Re: [Xen-users] existing VMs and future Xen versions

[Ian Campbell <ian.campbell@xxxxxxxxxx>]

I think 4.4 is probably fine for your needs, as would 4.5 be. Upgrading
to 4.6 when the time comes is unlikely to cause any major issues
(although as always deploying in a test env first is a good idea...)

Ian.

On Fri, 2015-04-03 at 15:35 +0800, H C wrote:
> Thanks for the terrific explanation.  I'm presently on 4.4 and I need
> to setup some Windows VMs in the short term.  I plan to upgrade my
> hardware in the medium term and will likely grab the latest Xen
> version.  I can probably hold off till 4.6.
> 
> 
> On Mon, Mar 30, 2015 at 5:15 PM, Ian Campbell <ian.campbell@xxxxxxxxxx> wrote:
> > On Mon, 2015-03-30 at 15:38 +0800, H C wrote:
> >> Hi,
> >>
> >> Can VMs created in an older version of Xen work in newer versions?  I
> >> have 4.4 running and am planning to invest in some licensed OSes
> >> (activating some Windows Licenses on a vms running in 4.4) .  Will I
> >> be stuck on 4,4 or does Xen have upgrade paths for VMs?  How is this
> >> sort of thing typically planned for?
> >
> > Yes, this sort of compatibility is in general supported. The Xen
> > hypercall guest interface (used by PV and PVHVM guests) has been
> > supported in a stable and backwards compatible manner since Xen 3.0.
> >
> > Windows licensing goes a bit further and (AIUI) operates on a points
> > system based on h/w changes. So it may occasionally be necessary to
> > tweak to your configuration when switching to a new version to retain
> > previous behaviour.
> >
> > For example if you had installed on Xen <=4.2, which by default used the
> > qemu-xen-tradition device model then when you upgraded to Xen >=4.3,
> > which switched to the qemu-xen device model by default, then you would
> > need to explicitly ask to use qemu-xen-traditional in the domain
> > configuration, otherwise the switch in the emulated hardware might be
> > enough to trigger reactivation.
> >
> > This sort of thing isn't very frequent though and in most cases things
> > just work or the changes aren't enough trigger reactivation.
> >
> > Ian.
> >



_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxx
http://lists.xen.org/xen-users