1.\" Copyright (c) 2007 The DragonFly Project.  All rights reserved.
2.\"
3.\" This code is derived from software contributed to The DragonFly Project
4.\" by Matthew Dillon <dillon@backplane.com>
5.\"
6.\" Redistribution and use in source and binary forms, with or without
7.\" modification, are permitted provided that the following conditions
8.\" are met:
9.\"
10.\" 1. Redistributions of source code must retain the above copyright
11.\"    notice, this list of conditions and the following disclaimer.
12.\" 2. Redistributions in binary form must reproduce the above copyright
13.\"    notice, this list of conditions and the following disclaimer in
14.\"    the documentation and/or other materials provided with the
15.\"    distribution.
16.\" 3. Neither the name of The DragonFly Project nor the names of its
17.\"    contributors may be used to endorse or promote products derived
18.\"    from this software without specific, prior written permission.
19.\"
20.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22.\" LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23.\" FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
24.\" COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25.\" INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
26.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
30.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31.\" SUCH DAMAGE.
32.\"
33.Dd October 7, 2011
34.Dt NEWFS_HAMMER 8
35.Os
36.Sh NAME
37.Nm newfs_hammer
38.Nd construct a new HAMMER file system
39.Sh SYNOPSIS
40.Nm
41.Fl L Ar label
42.Op Fl \&Ef
43.Op Fl b Ar bootsize
44.Op Fl m Ar savesize
45.Op Fl u Ar undosize
46.Op Fl V Ar version
47.Ar special ...
48.Sh DESCRIPTION
49The
50.Nm
51utility creates a
52.Nm HAMMER
53file system on device(s)
54.Ar special .
55If multiple devices are specified a single
56.Nm HAMMER
57file system is created
58which spans all of them.
59Each
60.Ar special
61will constitute a volume which the
62.Nm HAMMER
63file system is built on.
64.Nm HAMMER
65file systems are sector-size agnostic, however the
66.Dx
67implementation requires the sector size to be no larger than 16K.
68.Nm HAMMER
69file systems start at a relative offset of 0 and may only be created
70under out-of-band disk labels
71.Po
72.Xr disklabel64 5
73or
74.Xr gpt 8
75labels
76.Pc ,
77or in
78.Xr disklabel32 5
79partitions which do not overlap the label area (have a starting sector
80greater than 16).
81.Pp
82.Nm HAMMER
83file systems are designed for large storage systems, up to 1 Exabyte, and
84will not operate efficiently on small storage systems.
85The minimum recommended file system size is 50GB.
86.Nm HAMMER
87must reserve 500MB to 1GB of its storage for reblocking and UNDO/REDO.
88In addition,
89.Nm HAMMER
90file systems operating normally, with full history
91retention and daily snapshots, do not immediately reclaim space when
92files are deleted.
93A regular system maintenance job runs once a day by
94.Xr periodic 8
95to handle reclamation.
96.Pp
97.Nm HAMMER
98works best when the machine's normal workload would not otherwise fill
99the file system up in the course of 60 days of operation.
100.Pp
101The options are as follows:
102.Bl -tag -width indent
103.It Fl L Ar label
104All
105.Nm HAMMER
106file systems must be named and names should be unique on a
107per-machine basis.
108.It Fl b Ar bootsize
109Specify a fixed area in which a boot related kernel and data can be stored.
110The
111.Ar bootsize
112is specified in bytes.
113By default a boot area of approximately 4MB will be created.
114.It Fl f
115Force operation.
116This is needed for the creation of a
117.Nm HAMMER
118file system less than 10GB size or
119with less than 500MB UNDO/REDO FIFO.
120This should not be used under normal circumstances.
121.It Fl E
122Use TRIM to erase the device's data before creating the file system.
123The underlying device must have the TRIM sysctl enabled.
124Only devices that support TRIM will have such a sysctl option
125.Va ( kern.cam.da.X.trim_enabled ) .
126.It Fl m Ar savesize
127Specify a fixed area which
128.Nm HAMMER
129may use as a memory log.
130This area is currently unused.
131The
132.Ar savesize
133is specified in bytes.
134.It Fl u Ar undosize
135Specify the size of the fixed UNDO/REDO FIFO.
136The
137.Ar undosize
138is specified in bytes.
139By default 0.1% of the root
140volume's size is used, with a reasonable minimum and a reasonable cap.
141The UNDO/REDO FIFO is used to sequence meta-data out to the media for
142instant crash recovery.
143.It Fl V Ar version
144Specify the
145.Nm HAMMER
146file system version to format.
147By default
148.Nm
149formats the file system using the highest production version number
150supported by the
151.Nm HAMMER
152VFS by checking the
153.Va vfs.hammer.supported_version
154sysctl.
155If you need to maintain compatibility with an older version of
156.Nm HAMMER
157you may specify the version with this option.
158.El
159.Pp
160The
161.Ar bootsize ,
162.Ar savesize
163and
164.Ar undosize
165must be given with a suffix of
166.Cm K , M , G
167or
168.Cm T
169meaning kilobyte, megabyte, gigabyte and terabyte.
170Lower case can also be used for suffix.
171.Sh EXAMPLES
172.Bd -literal -offset indent
173newfs_hammer -L Home /dev/ad0s1d
174.Ed
175.Pp
176Create a file system named
177.Sq Home
178on
179.Pa /dev/ad0s1d .
180.Sh DIAGNOSTICS
181Exit status is 0 on success and 1 on error.
182.Sh SEE ALSO
183.Xr disklabel32 5 ,
184.Xr disklabel64 5 ,
185.Xr HAMMER 5 ,
186.Xr fdisk 8 ,
187.Xr gpt 8 ,
188.Xr newfs 8
189.Sh HISTORY
190The
191.Nm
192utility first appeared in
193.Dx 1.11 .
194.Sh AUTHORS
195.An Matthew Dillon Aq Mt dillon@backplane.com
196