[libvirt] Question about migration max downtime in domXML

[Daniel P. Berrange]

On Tue, Jan 20, 2015 at 11:00:26AM -0700, Jim Fehlig wrote:
> Hi All,
> 
> I've had a few user requests to add migration max downtime to the domain
> XML.  IIRC, this was discussed on the list quite some time ago, but I'm
> unable to find it in the archives.  My recollection is that max downtime
> is considered a tunable vs config and as such not included in the
> domXML.  But domXML does contain quite a few tunables, so perhaps my
> memory is incorrect.  Does anyone recall the details?  I'd be happy to
> work on this if folks find it acceptable.

It isn't so much about tunables vs config - rather it is about virtual
machine configuration vs API parameters. The various tunables we have
are all things related to configuration of the virtual machine, where
as the migration downtime is not really guest configuration data.

When you start moving management API parameters into the guest XML
it makes the operation of the API less predictable, because you
don't know what the semantics will be, without first consulting
the guest XML settings that might affect the API.

Regards,
Daniel
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