From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:52789) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S64wy-00042f-UR for qemu-devel@nongnu.org; Fri, 09 Mar 2012 13:54:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S64ww-0006SM-Nm for qemu-devel@nongnu.org; Fri, 09 Mar 2012 13:54:00 -0500 Received: from e36.co.us.ibm.com ([32.97.110.154]:43779) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S64ww-0006KE-5w for qemu-devel@nongnu.org; Fri, 09 Mar 2012 13:53:58 -0500 Received: from /spool/local by e36.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 9 Mar 2012 11:53:52 -0700 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id D889C19D804C for ; Fri, 9 Mar 2012 11:53:42 -0700 (MST) Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q29Irk2I111576 for ; Fri, 9 Mar 2012 11:53:47 -0700 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q29Irkvi006627 for ; Fri, 9 Mar 2012 11:53:46 -0700 Message-ID: <4F5A51B8.9030806@us.ibm.com> Date: Fri, 09 Mar 2012 12:53:44 -0600 From: Anthony Liguori MIME-Version: 1.0 References: <1331316786-7752-1-git-send-email-lcapitulino@redhat.com> <1331316786-7752-4-git-send-email-lcapitulino@redhat.com> <4F5A4A08.8030805@siemens.com> <4F5A4C98.6050401@us.ibm.com> <4F5A4FC2.7020501@redhat.com> In-Reply-To: <4F5A4FC2.7020501@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 3/4] Purge migration of (almost) everything to do with monitors List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: Luiz Capitulino , Jan Kiszka , "quintela@redhat.com" , "qemu-devel@nongnu.org" , "pbonzini@redhat.com" On 03/09/2012 12:45 PM, Eric Blake wrote: > On 03/09/2012 11:31 AM, Anthony Liguori wrote: >> On 03/09/2012 12:20 PM, Jan Kiszka wrote: >>> On 2012-03-09 19:13, Luiz Capitulino wrote: >>>> The Monitor object is passed back and forth within the migration/savevm >>>> code so that it can print errors and progress to the user. >>>> >>>> However, that approach assumes a HMP monitor, being completely invalid >>>> in QMP. >>>> >>>> This commit drops almost every single usage of the Monitor object, all >>>> monitor_printf() calls have been converted into DPRINTF() ones. >>> >>> I guess for most printfs, this is OK. But do you provide an alternative >>> for the block migration progress output? I did not find anything on >>> first glance. That is not a debugging feature. >> >> The block migration progress stuff is horribly broken and I regret ever >> merging it. Are you actively relying on this? >> >> Does block migration even work? >> >> Could we just remove block migration entirely... > > Libvirt has already exposed block migration to users, :-( Do you rely on the progress stats that are printed? > but it is > untested; if, as you say, it is horribly broken, then libvirt needs to > pass on the error message back to the user that it is broken. But we > regularly get people complaining that they don't have shared storage set > up, and they are looking for a magic bullet that will do block migration > alongside the domain migration; perhaps libvirt can still provide that > with block mirroring or other (working) solutions from the same API it > gives to the user if you end up pulling it out of the migrate QMP > command. Well block mirroring is hopefully around the corner. Regards, Anthony Liguori > At the end of the day, it's your call whether to pull it out, > and libvirt will adapt, but it would be nice to know what kosher working > alternative(s) to use instead. >