Re: [Qemu-devel] Block Migration and xbzrle

[Paolo Bonzini]

Il 16/09/2012 12:39, Peter Lieven ha scritto:
> 
> I remember that this was broken some time ago and currently with
> qemu-kvm 1.2.0 I am still not able to use
> block migration plus xbzrle. The migration fails if both are used
> together. XBZRLE without block migration works.
> 
> Can someone please advise what is the current expected behaviour?

Block migration is broken by design.  It will converge really slowly as
soon as you have real load in the VMs, and it will hamper the
convergence of RAM as well.

Hopefully a real alternative will be in 1.3 (based on drive-mirror on
the source + an embedded NBD server running on the destination), then in
1.4 we can reimplement the block migration monitor commands using the
alternative.

Paolo