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 logical 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 sectors.
-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 directory). 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.
-h number-of-hidden-sectors
Select the number of hidden sectors in the volume. Apparently some
digital cameras get indigestion if you feed them a CF card without
such hidden sectors, this option allows you to satisfy them. Assumes
'0' if no value is given on the command line.
-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 system. 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
mkdosfs
can not create bootable filesystems. This isn't as easy as you might
think at first glance for various reasons and has been discussed a lot
already.
mkdosfs
simply will not support it ;)
mkdosfs
is based on code from
mke2fs
(written by Remy Card - <[email protected]>) which is itself based on
mkfs
(written by Linus Torvalds - <[email protected]>).
