[virt-tools-list] Wrong Memory Usage Graphic on virt-manager?

[leandro maciel]

Hello,

I'm having some problems trying to understand how virt-manager count the
memory usage to plot in the graphics on both the Virtual Machine Manager
window and the Details tab after you open a guest.

I have two guests, one with 2GB of ram and another with 512 MB, both of
them running CentOS 7.1 minimal and both of them shows that the memory
usage on the graphs are almost the double of the value that I have after
running the 'free -h' command on the console of the machines.

On the tests I made, the guest with 2GB showed on the graph that 365 MB of
memory was in use, but the free -h command returned 51 MB in use and 113 MB
in cache, a total of 164 MB

The guest with 512 MB showed 240 MB in use in the graphs but the free -h
command returned 38 MB in use and 84 MB in cache, a total of 122 MB.

Both checks were done after a clean boot, with nothing running besides the
OS.

After that, i shutdown both machines, and the graph on the Virtual Machine
Manager still showed memory usage after a few minutes.

Is it a bug or am I doing something wrong on the configurations? Which
information should i trust to know how much memory is being used?

Has somebody here saw something like that before?

On the file attached you can see that one machine took a few minutes to
show no memory usage after the shutdown, and another still shows usage
after the shutdown, but half of what it was showing when it was turned on.


Thanks,

Leandro
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