[libvirt-users] Changing default nic and storage types

[Daniel P. Berrange]

On Wed, Nov 17, 2010 at 02:38:49PM +0800, Osier Yang wrote:
> 于 2010年11月16日 21:30, Chris Phillips 写道:
> >Hi,
> >
> >Simple question that I can't track down any notable discussion about,
> >let alone an answer...
> >
> >Is it possible to define what the "default" nic and storage types are?
> >I am deploying images out of cobbler using koan and all of them are
> >running virtio wherever applicable, but this is not the default, and
> >at present there is no way within koan or cobbler to define what type
> >of devices they should be. I've hard coded this device type
> >declaration into koan, but don't like that in the slightest, and would
> >typically expect to be able to just set "default=virtio" in a libvirt
> >config file somewhere.
> >
> >I fear I'm actually not missing anything and it's just hard coded for
> >the most compatible device with no recourse to override it.
> >
> 
> It seems reasonable to add a new preference in "/etc/libvirt/qemu.conf".
> Now libvirt use "ide" as the bus type for disk device if it fails on
> the series detections.

No, this doesn't belong in libvirt, because there is no default that
you can choose which is best for all OS. Any change in global defaults 
is just moving the problem around, not fixing it.  The long term
solution for this with apps using libvirt is the libosinfo library
which is intended to provide a set of metadata files describing the
defaults for every known operating system, as well as letting the
host admin customize those per OS defaults.  Apps that provision
VMs would use libosinfo when building up their XML description

Daniel
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