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 1.17 1998/09/11 07:08:49 grog 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. (We often refer to the 96.Dq special file 97as the 98.Dq disk , 99although the special file need not be a physical disk. In fact, it need not 100even be special.) 101Typically the defaults are reasonable, however 102.Nm 103has numerous options to allow the defaults to be selectively overridden. 104.Pp 105.Nm Mount_mfs 106is used to build a file system in virtual memory and then mount it 107on a specified node. 108.Nm Mount_mfs 109exits and the contents of the file system are lost 110when the file system is unmounted. 111If 112.Nm mount_mfs 113is sent a signal while running, 114for example during system shutdown, 115it will attempt to unmount its 116corresponding file system. 117The parameters to 118.Nm mount_mfs 119are the same as those to 120.Nm Ns . 121If the 122.Fl T 123flag is specified (see below), the special file is unused. 124Otherwise, it is only used to read the disk label which provides 125a set of configuration parameters for the memory based file system. 126The special file is typically that of the primary swap area, 127since that is where the file system will be backed up when 128free memory gets low and the memory supporting 129the file system has to be paged. 130.Pp 131The following options define the general layout policies: 132.Bl -tag -width indent 133.It Fl T Ar disktype 134For backward compatibility and for 135.Nm mount_mfs . 136.It Fl F Ar file 137.Nm Mount_mfs 138will use this file for the image of the filesystem. When 139.Nm mount_mfs 140exits, this file will be left behind. 141.It Fl N 142Cause the file system parameters to be printed out 143without really creating the file system. 144.It Fl O 145Create a 146.Bx 4.3 147format filesystem. 148This options is primarily used to build root filesystems 149that can be understood by older boot ROMs. 150.It Fl T 151Use information for the specified disk from 152.Pa /etc/disktab 153instead of trying to get the information from a disklabel. 154.It Fl a Ar maxcontig 155Specify the maximum number of contiguous blocks that will be 156laid out before forcing a rotational delay (see the 157.Fl d 158option). 159The default value is 1. 160See 161.Xr tunefs 8 162for more details on how to set this option. 163.It Fl b Ar block-size 164The block size of the file system, in bytes. 165.It Fl c Ar #cylinders/group 166The number of cylinders per cylinder group in a file system. 167The default value is 16. 168.It Fl d Ar rotdelay 169Specify the expected time (in milliseconds) to service a transfer 170completion interrupt and initiate a new transfer on the same disk. 171The default is 0 milliseconds. 172See 173.Xr tunefs 8 174for more details on how to set this option. 175.ne 1i 176.It Fl e Ar maxbpg 177Indicate the maximum number of blocks any single file can 178allocate out of a cylinder group before it is forced to begin 179allocating blocks from another cylinder group. 180The default is about one quarter of the total blocks in a cylinder group. 181See 182.Xr tunefs 8 183for more details on how to set this option. 184.It Fl f Ar frag-size 185The fragment size of the file system in bytes. 186The default is 1024 bytes. 187.It Fl i Ar number of bytes per inode 188Specify the density of inodes in the file system. 189The default is to create an inode for every (4 * frag-size) bytes of data space. 190If fewer inodes are desired, a larger number should be used; 191to create more inodes a smaller number should be given. 192.It Fl m Ar free space \&% 193The percentage of space reserved from normal users; the minimum free 194space threshold. 195The default value used is 196defined by 197.Dv MINFREE 198from 199.Ao Pa ufs/ffs/fs.h Ac , 200currently 8%. 201See 202.Xr tunefs 8 203for more details on how to set this option. 204.It Fl n Ar number of distinguished rotational positions 205Determine how many rotational time slots there are in one revolution of 206the disk. Defaults to 1, which essentially disables the rotational position 207table. 208.It Fl o Ar optimization\ preference 209.Pq ``space'' or ``time'' 210The file system can either be instructed to try to minimize the time spent 211allocating blocks, or to try to minimize the space fragmentation on the disk. 212If the value of minfree (see above) is less than 8%, 213the default is to optimize for space; 214if the value of minfree is greater than or equal to 8%, 215the default is to optimize for time. 216See 217.Xr tunefs 8 218for more details on how to set this option. 