[libvirt] [RFC] changing/regenerating domain uuid on migration

[Daniel P. Berrange]

On Thu, Apr 21, 2016 at 11:24:11AM +0300, Nikolay Shirokovskiy wrote:
> Hi all.
> 
> Consider next usecase. There are active domain DA on host A and active domain
> DB on host B and the uuids of domains are the same. This is quite uncommon of
> course but still possible. If we have option to change uuid on migration
> then migration of DA to host B is possible and if we don't have the option 
> we have to stop/edit/start DA to migrate.
> 
> What is you opinion on subject? Can this functionality be taken into upstream 
> and in what form? In form of setting uuid as a migration parameter or option to
> regenerate uuid on destination?

I consider that to be a deployment bug. If you're generating UUIDs using the
RFC spec for generation algorithm, the chance of collision of UUIDs should
be effectively zero.

Furthermore, the UUID is exposed to the guest via SMBIOS, and you can't
change that on the fly, so renaming UUID on the QEMU side is really not
an option during migration.

Regards,
Daniel
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