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. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)newfs.8 8.6 (Berkeley) 5/3/95 33.\" 34.Dd May 3, 1995 35.Dt NEWFS 8 36.Os BSD 4.2 37.Sh NAME 38.Nm newfs , 39.Nm mount_mfs 40.Nd construct a new file system 41.Sh SYNOPSIS 42.Nm newfs 43.Op Fl NO 44.Op Fl S Ar sector-size 45.Op Fl T Ar disktype 46.Op Fl a Ar maxcontig 47.Op Fl b Ar block-size 48.Op Fl c Ar cylinders 49.Op Fl d Ar rotdelay 50.Op Fl e Ar maxbpg 51.Op Fl f Ar frag-size 52.Op Fl i Ar bytes 53.Op Fl k Ar skew 54.Op Fl l Ar interleave 55.Op Fl m Ar free space 56.Op Fl n Ar rotational positions 57.Op Fl o Ar optimization 58.Op Fl p Ar sectors 59.Op Fl r Ar revolutions 60.Op Fl s Ar size 61.Op Fl t Ar tracks 62.Op Fl u Ar sectors 63.Op Fl x Ar sectors 64.Ar special 65.Nm mount_mfs 66.Op Fl N 67.Op Fl F Ar file 68.Op Fl T Ar disktype 69.Op Fl a Ar maxcontig 70.Op Fl b Ar block-size 71.Op Fl c Ar cylinders 72.Op Fl d Ar rotdelay 73.Op Fl e Ar maxbpg 74.Op Fl f Ar frag-size 75.Op Fl i Ar bytes 76.Op Fl m Ar free space 77.Op Fl n Ar rotational positions 78.Op Fl o Ar options 79.Op Fl s Ar size 80.Ar special node 81.Sh DESCRIPTION 82.Nm Newfs 83replaces the more obtuse 84.Xr mkfs 8 85program. 86Before running 87.Nm newfs 88or 89.Nm mount_mfs , 90the disk must be labeled using 91.Xr disklabel 8 . 92.Nm Newfs 93builds a file system on the specified special device. 94Typically the defaults are reasonable, however 95.Nm newfs 96has numerous options to allow the defaults to be selectively overridden. 97.Pp 98.Nm Mount_mfs 99is used to build a file system in virtual memory and then mount it 100on a specified node. 101.Nm Mount_mfs 102exits and the contents of the file system are lost 103when the file system is unmounted. 104If 105.Nm mount_mfs 106is sent a signal while running, 107for example during system shutdown, 108it will attempt to unmount its 109corresponding file system. 110The parameters to 111.Nm mount_mfs 112are the same as those to 113.Nm newfs . 114If the 115.Fl T 116flag is specified (see below), the special file is unused. 117Otherwise, it is only used to read the disk label which provides 118a set of configuration parameters for the memory based file system. 119The special file is typically that of the primary swap area, 120since that is where the file system will be backed up when 121free memory gets low and the memory supporting 122the file system has to be paged. 123.Pp 124The following options define the general layout policies. 125.Bl -tag -width Fl 126.It Fl T Ar disktype 127For backward compatibility and for 128.Nm mount_mfs . 129.It Fl F Ar file 130.Nm mount_mfs 131will use this file for the image of the filesystem. When 132.Nm mount_mfs 133exits, this file will be left behind. 134.It Fl N 135Causes the file system parameters to be printed out 136without really creating the file system. 137.It Fl O 138Creates a 4.3BSD format filesystem. 139This options is primarily used to build root filesystems 140that can be understood by older boot ROMs. 141.It Fl T 142Uses information for the specified disk from 143.Pa /etc/disktab 144instead of trying to get the information from a disklabel. 145.It Fl a Ar maxcontig 146This specifies the maximum number of contiguous blocks that will be 147laid out before forcing a rotational delay (see the 148.Fl d 149option). 150The default value is one. 151See 152.Xr tunefs 8 153for more details on how to set this option. 154.It Fl b Ar block-size 155The block size of the file system, in bytes. 156.It Fl c Ar #cylinders/group 157The number of cylinders per cylinder group in a file system. 158The default value is 16. 159.It Fl d Ar rotdelay 160This specifies the expected time (in milliseconds) to service a transfer 161completion interrupt and initiate a new transfer on the same disk. 162The default is 0 milliseconds. 163See 164.Xr tunefs 8 165for more details on how to set this option. 166.ne 1i 167.It Fl e Ar maxbpg 168This indicates the maximum number of blocks any single file can 169allocate out of a cylinder group before it is forced to begin 170allocating blocks from another cylinder group. 171The default is about one quarter of the total blocks in a cylinder group. 172See 173.Xr tunefs 8 174for more details on how to set this option. 175.It Fl f Ar frag-size 176The fragment size of the file system in bytes. 177The default is 1024 bytes. 178.It Fl i Ar number of bytes per inode 179This specifies the density of inodes in the file system. 180The default is to create an inode for every (4 * frag-size) bytes of data space. 181If fewer inodes are desired, a larger number should be used; 182to create more inodes a smaller number should be given. 183.It Fl m Ar free space \&% 184The percentage of space reserved from normal users; the minimum free 185space threshold. 