[Fedora-xen] xen-unstable => 3.2, binary packages

[Daniel P. Berrange]

On Mon, Dec 10, 2007 at 02:58:14PM +0000, Ian Jackson wrote:
> Daniel P. Berrange writes ("Re: [Fedora-xen] xen-unstable => 3.2, binary packages"):
> > On Mon, Dec 10, 2007 at 01:02:18PM +0000, Ian Jackson wrote:
> > > I don't know what Fedora's policy is about including new upstream
> > > versions in updates, but I would think that most sensible policies
> > > would generally frown on pushing a new hypervisor into an
> > > already-released distribution.
> > 
> > Since the userspace and hypervisor have a pretty tight ABI requirement we
> > cannot do major Xen upgrades during the life of any single Fedora release.
> 
> I don't necessarily disagree with your conclusion but I'm not sure
> this reasoning makes sense.  Certainly there's an ABI compatibility
> requirement but all that means is that you would want to upgrade both
> the hypervisor and the dom0 toolstack together.

The problem comes because when you upgrade the userspace that takes effect
immediately, but the hypervisor only takes effect upon reboot. So you have
a time of incompatbility. In addition if the new hypervisor doesn't work
out and you want to reboot to old version, then you're now incompatible 
with the userspace you upgraded. So while we could provide updates of
both hypervisor and userspace it generates more support problems & bug
reports that it is worth. So we decide to only update along the bugfix 
release trees. The release cycle of Fedora is fast enough (6 months) that
there isn't very long to wait before the next Fedora release to get the
newer Xen so there's no serious pressure to do major updates within one
release. 

> > So, during the rawhide development cycles we track to the latest Xen major
> > release, and then Fedora releases we track the minor bug fix release of
> > Xen. So,  Fedora 7 and 8 were released on Xen 3.1.0 and are now updated to
> > Xen 3.1.2.   We will not update Fedora 7 or 8 to Xen 3.2.0 because the
> > 3.2.0 hypervisor is ABI incompatible with the 3.1.x userspace and vica-verca
> 
> So do you think it would be worthwhile for Xensource to make binary
> packages of Xen 3.2 (both hypervisor and dom0 tools) backported to
> Fedora 8 ?

There may well be people interested in that. We won't be doing it as part of 
the official Fedora xen packages, so if you wish to provide those updates 
you won't be duplicating effort & some people may find it useful.

For sanity testing I'd recommend verifying the ability to run 'virt-install'
'virt-manager' & 'virsh' against your updated pacakges, since those are the 
primary virtualizatioln administration tools used in Fedora.
 
Regards,
Dan.
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