search for: make_zero

...ure that some image is > zero. Knowing whether an image is zero can help with that, but that can > be an implementation detail. > > For qcow2, the idea would be that there is some flag that remains true > as long as the image is guaranteed to be zero. Then we’d have some > bdrv_make_zero function, and qcow2’s implementation would use this > information to gauge whether there’s something to do as all. > > For NBD, we cannot use this idea directly because to implement such a > flag (as you’re describing in this mail), we’d need separate is_zero > infrastructure, and t...

...involve someone having to ensure that some image is zero. Knowing whether an image is zero can help with that, but that can be an implementation detail. For qcow2, the idea would be that there is some flag that remains true as long as the image is guaranteed to be zero. Then we’d have some bdrv_make_zero function, and qcow2’s implementation would use this information to gauge whether there’s something to do as all. For NBD, we cannot use this idea directly because to implement such a flag (as you’re describing in this mail), we’d need separate is_zero infrastructure, and that kind of makes the poi...

I will be following up to this email with four separate threads each addressed to the appropriate single list, with proposed changes to: - the NBD protocol - qemu: both server and client - libnbd: client - nbdkit: server The feature in question adds a new optional NBD_INFO_ packet to the NBD_OPT_GO portion of handshake, adding up to 16 bits of information that the server can advertise to the