From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:48114) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S23dy-0006bI-2z for qemu-devel@nongnu.org; Mon, 27 Feb 2012 11:41:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S23ds-0004DG-5y for qemu-devel@nongnu.org; Mon, 27 Feb 2012 11:41:45 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34826) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S23dr-0004DC-UY for qemu-devel@nongnu.org; Mon, 27 Feb 2012 11:41:40 -0500 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q1RGfd9B010529 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 27 Feb 2012 11:41:39 -0500 Message-ID: <4F4BB23F.6000204@redhat.com> Date: Mon, 27 Feb 2012 17:41:35 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] drive transactions (was Re: [PATCH 2/2 v2] Add the blockdev-reopen and blockdev-migrate commands) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Federico Simoncelli Cc: kwolf@redhat.com, armbru@redhat.com, Jeff Cody , mtosatti@redhat.com, qemu-devel@nongnu.org, Luiz Capitulino , Eric Blake On 02/27/2012 05:33 PM, Federico Simoncelli wrote: >> > >> > blockdev-begin-transaction >> > drive-reopen device new-image-file >> > drive-mirror streaming=false device dest >> > blockdev-commit-transaction >> > >> > No strange optional arguments, no proliferation of commands, etc. >> > The >> > only downside is that if someone tries to do (4) without transactions >> > (or without stopping the VM) they'll get corruption because atomicity >> > is >> > required. > I'm all for the modularity of the commands (I suggested it since the beginning), > but all this infrastructure goes way beyond what I'd need for oVirt now. > > When I submitted my patches we knew that my work wasn't the definitive solution > (eg: the future implementation of -blockdev). So I'd suggest to try and settle > with something that is good enough and that is not preventing a future improvement. > > What about having a (temporary) flag in drive-mirror to accept also a new-image-file > until we will have the optimal solution? What if libvirt could simply try blockdev-freeze and, if it's not there, try passing a new-image-file argument. Add the new-image-file downstream if you have time constraints, and leave it out upstream. Too ugly? Paolo