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. 114The 115default size is 32768 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 4096 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 2 * 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 k Ar held-for-metadata-blocks 167Set the amount of space to be held for metadata blocks in each cylinder group. 168When set, the file system preference routines will try to save 169the specified amount of space immediately following the inode blocks 170in each cylinder group for use by metadata blocks. 171Clustering the metadata blocks speeds up random file access 172and decreases the running time of 173.Xr fsck 8 . 174By default 175.Nm 176sets it to half of the space reserved to minfree. 177.It Fl l 178Enable multilabel MAC on the new file system. 179.It Fl m Ar free-space 180The percentage of space reserved from normal users; the minimum free 181space threshold. 182The default value used is 183defined by 184.Dv MINFREE 185from 186.In ufs/ffs/fs.h , 187currently 8%. 188See 189.Xr tunefs 8 190for more details on how to set this option. 191.It Fl n 192Do not create a 193.Pa .snap 194directory on the new file system. 195The resulting file system will not support snapshot generation, so 196.Xr dump 8 197in live mode and background 198.Xr fsck 8 199will not function properly. 200The traditional 201.Xr fsck 8 202and offline 203.Xr dump 8 204will work on the file system. 205This option is intended primarily for memory or vnode-backed file systems that 206do not require 207.Xr dump 8 208or 209.Xr fsck 8 210support. 211.It Fl o Ar optimization 212.Cm ( space 213or 214.Cm time ) . 215The file system can either be instructed to try to minimize the time spent 216allocating blocks, or to try to minimize the space fragmentation on the disk. 217If the value of minfree (see above) is less than 8%, 218the default is to optimize for 219.Cm space ; 220if the value of minfree is greater than or equal to 8%, 221the default is to optimize for 222.Cm time . 223See 224.Xr tunefs 8 225for more details on how to set this option. 226.It Fl p Ar partition 227The partition name (a..h) you want to use in case the underlying image 228is a file, so you do not have access to individual partitions through the 229filesystem. 230Can also be used with a device, e.g., 231.Nm 232.Fl p Ar f 233.Ar /dev/da1s3 234is equivalent to 235.Nm 236.Ar /dev/da1s3f . 237.It Fl r Ar reserved 238The size, in sectors, of reserved space 239at the end of the partition specified in 240.Ar special . 241This space will not be occupied by the file system; 242it can be used by other consumers such as 243.Xr geom 4 . 244Defaults to 0. 245.It Fl s Ar size 246The size of the file system in sectors. 247This value defaults to the size of the 248raw partition specified in 249.Ar special 250less the 251.Ar reserved 252space at its end (see 253.Fl r ) . 254A 255.Ar size 256of 0 can also be used to choose the default value. 257A valid 258.Ar size 259value cannot be larger than the default one, 260which means that the file system cannot extend into the reserved space. 261.It Fl t 262Turn on the TRIM enable flag. 263If enabled, and if the underlying device supports the BIO_DELETE 264command, the file system will send a delete request to the underlying 265device for each freed block. 266The trim enable flag is typically set for flash-memory devices to 267reduce write amplification which reduces wear on write-limited 268flash-memory and often improves long-term performance. 269Thinly provisioned storage also benefits by returning unused blocks to 270the global pool. 271.El 272.Pp 273The following options override the standard sizes for the disk geometry. 274Their default values are taken from the disk label. 275Changing these defaults is useful only when using 276.Nm 277to build a file system whose raw image will eventually be used on a 278different type of disk than the one on which it is initially created 279(for example on a write-once disk). 280Note that changing any of these values from their defaults will make 281it impossible for 282.Xr fsck 8 283to find the alternate superblocks if the standard superblock is lost. 284.Bl -tag -width indent 285.It Fl S Ar sector-size 286The size of a sector in bytes (almost never anything but 512). 287.El 288.Sh EXAMPLES 289.Dl newfs /dev/ada3s1a 290.Pp 291Creates a new ufs file system on 292.Pa ada3s1a . 293The 294.Nm 295utility will use a block size of 32768 bytes, a fragment size of 4096 bytes 296and the largest possible number of blocks per cylinders group. 297These values tend to produce better performance for most applications 298than the historical defaults 299(8192 byte block size and 1024 byte fragment size). 300This large fragment size may lead to much wasted space 301on file systems that contain many small files. 302.Sh SEE ALSO 303.Xr fdformat 1 , 304.Xr geom 4 , 305.Xr disktab 5 , 306.Xr fs 5 , 307.Xr camcontrol 8 , 308.Xr dump 8 , 309.Xr dumpfs 8 , 310.Xr fsck 8 , 311.Xr gpart 8 , 312.Xr gjournal 8 , 313.Xr growfs 8 , 314.Xr gvinum 8 , 315.Xr makefs 8 , 316.Xr mount 8 , 317.Xr tunefs 8 318.Rs 319.%A M. McKusick 320.%A W. Joy 321.%A S. Leffler 322.%A R. Fabry 323.%T A Fast File System for UNIX 324.%J ACM Transactions on Computer Systems 2 325.%V 3 326.%P pp 181-197 327.%D August 1984 328.%O (reprinted in the BSD System Manager's Manual) 329.Re 330.Sh HISTORY 331The 332.Nm 333utility appeared in 334.Bx 4.2 . 335