Re: [Qemu-block] [Qemu-devel] [PATCH 1/2] qapi: Add "detect-zeroes" option to drive-mirror

[Andrey Korolyov]

On Wed, Jun 10, 2015 at 7:04 PM, Alexandre DERUMIER <address@hidden> wrote:
>>>Sorry, forgot to mention - of course I`ve pulled all previous
>>>zeroing-related queue, so I haven`t had only the QMP-related fix
>>>running on top of the master :)
>
> Hi, I had a discussion about rbd mirroring, detect-zeroes and sparse target,  
> some months ago with paolo
>
> http://qemu.11.n7.nabble.com/qemu-drive-mirror-to-rbd-storage-no-sparse-rbd-image-td293642.html
>
> Not sure it's related but
>
> "Lack of bdrv_co_write_zeroes is why detect-zeroes does not work.
>
> Lack of bdrv_get_block_status is why sparse->sparse does not work
> without detect-zeroes.
>

Yes, I remember this one and the recent queue pull was the reason for
me to re-test it, despite the current patch variant would more likely
to be updated by comments from Eric, the behavior for non-file
backends like rbd can/will stay the same.