246 lines
8.4 KiB
Groff
246 lines
8.4 KiB
Groff
.\" Copyright (c) 1983, 1987, 1991 The Regents of the University of California.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)newfs.8 6.10 (Berkeley) 3/16/91
|
|
.\"
|
|
.\" $Header: /cvsroot/src/sbin/newfs/newfs.8,v 1.3 1993/03/23 00:29:22 cgd Exp $
|
|
.\"
|
|
.Dd March 16, 1991
|
|
.Dt NEWFS 8
|
|
.Os BSD 4.2
|
|
.Sh NAME
|
|
.Nm newfs ,
|
|
.Nm mfs
|
|
.Nd construct a new file system
|
|
.Sh SYNOPSIS
|
|
.Nm newfs
|
|
.Op Fl N
|
|
.Op Ar newfs-options
|
|
.Ar special
|
|
.Nm mfs
|
|
.Op Fl F Ar mount_flags
|
|
.Op Ar newfs-options
|
|
.Ar special node
|
|
.Sh DESCRIPTION
|
|
.Nm Newfs
|
|
replaces the more obtuse
|
|
.Xr mkfs 8
|
|
program.
|
|
Before running
|
|
.Nm newfs
|
|
or
|
|
.Nm mfs ,
|
|
the disk must be labeled using
|
|
.Xr disklabel 8 .
|
|
.Nm Newfs
|
|
builds a file system on the specified special device
|
|
basing its defaults on the information in the disk label.
|
|
Typically the defaults are reasonable, however
|
|
.Nm newfs
|
|
has numerous options to allow the defaults to be selectively overridden.
|
|
.Pp
|
|
.Nm Mfs
|
|
is used to build a file system in virtual memory and then mount it
|
|
on a specified node.
|
|
.Nm Mfs
|
|
exits and the contents of the file system are lost
|
|
when the file system is unmounted.
|
|
If
|
|
.Nm mfs
|
|
is sent a signal while running,
|
|
for example during system shutdown,
|
|
it will attempt to unmount its
|
|
corresponding file system.
|
|
The parameters to
|
|
.Nm mfs
|
|
are the same as those to
|
|
.Nm newfs .
|
|
The special file is only used to read the disk label which provides
|
|
a set of configuration parameters for the memory based file system.
|
|
The special file is typically that of the primary swap area,
|
|
since that is where the file system will be backed up when
|
|
free memory gets low and the memory supporting
|
|
the file system has to be paged.
|
|
.Pp
|
|
The following options define the general layout policies.
|
|
.Bl -tag -width Fl
|
|
.It Fl N
|
|
Causes the file system parameters to be printed out
|
|
without really creating the file system.
|
|
.It Fl b Ar block-size
|
|
The block size of the file system in bytes.
|
|
.It Fl f Ar frag-size
|
|
The fragment size of the file system in bytes.
|
|
.It Fl m Ar free space \&%
|
|
The percentage of space reserved from normal users; the minimum
|
|
free space threshold. The default value used is 10%.
|
|
See
|
|
.Xr tunefs 8
|
|
for more details on how to set this option.
|
|
.It Fl o Ar optimization\ preference
|
|
.Pq ``space'' or ``time''
|
|
The file system can either be instructed to try to minimize the time spent
|
|
allocating blocks, or to try to minimize the space fragmentation on the disk.
|
|
If the value of minfree (see above) is less than 10%,
|
|
the default is to optimize for space;
|
|
if the value of minfree greater than or equal to 10%,
|
|
the default is to optimize for time.
|
|
See
|
|
.Xr tunefs 8
|
|
for more details on how to set this option.
|
|
.It Fl a Ar maxcontig
|
|
This specifies the maximum number of contiguous blocks that will
|
|
be laid out before forcing a rotational delay (see
|
|
.Fl d
|
|
below).
|
|
The default value is one.
|
|
See
|
|
.Xr tunefs 8
|
|
for more details on how to set this option.
|
|
.It Fl d Ar rotdelay
|
|
This specifies the expected time (in milliseconds)
|
|
to service a transfer completion
|
|
interrupt and initiate a new transfer on the same disk.
|
|
The default is 4 milliseconds.
|
|
See
|
|
.Xr tunefs 8
|
|
for more details on how to set this option.
|
|
.It Fl e Ar maxbpg
|
|
This indicates the maximum number of blocks any single file can
|
|
allocate out of a cylinder group before it is forced to begin
|
|
allocating blocks from another cylinder group.
