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Date: Mon, 4 Mar 2013 17:04:01 +0100
From: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20130304160400.GH3929@dhcp-200-207.str.redhat.com>
References: <1362405755-3308-1-git-send-email-stefanha@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH v2 0/6] qcow2: cache flush fixes and
 performance improvements
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To: Stefan Hajnoczi <stefanha@redhat.com>
Cc: qemu-devel@nongnu.org

Am 04.03.2013 um 15:02 hat Stefan Hajnoczi geschrieben:
> Users have reported that qcow2 internal snapshot creation is slow.  I filed a
> bug report at https://bugs.launchpad.net/qemu/+bug/1126369.
> 
> This patch series reduces the time for qcow2 internal snapshot creation
> significantly, from more than 3 minutes to under 1 second.
> 
> In the process of removing unnecessary cache flushes, I also stumbled upon
> instances of bdrv_flush(bs->file) where we really want to flush metadata
> updates.  Since qcow2 caches metadata this actually does not write out the
> metadata updates to disk!  The fix is either bdrv_flush(bs) or a more specific
> cache flush (e.g. refcount block cache).
> 
> This series passes qemu-iotests.

Thanks, applied all to the block branch.

Kevin