newfs.8

<B>Digital的Unix操作系统VAX 4.2源码</B>

.\" SCCSID: @(#)newfs.8	6.4	8/31/89
.TH newfs 8
.SH Name
newfs \- construct a new file system
.SH Syntax
.B /etc/newfs 
[
.B \-N
] [
.B \-n
] [
.B \-v
] [
.I mkfs-options
]
.B special disk-type
.SH Description
.NXR "newfs command"
.NXA "mkfs command" "newfs command"
.NXR "newfs command" "mkfs and"
.NXR "file system" "creating"
The
.PN newfs
command is a front-end to the 
.MS mkfs 8 
program.  
The
.PN newfs
program looks up the type of disk a file system is
being created on in the disk description file 
.PN /etc/disktab ,
calculates the appropriate parameters to use in calling
.PN mkfs ,
then builds the file system by forking 
.PN mkfs . 
If the file system is a root partition,
.PN newfs
installs the necessary bootstrap program
in the initial 16 sectors of the device.
.PP
If there is no disk description for the specified disk type in the
.PN /etc/disktab
file, the 
.PN newfs
program will use the 
.PN creatdiskbyname(3x)
subroutine to derive disk geometry information from the controlling
device driver.  This functionality is provided for MSCP and SCSI disks.
.SH Options
.IP \-N 10
Runs 
.mkfs
in no update mode.  In this mode, 
.PN mkfs
will not write to
.PN special .
.IP \-n 10
Prevents the bootstrap program from being installed.
.IP \-v
Instructs 
.PN newfs
to print out its actions, including the parameters passed to
.PN mkfs .
.PP
Options which may be used to override default
parameters passed to
.PN mkfs
are:
.TP 10
\fB\-s \fIsize\fR
The size of the file system in sectors.
.TP 10
\fB\-b \fIblock-size\fR
The block size of the file system in bytes.  
.TP 10
\fB\-f \fIfrag-size\fR
The fragment size of the file system in bytes.
.TP 10
\fB\-t \fI#tracks/cylinder\fR
.ns
.TP 10
\fB\-c \fI#cylinders/group\fR
The number of cylinders per cylinder group in a file system.
The default value used is 16.
.TP 10
\fB\-m \fIfree space %\fR
The percentage of space reserved from normal users; the minimum
free space threshold.  The default value used is 10%.
.TP 10
\fB\-o \fIoptimization\fR
Specifies whether the file system will optimize for \fIspace\fR or 
for \fItime\fR.
.TP 10
\fB\-r \fIrevolutions/minute\fR
The speed of the disk in revolutions per minute (normally 3600).
.TP 10
\fB\-S \fIsector-size\fR
The size of a sector in bytes (almost never anything but 512).
.TP 10
\fB\-i \fInumber of bytes per inode\fR
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.
.SH Files
.TP 20
.PN /etc/disktab 
For disk geometry and file system partition information
.TP
.PN /etc/mkfs 
To actually build the file system
.TP
.PN /usr/mdec/vaxboot 
For boot strapping program
.SH See Also
disktab(5), fs(5), chpt(8), fsck(8), format(8v), 
creatediskbyname(3x), mkfs(8), tunefs(8)
.br
"A Fast File System for UNIX", 
\fISupplementary Documents, Volume 3: System Manager\fP