On Thu, Oct 06, 2016 at 10:59:06AM +0100, Ian Jackson wrote:
Martin Kletzander writes ("Re: [OSSTEST PATCH 2/2] libvirt: Do
not attempt save/restore when migration not advertised"):
> Since offline migration (as in migrating a domain between hosts without
> being running) is not that used in the code and talked about, I'm
> guessing offline means save restore. Looking at the history it was
> added before the "offline" migration, so it probably means
> save/restore. To avoid confusion, I would suggest we add either
> <offline/> or rather <save/> (the naming is not important) and document
> what it means. And then you can use it exactly how you'd like. And
> you'll be also sure it means what you need it to mean ;) The patches
> will be straigh-forward, let me know if I can help anyhow.
Except that the point of the exercise is to detect which features are
supported in which versions. Whatever I do in osstest needs to work
with older libvirt versions, which do not report
/capabilities/host/migration_features/save
even on x86, where it is supported. I suppose I could detect
/capabilities/host/migration_features/live
and assume that save/restore was supported (since it's unlikely that
live migration would be supported but not save/restore).
So for now I think I need to use
/capabilities/host/migration_features
as a proxy for save/restore ?
Well then, unfortunately you do.
Also, looking at how the code is structured, if you have live migration
but don't have save/restore, you won't have <migration_features/> there
at all.
Ian.