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Date: Tue, 23 Jul 2013 13:13:04 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 1/2] block: allow live commit of active
	image
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To: famz@redhat.com
Cc: kwolf@redhat.com, jcody@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com

Il 23/07/2013 04:03, Fam Zheng ha scritto:
>> >     stop
>> >     block-job-complete ide0-hd0
>> >     cont
>> > 
> I see, this way the job needs to stop vm in the point of all copying
> drained, then report 'ready' and wait for manual complete before
> swapping active, sounds not so good. Ideally we should mirror writes
> _synchronously_ to 'top' and 'base' after 'ready' state and wait for
> manual complete to switch image. Do you think this is easy to do?

Synchronous mirroring makes it harder to handle errors in writing the
target, especially if you're not running with rerror=stop/werror=stop
(they would be reported to the guest).

Paolo