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Date: Thu, 22 Aug 2013 17:42:46 +0800
From: Fam Zheng <famz@redhat.com>
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Subject: Re: [Qemu-devel] [RFC PATCH 3/4] qmp: Add "snapshot=" option to
 nbd-server-add
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: kwolf@redhat.com, Stefan Hajnoczi <stefanha@gmail.com>, imain@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com

On Thu, 08/22 11:22, Paolo Bonzini wrote:
> Il 22/08/2013 10:53, Fam Zheng ha scritto:
> >> > This is handy but only works if the QEMU process has permission to
> >> > create temporary files.
> >> > 
> > Yes, this is a shortcut, it has this limitation, but the good side is
> > it's easy to get and no other dependency.
> > 
> > To avoid creating file, we'll need blockdev-add to override backing_hd,
> > and blockdev-backup to use an existing BDS as target, then we simply use
> > current nbd-server-add to export it.
> > 
> > This series is still RFC, with above said, we still need to decide which
> > is the way we (QEMU and libvirt) want for 1.7.  any thoughts?
> 
> I think this was the initial design, but Kevin already said he didn't
> like the idea.
> 
> (Also, if you do this you have to add nbd-server-add to qmp-transaction,
> to atomically start fleecing of multiple devices).
> 
Rigth. And this stands the same as for blockdev-backup.

Fam