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Date: Wed, 29 Jun 2011 15:56:56 +0200
From: Christoph Hellwig <hch@lst.de>
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Subject: Re: [Qemu-devel] Default cache mode
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To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: Kevin Wolf <kwolf@redhat.com>, Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>, Qemu-devel@nongnu.org, Avi Kivity <avi@redhat.com>, Christoph Hellwig <hch@lst.de>

On Wed, Jun 29, 2011 at 01:52:19PM +0100, Stefan Hajnoczi wrote:
> Whether it is safe to transition to cache=none or not depends on what
> broken guests are still widely deployed.  Does CentOS 5 flush the disk
> cache?

Unless you use ext3 it does.  The same unfortunate story still applies to
current Linux mainline.