226 \fB\fBlz4_compress\fR\fR
 227 .ad
 228 .RS 4n
 229 .TS
 230 l l .
 231 GUID    org.illumos:lz4_compress
 232 READ\-ONLY COMPATIBLE   no
 233 DEPENDENCIES    none
 234 .TE
 235 
 236 \fBlz4\fR is a high-performance real-time compression algorithm that
 237 features significantly faster compression and decompression as well as a
 238 higher compression ratio than the older \fBlzjb\fR compression.
 239 Typically, \fBlz4\fR compression is approximately 50% faster on
 240 compressible data and 200% faster on incompressible data than
 241 \fBlzjb\fR. It is also approximately 80% faster on decompression, while
 242 giving approximately 10% better compression ratio.
 243 
 244 When the \fBlz4_compress\fR feature is set to \fBenabled\fR, the
 245 administrator can turn on \fBlz4\fR compression on any dataset on the
 246 pool using the \fBzfs\fR(1M) command. Please note that doing so will
 247 immediately activate the \fBlz4_compress\fR feature on the underlying
 248 pool (even before any data is written), and the feature will not be
 249 deactivated. Since this feature is not read-only compatible, this
 250 operation will render the pool unimportable on systems without support
 251 for the \fBlz4_compress\fR feature. Booting off of \fBlz4\fR-compressed
 252 root pools is supported.

 253 .RE
 254 
 255 .sp
 256 .ne 2
 257 .na
 258 \fB\fBspacemap_histogram\fR\fR
 259 .ad
 260 .RS 4n
 261 .TS
 262 l l .
 263 GUID    com.delphix:spacemap_histogram
 264 READ\-ONLY COMPATIBLE   yes
 265 DEPENDENCIES    none
 266 .TE
 267 
 268 This features allows ZFS to maintain more information about how free space
 269 is organized within the pool. If this feature is \fBenabled\fR, ZFS will
 270 set this feature to \fBactive\fR when a new space map object is created or
 271 an existing space map is upgraded to the new format. Once the feature is
 272 \fBactive\fR, it will remain in that state until the pool is destroyed.

 226 \fB\fBlz4_compress\fR\fR
 227 .ad
 228 .RS 4n
 229 .TS
 230 l l .
 231 GUID    org.illumos:lz4_compress
 232 READ\-ONLY COMPATIBLE   no
 233 DEPENDENCIES    none
 234 .TE
 235 
 236 \fBlz4\fR is a high-performance real-time compression algorithm that
 237 features significantly faster compression and decompression as well as a
 238 higher compression ratio than the older \fBlzjb\fR compression.
 239 Typically, \fBlz4\fR compression is approximately 50% faster on
 240 compressible data and 200% faster on incompressible data than
 241 \fBlzjb\fR. It is also approximately 80% faster on decompression, while
 242 giving approximately 10% better compression ratio.
 243 
 244 When the \fBlz4_compress\fR feature is set to \fBenabled\fR, the
 245 administrator can turn on \fBlz4\fR compression on any dataset on the
 246 pool using the \fBzfs\fR(1M) command. Also, all newly written metadata
 247 will be compressed with \fBlz4\fR algorithm. Since this feature is not
 248 read-only compatible, this operation will render the pool unimportable
 249 on systems without support for the \fBlz4_compress\fR feature. Booting
 250 off of \fBlz4\fR-compressed root pools is supported.
 251 
 252 This feature becomes \fBactive\fR as soon as it is enabled and will
 253 never return to being \fBenabled\fB.
 254 .RE
 255 
 256 .sp
 257 .ne 2
 258 .na
 259 \fB\fBspacemap_histogram\fR\fR
 260 .ad
 261 .RS 4n
 262 .TS
 263 l l .
 264 GUID    com.delphix:spacemap_histogram
 265 READ\-ONLY COMPATIBLE   yes
 266 DEPENDENCIES    none
 267 .TE
 268 
 269 This features allows ZFS to maintain more information about how free space
 270 is organized within the pool. If this feature is \fBenabled\fR, ZFS will
 271 set this feature to \fBactive\fR when a new space map object is created or
 272 an existing space map is upgraded to the new format. Once the feature is
 273 \fBactive\fR, it will remain in that state until the pool is destroyed.