1 '\" te
2 .\" Copyright (c) 2012 by Delphix. All rights reserved.
3 .\" Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
4 .\" Copyright (c) 2013, Joyent, Inc. All rights reserved.
5 .\" The contents of this file are subject to the terms of the Common Development
6 .\" and Distribution License (the "License"). You may not use this file except
7 .\" in compliance with the License. You can obtain a copy of the license at
8 .\" usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.
9 .\"
10 .\" See the License for the specific language governing permissions and
11 .\" limitations under the License. When distributing Covered Code, include this
12 .\" CDDL HEADER in each file and include the License file at
13 .\" usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this
14 .\" CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your
15 .\" own identifying information:
16 .\" Portions Copyright [yyyy] [name of copyright owner]
17 .TH ZPOOL-FEATURES 5 "Mar 16, 2012"
18 .SH NAME
19 zpool\-features \- ZFS pool feature descriptions
20 .SH DESCRIPTION
21 .sp
22 .LP
23 ZFS pool on\-disk format versions are specified via "features" which replace
24 the old on\-disk format numbers (the last supported on\-disk format number is
25 28). To enable a feature on a pool use the \fBupgrade\fR subcommand of the
26 \fBzpool\fR(1M) command, or set the \fBfeature@\fR\fIfeature_name\fR property
27 to \fBenabled\fR.
28 .sp
29 .LP
30 The pool format does not affect file system version compatibility or the ability
31 to send file systems between pools.
32 .sp
33 .LP
34 Since most features can be enabled independently of each other the on\-disk
35 format of the pool is specified by the set of all features marked as
36 \fBactive\fR on the pool. If the pool was created by another software version
37 this set may include unsupported features.
212 DEPENDENCIES none
213 .TE
214
215 \fBlz4\fR is a high-performance real-time compression algorithm that
216 features significantly faster compression and decompression as well as a
217 higher compression ratio than the older \fBlzjb\fR compression.
218 Typically, \fBlz4\fR compression is approximately 50% faster on
219 compressible data and 200% faster on incompressible data than
220 \fBlzjb\fR. It is also approximately 80% faster on decompression, while
221 giving approximately 10% better compression ratio.
222
223 When the \fBlz4_compress\fR feature is set to \fBenabled\fR, the
224 administrator can turn on \fBlz4\fR compression on any dataset on the
225 pool using the \fBzfs\fR(1M) command. Please note that doing so will
226 immediately activate the \fBlz4_compress\fR feature on the underlying
227 pool (even before any data is written). Since this feature is not
228 read-only compatible, this operation will render the pool unimportable
229 on systems without support for the \fBlz4_compress\fR feature. At the
230 moment, this operation cannot be reversed. Booting off of
231 \fBlz4\fR-compressed root pools is supported.
232
233 .RE
234
235 .sp
236 .ne 2
237 .na
238 \fB\fBmulti_vdev_crash_dump\fR\fR
239 .ad
240 .RS 4n
241 .TS
242 l l .
243 GUID com.joyent:multi_vdev_crash_dump
244 READ\-ONLY COMPATIBLE no
245 DEPENDENCIES none
246 .TE
247
248 This feature allows a dump device to be configured with a pool comprised
249 of multiple vdevs. Those vdevs may be arranged in any mirrored or raidz
250 configuration.
251
252 When the \fBmulti_vdev_crash_dump\fR feature is set to \fBenabled\fR,
|
1 '\" te
2 .\" Copyright (c) 2012 by Delphix. All rights reserved.
3 .\" Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
4 .\" Copyright (c) 2013, Joyent, Inc. All rights reserved.
5 .\" The contents of this file are subject to the terms of the Common Development
6 .\" and Distribution License (the "License"). You may not use this file except
7 .\" in compliance with the License. You can obtain a copy of the license at
8 .\" usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.
9 .\"
10 .\" See the License for the specific language governing permissions and
11 .\" limitations under the License. When distributing Covered Code, include this
12 .\" CDDL HEADER in each file and include the License file at
13 .\" usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this
14 .\" CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your
15 .\" own identifying information:
16 .\" Portions Copyright [yyyy] [name of copyright owner]
17 .TH ZPOOL-FEATURES 5 "Aug 27, 2013"
18 .SH NAME
19 zpool\-features \- ZFS pool feature descriptions
20 .SH DESCRIPTION
21 .sp
22 .LP
23 ZFS pool on\-disk format versions are specified via "features" which replace
24 the old on\-disk format numbers (the last supported on\-disk format number is
25 28). To enable a feature on a pool use the \fBupgrade\fR subcommand of the
26 \fBzpool\fR(1M) command, or set the \fBfeature@\fR\fIfeature_name\fR property
27 to \fBenabled\fR.
28 .sp
29 .LP
30 The pool format does not affect file system version compatibility or the ability
31 to send file systems between pools.
32 .sp
33 .LP
34 Since most features can be enabled independently of each other the on\-disk
35 format of the pool is specified by the set of all features marked as
36 \fBactive\fR on the pool. If the pool was created by another software version
37 this set may include unsupported features.
212 DEPENDENCIES none
213 .TE
214
215 \fBlz4\fR is a high-performance real-time compression algorithm that
216 features significantly faster compression and decompression as well as a
217 higher compression ratio than the older \fBlzjb\fR compression.
218 Typically, \fBlz4\fR compression is approximately 50% faster on
219 compressible data and 200% faster on incompressible data than
220 \fBlzjb\fR. It is also approximately 80% faster on decompression, while
221 giving approximately 10% better compression ratio.
222
223 When the \fBlz4_compress\fR feature is set to \fBenabled\fR, the
224 administrator can turn on \fBlz4\fR compression on any dataset on the
225 pool using the \fBzfs\fR(1M) command. Please note that doing so will
226 immediately activate the \fBlz4_compress\fR feature on the underlying
227 pool (even before any data is written). Since this feature is not
228 read-only compatible, this operation will render the pool unimportable
229 on systems without support for the \fBlz4_compress\fR feature. At the
230 moment, this operation cannot be reversed. Booting off of
231 \fBlz4\fR-compressed root pools is supported.
232 .RE
233
234 .sp
235 .ne 2
236 .na
237 \fB\fBspacemap_histogram\fR\fR
238 .ad
239 .RS 4n
240 .TS
241 l l .
242 GUID com.delphix:spacemap_histogram
243 READ\-ONLY COMPATIBLE yes
244 DEPENDENCIES none
245 .TE
246
247 This features allows ZFS to maintain more information about how free space
248 is organized within the pool. If this feature is \fBenabled\fR, ZFS will
249 set this feature to \fBactive\fR when a new space map object is created or
250 an existing space map is upgraded to the new format. Once the feature is
251 \fBactive\fR, it will remain in that state until the pool is destroyed.
252 .RE
253
254 .sp
255 .ne 2
256 .na
257 \fB\fBmulti_vdev_crash_dump\fR\fR
258 .ad
259 .RS 4n
260 .TS
261 l l .
262 GUID com.joyent:multi_vdev_crash_dump
263 READ\-ONLY COMPATIBLE no
264 DEPENDENCIES none
265 .TE
266
267 This feature allows a dump device to be configured with a pool comprised
268 of multiple vdevs. Those vdevs may be arranged in any mirrored or raidz
269 configuration.
270
271 When the \fBmulti_vdev_crash_dump\fR feature is set to \fBenabled\fR,
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