Re: [Qemu-devel] [Qemu-block] [PATCH] doc: Propose NBD_FLAG_INIT_ZEROES extension

2016-12-07 Thread Kevin Wolf
Am 07.12.2016 um 16:50 hat Eric Blake geschrieben: > On 12/07/2016 04:44 AM, Kevin Wolf wrote: > >> Just because the NBD spec describes the bit does NOT require that > >> servers HAVE to set the bit on all images that are all zeroes. It is > >> perfectly compliant if the server never advertises

Re: [Qemu-devel] [Qemu-block] [PATCH] doc: Propose NBD_FLAG_INIT_ZEROES extension

2016-12-07 Thread Eric Blake
On 12/07/2016 04:44 AM, Kevin Wolf wrote: >> Just because the NBD spec describes the bit does NOT require that >> servers HAVE to set the bit on all images that are all zeroes. It is >> perfectly compliant if the server never advertises the bit. > > True, but if no server exists that would

Re: [Qemu-devel] [Qemu-block] [PATCH] doc: Propose NBD_FLAG_INIT_ZEROES extension

2016-12-07 Thread Kevin Wolf
Am 06.12.2016 um 16:21 hat Eric Blake geschrieben: > On 12/06/2016 03:25 AM, Kevin Wolf wrote: > > Am 06.12.2016 um 00:42 hat Eric Blake geschrieben: > >> While not directly related to NBD_CMD_WRITE_ZEROES, the qemu > >> team discovered that it is useful if a server can advertise > >> whether an

Re: [Qemu-devel] [Qemu-block] [PATCH] doc: Propose NBD_FLAG_INIT_ZEROES extension

2016-12-06 Thread Eric Blake
On 12/06/2016 03:25 AM, Kevin Wolf wrote: > Am 06.12.2016 um 00:42 hat Eric Blake geschrieben: >> While not directly related to NBD_CMD_WRITE_ZEROES, the qemu >> team discovered that it is useful if a server can advertise >> whether an export is in a known-all-zeroes state at the time >> the

Re: [Qemu-devel] [Qemu-block] [PATCH] doc: Propose NBD_FLAG_INIT_ZEROES extension

2016-12-06 Thread Kevin Wolf
Am 06.12.2016 um 00:42 hat Eric Blake geschrieben: > While not directly related to NBD_CMD_WRITE_ZEROES, the qemu > team discovered that it is useful if a server can advertise > whether an export is in a known-all-zeroes state at the time > the client connects. Does a server usually have the