Tribblix: manual page: mkfs

MKFS_PCFS(8) Maintenance Commands and Procedures MKFS_PCFS(8)

NAME

mkfs_pcfs - construct a FAT file system

SYNOPSIS

mkfs -F pcfs [generic_options] [-o FSType_specific_options] raw_device_file

DESCRIPTION

The pcfs-specific module of mkfs constructs a File Allocation Table
(FAT) on removable media (diskette, JAZ disk, ZIP disk, PCMCIA card),
a hard disk, or a file (see NOTES). FATs are the standard MS-DOS and
Windows file system format. Note that you can use fdformat(1) to
construct a FAT file system only on a diskette or PCMCIA card.

mkfs for pcfs determines an appropriate FAT size for the medium, then
it installs an initial boot sector and an empty FAT. A sector size of
512 bytes is used. mkfs for pcfs can also install the initial file in
the file system (see the pcfs-specific -o i option). This first file
can optionally be marked as read-only, system, and/or hidden.

If you want to construct a FAT with mkfs for pcfs on a medium that is
not formatted, you must first perform a low-level format on the
medium with fdformat(1) or format(8). Non-diskette media must also be
partitioned with the fdisk(8) utility. Note that all existing data on
the diskette or disk partition, if any, is destroyed when a new FAT
is constructed.

generic_options are supported by the generic mkfs command. See
mkfs(8) for a description of these options.

raw_device_file indicates the device on which to write unless the -o
N option has been specified, or if the -V or -m generic options are
passed from the generic mkfs module.

OPTIONS

See mkfs(8) for the list of supported generic options.

The following options are supported:

-o FSType_specific_options
Specify pcfs file system-specific
options in a comma-separated list with
no intervening spaces. If invalid
options are specified, a warning
message is printed and the invalid
options are ignored.

b=label
Label the media with
volume label. The volume
label is restricted to 11
uppercase characters.

B=filename
Install filename as the
boot loader in the file
system's boot sector. If
you don't specify a boot
loader, an MS-DOS boot
loader is installed. The
MS-DOS boot loader
requires specific MS-DOS
system files to make the
diskette bootable. See
NOTES for more
information.

fat=n
The size of a FAT entry.
Currently, 12, 16, and 32
are valid values. The
default is 12 for
diskettes, 16 for larger
media.

h
Mark the first file
installed as a hidden
file. The -i option must
also be specified.

hidden=n
Set the number of hidden
sectors to n. This is the
number of sectors on the
physical disk preceding
the start of the volume
(which is the boot sector
itself). This defaults to
0 for diskettes or a
computed valued (based on
the fdisk table) for
disks. This option may be
used only in conjunction
with the nofdisk option.

i=filename
Install filename as the
initial file in the new
file system. The initial
file's contents are
guaranteed to occupy
consecutive clusters at
the start of the files
area. When creating
bootable media, a boot
program should be
specified as the initial
file.

nofdisk
Do not attempt to find an
fdisk table on the
medium. Instead rely on
the size option for
determining the partition
size. By default, the
created FAT is 16 bits
and begins at the first
sector of the device.
This origination sector
can be modified with the
hidden option (-h).

nsect=n
The number of sectors per
track on the disk. If not
specified, the value is
determined by using a
dkio(4I) ioctl to get the
disk geometry, or (for
diskette) from the
results of an FDIOGCHAR
ioctl.

ntrack=n
The number of tracks per
cylinder on the disk. If
not specified, the value
is determined by using a
dkio(4I) ioctl to get the
disk geometry, or (for
diskette) from the
results of an FDIOGCHAR
ioctl.

N
No execution mode. Print
normal output, but do not
actually write the file
system to the medium.
This is most useful when
used in conjunction with
the verbose option.

r
Mark the first file
installed as read-only.
The -i option must also
be specified.

reserve=n
Set the number of
reserved sectors to n.
This is the number of
sectors in the volume,
preceding the start of
the first FAT, including
the boot sector. The
value should always be at
least 1, and the default
value is exactly 1.

s
Mark the first file
installed as a system
file. The -i option must
also be specified.

size=n
The number of sectors in
the file system. If not
specified, the value is
determined from the size
of the partition given in
the fdisk table or (for
diskette) by way of
computation using the
FDIOGCHAR ioctl.

spc=n
The size of the
allocation unit for space
within the file system,
expressed as a number of
sectors. The default
value depends on the FAT
entry size and the size
of the file system.

v
Verbose output. Describe,
in detail, operations
being performed.

FILES

raw_device_file
The device on which to build the FAT. The device
name for a diskette must be specified as
/dev/rdiskette0 for the first diskette drive, or
/dev/rdiskette1 for a second diskette drive. For
non-diskette media, a disk device name must be
qualified with a suffix to indicate the proper
partition. For example, in the name
/dev/rdsk/c0t0d0p0:c, the :c suffix indicates that
the first partition on the disk should receive the
new FAT.

For a file, raw_device_file is the block device
name returned by lofiadm(8).

EXAMPLES

The media in these examples must be formatted before running mkfs for
pcfs. See DESCRIPTION for more details.

Example 1: Creating a FAT File System on a Diskette

The following command creates a FAT file system on a diskette:

mkfs -F pcfs /dev/rdiskette

Example 2: Creating a FAT File System on a Disk

The following command creates a FAT file system on the second fdisk
partition of a disk attached to an x86 based system:

mkfs -F pcfs /dev/rdsk/c0d0p0:d

Example 3: Creating a FAT File System on a ZIP Disk

The following command creates a FAT file system on a ZIP disk located
on a SPARC based system:

mkfs -F pcfs /dev/rdsk/c0t4d0s2:c

Example 4: Creating a FAT File System on a JAZ Disk

The following command creates a FAT file system on a JAZ disk located
on a SPARC based system and overrides the sectors/track and
tracks/cylinder values obtained from the device's controller:

mkfs -F pcfs -o nsect=32,ntrack=64 /dev/rdsk/c0t3d0s2:c

ATTRIBUTES

NOTES

The default MS-DOS boot loader, which is installed by default if -o B
is not specified, requires specific MS-DOS system files to make the
diskette bootable. These MS-DOS files are not installed when you
format a diskette with mkfs for pcfs, which makes a diskette
formatted this way not bootable. Trying to boot from it on an x86
based system will result in the following message:

Non-System disk or disk error
Replace and strike any key when ready

You must format a diskette with the DOS format command to install the
specific MS-DOS system files required by the default boot loader.

You can use lofiadm to create a file that appears to a mkfs command
(for example, mkfs_pcfs or mkfs_ufs) as a raw device. You can then
use a mkfs command to create a file system on that device. See
lofiadm(8) for examples of creating a UFS and a PC (FAT) file system
on a device created by lofiadm.

December 1, 2003 MKFS_PCFS(8)