From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: migrate_set_downtime bug Date: Mon, 05 Oct 2009 15:17:24 +0200 Message-ID: <4AC9F1E4.4070101@redhat.com> References: <4AC22A4D.5060805@codemonkey.ws> <20090929162345.GX29735@mothafucka.localdomain> <90D306BE6EBC8D428A824FBBA7A3113DFDCDF17D@ronja.maurer-it.com> <20090930044832.GA5149@mothafucka.localdomain> <90D306BE6EBC8D428A824FBBA7A3113DFDCDF184@ronja.maurer-it.com> <20090930112328.GB5149@mothafucka.localdomain> <90D306BE6EBC8D428A824FBBA7A3113DFDCDF18D@ronja.maurer-it.com> <20090930163951.GD5149@mothafucka.localdomain> <90D306BE6EBC8D428A824FBBA7A3113DFDCDF18E@ronja.maurer-it.com> <4AC9E3DA.6000607@redhat.com> <20091005130409.GD8092@mothafucka.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Dietmar Maurer , Anthony Liguori , kvm To: Glauber Costa Return-path: Received: from mx1.redhat.com ([209.132.183.28]:28365 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753488AbZJENR4 (ORCPT ); Mon, 5 Oct 2009 09:17:56 -0400 In-Reply-To: <20091005130409.GD8092@mothafucka.localdomain> Sender: kvm-owner@vger.kernel.org List-ID: On 10/05/2009 03:04 PM, Glauber Costa wrote: > On Mon, Oct 05, 2009 at 02:17:30PM +0200, Avi Kivity wrote: > >> On 09/30/2009 08:41 PM, Dietmar Maurer wrote: >> >>> I just think of common scenarios like 'maintanace mode', where all VM should migrate to another host. A endless migrate task can make that fail. >>> >>> For me, it is totally unclear what value I should set for 'max_downtime' to avoid that behavior? >>> >>> >>> >> We used to have a heuristic that said 'if an iteration transfers more >> pages than the previous iteration, we've stopped converging'. Why >> wouldn't that work? >> > Because it seems people agreed that mgmt tools would be the place for those heuristics. > Heuristics like number of pages, maybe. But since we don't export iteration information, we can't expect management tools to stop the guest if migration doesn't converge. I suppose it could issue a 'stop' after some amount of time (constant * memory size / bandwidth). -- error compiling committee.c: too many arguments to function