On Tue, Apr 10, 2018 at 6:00 PM Eric Blake <ebl...@redhat.com> wrote:
> On 04/10/2018 09:40 AM, Richard W.M. Jones wrote: > >> When the destination is a block device we cannot avoid zeroing since a > block > >> device may contain junk data (we usually get dirty empty images from our > >> local > >> xtremio server). > > > > (Off topic for qemu-block but ...) We don't have enough information > > at our end to know about any of this. > > Yep, see my other email about a possible NBD protocol extension to > actually let the client learn up-front if the exported device is known > to start in an all-zero state. > In the future we can report all-zero state in OPTIONS, but since this info is already known on engine side when creating a disk, I think reporting it in engine is better. Nir
