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From: Avi Kivity <avi@redhat.com>
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Subject: Re: [Qemu-devel] Re: [PATCH v2 6/7] qed: Read/write support
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To: Anthony Liguori <aliguori@linux.vnet.ibm.com>
Cc: Kevin Wolf <kwolf@redhat.com>, Christoph Hellwig <hch@lst.de>, Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>, qemu-devel@nongnu.org

  On 10/13/2010 04:11 PM, Anthony Liguori wrote:
>> Why would you ever update the header, apart from relocating L1 for 
>> some reason?
>
>
> To update the L1/L2 tables clean bit.  That's what prevents a check in 
> the normal case where you have a clean shutdown.

I see - so you wouldn't update it every allocation, only when the disk 
has been quiet for a while.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.