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.\" $DragonFly: src/sbin/newfs_hammer/newfs_hammer.8,v 1.10 2008/07/27 16:47:19 thomas Exp $ 34.Dd September 28, 2009 35.Dt NEWFS_HAMMER 8 36.Os 37.Sh NAME 38.Nm newfs_hammer 39.Nd construct a new HAMMER file system 40.Sh SYNOPSIS 41.Nm 42.Fl L Ar label 43.Op Fl f 44.Op Fl b Ar bootsize 45.Op Fl m Ar savesize 46.Op Fl u Ar undosize 47.Op Fl V Ar version 48.Ar special ... 49.Sh DESCRIPTION 50The 51.Nm 52utility creates a 53.Nm HAMMER 54file system on device(s) 55.Ar special . 56If multiple devices are specified a single 57.Nm HAMMER 58file system is created 59which spans all of them. 60Each 61.Ar special 62will constitute a volume which the 63.Nm HAMMER 64file system is built on. 65.Nm HAMMER 66file systems are sector-size agnostic, however the 67.Dx 68implementation requires the sector size to be no larger than 16K. 69.Nm HAMMER 70file systems start at a relative offset of 0 and may only be created 71under out-of-band disk labels 72.Po 73.Xr disklabel64 5 74or 75.Xr gpt 8 76labels 77.Pc , 78or in 79.Xr disklabel 5 80partitions which do not overlap the label area (have a starting sector 81greater than 16). 82.Pp 83.Nm HAMMER 84file systems are designed for large storage systems, up to 1 Exabyte, and 85will not operate efficiently on small storage systems. 86The minimum recommended file system size is 50GB. 87.Nm HAMMER 88must reserve 500MB to 1GB of its storage for reblocking and UNDO. 89In addition, 90.Nm HAMMER 91file systems operating normally, with full history 92retention and daily snapshots, do not immediately reclaim space when 93files are deleted. 94A regular system maintenance job runs once a day by 95.Xr periodic 8 96to handle reclamation. 97.Pp 98.Nm HAMMER 99works best when the machine's normal workload would not otherwise fill 100the file system up in the course of 60 days of operation. 101.Pp 102The options are as follows: 103.Bl -tag -width indent 104.It Fl L Ar label 105All 106.Nm HAMMER 107file systems must be named and names should be unique on a 108per-machine basis. 109.It Fl b Ar bootsize 110Specify a fixed area in which a boot related kernel and data can be stored. 111The 112.Ar bootsize 113is specified in bytes. 114By default a boot area of approximately 4MB will be created. 115.It Fl f 116Force the creation of a 117.Nm HAMMER 118file system with less than 100MB UNDO FIFO. 119This should not be used under normal circumstances. 120.It Fl m Ar savesize 121Specify a fixed area which 122.Nm HAMMER 123may use as a memory log. 124This area is currently unused. 125The 126.Ar savesize 127is specified in bytes. 128.It Fl u Ar undosize 129Specify the size of the fixed UNDO FIFO. 130The 131.Ar undosize 132is specified in bytes. 133By default 0.1% of the root 134volume's size is used, with a reasonable minimum and a reasonable cap. 135The UNDO FIFO is used to sequence meta-data out to the media for instant 136crash recovery. 137.It Fl V Ar version 138Specify the 139.Nm HAMMER 140file system version to format. 141By default 142.Nm 143formats the file system using the highest production version number 144supported by the 145.Nm HAMMER 146VFS by checking the 147.Va vfs.hammer.supported_version 148sysctl. 149If you need to maintain compatibility with an older version of 150.Nm HAMMER 151you may specify the version with this option. 152.El 153.Pp 154The 155.Ar bootsize , 156.Ar savesize 157and 158.Ar undosize 159can be given with a suffix of 160.Cm K , M , G 161or 162.Cm T 163meaning kilobyte, megabyte, gigabyte and terabyte. 164Lower case can also be used for suffix. 165.Sh EXAMPLES 166.Bd -literal -offset indent 167newfs_hammer -L Home /dev/ad0s1d 168.Ed 169.Pp 170Create a file system named 171.Sq Home 172on 173.Pa /dev/ad0s1d . 174.Sh DIAGNOSTICS 175Exit status is 0 on success and 1 on error. 176.Sh SEE ALSO 177.Xr disklabel 5 , 178.Xr disklabel64 5 , 179.Xr HAMMER 5 , 180.Xr fdisk 8 , 181.Xr gpt 8 , 182.Xr newfs 8 183.Sh HISTORY 184The 185.Nm 186utility first appeared in 187.Dx 1.11 . 188.Sh AUTHORS 189.An Matthew Dillon Aq dillon@backplane.com 190