used for this - a Container is just a better "chroot" under the control of the host's kernel. It is not encapsulated as in a VM with its own memory management.

Perhaps that is the reason...

 

[Divergence]

They are all VMs.