Re: [libvirt] [PATCH V4] implement offline migration

(2012/09/06 14:32), liguang wrote: > 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. > Can you try to move the definition in an atomic way ? copy to the dest + delete the original with preventing other ops to the target vm. I hope virsh migrate can support this "move" of definition....

Thanks, -Kame