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.
Thanks!