mkfs.fat - create an MS-DOS filesystem under Linux




   mkfs.fat is used to create an MS-DOS filesystem under Linux on a device
   (usually a disk partition).  DEVICE is the special  file  corresponding
   to the device (e.g. /dev/sdXX).  BLOCK-COUNT is the number of blocks on
   the  device.   If  omitted,  mkfs.fat  automatically   determines   the
   filesystem size.


   -a  Normally,  for any filesystem except very small ones, mkfs.fat will
       align all the data structures to cluster size, to make sure that as
       long  as  the  partition  is properly aligned, so will all the data
       structures in the filesystem.  This option disables alignment; this
       may  provide  a  handful  of  additional clusters of storage at the
       expense of a significant performance degradation  on  RAIDs,  flash
       media or large-sector hard disks.

    -A Use  Atari  variation of the MS-DOS filesystem.  This is default if
       mkfs.fat 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, mkfs.fat 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.

       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 filesystem.

   -C  Create  the file given as DEVICE on the command line, and write the
       to-be-created filesystem to it.  This can be used to create the new
       filesystem  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  filesystem  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.

       Specify  the BIOS drive number to be stored in the FAT boot sector.
       This value is usually 0x80 for  hard  disks  and  0x00  for  floppy
       devices or partitions to be used for floppy emulation.

       Specify  the  number  of  file allocation tables in the filesystem.
       The default is 2.

       Specifies the type of file allocation tables used  (12,  16  or  32
       bit).   If nothing is specified, mkfs.fat will automatically select
       between 12, 16 and 32 bit, whatever fits better for the  filesystem

       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.

       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  It  is  typical  for  fixed  disk  devices to be partitioned so, by
       default, you are not permitted to create a  filesystem  across  the
       entire device.  mkfs.fat will complain and tell you that it refuses
       to work.  This is different  when  using  MO  disks.   One  doesn't
       always need partitions on MO disks.  The filesystem can go directly
       to the  whole  disk.   Under  other  OSes  this  is  known  as  the
       'superfloppy'  format.   This  switch  will  force mkfs.fat to work

       Read the bad blocks list from FILENAME.

       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.

       Specify  the  media type to be stored in the FAT boot sector.  This
       value is usually 0xF8 for hard disks and is 0xF0 or  a  value  from
       0xF9  to  0xFF  for  floppies  or  partitions to be used for floppy

       Sets the volume name (label) of the filesystem.   The  volume  name
       can be up to 11 characters long.  The default is no label.

       Select  the number of entries available in the root directory.  The
       default is 112 or 224 for floppies and 512 for hard disks.

       Select the number of reserved sectors.  With FAT32 format at  least
       2  reserved  sectors  are needed, the default is 32.  Otherwise the
       default is 1 (only the boot sector).

       Specify the number of disk sectors per cluster.  Must be a power of
       2, i.e. 1, 2, 4, 8, ... 128.

       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.  Values larger than 4096 are not conforming
       to the FAT file system specification and may not work everywhere.

   -v  Verbose execution.

       Use constants for normally randomly generated or  time  based  data
       such  as volume ID and creation time.  Multiple runs of mkfs.fat on
       the same device create identical results  with  this  option.   Its
       main purpose is testing mkfs.fat.

       Display option summary and exit.


   mkfs.fat  can  not create boot-able filesystems.  This isn't as easy as
   you might think at first  glance  for  various  reasons  and  has  been
   discussed a lot already.  mkfs.fat simply will not support it ;)




   The  home  for  the  dosfstools  project  is  its  GitHub  project page


   dosfstools were  written  by  Werner  Almesberger  werner.almesberger@,  Roman Hodek,
   and others.  The current maintainer is Andreas Bombe


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