[libvirt] Current cpu and memory usage for Host and Domains

[Daniel Veillard]

On Sun, Jan 17, 2010 at 01:02:33PM +0000, Daniel P. Berrange wrote:
> On Fri, Jan 15, 2010 at 11:52:09AM -0800, su disheng wrote:
> > Seem there is no way to get host CPU usage in libvirt API? I can get
> > freeMemory by  virNodeGetFreeMemory, but no cpu usage API.
> > How about add a new api for it? The host CPU usage is also important for VM
> > creation and migration decision, like the free memory.
> > Yes, I know, I can got it from "top"...:)
> 
> We've historically thought that monitoring of the host OS is out of
> scope of the libvirt API, since there are already a huge variety of
> monitoring services / APIs available for people.  I wonder if we need
> to reconsider that now we have the VMWare drivers though - apps using
> libvirt don't get to installl stuff in VMWare host OS, so the only
> access to some of this host CPU data is probably via the VMWare APIs.
> Which in turn suggests we'd need to expose some minimal hosting API
> for this in libvirt

  I think in both case it boils down to be able to rely on a single
access method for the monitoring of virtualization and host capacity,
the pressure has increased with usage or remote access and new
hypervisors.
  It's not like providing those new APIs would be hard, but we still
have pure virtualization code to focuse on,

Daniel

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