From: Peter Krempa <pkrempa@redhat.com>
To: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Cc: John Snow <jsnow@redhat.com>, qemu-devel <qemu-devel@nongnu.org>,
Qemu-block <qemu-block@nongnu.org>, Max Reitz <mreitz@redhat.com>
Subject: Re: bitmap migration bug with -drive while block mirror runs
Date: Tue, 1 Oct 2019 13:45:14 +0200 [thread overview]
Message-ID: <20191001114514.GA9210@angien.pipo.sk> (raw)
In-Reply-To: <f84745dc-68df-c10a-a91b-a28498e54870@virtuozzo.com>
On Tue, Oct 01, 2019 at 08:57:37 +0000, Vladimir Sementsov-Ogievskiy wrote:
> 01.10.2019 3:09, John Snow wrote:
> > Hi folks, I identified a problem with the migration code that Red Hat QE
> > found and thought you'd like to see it:
> >
> > https://bugzilla.redhat.com/show_bug.cgi?id=1652424#c20
> >
> > Very, very briefly: drive-mirror inserts a filter node that changes what
> > bdrv_get_device_or_node_name() returns, which causes a migration problem.
> >
> >
> > Ignorant question #1: Can we multi-parent the filter node and
> > source-node? It looks like at the moment both consider their only parent
> > to be the block-job and don't have a link back to their parents otherwise.
> >
> >
> > Otherwise: I have a lot of cloudy ideas on how to solve this, but
> > ultimately what we want is to be able to find the "addressable" name for
> > the node the bitmap is attached to, which would be the name of the first
> > ancestor node that isn't a filter. (OR, the name of the block-backend
> > above that node.)
>
>
> Better would be to migrate by node-name only.. But am I right that node-names
> are different on source and destination? Or this situation changed?
They may be different. Some time ago when I asked I was told that node
names are not bound to any state in qemu and thus can be re-created on
destination. Otherwise they technically become guest ABI which would
require changes to libvirt's blockdev usage.
next prev parent reply other threads:[~2019-10-01 11:47 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-01 0:09 bitmap migration bug with -drive while block mirror runs John Snow
2019-10-01 4:28 ` Peter Krempa
2019-10-01 9:07 ` Vladimir Sementsov-Ogievskiy
2019-10-01 8:57 ` Vladimir Sementsov-Ogievskiy
2019-10-01 9:54 ` Kevin Wolf
2019-10-01 10:05 ` Vladimir Sementsov-Ogievskiy
2019-10-01 13:24 ` Peter Krempa
2019-10-01 15:09 ` John Snow
2019-10-01 15:58 ` Kevin Wolf
2019-10-01 16:12 ` Vladimir Sementsov-Ogievskiy
2019-10-01 16:24 ` Kevin Wolf
2019-10-01 16:23 ` John Snow
2019-10-01 11:45 ` Peter Krempa [this message]
2019-10-01 9:17 ` Vladimir Sementsov-Ogievskiy
2019-10-01 14:00 ` Vladimir Sementsov-Ogievskiy
2019-10-01 14:10 ` John Snow
2019-10-01 15:57 ` Vladimir Sementsov-Ogievskiy
2019-10-01 16:07 ` John Snow
2019-10-02 8:12 ` Kevin Wolf
2019-10-02 10:46 ` Peter Krempa
2019-10-02 11:11 ` Kevin Wolf
2019-10-02 12:22 ` Vladimir Sementsov-Ogievskiy
2019-10-02 13:48 ` Peter Krempa
2019-10-02 13:43 ` Peter Krempa
2019-10-02 14:03 ` Vladimir Sementsov-Ogievskiy
2019-10-02 21:35 ` John Snow
2019-10-03 10:14 ` Vladimir Sementsov-Ogievskiy
2019-10-03 23:34 ` John Snow
2019-10-04 8:33 ` Peter Krempa
2019-10-04 9:21 ` Vladimir Sementsov-Ogievskiy
2019-10-06 3:15 ` John Snow
2019-10-04 9:24 ` Vladimir Sementsov-Ogievskiy
2019-10-04 13:07 ` Eric Blake
2019-10-06 3:19 ` John Snow
2019-10-01 16:16 ` Kevin Wolf
2019-10-01 16:17 ` Vladimir Sementsov-Ogievskiy
2019-10-01 14:13 ` Max Reitz
2019-10-01 14:27 ` Vladimir Sementsov-Ogievskiy
2019-10-01 14:34 ` Max Reitz
2019-10-01 14:53 ` Vladimir Sementsov-Ogievskiy
2019-10-01 15:26 ` Max Reitz
2019-10-02 7:34 ` Peter Krempa
2019-10-01 15:09 ` Kevin Wolf
2019-10-01 15:27 ` Max Reitz
2019-10-01 16:12 ` Kevin Wolf
2019-10-01 16:17 ` Max Reitz
2019-10-01 16:22 ` Vladimir Sementsov-Ogievskiy
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