DISKTAB(5)                OpenBSD Programmer's Manual               DISKTAB(5)

NAME
     disktab - disk description file

SYNOPSIS
     #include <disktab.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
     database.  Entries in disktab consist of a number of colon (`:') separat-
     ed fields.  The first entry for each disk gives the names which are known
     for the disk, separated by ``|'' characters.  The last name given should
     be a long name fully identifying the disk.

     The following list indicates the normal values stored for each disk en-
     try:

     Name      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 (default: ns*nt).
     su        num      Number of sectors per unit (default: sc*nc).
     se        num      Sector size in bytes (default: DEV_BSIZE).
     sf        bool     Controller supports bad144-style bad sector
                        forwarding.
     rm        num      Rotation speed in RPM (default: 3600).
     sk        num      Sector skew per track (default: 0).
     cs        num      Sector skew per cylinder (default: 0).
     hs        num      Headswitch time in usec (default: 0).
     ts        num      One-cylinder seek time in usec (default: 0).
     il        num      Sector interleave (n:1) (default: 1).
     d[0-4]    num      Drive-type-dependent parameters.
     b0        str      Pathname to primary bootstrap.
     b1        str      Pathname to secondary bootstrap.
     bs        num      Boot block size (default: BBSIZE).
     sb        num      Superblock size (default: SBSIZE).

     ba        num      Block size for partition ``a'' (bytes).
     bd        num      Block size for partition ``d'' (bytes).
     be        num      Block size for partition ``e'' (bytes).
     [...]
     bp        num      Block size for partition ``p'' (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).
     [...]
     fp        num      Fragment size for partition ``p'' (bytes).

     oa        num      Offset of partition ``a'' (sectors).
     ob        num      Offset of partition ``b'' (sectors).
     oc        num      Offset of partition ``c'' (sectors).
     [...]
     op        num      Offset of partition ``p'' (sectors).

     pa        num      Size of partition ``a'' (sectors).
     pb        num      Size of partition ``b'' (sectors).
     pc        num      Size of partition ``c'' (sectors).
     [...]
     pp        num      Size of partition ``p'' (sectors).

     ta        str      Type of partition ``a'' (4.2BSD, swap, etc.).
     tb        str      Type of partition ``b''.
     tc        str      Type of partition ``c''.
     [...]
     tp        str      Type of partition ``p''.

FILES
     /etc/disktab

SEE ALSO
     getdiskbyname(3), disklabel(5), disklabel(8), newfs(8)

HISTORY
     The disktab description file appeared in 4.2BSD.

OpenBSD 4.7                      May 31, 2007                                2
