Re: [Qemu-devel] [PATCH] block-migration: deprecate block migration for the 1.2 release

[Paolo Bonzini]

Il 15/08/2012 14:38, Stefan Hajnoczi ha scritto:
> The new live block copy approach is different and that's why classic
> block migration is only deprecated but not dropped:
> 
> Live block copy doesn't transfer data in-band during live migration.
> Instead it currently requires storage access from both hosts, for
> example:
> 1. NFS or CIFS
> 2. iSCSI or NBD
> 
> I think when classic block migration is removed for good it should be
> just as easy to use through libvirt using TCP because that's still a
> valid use case and probably the simplest one to get started.  (Libvirt
> could orchestrate an NBD connection behind the scenes, for example.)

That's correct.  Live block migration will use two ports, both served by
the destination, one using NBD and one for RAM/device migration data.
It will be a little more complicated than just migrate -b, but nothing
that libvirt cannot orchestrate.

Paolo