[libvirt] [PATCH V4] implement offline migration

[liguang]

Hello, Eric & Daniel

在 2012-09-05三的 11:08 -0600，Eric Blake写道：
> On 09/05/2012 02:48 AM, Daniel P. Berrange wrote:
> >>>
> >>> I really don't like the general design of this patch, even
> >>> ignoring all the code bugs. I think this entire patch is
> >>> really just a solution in search of a problem. Offline migration
> >>> is already possible with existing libvirt APIs:
> 
> I agree that the existing patches are making too many assumptions and
> not honoring flags correctly; but I'm still not sure why the user must
> decompose offline migration into a sequence of calls...

yes, my original thought was to do all things together.

> 
> >>>
> >>>    domsrc = virDomainLookupByName(connsrc, "someguest");
> >>>    xml = virDomainGetXMLDesc(domsrc);
> >>>    domdst virDomainDefine(conndst, xml);
> >>>
> >>
> >> Um, maybe you mean offline migration is just redefinition of domain at
> >> target side, but what about disk images the domain used without sharing
> >> files between source and target, do we have to take a look at this case?
> > 
> > Which can also be done already
> > 
> >    virStorageVolDownload + virStorageVolUpload
> 
> ...when a single virMigrate API could do the same decomposition as
> syntactic sugar, if the patch were cleaned up to actually obey flags.
> That is, why must virMigrate be a live-only operation, forcing
> virt-manager and all other wrappers to re-implement the same giant
> sequence of API calls for offline migration?
> 

so, libvirt may prefer APIs do one thing only?
maybe I have to just migrate the definition.


-- 
liguang    lig.fnst at cn.fujitsu.com
FNST linux kernel team