Re: [Qemu-devel] [PATCH] qemu-img: let qemu-img behave as the manual advertise

[Liu Yuan]

On 04/11/2012 03:49 PM, Kevin Wolf wrote:

> I don't agree with this patch. If the documentation says that qemu-img
> always uses writeback, then the documentation must be fixed.
> 
> We really don't care about flushes during an image conversion. It should
> just go as fast as it can. If any error happens in the middle, you'll
> have to throw the image away anyway, because it contains only half of
> what you need. So not having flushed doesn't really make any difference.
> 
> As soon as a guest begins using the image with data that we really care
> about, it's probably running in a VM with non-unsafe mode, and then it
> gets flushed.


But we can set cache mode for qemu-img convert. So at least if we set
explicitly with other modes(for e.g, writeback) that ask to flush the
dirty bits, I think we should call brdv_flush().

If you agree, I'll update the patch with this modification.

Thanks,
Yuan