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.\" 3. 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 July 7, 2017 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 k Ar held-for-metadata-blocks 54.Op Fl m Ar free-space 55.Op Fl o Ar optimization 56.Op Fl p Ar partition 57.Op Fl r Ar reserved 58.Op Fl s Ar size 59.Ar special 60.Sh DESCRIPTION 61The 62.Nm 63utility is used to initialize and clear file systems before first use. 64The 65.Nm 66utility builds a file system on the specified special file. 67(We often refer to the 68.Dq special file 69as the 70.Dq disk , 71although the special file need not be a physical disk. 72In fact, it need not even be special.) 73Typically the defaults are reasonable, however 74.Nm 75has numerous options to allow the defaults to be selectively overridden. 76.Pp 77The following options define the general layout policies: 78.Bl -tag -width indent 79.It Fl E 80Erase the content of the disk before making the filesystem. 81The reserved area in front of the superblock (for bootcode) will not be erased. 82Erasing is only relevant to flash-memory or thinly provisioned devices. 83Erasing may take a long time. 84If the device does not support BIO_DELETE, the command will fail. 85.It Fl J 86Enable journaling on the new file system via gjournal. 87See 88.Xr gjournal 8 89for details. 90.It Fl L Ar volname 91Add a volume label to the new file system. 92.It Fl N 93Cause the file system parameters to be printed out 94without really creating the file system. 95.It Fl O Ar filesystem-type 96Use 1 to specify that a UFS1 format file system be built; 97use 2 to specify that a UFS2 format file system be built. 98The default format is UFS2. 99.It Fl T Ar disktype 100For backward compatibility. 101.It Fl U 102Enable soft updates on the new file system. 103.It Fl a Ar maxcontig 104Specify the maximum number of contiguous blocks that will be 105laid out before forcing a rotational delay. 106The default value is 16. 107See 108.Xr tunefs 8 109for more details on how to set this option. 110.It Fl b Ar block-size 111The block size of the file system, in bytes. 112It must be a power of 2. 113The 114default size is 32768 bytes, and the smallest allowable size is 4096 bytes. 115The optimal block:fragment ratio is 8:1. 116Other ratios are possible, but are not recommended, 117and may produce poor results. 118.It Fl c Ar blocks-per-cylinder-group 119The number of blocks per cylinder group in a file system. 120The default is to compute the maximum allowed by the other parameters. 121This value is 122dependent on a number of other parameters, in particular the block size 123and the number of bytes per inode. 124.It Fl d Ar max-extent-size 125The file system may choose to store large files using extents. 126This parameter specifies the largest extent size that may be used. 127The default value is the file system blocksize. 128It is presently limited to a maximum value of 16 times the 129file system blocksize and a minimum value of the 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 4096 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 2 * 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 j 160Enable soft updates journaling on the new file system. 161This flag is implemented by running the 162.Xr tunefs 8 163utility found in the user's 164.Dv $PATH . 165.It Fl k Ar held-for-metadata-blocks 166Set the amount of space to be held for metadata blocks in each cylinder group. 167When set, the file system preference routines will try to save 168the specified amount of space immediately following the inode blocks 169in each cylinder group for use by metadata blocks. 170Clustering the metadata blocks speeds up random file access 171and decreases the running time of 172.Xr fsck 8 . 173By default 174.Nm 175sets it to half of the space reserved to minfree. 176.It Fl l 177Enable multilabel MAC on the new file system. 178.It Fl m Ar free-space 179The percentage of space reserved from normal users; the minimum free 180space threshold. 181The default value used is 182defined by 183.Dv MINFREE 184from 185.In ufs/ffs/fs.h , 186currently 8%. 187See 188.Xr tunefs 8 189for more details on how to set this option. 190.It Fl n 191Do not create a 192.Pa .snap 193directory on the new file system. 