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 January 29, 2019 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. 92Legal characters are alphanumerics, dashes, and underscores. 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. 114.\" If changing the default block size and it causes the default 115.\" fragment size to change, be sure to update the location of 116.\" the first backup superblock on the fsck_ffs.8 manual page. 117The 118default size is 32768 bytes, and the smallest allowable size is 4096 bytes. 119The optimal block:fragment ratio is 8:1. 120Other ratios are possible, but are not recommended, 121and may produce poor results. 122.It Fl c Ar blocks-per-cylinder-group 123The number of blocks per cylinder group in a file system. 124The default is to compute the maximum allowed by the other parameters. 125This value is 126dependent on a number of other parameters, in particular the block size 127and the number of bytes per inode. 128.It Fl d Ar max-extent-size 129The file system may choose to store large files using extents. 130This parameter specifies the largest extent size that may be used. 131The default value is the file system blocksize. 132It is presently limited to a maximum value of 16 times the 133file system blocksize and a minimum value of the file system blocksize. 134.It Fl e Ar maxbpg 135Indicate the maximum number of blocks any single file can 136allocate out of a cylinder group before it is forced to begin 137allocating blocks from another cylinder group. 138The default is about one quarter of the total blocks in a cylinder group. 139See 140.Xr tunefs 8 141for more details on how to set this option. 142.It Fl f Ar frag-size 143The fragment size of the file system in bytes. 144It must be a power of two 145ranging in value between 146.Ar blocksize Ns /8 147and 148.Ar blocksize . 149.\" If changing the default fragment size or it changes because of a 150.\" change to the default block size, be sure to update the location 151.\" of the first backup superblock on the fsck_ffs.8 manual page. 152The default is 4096 bytes. 153.It Fl g Ar avgfilesize 154The expected average file size for the file system. 155.It Fl h Ar avgfpdir 156The expected average number of files per directory on the file system. 157.It Fl i Ar bytes 158Specify the density of inodes in the file system. 159The default is to create an inode for every 160.Pq 2 * Ar frag-size 161bytes of data space. 162If fewer inodes are desired, a larger number should be used; 163to create more inodes a smaller number should be given. 164One inode is required for each distinct file, so this value effectively 165specifies the average file size on the file system. 166.It Fl j 167Enable soft updates journaling on the new file system. 168This flag is implemented by running the 169.Xr tunefs 8 170utility found in the user's 171.Dv $PATH . 172.It Fl k Ar held-for-metadata-blocks 173Set the amount of space to be held for metadata blocks in each cylinder group. 174When set, the file system preference routines will try to save 175the specified amount of space immediately following the inode blocks 176in each cylinder group for use by metadata blocks. 177Clustering the metadata blocks speeds up random file access 178and decreases the running time of 179.Xr fsck 8 . 180By default 181.Nm 182sets it to half of the space reserved to minfree. 183.It Fl l 184Enable multilabel MAC on the new file system. 185.It Fl m Ar free-space 186The percentage of space reserved from normal users; the minimum free 187space threshold. 188The default value used is 189defined by 190.Dv MINFREE 191from 192.In ufs/ffs/fs.h , 193currently 8%. 194See 195.Xr tunefs 8 196for more details on how to set this option. 197.It Fl n 198Do not create a 199.Pa .snap 200directory on the new file system. 201The resulting file system will not support snapshot generation, so 202.Xr dump 8 203in live mode and background 204.Xr fsck 8 205will not function properly. 206The traditional 207.Xr fsck 8 208and offline 209.Xr dump 8 210will work on the file system. 211This option is intended primarily for memory or vnode-backed file systems that 212do not require 213.Xr dump 8 214or 215.Xr fsck 8 216support. 217.It Fl o Ar optimization 218.Cm ( space 219or 220.Cm time ) . 221The file system can either be instructed to try to minimize the time spent 222allocating blocks, or to try to minimize the space fragmentation on the disk. 223If the value of minfree (see above) is less than 8%, 224the default is to optimize for 225.Cm space ; 226if the value of minfree is greater than or equal to 8%, 227the default is to optimize for 228.Cm time . 229See 230.Xr tunefs 8 231for more details on how to set this option. 232.It Fl p Ar partition 233The partition name (a..h) you want to use in case the underlying image 234is a file, so you do not have access to individual partitions through the 235filesystem. 236Can also be used with a device, e.g., 237.Nm 238.Fl p Ar f 239.Ar /dev/da1s3 240is equivalent to 241.Nm 242.Ar /dev/da1s3f . 243.It Fl r Ar reserved 244The size, in sectors, of reserved space 245at the end of the partition specified in 246.Ar special . 247This space will not be occupied by the file system; 248it can be used by other consumers such as 249.Xr geom 4 . 250Defaults to 0. 251.It Fl s Ar size 252The size of the file system in sectors. 253This value defaults to the size of the 254raw partition specified in 255.Ar special 256less the 257.Ar reserved 258space at its end (see 259.Fl r ) . 260A 261.Ar size 262of 0 can also be used to choose the default value. 263A valid 264.Ar size 265value cannot be larger than the default one, 266which means that the file system cannot extend into the reserved space. 267.It Fl t 268Turn on the TRIM enable flag. 269If enabled, and if the underlying device supports the BIO_DELETE 270command, the file system will send a delete request to the underlying 271device for each freed block. 272The trim enable flag is typically set for flash-memory devices to 273reduce write amplification which reduces wear on write-limited 274flash-memory and often improves long-term performance. 275Thinly provisioned storage also benefits by returning unused blocks to 276the global pool. 277.El 278.Pp 279The following options override the standard sizes for the disk geometry. 280Their default values are taken from the disk label. 281Changing these defaults is useful only when using 282.Nm 283to build a file system whose raw image will eventually be used on a 284different type of disk than the one on which it is initially created 285(for example on a write-once disk). 286Note that changing any of these values from their defaults will make 287it impossible for 288.Xr fsck 8 289to find the alternate superblocks if the standard superblock is lost. 290.Bl -tag -width indent 291.It Fl S Ar sector-size 292The size of a sector in bytes (almost never anything but 512). 293.El 294.Sh EXAMPLES 295.Dl newfs /dev/ada3s1a 296.Pp 297Creates a new ufs file system on 298.Pa ada3s1a . 299The 300.Nm 301utility will use a block size of 32768 bytes, a fragment size of 4096 bytes 302and the largest possible number of blocks per cylinders group. 303These values tend to produce better performance for most applications 304than the historical defaults 305(8192 byte block size and 1024 byte fragment size). 306This large fragment size may lead to much wasted space 307on file systems that contain many small files. 308.Sh SEE ALSO 309.Xr fdformat 1 , 310.Xr geom 4 , 311.Xr disktab 5 , 312.Xr fs 5 , 313.Xr camcontrol 8 , 314.Xr dump 8 , 315.Xr dumpfs 8 , 316.Xr fsck 8 , 317.Xr gpart 8 , 318.Xr gjournal 8 , 319.Xr growfs 8 , 320.Xr gvinum 8 , 321.Xr makefs 8 , 322.Xr mount 8 , 323.Xr tunefs 8 324.Rs 325.%A M. McKusick 326.%A W. Joy 327.%A S. Leffler 328.%A R. Fabry 329.%T A Fast File System for UNIX 330.%J ACM Transactions on Computer Systems 2 331.%V 3 332.%P pp 181-197 333.%D August 1984 334.%O (reprinted in the BSD System Manager's Manual) 335.Re 336.Sh HISTORY 337The 338.Nm 339utility appeared in 340.Bx 4.2 . 341