186The default value used is 187defined by 188.Dv MINFREE 189from 190.Ao Pa ufs/ffs/fs.h Ac , 191currently 8%. 192See 193.Xr tunefs 8 194for more details on how to set this option. 195.It Fl n Ar number of distinguished rotational positions 196Determines how many rotational time slots there are in one revolution of 197the disk. Defaults to 1, which essentially disables the rotational position table. 198.It Fl o Ar optimization\ preference 199.Pq ``space'' or ``time'' 200The file system can either be instructed to try to minimize the time spent 201allocating blocks, or to try to minimize the space fragmentation on the disk. 202If the value of minfree (see above) is less than 8%, 203the default is to optimize for space; 204if the value of minfree is greater than or equal to 8%. 205the default is to optimize for time. 206See 207.Xr tunefs 8 208for more details on how to set this option. 209.It Fl s Ar size 210The size of the file system in sectors. 211.El 212.Pp 213The following options override the standard sizes for the disk geometry. 214Their default values are taken from the disk label. 215Changing these defaults is useful only when using 216.Nm newfs 217to build a file system whose raw image will eventually be used on a 218different type of disk than the one on which it is initially created 219(for example on a write-once disk). 220Note that changing any of these values from their defaults will make 221it impossible for 222.Xr fsck 223to find the alternate superblocks if the standard superblock is lost. 224.Bl -tag -width Fl 225.It Fl S Ar sector-size 226The size of a sector in bytes (almost never anything but 512). 227.It Fl k Ar sector \&0 skew , per track 228Used to describe perturbations in the media format to compensate for 229a slow controller. 230Track skew is the offset of sector 0 on track N relative to sector 0 231on track N-1 on the same cylinder. 232.It Fl l Ar hardware sector interleave 233Used to describe perturbations in the media format to compensate for 234a slow controller. 235Interleave is physical sector interleave on each track, 236specified as the denominator of the ratio: 237.Dl sectors read/sectors passed over 238Thus an interleave of 1/1 implies contiguous layout, while 1/2 implies 239logical sector 0 is separated by one sector from logical sector 1. 240.It Fl p Ar spare sectors per track 241Spare sectors (bad sector replacements) are physical sectors that occupy 242space at the end of each track. 243They are not counted as part of the sectors/track 244.Pq Fl u 245since they are not available to the file system for data allocation. 246.It Fl r Ar revolutions/minute 247The speed of the disk in revolutions per minute. 248.ne 1i 249.It Fl t Ar #tracks/cylinder 250The number of tracks/cylinder available for data allocation by the file 251system. 252The default is 1. 253If zero is specified, the value from the disklabel will be used. 254.It Fl u Ar sectors/track 255The number of sectors per track available for data allocation by the file 256system. 257The default is 4096. 258If zero is specified, the value from the disklabel will be used. 259This does not include sectors reserved at the end of each track for bad 260block replacement (see the 261.Fl p 262option.) 263.It Fl x Ar spare sectors per cylinder 264Spare sectors (bad sector replacements) are physical sectors that occupy 265space at the end of the last track in the cylinder. 266They are deducted from the sectors/track 267.Pq Fl u 268of the last track of each cylinder since they are not available to the file 269system for data allocation. 270.El 271.Pp 272The options to the 273.Nm mount_mfs 274command are as described for the 275.Nm newfs 276command, except for the 277.Fl o 278option. 279.Pp 280That option is as follows: 281.Bl -tag -width indent 282.It Fl o 283Options are specified with a 284.Fl o 285flag followed by a comma separated string of options. 286See the 287.Xr mount 8 288man page for possible options and their meanings. 289.El 290.Sh EXAMPLES 291.Pp 292.Dl mount_mfs -s=20480 -o nosuid,nodev /dev/sd0b /tmp 293.Pp 294Mount a 10240 KB large memory file system on /tmp, with 295.Xr mount 8 296options nosuid and nodev. 297.Sh SEE ALSO 298.Xr fdformat 1 , 299.Xr disktab 5 , 300.Xr fs 5 , 301.Xr disklabel 8 , 302.Xr diskpart 8 , 303.Xr dumpfs 8 , 304.Xr fsck 8 , 305.Xr mount 8 , 306.Xr scsiformat 8 , 307.Xr tunefs 8 308.Rs 309.%A M. McKusick 310.%A W. Joy 311.%A S. Leffler 312.%A R. Fabry 313.%T A Fast File System for UNIX , 314.%J ACM Transactions on Computer Systems 2 315.%V 3 316.%P pp 181-197 317.%D August 1984 318.%O (reprinted in the BSD System Manager's Manual) 319.Re 320.Sh HISTORY 321The 322.Nm 323command appeared in 324.Bx 4.2 . 325