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Date: Sun, 14 Dec 2008 18:12:52 +0000
From: Jamie Lokier <jamie@shareable.org>
Subject: Re: [Qemu-devel] Re: snapshot vs COW?
Message-ID: <20081214181252.GE28984@shareable.org>
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To: qemu-devel@nongnu.org

walt wrote:
> Jun Koi wrote:
> >Hi,
> >
> > From what I see, both snapshot and COW features can be used to try
> >some changes on the file image before we the change back to the
> >original image.
> >
> >But what is the advantages of snapshot over COW, and in which case we
> >should use snapshot, but not COW? Vice verse, when COW is more
> >appropriate?
> >
> >Many thanks,
> >Jun
> 
> COW is a nice feature but it is currently broken, so don't use it
> until it gets fixed.  When you commit any changes your backing file
> will be corrupted.

Aieee!  I use COW instead of snapshots in my management scripts,
because snapshots are harder to manage.

Is the COW brokenness documented?  What version did it start being broken?

-- Jamie