disktab

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 (`:')
     separated 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
     entry:

     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 5.1                    September 3, 2011                   OpenBSD 5.1