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

[Cole Robinson]

On 04/26/2015 12:32 AM, leandro maciel wrote:
> 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.
> 

Once the machine is listed as 'shutoff' in virt-manager, the VM is not
consuming any memory. If the UI is reporting anything new for a shutoff VM in
_any_ of the graphs, then it's a virt-manager bug.

Please try to reproduce with virt-manager upstream:

git clone git://git.fedorahosted.org/virt-manager.git
cd virt-manager
./virt-manager --debug

And if you reproduce, take the --debug output and file an upstream bug report:

https://virt-manager.org/bugs/

Thanks,
Cole