From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50843) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gSjV8-00017l-0I for qemu-devel@nongnu.org; Fri, 30 Nov 2018 09:10:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gSjV5-00078x-SS for qemu-devel@nongnu.org; Fri, 30 Nov 2018 09:10:37 -0500 Date: Fri, 30 Nov 2018 15:10:17 +0100 From: Kevin Wolf Message-ID: <20181130141017.GF5106@localhost.localdomain> References: <20181129101801.6421-1-vsementsov@virtuozzo.com> <20181129101801.6421-3-vsementsov@virtuozzo.com> <2f4c1bec-b5ca-e97f-88f9-75f3d2cb210c@redhat.com> <73cb2885-3a40-6d2b-24fa-c528decdbc9b@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <73cb2885-3a40-6d2b-24fa-c528decdbc9b@virtuozzo.com> Subject: Re: [Qemu-devel] [PATCH v2 2/2] iotests: simple mirror test with kvm on 1G image List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vladimir Sementsov-Ogievskiy Cc: Max Reitz , "qemu-block@nongnu.org" , "qemu-devel@nongnu.org" , "jcody@redhat.com" , "pbonzini@redhat.com" , Denis Plotnikov , Denis Lunev , "qemu-stable@nongnu.org" Am 30.11.2018 um 14:48 hat Vladimir Sementsov-Ogievskiy geschrieben: > 30.11.2018 16:13, Max Reitz wrote: > > On 30.11.18 14:06, Vladimir Sementsov-Ogievskiy wrote: > >> 30.11.2018 15:30, Max Reitz wrote: > >>> On 29.11.18 11:18, Vladimir Sementsov-Ogievskiy wrote: > >>>> This test is broken without previous commit fixing dead-lock in mirror. > >>>> > >>>> Signed-off-by: Vladimir Sementsov-Ogievskiy > >>>> --- > >>>> tests/qemu-iotests/235 | 59 ++++++++++++++++++++++++++++++++++++++ > >>>> tests/qemu-iotests/235.out | 1 + > >>>> tests/qemu-iotests/group | 1 + > >>>> 3 files changed, 61 insertions(+) > >>>> create mode 100755 tests/qemu-iotests/235 > >>>> create mode 100644 tests/qemu-iotests/235.out > >>> I'll get to the first patch in a second, but first a suggestion for this > >>> patch: I think it's not so good to use 2 GB of space for a test (1 GB > >>> for the source, 1 GB for the target). So I tried my luck and found that > >>> the test works, too, if you just use preallocation=metadata for the > >>> source (instead of actually writing data) and blockdev-mirror'ing the > >>> data to a throttled null-co device. > >> > >> Hmm, so parsing metadata is enough for qcow2 to yield on write, yes? > > > > Apparently so. If you can confirm that applying those changes to the > > test still make it work (i.e., fail before patch 1, pass afterwards), > > then I think it is just as good. > > Ok, I've checked that your changes works for me. > > hm, but we write to null, so, yield on write comes from throttling, however, > without preallocation=metadata, it don't work.., do you know, why we need > preallocation to reproduce? If I should take a guess, probably because mirror only copies allocated clusters? Kevin