1.\" Copyright (c) 1983, 1987, 1991, 1993, 1994 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 4. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)newfs.8 8.6 (Berkeley) 5/3/95 29.\" $FreeBSD$ 30.\" 31.Dd March 21, 2008 32.Dt NEWFS 8 33.Os 34.Sh NAME 35.Nm newfs 36.Nd construct a new UFS1/UFS2 file system 37.Sh SYNOPSIS 38.Nm 39.Op Fl EJNUln 40.Op Fl L Ar volname 41.Op Fl O Ar filesystem-type 42.Op Fl S Ar sector-size 43.Op Fl T Ar disktype 44.Op Fl a Ar maxcontig 45.Op Fl b Ar block-size 46.Op Fl c Ar blocks-per-cylinder-group 47.Op Fl d Ar max-extent-size 48.Op Fl e Ar maxbpg 49.Op Fl f Ar frag-size 50.Op Fl g Ar avgfilesize 51.Op Fl h Ar avgfpdir 52.Op Fl i Ar bytes 53.Op Fl m Ar free-space 54.Op Fl o Ar optimization 55.Op Fl p Ar partition 56.Op Fl r Ar reserved 57.Op Fl s Ar size 58.Ar special 59.Sh DESCRIPTION 60The 61.Nm 62utility is used to initialize and clear file systems before first use. 63The 64.Nm 65utility builds a file system on the specified special file. 66(We often refer to the 67.Dq special file 68as the 69.Dq disk , 70although the special file need not be a physical disk. 71In fact, it need not even be special.) 72Typically the defaults are reasonable, however 73.Nm 74has numerous options to allow the defaults to be selectively overridden. 75.Pp 76The following options define the general layout policies: 77.Bl -tag -width indent 78.It Fl E 79Erase the content of the disk before making the filesystem. 80The reserved area in front of the superblock (for bootcode) will not be erased. 81.Pp 82This is a relevant option for flash based storage devices that use 83wear levelling algorithms. 84.Pp 85NB: Erasing may take as long time as writing every sector on the disk. 86.It Fl J 87Enable journaling on the new file system via gjournal. 88See 89.Xr gjournal 8 90for details. 91.It Fl L Ar volname 92Add a volume label to the new file system. 93.It Fl N 94Cause the file system parameters to be printed out 95without really creating the file system. 96.It Fl O Ar filesystem-type 97Use 1 to specify that a UFS1 format file system be built; 98use 2 to specify that a UFS2 format file system be built. 99The default format is UFS2. 100.It Fl T Ar disktype 101For backward compatibility. 102.It Fl U 103Enable soft updates on the new file system. 104.It Fl a Ar maxcontig 105Specify the maximum number of contiguous blocks that will be 106laid out before forcing a rotational delay. 107The default value is 16. 108See 109.Xr tunefs 8 110for more details on how to set this option. 111.It Fl b Ar block-size 112The block size of the file system, in bytes. 113It must be a power of 2. 114The 115default size is 16384 bytes, and the smallest allowable size is 4096 bytes. 116The optimal block:fragment ratio is 8:1. 117Other ratios are possible, but are not recommended, 118and may produce poor results. 119.It Fl c Ar blocks-per-cylinder-group 120The number of blocks per cylinder group in a file system. 121The default is to compute the maximum allowed by the other parameters. 122This value is 123dependent on a number of other parameters, in particular the block size 124and the number of bytes per inode. 125.It Fl d Ar max-extent-size 126The file system may choose to store large files using extents. 127This parameter specifies the largest extent size that may be used. 128It is presently limited to its default value which is 16 times 129the file system blocksize. 130.It Fl e Ar maxbpg 131Indicate the maximum number of blocks any single file can 132allocate out of a cylinder group before it is forced to begin 133allocating blocks from another cylinder group. 134The default is about one quarter of the total blocks in a cylinder group. 135See 136.Xr tunefs 8 137for more details on how to set this option. 138.It Fl f Ar frag-size 139The fragment size of the file system in bytes. 140It must be a power of two 141ranging in value between 142.Ar blocksize Ns /8 143and 144.Ar blocksize . 145The default is 2048 bytes. 146.It Fl g Ar avgfilesize 147The expected average file size for the file system. 148.It Fl h Ar avgfpdir 149The expected average number of files per directory on the file system. 150.It Fl i Ar bytes 151Specify the density of inodes in the file system. 152The default is to create an inode for every 153.Pq 4 * Ar frag-size 154bytes of data space. 