On 07-12-2014 23:16, Daniel Henrique Barboza wrote:

Because I am starting to think that, in the end, this kind of info is strict to the guest OS [...]

But it is. That information is specific to the guest OS, I believe there's no way of retrieving it without actually connecting to the guest (via a specialized agent or SSH or whatever). And we're talking about only Unix/Linux; e.g. Windows provides a different method to retrieve its memory usage.

So you're right, this is very dependent on the guest OS and I guess there's no way of doing it in a way that works for every guest.