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Date: Thu, 20 May 2010 13:58:58 -0500
From: Anthony Liguori <aliguori@linux.vnet.ibm.com>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] [PATCH] QEMU: change default disk cache behavior
References: <1274347924-9188-1-git-send-email-Jes.Sorensen@redhat.com>
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To: Jes Sorensen <Jes.Sorensen@redhat.com>
Cc: hch@infradead.org, Anthony Liguori <aliguori@us.ibm.com>, qemu-devel@nongnu.org, crobinso@redhat.com

On 05/20/2010 08:49 AM, Jes Sorensen wrote:
> On 05/20/10 15:40, Anthony Liguori wrote:
>    
>> On 05/20/2010 08:36 AM, Jes Sorensen wrote:
>>      
>>>> And I strongly suspect that such a blanket change would be wrong but
>>>> that a more targeted change like making cache=none default for physical
>>>> devices would satisfy mostly everyone.
>>>>
>>>>          
>>> Is there any other thing than physical devices attached to the -drive
>>> parameter?
>>>        
>> Image files which are the overwhelming more common use-case.
>>      
> For image files we certainly want it too, at least for proper ones (ie.
> raw).

What makes you say that?

>   It could be that it causes problems for qcow2.
>    

It's definitely the wrong thing for qcow2 with backing files.

Regards,

Anthony Liguori

> I'll try and look at it when I am back.
>
> Cheers,
> Jes
>
>