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
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.
d[0-4]	num	Drive-type-dependent parameters.
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.