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Date: Wed, 14 Aug 2013 17:32:16 +0200
From: Kevin Wolf <kwolf@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH] Introduce cache images for the QCOW2 format
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To: Kaveh Razavi <kaveh@cs.vu.nl>
Cc: Stefan Hajnoczi <stefanha@redhat.com>, qemu-devel@nongnu.org, Alex Bligh <alex@alex.org.uk>

Am 14.08.2013 um 16:26 hat Kaveh Razavi geschrieben:
> On 08/14/2013 03:50 PM, Alex Bligh wrote:
> > Assuming the cache quota is not exhausted, how do you know how that
> > a VM has finished 'creating' the cache? At any point it might
> > read a bit more from the backing image.
> 
> I was assuming on shutdown.

Wait, so you're not really changing the cache while it's used, but you
only create it once and then use it like a regular backing file?  If so,
the only thing we need to talk about is the creation, because there's no
difference for using it.

Creation can use the existing copy-on-read functionality, and the only
thing you need additionally is a way to turn copy-on-read off at the
right point.

Or do I misunderstand what you're doing?

Kevin