FDFORMAT(8)             FreeBSD System Manager's Manual            FDFORMAT(8)

NAME

     fdformat - format floppy disks

SYNOPSIS

     fdformat [-F fill] [-f fmt] [-s fmtstr] [-nqvy] device

DEPRECATION NOTICE

     fdformat is deprecated and may not be present in FreeBSD 16.0 and later.

DESCRIPTION

     The fdformat utility formats a floppy disk at device, where device may
     either be given as a full path name of a device node for a floppy disk
     drive (e.g., /dev/fd0), or using an abbreviated name that will be looked
     up under /dev (e.g., "fd0").

     The options are as follows:

     -F fill      Use fill as the fill byte for newly formatted sectors.  The
                  fill argument must be a number in the range 0 through 255
                  using common C language notation.  The default value is
                  "0xf6".

     -f fmt       Specify the density settings for a fmt kilobyte format, as
                  described in fdcontrol(8).

     -s fmtstr    Specify the density settings using explicit parameters, as
                  described in fdcontrol(8).

     -n           Do not verify floppy after formatting.

     -q           Suppress any normal output from the command, and do not ask
                  the user for a confirmation whether to format the floppy
                  disk at device.

     -v           Do not format, verify only.

     -y           Do not ask for confirmation whether to format the floppy
                  disk but still report formatting status.

     For non-autoselecting subdevices, neither -f fmt nor -s fmtstr may be
     specified, since the preconfigured media density settings from the kernel
     driver will always be used.  However, if device is a device with
     automatic media density selection (see fdc(4)), both methods can be used
     to override the density settings for the newly formatted medium (without
     permanently changing the density settings of device).

     If the -q flag has not been specified, the user is asked for a
     confirmation of the intended formatting process.  In order to continue,
     an answer of `y' must be given.

     Note that fdformat does only perform low-level formatting.  In order to
     create a file system on the medium, see the commands newfs(8) for a UFS
     file system, or newfs_msdos(8) for an MS-DOS (FAT) file system.

EXIT STATUS

     An exit status of 0 is returned upon successful operation.  Exit status 1
     is returned on any errors during floppy formatting, and an exit status of
     2 reflects invalid arguments given to the program (along with an
     appropriate information written to diagnostic output).

EXAMPLES

     To format a new double-sided, high-density (HD) 1.44 MB disk inserted in
     the first floppy disk drive, issue:

           /usr/sbin/fdformat -f 1440 /dev/fd0

     After low-level formatting the disk with fdformat, create a disk label so
     that the system can determine the size and geometry of the disk.  The
     supported geometry values are listed in /etc/disktab, and we will use
     fd1440 for this example.  To write the disk label, use bsdlabel(8):

           /sbin/bsdlabel -B -w /dev/fd0 fd1440

     The floppy is now ready to be high-level formatted with a file system.
     To format the floppy disk with FAT, issue:

           /sbin/newfs_msdos /dev/fd0

DIAGNOSTICS

     Unless -q has been specified, a single letter is printed to standard
     output to inform the user about the progress of work.  First, an `F' is
     printed when the track is being formatted, then a `V' while it is being
     verified, and if an error has been detected, it will finally change to
     `E'.  Detailed status information (cylinder, head and sector number, and
     the exact cause of the error) will be printed for up to 10 errors after
     the entire formatting process has completed.

SEE ALSO

     fdc(4), bsdlabel(8), fdcontrol(8), newfs(8), newfs_msdos(8)

HISTORY

     The fdformat utility has been developed for 386BSD-0.1 and upgraded to
     the new fdc(4) floppy disk driver.  It later became part of the
     FreeBSD 1.1 system.  Starting with FreeBSD 5.0, it uses the unified
     density specifications as described in fdcontrol(8).

AUTHORS

     The program has been contributed by Jorg Wunsch, Dresden, with changes by
     Serge Vakulenko and Andrey A. Chernov, Moscow.

FreeBSD 15.1-STABLE-HBSD       November 16, 2025                   FDFORMAT(8)