Re: Questions about xenapi/libvirt and Memory overcommiting

[Zhigang Wang <zhigang.x.wang@oracle.com>]

viets@work.de wrote:
> Hello,
> 
> I'm unsure whether this question is for xen-devel or for the (dead?)
> xen-api mailinglist?
> 
> Inspired by Dan Magenheimers xenballoond patch ("[PATCH] xenballoond
> (memory overcommit) scripts"), I'd like to program the xenballoond for a
> Dom0, so that there is no need to run it in every DomU, which improves
> the possibility for policing and probably the monitoring.
very good idea! but I'm wandering whether we can get these info from hypervisor.
> 
> My question is what api I should use to program it? xenapi or libvirt?
> 
> And how do I get values that are in xenstored? I didn't find a function
> in the xenapi or libvirt? Are there any examples?
> 
xenapi and libvirt are interfaces for other tools to manage xen. but your
xenballoond should belong to the infrastructure of xen. I think should be
implement in xend as a thread or stand alone process.

And if you want make it configurable (eg. change policy) by other tools (xm),
you should add APIs to xenapi or libvirt.

> My first implementation of the program, was made in the bash, but I
> guess C or python is the better way for it.
> 
> The first implementation was based on the attached kernel patch, which
> only make the memory information of the domU kernel accessible by
> xenstore, if CONFIG_XEN_DAEMON_BALLOON is set.
> 
> Attached to this email is my first implementation of the program. It
> looks every second whether a domain needs more or less memory and change
> the value.
> 
> greetings
> Viets
> 
> 
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