DISKTAB(5)                FreeBSD File Formats Manual               DISKTAB(5)

NAME
     disktab - disk description file

SYNOPSIS
     #include <disklabel.h>

DESCRIPTION
     Disktab is a simple database which describes disk geometries and disk
     partition characteristics.  It is used to initialize the disk label on
     the disk.  The format is patterned after the termcap(5) terminal data
     base.  Entries in disktab consist of a number of `:'-separated fields.
     The first field for each entry gives the names by which a disk's entry
     may be selected, separated by `|' characters.  The last name given should
     be a long name fully identifying the disk.

     The optional fields for each entry are:

     ID        Type     Description
     ty        str      Type of disk (e.g. removable, winchester)
     dt        str      Type of controller (e.g. SMD, ESDI, floppy)
     ns        num      Number of sectors per track
     nt        num      Number of tracks per cylinder
     nc        num      Total number of cylinders on the disk
     sc        num      Number of sectors per cylinder, ns*nt default
     su        num      Number of sectors per unit, sc*nc default
     se        num      Sector size in bytes, DEV_BSIZE default
     sf        bool     Controller supports bad144-style bad sector forwarding
     rm        num      Rotation speed, rpm, 3600 default
     sk        num      Sector skew per track, default 0
     cs        num      Sector skew per cylinder, default 0
     hs        num      Headswitch time, usec, default 0
     ts        num      One-cylinder seek time, usec, default 0
     il        num      Sector interleave (n:1), 1 default
     d[0-4]    num      Drive-type-dependent parameters
     bs        num      Boot block size, default BBSIZE
     sb        num      Superblock size, default 0
     ba        num      Block size for partition `a' (bytes)
     bd        num      Block size for partition `d' (bytes)
     be        num      Block size for partition `e' (bytes)
     bf        num      Block size for partition `f' (bytes)
     bg        num      Block size for partition `g' (bytes)
     bh        num      Block size for partition `h' (bytes)
     fa        num      Fragment size for partition `a' (bytes)
     fd        num      Fragment size for partition `d' (bytes)
     fe        num      Fragment size for partition `e' (bytes)
     ff        num      Fragment size for partition `f' (bytes)
     fg        num      Fragment size for partition `g' (bytes)
     fh        num      Fragment size for partition `h' (bytes)
     oa        num      Offset of partition `a' in sectors
     ob        num      Offset of partition `b' in sectors
     oc        num      Offset of partition `c' in sectors
     od        num      Offset of partition `d' in sectors
     oe        num      Offset of partition `e' in sectors
     of        num      Offset of partition `f' in sectors
     og        num      Offset of partition `g' in sectors
     oh        num      Offset of partition `h' in sectors
     pa        num      Size of partition `a' in sectors
     pb        num      Size of partition `b' in sectors
     pc        num      Size of partition `c' in sectors
     pd        num      Size of partition `d' in sectors
     pe        num      Size of partition `e' in sectors
     pf        num      Size of partition `f' in sectors
     pg        num      Size of partition `g' in sectors
     ph        num      Size of partition `h' in sectors
     ta        str      Partition type of partition `a' (4.2BSD file system,
                        swap, etc)
     tb        str      Partition type of partition `b'
     tc        str      Partition type of partition `c'
     td        str      Partition type of partition `d'
     te        str      Partition type of partition `e'
     tf        str      Partition type of partition `f'
     tg        str      Partition type of partition `g'
     th        str      Partition type of partition `h'

FILES
     /etc/disktab

SEE ALSO
     getdiskbyname(3), bsdlabel(8), newfs(8)

HISTORY
     The disktab description file appeared in 4.2BSD.

FreeBSD 13.1-RELEASE-p6        October 14, 2006        FreeBSD 13.1-RELEASE-p6