From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: Block Migration and xbzrle Date: Tue, 02 Oct 2012 12:09:44 +0200 Message-ID: <506ABD68.4060508@redhat.com> References: <5055AC78.8040606@dlhnet.de> <506AB631.8090206@redhat.com> <135E8E0A-174B-4A0A-ABF3-9B41F224F88A@dlhnet.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "qemu-devel@nongnu.org" , "kvm@vger.kernel.org" To: Peter Lieven Return-path: In-Reply-To: <135E8E0A-174B-4A0A-ABF3-9B41F224F88A@dlhnet.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org List-Id: kvm.vger.kernel.org Il 02/10/2012 11:44, Peter Lieven ha scritto: > > Am 02.10.2012 um 11:38 schrieb 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. > > Hi Paolo, i know that block migration is not that good, but it seems that > there is a bug in XBZRLE that is independent of block migration. Understood---but hopefully you can stop using it with 1.3, which would also work around the bug. :) Paolo