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 February 22, 2011 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 EJNUjlnt 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 option is only relevant for flash based storage devices that use 83wear-leveling algorithms. 84.Pp 85Erasing may take a long time as it writes to 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. 128The default value is the file system blocksize. 129It is presently limited to a maximum value of 16 times the 130file system blocksize and a minimum value of the file system blocksize. 131.It Fl e Ar maxbpg 132Indicate the maximum number of blocks any single file can 133allocate out of a cylinder group before it is forced to begin 134allocating blocks from another cylinder group. 135The default is about one quarter of the total blocks in a cylinder group. 136See 137.Xr tunefs 8 138for more details on how to set this option. 139.It Fl f Ar frag-size 140The fragment size of the file system in bytes. 141It must be a power of two 142ranging in value between 143.Ar blocksize Ns /8 144and 145.Ar blocksize . 146The default is 2048 bytes. 147.It Fl g Ar avgfilesize 148The expected average file size for the file system. 149.It Fl h Ar avgfpdir 150The expected average number of files per directory on the file system. 151.It Fl i Ar bytes 152Specify the density of inodes in the file system. 153The default is to create an inode for every 154.Pq 4 * Ar frag-size 155bytes of data space. 156If fewer inodes are desired, a larger number should be used; 157to create more inodes a smaller number should be given. 158One inode is required for each distinct file, so this value effectively 159specifies the average file size on the file system. 160.It Fl j 161Enable soft updates journaling on the new file system. 162This flag is implemented by running the 163.Xr tunefs 8 164utility found in the user's 165.Dv $PATH . 166.It Fl l 167Enable multilabel MAC on the new file system. 168.It Fl m Ar free-space 169The percentage of space reserved from normal users; the minimum free 170space threshold. 171The default value used is 172defined by 173.Dv MINFREE 174from 175.In ufs/ffs/fs.h , 176currently 8%. 177See 178.Xr tunefs 8 179for more details on how to set this option. 180.It Fl n 181Do not create a 182.Pa .snap 183directory on the new file system. 184The resulting file system will not support snapshot generation, so 185.Xr dump 8 186in live mode and background 187.Xr fsck 8 188will not function properly. 189The traditional 190.Xr fsck 8 191and offline 192.Xr dump 8 193will work on the file system. 194This option is intended primarily for memory or vnode-backed file systems that 195do not require 196.Xr dump 8 197or 198.Xr fsck 8 199support. 200.It Fl o Ar optimization 201.Cm ( space 202or 203.Cm time ) . 204The file system can either be instructed to try to minimize the time spent 205allocating blocks, or to try to minimize the space fragmentation on the disk. 206If the value of minfree (see above) is less than 8%, 207the default is to optimize for 208.Cm space ; 209if the value of minfree is greater than or equal to 8%, 210the default is to optimize for 211.Cm time . 212See 213.Xr tunefs 8 214for more details on how to set this option. 215.It Fl p Ar partition 216The partition name (a..h) you want to use in case the underlying image 217is a file, so you don't have access to individual partitions through the 218filesystem. 219Can also be used with a device, e.g. 220.Nm 221.Fl p Ar f 222.Ar /dev/da1s3 223is equivalent to 224.Nm 225.Ar /dev/da1s3f . 226.It Fl r Ar reserved 227The size, in sectors, of reserved space 228at the end of the partition specified in 229.Ar special . 230This space will not be occupied by the file system; 231it can be used by other consumers such as 232.Xr geom 4 . 233Defaults to 0. 234.It Fl s Ar size 235The size of the file system in sectors. 236This value defaults to the size of the 237raw partition specified in 238.Ar special 239less the 240.Ar reserved 241space at its end (see 242.Fl r ) . 243A 244.Ar size 245of 0 can also be used to choose the default value. 246A valid 247.Ar size 248value cannot be larger than the default one, 249which means that the file system cannot extend into the reserved space. 250.It Fl t 251Turn on the TRIM enable flag. 252If enabled, and if the underlying device supports the BIO_DELETE 253command, the file system will send a delete request to the underlying 254device for each freed block. 255The trim enable flag is typically set when the underlying device 256uses flash-memory as the device can use the delete command to 257pre-zero or at least avoid copying blocks that have been deleted. 258.El 259.Pp 260The following options override the standard sizes for the disk geometry. 261Their default values are taken from the disk label. 262Changing these defaults is useful only when using 263.Nm 264to build a file system whose raw image will eventually be used on a 265different type of disk than the one on which it is initially created 266(for example on a write-once disk). 267Note that changing any of these values from their defaults will make 268it impossible for 269.Xr fsck 8 270to find the alternate superblocks if the standard superblock is lost. 271.Bl -tag -width indent 272.It Fl S Ar sector-size 273The size of a sector in bytes (almost never anything but 512). 274.El 275.Sh EXAMPLES 276.Dl newfs /dev/ad3s1a 277.Pp 278Creates a new ufs file system on 279.Pa ad3s1a . 280The 281.Nm 282utility will use a block size of 16384 bytes, a fragment size of 2048 bytes 283and the largest possible number of blocks per cylinders group. 284These values tend to produce better performance for most applications 285than the historical defaults 286(8192 byte block size and 1024 byte fragment size). 287This large fragment size may lead to much wasted space 288on file systems that contain many small files. 289.Sh SEE ALSO 290.Xr fdformat 1 , 291.Xr geom 4 , 292.Xr disktab 5 , 293.Xr fs 5 , 294.Xr bsdlabel 8 , 295.Xr camcontrol 8 , 296.Xr dump 8 , 297.Xr dumpfs 8 , 298.Xr fsck 8 , 299.Xr gjournal 8 , 300.Xr makefs 8 , 301.Xr mount 8 , 302.Xr tunefs 8 , 303.Xr gvinum 8 304.Rs 305.%A M. McKusick 306.%A W. Joy 307.%A S. Leffler 308.%A R. Fabry 309.%T A Fast File System for UNIX 310.%J ACM Transactions on Computer Systems 2 311.%V 3 312.%P pp 181-197 313.%D August 1984 314.%O (reprinted in the BSD System Manager's Manual) 315.Re 316.Sh HISTORY 317The 318.Nm 319utility appeared in 320.Bx 4.2 . 321