From mboxrd@z Thu Jan  1 00:00:00 1970
From: Anthony Liguori <anthony@codemonkey.ws>
Subject: Re: qemu and qemu.git -> Migration + disk stress
 introduces qcow2 corruptions
Date: Wed, 09 Nov 2011 15:01:39 -0600
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Cc: Lucas Meneghel Rodrigues <lmr@redhat.com>, Kevin Wolf <kwolf@redhat.com>,
	KVM mailing list <kvm@vger.kernel.org>,
	Juan Jose Quintela Carreira <quintela@redhat.com>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	QEMU devel <qemu-devel@nongnu.org>, Avi Kivity <avi@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
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On 11/09/2011 03:00 PM, Michael S. Tsirkin wrote:
> On Wed, Nov 09, 2011 at 02:22:02PM -0600, Anthony Liguori wrote:
>> On 11/09/2011 02:18 PM, Michael S. Tsirkin wrote:
>>> On Wed, Nov 09, 2011 at 11:35:54AM -0600, Anthony Liguori wrote:
>>>> 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.
>>>
>>> A simple solution is not to do any probing before the VM is first
>>> started on the incoming path.
>>>
>>> Any issues with this?
>>>
>>
>> http://mid.gmane.org/1284213896-12705-4-git-send-email-aliguori@us.ibm.com
>> I think Kevin wanted open to get delayed.
>>
>> Regards,
>>
>> Anthony Liguori
>
> So, this patchset just needs to be revived and polished up?

What I took from the feedback was that Kevin wanted to defer open until the 
device model started.  That eliminates the need to reopen or have a invalidation 
callback.

I think it would be good for Kevin to comment here though because I might have 
misunderstood his feedback.

Regards,

Anthony Liguori

>