From: Anthony Liguori <anthony@codemonkey.ws>
To: Avi Kivity <avi@redhat.com>
Cc: Lucas Meneghel Rodrigues <lmr@redhat.com>,
Kevin Wolf <kwolf@redhat.com>,
KVM mailing list <kvm@vger.kernel.org>,
"Michael S. Tsirkin" <mst@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
QEMU devel <qemu-devel@nongnu.org>,
Juan Jose Quintela Carreira <quintela@redhat.com>
Subject: Re: [Qemu-devel] qemu and qemu.git -> Migration + disk stress introduces qcow2 corruptions
Date: Wed, 09 Nov 2011 11:35:54 -0600 [thread overview]
Message-ID: <4EBAB9FA.3070601@codemonkey.ws> (raw)
In-Reply-To: <4EBAB236.2060409@redhat.com>
On 11/09/2011 11:02 AM, Avi Kivity wrote:
> On 11/09/2011 06:39 PM, Anthony Liguori wrote:
>>
>> Migration with qcow2 is not a supported feature for 1.0. Migration is
>> only supported with raw images using coherent shared storage[1].
>>
>> [1] NFS is only coherent with close-to-open which right now is not
>> good enough for migration.
>
> Say what?
Due to block format probing, we read at least the first sector of the disk
during start up.
Strictly going by what NFS guarantees, since we don't open on the destination
*after* as close on the source, we aren't guaranteed to see what's written by
the source.
In practice, because of block format probing, unless we're using cache=none, the
first sector can be out of sync with the source on the destination. If you use
cache=none on a Linux client with at least a Linux NFS server, you should be
relatively safe.
Regards,
Anthony Liguori
next prev parent reply other threads:[~2011-11-09 17:36 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-09 16:29 [Qemu-devel] qemu and qemu.git -> Migration + disk stress introduces qcow2 corruptions Lucas Meneghel Rodrigues
2011-11-09 16:39 ` Anthony Liguori
2011-11-09 17:02 ` Avi Kivity
2011-11-09 17:35 ` Anthony Liguori [this message]
2011-11-09 19:53 ` Juan Quintela
2011-11-09 20:18 ` Michael S. Tsirkin
2011-11-09 20:22 ` Anthony Liguori
2011-11-09 21:00 ` Michael S. Tsirkin
2011-11-09 21:01 ` Anthony Liguori
2011-11-10 10:41 ` Kevin Wolf
2011-11-10 16:50 ` Juan Quintela
2011-11-10 17:59 ` Anthony Liguori
2011-11-10 18:00 ` Anthony Liguori
2011-11-09 20:57 ` Juan Quintela
2011-11-10 8:55 ` Avi Kivity
2011-11-10 17:50 ` Juan Quintela
2011-11-10 17:54 ` Anthony Liguori
2011-11-12 10:20 ` Avi Kivity
2011-11-12 13:30 ` Anthony Liguori
2011-11-12 14:36 ` Avi Kivity
2011-11-10 18:27 ` Anthony Liguori
2011-11-10 18:42 ` Daniel P. Berrange
2011-11-10 19:11 ` Anthony Liguori
2011-11-10 20:06 ` Daniel P. Berrange
2011-11-10 20:07 ` Anthony Liguori
2011-11-10 21:30 ` Anthony Liguori
2011-11-11 10:15 ` Kevin Wolf
2011-11-11 14:03 ` Anthony Liguori
2011-11-11 14:29 ` Kevin Wolf
2011-11-11 14:35 ` Anthony Liguori
2011-11-11 14:44 ` Kevin Wolf
2011-11-11 20:38 ` Anthony Liguori
2011-11-12 10:27 ` Avi Kivity
2011-11-12 13:39 ` Anthony Liguori
2011-11-12 14:43 ` Avi Kivity
2011-11-12 16:01 ` Anthony Liguori
2011-11-12 10:25 ` Avi Kivity
2011-11-14 9:58 ` Kevin Wolf
2011-11-14 10:10 ` Michael S. Tsirkin
2011-11-15 13:28 ` Avi Kivity
2011-11-14 10:16 ` Daniel P. Berrange
2011-11-14 10:24 ` Michael S. Tsirkin
2011-11-14 11:08 ` Daniel P. Berrange
2011-11-14 11:21 ` Kevin Wolf
2011-11-14 11:29 ` Daniel P. Berrange
2011-11-14 11:34 ` Michael S. Tsirkin
2011-11-14 11:37 ` Daniel P. Berrange
2011-11-14 11:51 ` Michael S. Tsirkin
2011-11-14 11:55 ` Daniel P. Berrange
2011-11-14 11:56 ` Michael S. Tsirkin
2011-11-14 11:58 ` Daniel P. Berrange
2011-11-14 12:17 ` Michael S. Tsirkin
2011-11-14 11:36 ` Gleb Natapov
2011-11-14 11:32 ` Michael S. Tsirkin
2011-11-14 14:19 ` Anthony Liguori
2011-11-15 13:20 ` Juan Quintela
2011-11-15 13:56 ` Anthony Liguori
2011-11-09 19:25 ` Juan Quintela
2011-11-09 23:33 ` Lucas Meneghel Rodrigues
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