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Date: Tue, 08 Jan 2013 17:45:54 +0800
From: Liu Yuan <namei.unix@gmail.com>
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Subject: Re: [Qemu-devel] [PATCH] sheepdog: implement direct write semantics
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To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: Kevin Wolf <kwolf@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, qemu-devel@nongnu.org, MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>

On 01/08/2013 05:40 PM, Stefan Hajnoczi wrote:
> Otherwise use sheepdog writeback and let QEMU block.c decide when to
> flush.  Never use sheepdog writethrough because it's redundant here.

I don't get it. What do you mean by 'redundant'? If we use virtio &
sheepdog block driver, how can we specify writethrough mode for Sheepdog
cache? Here 'writethrough' means use a pure read cache, which doesn't
need flush at all.

Thanks,
Yuan