155If fewer inodes are desired, a larger number should be used; 156to create more inodes a smaller number should be given. 157One inode is required for each distinct file, so this value effectively 158specifies the average file size on the file system. 159.It Fl l 160Enable multilabel MAC on the new file system. 161.It Fl m Ar free-space 162The percentage of space reserved from normal users; the minimum free 163space threshold. 164The default value used is 165defined by 166.Dv MINFREE 167from 168.In ufs/ffs/fs.h , 169currently 8%. 170See 171.Xr tunefs 8 172for more details on how to set this option. 173.It Fl n 174Do not create a 175.Pa .snap 176directory on the new file system. 177The resulting file system will not support snapshot generation, so 178.Xr dump 8 179in live mode and background 180.Xr fsck 8 181will not function properly. 182The traditional 183.Xr fsck 8 184and offline 185.Xr dump 8 186will work on the file system. 187This option is intended primarily for memory or vnode-backed file systems that 188do not require 189.Xr dump 8 190or 191.Xr fsck 8 192support. 193.It Fl o Ar optimization 194.Cm ( space 195or 196.Cm time ) . 197The file system can either be instructed to try to minimize the time spent 198allocating blocks, or to try to minimize the space fragmentation on the disk. 199If the value of minfree (see above) is less than 8%, 200the default is to optimize for 201.Cm space ; 202if the value of minfree is greater than or equal to 8%, 203the default is to optimize for 204.Cm time . 205See 206.Xr tunefs 8 207for more details on how to set this option. 208.It Fl p Ar partition 209The partition name (a..h) you want to use in case the underlying image 210is a file, so you don't have access to individual partitions through the 211filesystem. 212Can also be used with a device, e.g. 213.Nm 214.Fl p Ar f 215.Ar /dev/da1s3 216is equivalent to 217.Nm 218.Ar /dev/da1s3f . 219.It Fl r Ar reserved 220The size, in sectors, of reserved space 221at the end of the partition specified in 222.Ar special . 223This space will not be occupied by the file system; 224it can be used by other consumers such as 225.Xr geom 4 . 226Defaults to 0. 227.It Fl s Ar size 228The size of the file system in sectors. 229This value defaults to the size of the 230raw partition specified in 231.Ar special 232less the 233.Ar reserved 234space at its end (see 235.Fl r ) . 236A 237.Ar size 238of 0 can also be used to choose the default value. 239A valid 240.Ar size 241value cannot be larger than the default one, 242which means that the file system cannot extend into the reserved space. 243.El 244.Pp 245The following options override the standard sizes for the disk geometry. 246Their default values are taken from the disk label. 247Changing these defaults is useful only when using 248.Nm 249to build a file system whose raw image will eventually be used on a 250different type of disk than the one on which it is initially created 251(for example on a write-once disk). 252Note that changing any of these values from their defaults will make 253it impossible for 254.Xr fsck 8 255to find the alternate superblocks if the standard superblock is lost. 256.Bl -tag -width indent 257.It Fl S Ar sector-size 258The size of a sector in bytes (almost never anything but 512). 259.El 260.Sh EXAMPLES 261.Dl newfs /dev/ad3s1a 262.Pp 263Creates a new ufs file system on 264.Pa ad3s1a . 265The 266.Nm 267utility will use a block size of 16384 bytes, a fragment size of 2048 bytes 268and the largest possible number of blocks per cylinders group. 269These values tend to produce better performance for most applications 270than the historical defaults 271(8192 byte block size and 1024 byte fragment size). 272This large fragment size may lead to much wasted space 273on file systems that contain many small files. 274.Sh SEE ALSO 275.Xr fdformat 1 , 276.Xr geom 4 , 277.Xr disktab 5 , 278.Xr fs 5 , 279.Xr bsdlabel 8 , 280.Xr camcontrol 8 , 281.Xr dump 8 , 282.Xr dumpfs 8 , 283.Xr fsck 8 , 284.Xr gjournal 8 , 285.Xr mount 8 , 286.Xr tunefs 8 , 287.Xr gvinum 8 288.Rs 289.%A M. McKusick 290.%A W. Joy 291.%A S. Leffler 292.%A R. Fabry 293.%T A Fast File System for UNIX 294.%J ACM Transactions on Computer Systems 2 295.%V 3 296.%P pp 181-197 297.%D August 1984 298.%O (reprinted in the BSD System Manager's Manual) 299.Re 300.Sh HISTORY 301The 302.Nm 303utility appeared in 304.Bx 4.2 . 305