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.\" $Id: newfs.8,v 1.19 1998/11/28 09:59:40 rnordier Exp $ 34.\" 35.Dd May 3, 1995 36.Dt NEWFS 8 37.Os BSD 4.2 38.Sh NAME 39.Nm newfs , 40.Nm mount_mfs 41.Nd construct a new file system 42.Sh SYNOPSIS 43.Nm newfs 44.Op Fl NO 45.Op Fl S Ar sector-size 46.Op Fl T Ar disktype 47.Op Fl a Ar maxcontig 48.Op Fl b Ar block-size 49.Op Fl c Ar cylinders 50.Op Fl d Ar rotdelay 51.Op Fl e Ar maxbpg 52.Op Fl f Ar frag-size 53.Op Fl i Ar bytes 54.Op Fl k Ar skew 55.Op Fl l Ar interleave 56.Op Fl m Ar free space 57.Op Fl n Ar rotational positions 58.Op Fl o Ar optimization 59.Op Fl p Ar sectors 60.Op Fl r Ar revolutions 61.Op Fl s Ar size 62.Op Fl t Ar tracks 63.Op Fl u Ar sectors 64.Op Fl v 65.Op Fl x Ar sectors 66.Ar special 67.Nm mount_mfs 68.Op Fl N 69.Op Fl F Ar file 70.Op Fl T Ar disktype 71.Op Fl a Ar maxcontig 72.Op Fl b Ar block-size 73.Op Fl c Ar cylinders 74.Op Fl d Ar rotdelay 75.Op Fl e Ar maxbpg 76.Op Fl f Ar frag-size 77.Op Fl i Ar bytes 78.Op Fl m Ar free space 79.Op Fl n Ar rotational positions 80.Op Fl o Ar options 81.Op Fl s Ar size 82.Ar special node 83.Sh DESCRIPTION 84.Nm Newfs 85replaces the more obtuse 86.Xr mkfs 8 87program. 88Before running 89.Nm 90or 91.Nm mount_mfs , 92the disk must be labeled using 93.Xr disklabel 8 . 94.Nm Newfs 95builds a file system on the specified special file. 96(We often refer to the 97.Dq special file 98as the 99.Dq disk , 100although the special file need not be a physical disk. 101In fact, it need not even be special.) 102Typically the defaults are reasonable, however 103.Nm 104has numerous options to allow the defaults to be selectively overridden. 105.Pp 106.Nm Mount_mfs 107is used to build a file system in virtual memory and then mount it 108on a specified node. 109.Nm Mount_mfs 110exits and the contents of the file system are lost 111when the file system is unmounted. 112If 113.Nm mount_mfs 114is sent a signal while running, 115for example during system shutdown, 116it will attempt to unmount its 117corresponding file system. 118The parameters to 119.Nm mount_mfs 120are the same as those to 121.Nm Ns . 122If the 123.Fl T 124flag is specified (see below), the special file is unused. 125Otherwise, it is only used to read the disk label which provides 126a set of configuration parameters for the memory based file system. 127The special file is typically that of the primary swap area, 128since that is where the file system will be backed up when 129free memory gets low and the memory supporting 130the file system has to be paged. 131.Pp 132The following options define the general layout policies: 133.Bl -tag -width indent 134.It Fl T Ar disktype 135For backward compatibility and for 136.Nm mount_mfs . 137.It Fl F Ar file 138.Nm Mount_mfs 139will use this file for the image of the filesystem. When 140.Nm mount_mfs 141exits, this file will be left behind. 142.It Fl N 143Cause the file system parameters to be printed out 144without really creating the file system. 145.It Fl O 146Create a 147.Bx 4.3 148format filesystem. 149This options is primarily used to build root filesystems 150that can be understood by older boot ROMs. 151.It Fl T 152Use information for the specified disk from 153.Pa /etc/disktab 154instead of trying to get the information from a disklabel. 155.It Fl a Ar maxcontig 156Specify the maximum number of contiguous blocks that will be 157laid out before forcing a rotational delay (see the 158.Fl d 159option). 160The default value is 1. 161See 162.Xr tunefs 8 163for more details on how to set this option. 164.It Fl b Ar block-size 165The block size of the file system, in bytes. 166.It Fl c Ar #cylinders/group 167The number of cylinders per cylinder group in a file system. 168The default value is 16. 169.It Fl d Ar rotdelay 170Specify the expected time (in milliseconds) to service a transfer 171completion interrupt and initiate a new transfer on the same disk. 172The default is 0 milliseconds. 173See 174.Xr tunefs 8 175for more details on how to set this option. 176.ne 1i 177.It Fl e Ar maxbpg 178Indicate the maximum number of blocks any single file can 179allocate out of a cylinder group before it is forced to begin 180allocating blocks from another cylinder group. 181The default is about one quarter of the total blocks in a cylinder group. 182See 183.Xr tunefs 8 184for more details on how to set this option. 185.It Fl f Ar frag-size 186The fragment size of the file system in bytes. 187The default is 1024 bytes. 188.It Fl i Ar number of bytes per inode 189Specify the density of inodes in the file system. 190The default is to create an inode for every (4 * frag-size) bytes of data space. 191If fewer inodes are desired, a larger number should be used; 192to create more inodes a smaller number should be given. 193.It Fl m Ar free space \&% 194The percentage of space reserved from normal users; the minimum free 195space threshold. 196The default value used is 197defined by 198.Dv MINFREE 199from 200.Ao Pa ufs/ffs/fs.h Ac , 201currently 8%. 