illumos/illumos-gate@5749c352345749c35234https://www.illumos.org/issues/7276
The "used" and "written" properties could be described better by the zfs.1m
manpage.
"written" could be better described as "The amount of space referenced by this
dataset, that was written since the previous snapshot (i.e. that is not
referenced by the previous snapshot)."
The "used" section needs more work, but at a minimum it could say that the
"used" space of a snapshot is the space unique to the snapshot (i.e. the space
referenced only by this snapshot). The "used" space of a snapshot is a subset
of the "written" space of the snapshot.
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
cce6c1c241