xref: /openbsd-src/share/man/man5/disktab.5 (revision c0a65584a79812e87f592860ebd3a49db8c371ec)
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31.\"     @(#)disktab.5	8.1 (Berkeley) 6/5/93
32.\"
33.Dd $Mdocdate: November 7 2022 $
34.Dt DISKTAB 5
35.Os
36.Sh NAME
37.Nm disktab
38.Nd disk description file
39.Sh DESCRIPTION
40.Nm
41is a simple database which describes disk geometries and
42disk partition characteristics.
43It is used
44to initialize the disk label on the disk.
45The format is patterned after the
46.Xr termcap 5
47terminal database.
48Entries in
49.Nm
50consist of a number of colon
51.Pq Ql \&:
52separated fields.
53The first entry for each disk gives the names which are
54known for the disk, separated by
55.Dq \&|
56characters.
57The last name given should be a long name fully identifying the disk.
58.Pp
59The following list indicates the normal values stored for each disk entry:
60.Bl -column "d[0-4]" "bool" "Description"
61.It Sy Name Ta Sy Type Ta Sy Description
62.It \&dt Ta str Ta "Type of controller (e.g., SMD, ESDI, floppy)."
63.It \&ns Ta num Ta "Number of sectors per track."
64.It \&nt Ta num Ta "Number of tracks per cylinder."
65.It \&nc Ta num Ta "Total number of cylinders on the disk."
66.It \&sc Ta num Ta "Number of sectors per cylinder (default: ns*nt)."
67.It \&su Ta num Ta "Number of sectors per unit (default: sc*nc)."
68.It \&se Ta num Ta "Sector size in bytes (default:"
69.Dv DEV_BSIZE ) .
70.Pp
71.It \&ba Ta num Ta "Block size for partition"
72.Dq a
73(bytes).
74.It \&bd Ta num Ta "Block size for partition"
75.Dq d
76(bytes).
77.It \&be Ta num Ta "Block size for partition"
78.Dq e
79(bytes).
80.It [...] Ta "" Ta ""
81.It \&bp Ta num Ta "Block size for partition"
82.Dq p
83(bytes).
84.Pp
85.It \&fa Ta num Ta "Fragment size for partition"
86.Dq a
87(bytes).
88.It \&fd Ta num Ta "Fragment size for partition"
89.Dq d
90(bytes).
91.It \&fe Ta num Ta "Fragment size for partition"
92.Dq e
93(bytes).
94.It [...] Ta "" Ta ""
95.It \&fp Ta num Ta "Fragment size for partition"
96.Dq p
97(bytes).
98.Pp
99.It \&oa Ta num Ta "Offset of partition"
100.Dq a
101(sectors).
102.It \&ob Ta num Ta "Offset of partition"
103.Dq b
104(sectors).
105.It \&oc Ta num Ta "Offset of partition"
106.Dq c
107(sectors).
108.It [...] Ta "" Ta ""
109.It \&op Ta num Ta "Offset of partition"
110.Dq p
111(sectors).
112.Pp
113.It \&pa Ta num Ta "Size of partition"
114.Dq a
115(sectors).
116.It \&pb Ta num Ta "Size of partition"
117.Dq b
118(sectors).
119.It \&pc Ta num Ta "Size of partition"
120.Dq c
121(sectors).
122.It [...] Ta "" Ta ""
123.It \&pp Ta num Ta "Size of partition"
124.Dq p
125(sectors).
126.Pp
127.It \&ta Ta str Ta "Type of partition"
128.Dq a
129(4.2BSD, swap, etc.).
130.It \&tb Ta str Ta "Type of partition"
131.Dq b .
132.It \&tc Ta str Ta "Type of partition"
133.Dq c .
134.It [...] Ta "" Ta ""
135.It \&tp Ta str Ta "Type of partition"
136.Dq p .
137.El
138.Sh FILES
139.Bl -tag -width /etc/disktab -compact
140.It Pa /etc/disktab
141.El
142.Sh SEE ALSO
143.Xr getdiskbyname 3 ,
144.Xr disklabel 5 ,
145.Xr disklabel 8 ,
146.Xr newfs 8
147.Sh HISTORY
148The
149.Nm
150description file appeared in
151.Bx 4.2 .
152