Illumos #3588

3588 provide zfs properties for logical (uncompressed) space
     used and referenced
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Dan McDonald <danmcd@nexenta.com>
Reviewed by: Richard Elling <richard.elling@dey-sys.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

References:
  https://www.illumos.org/issues/3588
  illumos/illumos-gate@77372cb0f3

Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

man/man8/zfs.8

@@ -431,6 +431,40 @@ This property is \fBon\fR if the snapshot has been marked for deferred destructi
 .ne 2
 .mk
 .na
+\fB\fBlogicalreferenced\fR\fR
+.ad
+.sp .6
+.RS 4n
+The amount of space that is "logically" accessible by this dataset.  See
+the \fBreferenced\fR property.  The logical space ignores the effect of
+the \fBcompression\fR and \fBcopies\fR properties, giving a quantity
+closer to the amount of data that applications see.  However, it does
+include space consumed by metadata.
+.sp
+This property can also be referred to by its shortened column name,
+\fBlrefer\fR.
+.RE
+
+.sp
+.ne 2
+.na
+\fB\fBlogicalused\fR\fR
+.ad
+.sp .6
+.RS 4n
+The amount of space that is "logically" consumed by this dataset and all
+its descendents.  See the \fBused\fR property.  The logical space
+ignores the effect of the \fBcompression\fR and \fBcopies\fR properties,
+giving a quantity closer to the amount of data that applications see.
+However, it does include space consumed by metadata.
+.sp
+This property can also be referred to by its shortened column name,
+\fBlused\fR.
+.RE
+
+.sp
+.ne 2
+.na
 \fB\fBmounted\fR\fR
 .ad
 .sp .6