Eric Blake writes:
> Qemu's attempts to learn whether a destination file starts life with
QEMU (multiple times).
> all zero contents are just a hueristic. There may be cases where the
heuristic
> caller is aware of information that qemu cannot learn quickly, in
> which case telling qemu what
Qemu's attempts to learn whether a destination file starts life with
all zero contents are just a hueristic. There may be cases where the
caller is aware of information that qemu cannot learn quickly, in
which case telling qemu what to assume about the destination can make
the mirror operation fas