|
|
The default is about one quarter of the total blocks in a cylinder group.
|
|
See
|
|
.Xr tunefs 8
|
|
for more details on how to set this option.
|
|
.It Fl i Ar number of bytes per inode
|
|
This specifies the density of inodes in the file system.
|
|
The default is to create an inode for each 2048 bytes of data space.
|
|
If fewer inodes are desired, a larger number should be used;
|
|
to create more inodes a smaller number should be given.
|
|
.It Fl c Ar #cylinders/group
|
|
The number of cylinders per cylinder group in a file system.
|
|
The default value used is 16.
|
|
.It Fl s Ar size
|
|
The size of the file system in sectors.
|
|
.Pp
|
|
The following options override the standard sizes for the disk geometry.
|
|
Their default values are taken from the disk label.
|
|
Changing these defaults is useful only when using
|
|
.Nm newfs
|
|
to build a file system whose raw image will eventually be used
|
|
on a different type of disk than the one on which it is initially
|
|
created (for example on a write-once disk).
|
|
Note that changing any of these values from their
|
|
defaults will make it impossible for
|
|
.Xr fsck
|
|
to find the alternate superblocks if the standard super block is lost.
|
|
.It Fl r Ar revolutions/minute
|
|
The speed of the disk in revolutions per minute.
|
|
.It Fl S Ar sector-size
|
|
The size of a sector in bytes (almost never anything but 512).
|
|
.It Fl u Ar sectors/track
|
|
The number of sectors per track available for data
|
|
allocation by the file system. This does not
|
|
include sectors reserved at the end of each track
|
|
for bad block replacement (see
|
|
.Fl p
|
|
below).
|
|
.It Fl t Ar #tracks/cylinder
|
|
The number of tracks/cylinder available for data
|
|
allocation by the file system.
|
|
.It Fl p Ar spare sectors per track
|
|
Spare sectors (bad sector replacements) are physical sectors
|
|
that occupy space at the end of each track.
|
|
They are not counted as part of the sectors/track
|
|
.Pq Fl u
|
|
since they are not available to the file system for data allocation.
|
|
.It Fl x Ar spare sectors per cylinder
|
|
Spare sectors (bad sector replacements) are physical sectors
|
|
that occupy space at the end of the last track in the cylinder.
|
|
They are deducted from the sectors/track
|
|
.Pq Fl u
|
|
of the last track of each cylinder
|
|
since they are not available to the file system for data allocation.
|
|
.It Fl l Ar hardware sector interleave
|
|
Used to describe perturbations in the media format to
|
|
compensate for a slow controller.
|
|
Interleave is physical sector interleave on each track,
|
|
specified as the denominator of the ratio:
|
|
.Dl sectors read/sectors passed over
|
|
Thus an interleave of 1/1 implies contiguous layout, while 1/2
|
|
implies logical sector 0 is separated by one sector from logical
|
|
sector 1.
|
|
.It Fl k Ar sector \&0 skew , per track
|
|
Used to describe perturbations in the media format to
|
|
compensate for a slow controller.
|
|
Track skew is the offset of sector 0 on track N
|
|
relative to sector 0 on track N-1 on the same cylinder.
|
|
.Pp
|
|
.El
|
|
The following option applies only to
|
|
.Nm mfs .
|
|
.Bl -tag -width Fl
|
|
.It Fl F Ar mount flags
|
|
Used to pass in a decimal numeric value to be passed
|
|
as mount flags when running as a memory based file system.
|
|
This option is primarily intended for use when
|
|
.Nm mfs
|
|
is started by the
|
|
.Xr mount 8
|
|
command.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr disktab 5 ,
|
|
.Xr fs 5 ,
|
|
.Xr disklabel 8 ,
|
|
.Xr diskpart 8 ,
|
|
.Xr fsck 8 ,
|
|
.Xr format 8 ,
|
|
.Xr tunefs 8
|
|
.Rs
|
|
.%A M. McKusick
|
|
.%A W. Joy
|
|
.%A S. Leffler
|
|
.%A R. Fabry
|
|
.%T A Fast File System for UNIX ,
|
|
.%J ACM Transactions on Computer Systems 2
|
|
.%V 3
|
|
.%P pp 181-197
|
|
.%D August 1984
|
|
.%O (reprinted in the BSD System Manager's Manual)
|
|
.Re
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
command appeared in
|
|
.Bx 4.2 .
|