[libvirt] libvirt memory flags

[Claudio Bley]

[please, do not top-post on technical lists. And, can you teach your
 mailer to wrap long lines. Thanks.]

At Fri, 2 Jan 2015 15:36:19 +0000,
Narayanan, Krishnaprasad wrote:
> 
> Hi Martin,
> 
> Thanks for your reply.  Please correct me if I am wrong here. 
> 
> The latest version of libvirt generates the following flags with respect to memory
> a) swap_in
> b) swap_out
> c) major_fault
> d) minor_fault
> e) unused
> f) available
> g) actual_balloon
> h) rss
> 
> I assumed that the "unused" flag represents the memory that is not consumed / not used by the virtual machine. In order to calculate the memory that is used by the VM / KVM process associated with the VM, I thought I should subtract the available or set memory - unused memory.

The actual data available depends on the hypervisor, the guest OS and
whether you have the balloon driver running inside the guest. If you
provide that information we probably would be able to help you better.

For some of the statistics, you have to instruct the driver to collect
them in the first place. Try running the dommemstat command with the
--period N option once. Then, try running it repeatedly without that
option.

Claudio
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