From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:55186) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TIywZ-0007l8-Gg for qemu-devel@nongnu.org; Tue, 02 Oct 2012 05:39:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TIywT-0001Vt-Rn for qemu-devel@nongnu.org; Tue, 02 Oct 2012 05:39:11 -0400 Received: from mail-pa0-f45.google.com ([209.85.220.45]:60583) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TIywT-0001Vp-LA for qemu-devel@nongnu.org; Tue, 02 Oct 2012 05:39:05 -0400 Received: by padfb10 with SMTP id fb10so5150034pad.4 for ; Tue, 02 Oct 2012 02:39:04 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <506AB631.8090206@redhat.com> Date: Tue, 02 Oct 2012 11:38:57 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <5055AC78.8040606@dlhnet.de> In-Reply-To: <5055AC78.8040606@dlhnet.de> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] Block Migration and xbzrle List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Lieven Cc: "qemu-devel@nongnu.org" , "kvm@vger.kernel.org" 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