[Libvir] Next features and target for development

[Daniel Veillard]

On Tue, Jul 10, 2007 at 03:01:27PM -0700, Dan Smith wrote:
> DL> This question comes up in other contexts than migration, too, for
> DL> example, when you want to start an image you just downloaded. I
> DL> think it would make sense if there was a common baseline in
> DL> libvirt that could tell you if a VM has any chance of running at
> DL> all - otherwise that logic will be scattered across lots of apps.
> 
> The migration case is significantly more strict, though, at least for
> Xen.  A domain image may start up on two machines that are different,
> but the same domain would not migrate from one to the other.
> 
> On that note, how about a libvirt function that allows you to compare
> the capabilities of two hypervisors for varying levels of
> compatibility?  A given implementation such as Xen could analyze the
> hypervisor and machine characteristics to provide a "compatible for
> migration" result, as well as a "can run on" result (and perhaps
> others).  Something like the following:
> 
>   virIsCompatible(hyp1, hyp2, COMPAT_MIGRATION);
>   virIsCompatible(hyp1, hyp3, COMPAT_MIGRATION | COMPAT_RUN);
> 
> The former would return true (in the Xen case) only if both machines
> were the same bitness, processor revision, etc.
> 
> The latter could, potentially, return true for a given domain across
> Xen and qemu, if that domain is fully-virtualized.

  Hum, we would probably need some logic like this between 2 hypervisor
of the same type, but I'm afraid the matrix is gonna be a bit of hell
if we want to handle all cases over time. It also feels a bit low level
to me though I think I understand why you would like this :-)

Daniel

-- 
Red Hat Virtualization group http://redhat.com/virtualization/
Daniel Veillard      | virtualization library  http://libvirt.org/
veillard at redhat.com  | libxml GNOME XML XSLT toolkit  http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine  http://rpmfind.net/