202See 203.Xr tunefs 8 204for more details on how to set this option. 205.It Fl n Ar number of distinguished rotational positions 206Determine how many rotational time slots there are in one revolution of 207the disk. Defaults to 1, which essentially disables the rotational position 208table. 209.It Fl o Ar optimization\ preference 210.Pq ``space'' or ``time'' 211The file system can either be instructed to try to minimize the time spent 212allocating blocks, or to try to minimize the space fragmentation on the disk. 213If the value of minfree (see above) is less than 8%, 214the default is to optimize for space; 215if the value of minfree is greater than or equal to 8%, 216the default is to optimize for time. 217See 218.Xr tunefs 8 219for more details on how to set this option. 220.It Fl s Ar size 221The size of the file system in sectors. 222.It Fl v 223Specify that the disk does not contain any partitions, and that 224.Nm 225should build a file system on the whole disk. 226This option is useful for synthetic disks such as 227.Nm vinum. 228.El 229.Pp 230The following options override the standard sizes for the disk geometry. 231Their default values are taken from the disk label. 232Changing these defaults is useful only when using 233.Nm 234to build a file system whose raw image will eventually be used on a 235different type of disk than the one on which it is initially created 236(for example on a write-once disk). 237Note that changing any of these values from their defaults will make 238it impossible for 239.Xr fsck 8 240to find the alternate superblocks if the standard superblock is lost. 241.Bl -tag -width indent 242.It Fl S Ar sector-size 243The size of a sector in bytes (almost never anything but 512). 244.It Fl k Ar sector \&0 skew , per track 245Used to describe perturbations in the media format to compensate for 246a slow controller. 247Track skew is the offset of sector 0 on track N relative to sector 0 248on track N-1 on the same cylinder. 249.It Fl l Ar hardware sector interleave 250Used to describe perturbations in the media format to compensate for 251a slow controller. 252Interleave is physical sector interleave on each track, 253specified as the denominator of the ratio: 254.Dl sectors read/sectors passed over 255Thus an interleave of 1/1 implies contiguous layout, while 1/2 implies 256logical sector 0 is separated by one sector from logical sector 1. 257.It Fl p Ar spare sectors per track 258Spare sectors (bad sector replacements) are physical sectors that occupy 259space at the end of each track. 260They are not counted as part of the sectors/track 261.Pq Fl u 262since they are not available to the file system for data allocation. 263.It Fl r Ar revolutions/minute 264The speed of the disk in revolutions per minute. 265.ne 1i 266.It Fl t Ar #tracks/cylinder 267The number of tracks/cylinder available for data allocation by the file 268system. 269The default is 1. 270If zero is specified, the value from the disklabel will be used. 271.It Fl u Ar sectors/track 272The number of sectors per track available for data allocation by the file 273system. 274The default is 4096. 275If zero is specified, the value from the disklabel will be used. 276This does not include sectors reserved at the end of each track for bad 277block replacement (see the 278.Fl p 279option). 280.It Fl x Ar spare sectors per cylinder 281Spare sectors (bad sector replacements) are physical sectors that occupy 282space at the end of the last track in the cylinder. 283They are deducted from the sectors/track 284.Pq Fl u 285of the last track of each cylinder since they are not available to the file 286system for data allocation. 287.El 288.Pp 289The options to the 290.Nm mount_mfs 291command are as described for the 292.Nm 293command, except for the 294.Fl o 295option. 296.Pp 297That option is as follows: 298.Bl -tag -width indent 299.It Fl o 300Options are specified with a 301.Fl o 302flag followed by a comma separated string of options. 303See the 304.Xr mount 8 305man page for possible options and their meanings. 306.El 307.Sh EXAMPLES 308.Pp 309.Dl mount_mfs -s 131072 -o nosuid,nodev /dev/da0s1b /tmp 310.Pp 311Mount a 64 MB large memory file system on /tmp, with 312.Xr mount 8 313options nosuid and nodev. 314.Sh BUGS 315The boot code of 316.Bx Free 317assumes that the file system that carries the 318kernel has blocks of 8 kilobytes and fragments of 1 kilobyte. You will 319not be able to boot from a file system that uses another size. 320.Sh SEE ALSO 321.Xr fdformat 1 , 322.Xr disktab 5 , 323.Xr fs 5 , 324.Xr disklabel 8 , 325.Xr diskpart 8 , 326.Xr dumpfs 8 , 327.Xr fsck 8 , 328.Xr mount 8 , 329.Xr scsiformat 8 , 330.Xr tunefs 8 , 331.Xr vinum 8 332.Rs 333.%A M. McKusick 334.%A W. Joy 335.%A S. Leffler 336.%A R. Fabry 337.%T A Fast File System for UNIX , 338.%J ACM Transactions on Computer Systems 2 339.%V 3 340.%P pp 181-197 341.%D August 1984 342.%O (reprinted in the BSD System Manager's Manual) 343.Re 344.Sh HISTORY 345The 346.Nm 347command appeared in 348.Bx 4.2 . 349