DISKTAB(5)

NAME
disktab - disk description file

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).

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.