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 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, nc*nt default
su | num | Number of sectors per unit, sc*nc default
se | num | Sector size in bytes,
DEV_BSIZE default
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
bs | num | Boot block size, default
BBSIZE disklabel(8)
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)
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 filesystem, 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'

The following entries have been discontinued and are no longer supported:
d[0-4] | num | Drive-type-dependent parameters
b[0-1] | num | Boot block filenames
sf | bool | Controller supports bad144-style bad sector forwarding

FILES
/etc/disktab

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

HISTORY
The disktab description file appeared in 4.2BSD.