diskformat(1M)                                     diskformat(1M)



NAME
     diskformat -  formats  a  disk  through  a  driver-dependent
     format operation

SYNOPSIS
     diskformat [-cyl start[-[end]]] [-dens n] [-head 0]
          floppy-device

     diskformat [-size 532] hard-disk-device

ARGUMENTS
     -cyl start[-[end]]
          Formats cylinders starting from start and ending with
          end.  A specification such as start- means starting
          from start and proceeding to the end of the media.
          Note that while start and end cylinders can be
          specified for any device, they are only honored if the
          device driver supports them.  See Section 7 in the
          Programmer's Reference Manual for details about
          particular device drivers, such as fd(7).

     -dens n
          Indicates formatting density for floppy disks only.
          Replacing n with a value of 400 specifies 400K single-
          sided, 720 specifies 720K, 800 specifies 800K double-
          sided, and 1440 specifies 1440K.

     floppy-device
          Specifies the floppy disk device to be initialized.

     hard-disk-device
          Specifies the hard disk device to be initialized.

     -head 0
          Formats a floppy disk for single-sided use (400K).
          This option is available as well as the 400 argument
          for -dens so that drives referenced as fixed density
          can be forced to honor the command without reporting
          errors.

     -size 532
          Formats the hard disk at 532 bytes per physical disk
          block for compatibility with some early Macintosh hard
          disk drives.  Logical blocks remain 512 bytes per
          block. A/UX simply ignores the extra tag bytes at the
          beginning of each physcial block.

DESCRIPTION
     diskformat initializes a hard or floppy disk by passing any
     specified parameters through the corresponding generic
     device interface, such as fd or gd.  This means that the
     parameters for diskformat can be interpreted differently for



January 1992                                                    1

diskformat(1M)                                     diskformat(1M)



     different classes of devices.  For example, one form of this
     command can be used to format hard disks, and in that case
     the head option is ignored.  However, the head argument is
     honored whenever it is passed through the fd (floppy)
     interface.

     For Apple and most third-party hard disks, the preferred
     method is to use Apple HD SC Setup to format and partition
     disks.  That way, Apple HD SC Setup, as well as other
     Macintosh utilities, are able to read the partition map and
     discover the whereabouts of any Macintosh file systems.

     Before diskformat actually formats a disk, it issues the
     following message:

        About to format device. Type return to continue:

     and waits for you to confirm the operation.  This gives you
     a final opportunity to cancel the format operation, because
     it overwrites any previous data and programs on the media
     referenced as floppy-device or hard-disk-device.  Note that
     any response at all, other than the interrupt or suspend
     character, causes diskformat to continue its operation.

     You must specify a raw floppy-device or hard-disk-device for
     this command, as described in fd(7) and gd(7).

     Without any options, the floppy disk is formatted at the
     highest recording density supported by the media and the
     drive, as long as floppy-device references one of the
     following autodensity device files:

        /dev/rfloppy[01]
        /dev/rfd/d[01]

     However, if the diskformat command is specified without any
     options and the floppy media is referenced through a device
     file of fixed density, the media is formatted at the
     expected density, if at all possible.  See fd(7) for a list
     of the device files with fixed densities.

NOTES
     Before floppy disks can be used with commands such as tar or
     cpio, they must be formatted using diskformat or the
     Macintosh Operating System.

     Writing to a floppy disk previously formatted under the
     Macintosh  Operating System, using utilities such as tar and
     cpio, destroys any previously recorded Macintosh data and
     programs.





2                                                    January 1992

diskformat(1M)                                     diskformat(1M)



     Before a diskformat operation is started, the device is
     accessed in exclusive-use mode. This prevents anyone from
     formatting the media in a drive already being used, or
     prevents anyone from using the device while it is formatting
     media.

     The default formatting density chosen in the absence of the
     dens and head options is determined by the floppy device
     driver based on the floppy-device device file specified, the
     type of floppy drive, and the media inserted.  See fd(7) for
     details.

FILES
     /bin/diskformat
          Executable file

SEE ALSO
     fd(7), gd(7) in A/UX Programmer's Reference





































January 1992                                                    3