Provided by: dosfstools_3.0.12-1ubuntu1_amd64 bug


       mkdosfs - create an MS-DOS file system under Linux


       mkdosfs|mkfs.msdos|mkfs.vfat  [ -a ] [ -A ] [ -b sector-of-backup ] [ -c ] [ -l filename ]
       [ -C ] [ -f number-of-FATs ] [ -F FAT-size ] [ -h number-of-hidden-sectors ] [ -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 ]


       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
       determines the file system size.


       -a     Normally, for any filesystem except very small ones, mkdosfs  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 file system. 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 file systems are
              managed by raising  the  logical  sector  size.   Under  Atari  format,  an  Atari-
              compatible serial number for the file system is generated, and a 12 bit FAT is used
              only for file systems 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

       -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, 16 and 32 bit, whatever
              fits better for the file system 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  file  system;  volume-id  is  a  32-bit
              hexadecimal  number (for example, 2e24ec82).  The default is a number which depends
              on the file system 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.  mkdosfs 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 file system 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  file  system  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 file system.  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. Otherwise the default is 1 (only the boot

       -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.


       mkdosfs can not create boot-able file systems. 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 ;)


       Dave Hudson - <>;  modified  by  Peter  Anvin  <>.
       Fixes and additions by Roman Hodek <> for Debian/GNU Linux.


       mkdosfs  is based on code from mke2fs (written by Remy Card - <>) which is
       itself based on mkfs (written by Linus Torvalds - <>).


       dosfsck(8), dosfslabel(8), mkfs(8)