219.It Fl s Ar size 220The size of the file system in sectors. 221.It Fl v 222Specify that the special device does not contain any partitions, and that 223.Nm 224should treat the whole slice as the file system. This option is useful for 225synthetic disks such as 226.Nm vinum. 227.El 228.Pp 229The following options override the standard sizes for the disk geometry. 230Their default values are taken from the disk label. 231Changing these defaults is useful only when using 232.Nm 233to build a file system whose raw image will eventually be used on a 234different type of disk than the one on which it is initially created 235(for example on a write-once disk). 236Note that changing any of these values from their defaults will make 237it impossible for 238.Xr fsck 8 239to find the alternate superblocks if the standard superblock is lost. 240.Bl -tag -width indent 241.It Fl S Ar sector-size 242The size of a sector in bytes (almost never anything but 512). 243.It Fl k Ar sector \&0 skew , per track 244Used to describe perturbations in the media format to compensate for 245a slow controller. 246Track skew is the offset of sector 0 on track N relative to sector 0 247on track N-1 on the same cylinder. 248.It Fl l Ar hardware sector interleave 249Used to describe perturbations in the media format to compensate for 250a slow controller. 251Interleave is physical sector interleave on each track, 252specified as the denominator of the ratio: 253.Dl sectors read/sectors passed over 254Thus an interleave of 1/1 implies contiguous layout, while 1/2 implies 255logical sector 0 is separated by one sector from logical sector 1. 256.It Fl p Ar spare sectors per track 257Spare sectors (bad sector replacements) are physical sectors that occupy 258space at the end of each track. 259They are not counted as part of the sectors/track 260.Pq Fl u 261since they are not available to the file system for data allocation. 262.It Fl r Ar revolutions/minute 263The speed of the disk in revolutions per minute. 264.ne 1i 265.It Fl t Ar #tracks/cylinder 266The number of tracks/cylinder available for data allocation by the file 267system. 268The default is 1. 269If zero is specified, the value from the disklabel will be used. 270.It Fl u Ar sectors/track 271The number of sectors per track available for data allocation by the file 272system. 273The default is 4096. 274If zero is specified, the value from the disklabel will be used. 275This does not include sectors reserved at the end of each track for bad 276block replacement (see the 277.Fl p 278option). 279.It Fl x Ar spare sectors per cylinder 280Spare sectors (bad sector replacements) are physical sectors that occupy 281space at the end of the last track in the cylinder. 282They are deducted from the sectors/track 283.Pq Fl u 284of the last track of each cylinder since they are not available to the file 285system for data allocation. 286.El 287.Pp 288The options to the 289.Nm mount_mfs 290command are as described for the 291.Nm 292command, except for the 293.Fl o 294option. 295.Pp 296That option is as follows: 297.Bl -tag -width indent 298.It Fl o 299Options are specified with a 300.Fl o 301flag followed by a comma separated string of options. 302See the 303.Xr mount 8 304man page for possible options and their meanings. 305.El 306.Sh EXAMPLES 307.Pp 308.Dl mount_mfs -s 131072 -o nosuid,nodev /dev/sd0s1b /tmp 309.Pp 310Mount a 64 MB large memory file system on /tmp, with 311.Xr mount 8 312options nosuid and nodev. 313.Sh BUGS 314The boot code of 315.Bx Free 316assumes that the file system that carries the 317kernel has blocks of 8 kilobytes and fragments of 1 kilobyte. You will 318not be able to boot from a file system that uses another size. 319.Sh SEE ALSO 320.Xr fdformat 1 , 321.Xr disktab 5 , 322.Xr fs 5 , 323.Xr disklabel 8 , 324.Xr diskpart 8 , 325.Xr dumpfs 8 , 326.Xr fsck 8 , 327.Xr mount 8 , 328.Xr scsiformat 8 , 329.Xr tunefs 8 , 330.Xr vinum 8 331.Rs 332.%A M. McKusick 333.%A W. Joy 334.%A S. Leffler 335.%A R. Fabry 336.%T A Fast File System for UNIX , 337.%J ACM Transactions on Computer Systems 2 338.%V 3 339.%P pp 181-197 340.%D August 1984 341.%O (reprinted in the BSD System Manager's Manual) 342.Re 343.Sh HISTORY 344The 345.Nm 346command appeared in 347.Bx 4.2 . 348