I was looking at the following item in the backlog:
Guests
Stats: Display
memory utilization (use virt-df or virt-top or ...)
If I understood it right, the idea here is to show the -inner-
memory allocation of the guest. If you have a VM with 4Gb of RAM
running an Ubuntu, we want to know how much memory the Ubuntu OS and
its processes are using.
I've done an investigation and I haven't found any tool to
accomplish this. "virt-top", "virsh dommemstat" and the libvirt API
retrieves the information of the memory usage of the guest relative
to the host. In the example mentioned before, supposing that the
host has 64Gb of RAM, all these tools would show that the VM is
using 12% of the host RAM. They do not dive in the VM and shows the
actual mem usage of the Ubuntu and its processes running there.
Haven't found anything useful in other MLs and forums. The common
answer is 'run top in a terminal inside the VM', which of course
does not suit us. My question is: any thoughts about how we can
implement this feature? Because I am starting to think that, in the
end, this kind of info is strict to the guest OS and can't be polled
from the outside.