mkdosfs
MKDOSFS(8) MKDOSFS(8)
NAME
mkdosfs - create an MS-DOS file system under Linux
SYNOPSIS
mkdosfs [ -A ] [ -b sector-of-backup ] [ -c ] [ -l filename ] [ -C ] [
-f number-of-FATs ] [ -F FAT-size ] [ -i volume-id ] [ -I ] [ -m mes-
sage-file ] [ -n volume-name ] [ -r root-dir-entries ] [ -R number-of-
reserved-sectors ] [ -s sectors-per-cluster ] [ -S logical-sector-size
] [ -v ] device [ block-count ]
DESCRIPTION
mkdosfs is used to create an MS-DOS file system under Linux on a device
(usually a disk partition). device is the special file corresponding
to the device (e.g /dev/hdXX). block-count is the number of blocks on
the device. If omitted, mkdosfs automatically determiness the file
system size.
OPTIONS
-A Use Atari variation of the MS-DOS filesystem. This is default if
mkdosfs is run on an Atari, then this option turns off Atari
format. There are some differences when using Atari format: If
not directed otherwise by the user, mkdosfs will always use 2
sectors per cluster, since GEMDOS doesn't like other values very
much. It will also obey the maximum number of sectors GEMDOS
can handle. Larger filesystems are managed by raising the logi-
cal sector size. Under Atari format, an Atari-compatible serial
number for the filesystem is generated, and a 12 bit FAT is used
only for filesystems that have one of the usual floppy sizes
(720k, 1.2M, 1.44M, 2.88M), a 16 bit FAT otherwise. This can be
overridden with the -F option. Some PC-specific boot sector
fields aren't written, and a boot message (option -m) is
ignored.
-b sector-of-backup
Selects the location of the backup boot sector for FAT32.
Default depends on number of reserved sectors, but usually is
sector 6. The backup must be within the range of reserved sec-
tors.
-c Check the device for bad blocks before creating the file system.
-C Create the file given as device on the command line, and write
the to-be-created file system to it. This can be used to create
the new file system in a file instead of on a real device, and
to avoid using dd in advance to create a file of appropriate
size. With this option, the block-count must be given, because
otherwise the intended size of the file system wouldn't be
known. The file created is a sparse file, which actually only
contains the meta-data areas (boot sector, FATs, and root direc-
tory). The data portions won't be stored on the disk, but the
file nevertheless will have the correct size. The resulting file
can be copied later to a floppy disk or other device, or mounted
through a loop device.
-f number-of-FATs
Specify the number of file allocation tables in the file system.
The default is 2. Currently the Linux MS-DOS file system does
not support more than 2 FATs.
-F FAT-size
Specifies the type of file allocation tables used (12, 16 or 32
bit). If nothing is specified, mkdosfs will automatically
select between 12 and 16 bit, whatever fits better for the
filesystem size. 32 bit FAT (FAT32 format) must (still) be
selected explicitly if you want it.
-i volume-id
Sets the volume ID of the newly created filesystem; volume-id is
a 32-bit hexadecimal number (for example, 2e24ec82). The
default is a number which depends on the filesystem creation
time.
-I Normally you are not allowed to use any 'full' fixed disk
devices. mkdosfs will complain and tell you that it refuses to
work. This is different when usind MO disks. One doesn't
always need partitions on MO disks. The filesytem can go
directly to the whole disk. Under other OSes this is known as
the 'superfloppy' format.
This switch will force mkdosfs to work properly.
-l filename
Read the bad blocks list from filename.
-m message-file
Sets the message the user receives on attempts to boot this
filesystem without having properly installed an operating sys-
tem. The message file must not exceed 418 bytes once line feeds
have been converted to carriage return-line feed combinations,
and tabs have been expanded. If the filename is a hyphen (-),
the text is taken from standard input.
-n volume-name
Sets the volume name (label) of the filesystem. The volume name
can be up to 11 characters long. The default is no label.
-r root-dir-entries
Select the number of entries available in the root directory.
The default is 112 or 224 for floppies and 512 for hard disks.
-R number-of-reserved-sectors
Select the number of reserved sectos. With FAT32 format at least
2 reserved sectors are needed, the default is 32. Otherwise the
default is 1 (only the boot sector).
-s sectors-per-cluster
Specify the number of disk sectors per cluster. Must be a power
of 2, i.e. 1, 2, 4, 8, ... 128.
-S logical-sector-size
Specify the number of bytes per logical sector. Must be a power
of 2 and greater than or equal to 512, i.e. 512, 1024, 2048,
4096, 8192, 16384, or 32768.
-v Verbose execution.
BUGS
None are know at the moment. If you find any, please report it them to
<hpa@yggdrasil.com>. Please include the version number (Yggdrasil
0.3a).
AUTHOR
Dave Hudson - <dave@humbug.demon.co.uk>; modified by Peter Anvin
<hpa@yggdrasil.com>. Fixes and additions by Roman Hodek
<Roman.Hodek@informatik.uni-erlangen.de> for Debian/GNU Linux.
ACKNOWLEDGEMENTS
mkdosfs is based on code from mke2fs (written by Remy Card -
<card@masi.ibp.fr>) which is itself based on mkfs (written by Linus
Torvalds - <torvalds@cs.helsinki.fi>).
SEE ALSO
dosfsck(8), mkfs(8)
Version 2.x 5 May 1995 MKDOSFS(8)
