1 '\" te
2 .\" Copyright (c) 2012 by Delphix. All rights reserved.
3 .\" The contents of this file are subject to the terms of the Common Development
4 .\" and Distribution License (the "License"). You may not use this file except
5 .\" in compliance with the License. You can obtain a copy of the license at
6 .\" usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.
7 .\"
8 .\" See the License for the specific language governing permissions and
9 .\" limitations under the License. When distributing Covered Code, include this
10 .\" CDDL HEADER in each file and include the License file at
11 .\" usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this
12 .\" CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your
13 .\" own identifying information:
14 .\" Portions Copyright [yyyy] [name of copyright owner]
15 .TH ZPOOL-FEATURES 5 "Mar 16, 2012"
16 .SH NAME
17 zpool\-features \- ZFS pool feature descriptions
18 .SH DESCRIPTION
19 .sp
20 .LP
21 ZFS pool on\-disk format versions are specified via "features" which replace
22 the old on\-disk format numbers (the last supported on\-disk format number is
23 28). To enable a feature on a pool use the \fBupgrade\fR subcommand of the
24 \fBzpool\fR(1M) command, or set the \fBfeature@\fR\fIfeature_name\fR property
25 to \fBenabled\fR.
26 .sp
27 .LP
28 The pool format does not affect file system version compatibility or the ability
29 to send file systems between pools.
30 .sp
31 .LP
32 Since most features can be enabled independently of each other the on\-disk
33 format of the pool is specified by the set of all features marked as
34 \fBactive\fR on the pool. If the pool was created by another software version
35 this set may include unsupported features.
180 l l .
181 GUID com.delphix:empty_bpobj
182 READ\-ONLY COMPATIBLE yes
183 DEPENDENCIES none
184 .TE
185
186 This feature increases the performance of creating and using a large
187 number of snapshots of a single filesystem or volume, and also reduces
188 the disk space required.
189
190 When there are many snapshots, each snapshot uses many Block Pointer
191 Objects (bpobj's) to track blocks associated with that snapshot.
192 However, in common use cases, most of these bpobj's are empty. This
193 feature allows us to create each bpobj on-demand, thus eliminating the
194 empty bpobjs.
195
196 This feature is \fBactive\fR while there are any filesystems, volumes,
197 or snapshots which were created after enabling this feature.
198 .RE
199
200 .SH "SEE ALSO"
201 \fBzpool\fR(1M)
|
1 '\" te
2 .\" Copyright (c) 2012 by Delphix. All rights reserved.
3 .\" Copyright (c) 2012 Joyent, Inc. All rights reserved.
4 .\" The contents of this file are subject to the terms of the Common Development
5 .\" and Distribution License (the "License"). You may not use this file except
6 .\" in compliance with the License. You can obtain a copy of the license at
7 .\" usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.
8 .\"
9 .\" See the License for the specific language governing permissions and
10 .\" limitations under the License. When distributing Covered Code, include this
11 .\" CDDL HEADER in each file and include the License file at
12 .\" usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this
13 .\" CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your
14 .\" own identifying information:
15 .\" Portions Copyright [yyyy] [name of copyright owner]
16 .TH ZPOOL-FEATURES 5 "Oct 24, 2012"
17 .SH NAME
18 zpool\-features \- ZFS pool feature descriptions
19 .SH DESCRIPTION
20 .sp
21 .LP
22 ZFS pool on\-disk format versions are specified via "features" which replace
23 the old on\-disk format numbers (the last supported on\-disk format number is
24 28). To enable a feature on a pool use the \fBupgrade\fR subcommand of the
25 \fBzpool\fR(1M) command, or set the \fBfeature@\fR\fIfeature_name\fR property
26 to \fBenabled\fR.
27 .sp
28 .LP
29 The pool format does not affect file system version compatibility or the ability
30 to send file systems between pools.
31 .sp
32 .LP
33 Since most features can be enabled independently of each other the on\-disk
34 format of the pool is specified by the set of all features marked as
35 \fBactive\fR on the pool. If the pool was created by another software version
36 this set may include unsupported features.
181 l l .
182 GUID com.delphix:empty_bpobj
183 READ\-ONLY COMPATIBLE yes
184 DEPENDENCIES none
185 .TE
186
187 This feature increases the performance of creating and using a large
188 number of snapshots of a single filesystem or volume, and also reduces
189 the disk space required.
190
191 When there are many snapshots, each snapshot uses many Block Pointer
192 Objects (bpobj's) to track blocks associated with that snapshot.
193 However, in common use cases, most of these bpobj's are empty. This
194 feature allows us to create each bpobj on-demand, thus eliminating the
195 empty bpobjs.
196
197 This feature is \fBactive\fR while there are any filesystems, volumes,
198 or snapshots which were created after enabling this feature.
199 .RE
200
201 .sp
202 .ne 2
203 .na
204 \fB\fBfilesystem_limits\fR\fR
205 .ad
206 .RS 4n
207 .TS
208 l l .
209 GUID com.joyent:filesystem_limits
210 READ\-ONLY COMPATIBLE yes
211 DEPENDENCIES none
212 .TE
213
214 This feature enables filesystem and snapshot limits. These limits can be used
215 to control how many filesystems and/or snapshots can be created at the point in
216 the tree on which the limits are set.
217
218 This feature is \fBactive\fR once either of the limit properties has been
219 set on a dataset and is deactivated when the last limit is removed.
220 .RE
221
222 .SH "SEE ALSO"
223 \fBzpool\fR(1M)
|