+
+.sp
+.ne 2
+.na
+\fB\fBempty_bpobj\fR\fR
+.ad
+.RS 4n
+.TS
+l l .
+GUID com.delphix:empty_bpobj
+READ\-ONLY COMPATIBLE yes
+DEPENDENCIES none
+.TE
+
+This feature increases the performance of creating and using a large
+number of snapshots of a single filesystem or volume, and also reduces
+the disk space required.
+
+When there are many snapshots, each snapshot uses many Block Pointer
+Objects (bpobj's) to track blocks associated with that snapshot.
+However, in common use cases, most of these bpobj's are empty. This
+feature allows us to create each bpobj on-demand, thus eliminating the
+empty bpobjs.
+
+This feature is \fBactive\fR while there are any filesystems, volumes,
+or snapshots which were created after enabling this feature.
+.RE
+
+.sp
+.ne 2
+.na
+\fB\fBlz4_compress\fR\fR
+.ad
+.RS 4n
+.TS
+l l .
+GUID org.illumos:lz4_compress
+READ\-ONLY COMPATIBLE no
+DEPENDENCIES none
+.TE
+
+\fBlz4\fR is a high-performance real-time compression algorithm that
+features significantly faster compression and decompression as well as a
+higher compression ratio than the older \fBlzjb\fR compression.
+Typically, \fBlz4\fR compression is approximately 50% faster on
+compressible data and 200% faster on incompressible data than
+\fBlzjb\fR. It is also approximately 80% faster on decompression, while
+giving approximately 10% better compression ratio.
+
+When the \fBlz4_compress\fR feature is set to \fBenabled\fR, the
+administrator can turn on \fBlz4\fR compression on any dataset on the
+pool using the \fBzfs\fR(1M) command. Please note that doing so will
+immediately activate the \fBlz4_compress\fR feature on the underlying
+pool (even before any data is written). Since this feature is not
+read-only compatible, this operation will render the pool unimportable
+on systems without support for the \fBlz4_compress\fR feature. At the
+moment, this operation cannot be reversed. Booting off of
+\fBlz4\fR-compressed root pools is supported.
+
+.RE
+