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MKFS.FAT(8)                       dosfstools                       MKFS.FAT(8)

NAME
       mkfs.fat - create an MS-DOS filesystem under Linux
SYNOPSIS
       mkfs.fat [ -a ] [ -A ] [ -b sector-of-backup ] [ -c ] [ -l filename ] [
       -C ] [ -f number-of-FATs ] [ -F FAT-size ] [  -h  number-of-hidden-sec-
       tors ] [ -i volume-id ] [ -I ] [ -m message-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
       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/hdXX).  block-count is the number of blocks on
       the device.  If omitted, mkfs.fat automatically determines the filesys-
       tem size.
OPTIONS
       -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 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 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 other-
              wise 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 never-
              theless 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  filesystem.
              The  default  is  2.  Currently the Linux MS-DOS filesystem 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,  mkfs.fat will automatically
              select between 12, 16 and 32 bit, whatever fits better  for  the
              filesystem size.
       -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     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 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  sectors.  With  FAT32  format  at
              least  2  reserved sectors are needed, the default is 32. Other-
              wise 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
       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  dis-
       cussed a lot already.  mkfs.fat simply will not support it ;)
AUTHOR
       Dave  Hudson  -  <dave AT humbug.uk>;  modified  by  Peter  Anvin
       <hpa AT yggdrasil.com>.   Fixes   and    additions    by    Roman    Hodek
       <roman AT hodek.net> for Debian GNU/Linux.
ACKNOWLEDGMENTS
       mkfs.fat  is  based  on  code  from  mke2fs  (written  by  Remy  Card -
       <card AT masi.fr>) which is itself based on  mkfs  (written  by  Linus
       Torvalds - <torvalds AT cs.fi>).
SEE ALSO
       fsck.fat(8), fatlabel(8), mkfs(8)

3.0.19                            2013-06-11                       MKFS.FAT(8)