194The resulting file system will not support snapshot generation, so 195.Xr dump 8 196in live mode and background 197.Xr fsck 8 198will not function properly. 199The traditional 200.Xr fsck 8 201and offline 202.Xr dump 8 203will work on the file system. 204This option is intended primarily for memory or vnode-backed file systems that 205do not require 206.Xr dump 8 207or 208.Xr fsck 8 209support. 210.It Fl o Ar optimization 211.Cm ( space 212or 213.Cm time ) . 214The file system can either be instructed to try to minimize the time spent 215allocating blocks, or to try to minimize the space fragmentation on the disk. 216If the value of minfree (see above) is less than 8%, 217the default is to optimize for 218.Cm space ; 219if the value of minfree is greater than or equal to 8%, 220the default is to optimize for 221.Cm time . 222See 223.Xr tunefs 8 224for more details on how to set this option. 225.It Fl p Ar partition 226The partition name (a..h) you want to use in case the underlying image 227is a file, so you do not have access to individual partitions through the 228filesystem. 229Can also be used with a device, e.g., 230.Nm 231.Fl p Ar f 232.Ar /dev/da1s3 233is equivalent to 234.Nm 235.Ar /dev/da1s3f . 236.It Fl r Ar reserved 237The size, in sectors, of reserved space 238at the end of the partition specified in 239.Ar special . 240This space will not be occupied by the file system; 241it can be used by other consumers such as 242.Xr geom 4 . 243Defaults to 0. 244.It Fl s Ar size 245The size of the file system in sectors. 246This value defaults to the size of the 247raw partition specified in 248.Ar special 249less the 250.Ar reserved 251space at its end (see 252.Fl r ) . 253A 254.Ar size 255of 0 can also be used to choose the default value. 256A valid 257.Ar size 258value cannot be larger than the default one, 259which means that the file system cannot extend into the reserved space. 260.It Fl t 261Turn on the TRIM enable flag. 262If enabled, and if the underlying device supports the BIO_DELETE 263command, the file system will send a delete request to the underlying 264device for each freed block. 265The trim enable flag is typically set for flash-memory devices to 266reduce write amplification which reduces wear on write-limited 267flash-memory and often improves long-term performance. 268Thinly provisioned storage also benefits by returning unused blocks to 269the global pool. 270.El 271.Pp 272The following options override the standard sizes for the disk geometry. 273Their default values are taken from the disk label. 274Changing these defaults is useful only when using 275.Nm 276to build a file system whose raw image will eventually be used on a 277different type of disk than the one on which it is initially created 278(for example on a write-once disk). 279Note that changing any of these values from their defaults will make 280it impossible for 281.Xr fsck 8 282to find the alternate superblocks if the standard superblock is lost. 283.Bl -tag -width indent 284.It Fl S Ar sector-size 285The size of a sector in bytes (almost never anything but 512). 286.El 287.Sh EXAMPLES 288.Dl newfs /dev/ada3s1a 289.Pp 290Creates a new ufs file system on 291.Pa ada3s1a . 292The 293.Nm 294utility will use a block size of 32768 bytes, a fragment size of 4096 bytes 295and the largest possible number of blocks per cylinders group. 296These values tend to produce better performance for most applications 297than the historical defaults 298(8192 byte block size and 1024 byte fragment size). 299This large fragment size may lead to much wasted space 300on file systems that contain many small files. 301.Sh SEE ALSO 302.Xr fdformat 1 , 303.Xr geom 4 , 304.Xr disktab 5 , 305.Xr fs 5 , 306.Xr camcontrol 8 , 307.Xr dump 8 , 308.Xr dumpfs 8 , 309.Xr fsck 8 , 310.Xr gpart 8 , 311.Xr gjournal 8 , 312.Xr growfs 8 , 313.Xr gvinum 8 , 314.Xr makefs 8 , 315.Xr mount 8 , 316.Xr tunefs 8 317.Rs 318.%A M. McKusick 319.%A W. Joy 320.%A S. Leffler 321.%A R. Fabry 322.%T A Fast File System for UNIX 323.%J ACM Transactions on Computer Systems 2 324.%V 3 325.%P pp 181-197 326.%D August 1984 327.%O (reprinted in the BSD System Manager's Manual) 328.Re 329.Sh HISTORY 330The 331.Nm 332utility appeared in 333.Bx 4.2 . 334