MKFS_PCFS(1M)MKFS_PCFS(1M)NAMEmkfs_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 Win‐
dows 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(1M). Non-diskette media must also be parti‐
tioned with the fdisk(1M) utility. Note that all existing data on the
diskette or disk partition, if any, is destroyed when a new FAT is con‐
structed.
generic_options are supported by the generic mkfs command. See mkfs(1M)
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(1M) 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 inter‐
vening 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 guaran‐
teed to occupy consecutive
clusters at the start of
the files area. When creat‐
ing 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(7I) 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(7I) 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 ver‐
bose 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 compu‐
tation 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 qual‐
ified with a suffix to indicate the proper parti‐
tion. 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(1M).
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
See attributes(5) for descriptions of the following attributes:
┌────────────────────┬─────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼─────────────────┤
│Interface Stability │ Stable │
└────────────────────┴─────────────────┘
SEE ALSOfdformat(1), fdisk(1M), format(1M), lofiadm(1M), mkfs(1M),
attributes(5), fd(7D), dkio(7I), fdio(7I)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(1M)
for examples of creating a UFS and a PC (FAT) file system on a device
created by lofiadm.
Dec 1, 2003 MKFS_PCFS(1M)
