Manual page for NEWFS(8)
newfs - create a new file system
SYNOPSIS
/usr/etc/newfs
[
-Nv
] [
mkfs-options
]
raw-special-device
DESCRIPTION
newfs
is a ``friendly'' front-end to the
mkfs.8
program.
On Sun systems, the disk type is
determined by reading the disk label for the specified
raw-special-device.
raw-special-device
is the name of a raw special device residing in
/dev,
including the disk partition,
where you want the new file system to be created.
If you want to make a file system on
sd0[a-h],
specify
sd0[a-h],
rsd0[a-h]
or
/dev/rsd0[a-h];
if you only specify
sd0[a-h],
newfs
will find the proper device.
newfs
then calculates the appropriate parameters to use in calling
mkfs,
and builds the file system by forking
mkfs.
You must be super-user to use this command.
OPTIONS
- -N
-
Print out the file system parameters
without actually creating the file system.
- -v
-
Verbose.
newfs
prints out its actions,
including the parameters passed to
mkfs.
- mkfs-options
-
Options that override the default parameters passed to
mkfs.8
are:
-
- -a apc
-
Number of alternates per cylinder
(SCSI devices only).
- -b block-size
-
The block size of the file system in bytes.
The default is
8192.
- -C maxcontig
-
The maximum number of blocks, belonging to one file, that will be
allocated contiguously before inserting a rotational delay.
The default varies from drive to drive. Drives without internal buffers
(or drives/controllers that don't advertise the existence of an internal buffer)
default to
1.
Drives with buffers default to
7.
This parameter is limited in the following way:
blocksize * maxcontig must be <= maxphys
maxphys
is a read-only
kernel variable that specifies the maximum block transfer size (in bytes) that
the I/O subsystem is capable of satisfying. (This limit is enforced by
mount.2
not by
newfs
or
mkfs.)
Note:
This parameter also controls
clustering. Regardless of the value of
rotdelay,
clustering is enabled only when
maxcontig
is greater than 1.
Clustering allows higher I/O rates for sequential
I/O and is described in
tunefs.8
- -c #cylinders/group
-
The number of cylinders per cylinder group in a file system.
The default is
16.
- -d rotdelay
-
This specifies the expected time (in milliseconds)
to service a transfer completion
interrupt and initiate a new transfer on the same disk.
It is used to decide how much rotational spacing to place between
successive clusters/blocks in a file.
- -f frag-size
-
The fragment size of the file system in bytes.
The default is
1024.
- -i bytes/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.
- -m free-space%
-
The percentage of space reserved from normal users; the minimum
free space threshold.
The default is
10%.
- -o optimization
-
(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 minimum free space threshold (as specified by the
-m
option) is less than 10%,
the default is to optimize for
space;
if the minimum free space threshold is greater than or equal to 10%,
the default is to optimize for
time.
- -r revolutions/minute
-
The speed of the disk in revolutions per minute (frequently 3600).
- -s size
-
The size of the file system in sectors.
- -t #tracks/cylinder
-
The number of tracks per cylinders on the disk.
The default is
16.
- -n #rotational-positions
-
The number of distinguished rotational positions.
The default is
8.
EXAMPLES
The following example verbosely displays the parameters
for the raw special device,
sd0a,
but does not actually create a new file system:
-
example% /usr/etc/newfs -vN sd0a
mkfs -N /dev/rsd0a 16048 34 8 8192 1024 16 10 60 2048 t 0 -1 8 -1
/dev/rsd0a: 16048 sectors in 59 cylinders of 8 tracks, 34 sectors
8.2Mb in 4 cyl groups (16 c/g, 2.23Mb/g, 896 i/g)
super-block backups (for fsck -b#) at:
32, 4432, 8832, 13232,
example%
SEE ALSO
fs.5
fsck.8
installboot.8s
mkfs.8
tunefs.8
[a manual with the abbreviation ADMIN]
DIAGNOSTICS
- newfs: special No such file or directory
-
The device specified does not exist, or a disk partition was not
specified.
- special: cannot open
-
You must be super-user to use this command.
NOTES
To install the bootstrap programs for a root partition,
run
installboot.8s
after
newfs.
Created by unroff & hp-tools.
© somebody (See intro for details). All Rights Reserved.
Last modified 11/5/97