Re: [Libguestfs] [Qemu-block] v2v: -o rhv-upload: Long time spent zeroing the disk

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.