Name

newfs − construct a new file system

Syntax

/etc/newfs [ −v ] [ −n ] [ −N ] [ mkfs-options ] special disk-type

Description

The newfs command is a front-end to the mkfs() program.  The -N option is used to run in no update mode.  In this mode, mkfs will not write to special. The newfs program looks up the type of disk a file system is being created on in the disk description file /etc/disktab, calculates the appropriate parameters to use in calling mkfs, then builds the file system by forking mkfs and, if the file system is a root partition and installs the necessary bootstrap program in the initial 16 sectors of the device.

If there is no disk description for the specified disk type in the /etc/disktab file, the newfs program will use the creatdiskbyname(3x) subroutine to derive disk geometry information from the controlling device driver.  This functionality is provided for MSCP and SCSI disks.

Options

−nprevents the bootstrap program from being installed. 

−vinstructs newfs to print out its actions, including the parameters passed to mkfs.

Options which may be used to override default parameters passed to mkfs are:

−s size The size of the file system in sectors. 

−b block-size
The block size of the file system in bytes.

−f frag-size
The fragment size of the file system in bytes.

−t #tracks/cylinder

−c #cylinders/group
The number of cylinders per cylinder group in a file system. The default value used is 16.

−m free space %
The percentage of space reserved from normal users; the minimum free space threshold.  The default value used is 10%.

−r revolutions/minute
The speed of the disk in revolutions per minute (normally 3600).

−S sector-size
The size of a sector in bytes (almost never anything but 512).

−i 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.

Files

/etc/disktab (for disk geometry and file system partition information)
/etc/mkfs (to actually build the file system)
/usr/mdec/vaxboot (for boot strapping program)

See Also

disktab(5), fs(5), chpt(8), fsck(8), format(8v), creatediskbyname(3x), mkfs(8), tunefs(8)
"A Fast File System for Unix," ULTRIX Supplementary Documents, Vol. III: System Manager