1HD(4) Linux Programmer's Manual HD(4)
2
6 hd - MFM/IDE hard disk devices
7
9 The hd* devices are block devices to access MFM/IDE hard disk drives in
10 raw mode. The master drive on the primary IDE controller (major device
11 number 3) is hda; the slave drive is hdb. The master drive of the sec‐
12 ond controller (major device number 22) is hdc and the slave is hdd.
13 General IDE block device names have the form hdX, or hdXP, where X is a
15 letter denoting the physical drive, and P is a number denoting the par‐
16 tition on that physical drive. The first form, hdX, is used to address
17 the whole drive. Partition numbers are assigned in the order the par‐
18 titions are discovered, and only nonempty, nonextended partitions get a
19 number. However, partition numbers 1–4 are given to the four parti‐
20 tions described in the MBR (the "primary" partitions), regardless of
21 whether they are unused or extended. Thus, the first logical partition
22 will be hdX5. Both DOS-type partitioning and BSD-disklabel partition‐
23 ing are supported. You can have at most 63 partitions on an IDE disk.
24 For example, /dev/hda refers to all of the first IDE drive in the sys‐
26 tem; and /dev/hdb3 refers to the third DOS "primary" partition on the
27 second one.
28 They are typically created by:
30 mknod -m 660 /dev/hda b 3 0
32 mknod -m 660 /dev/hda1 b 3 1
33 mknod -m 660 /dev/hda2 b 3 2
34 ...
35 mknod -m 660 /dev/hda8 b 3 8
36 mknod -m 660 /dev/hdb b 3 64
37 mknod -m 660 /dev/hdb1 b 3 65
38 mknod -m 660 /dev/hdb2 b 3 66
39 ...
40 mknod -m 660 /dev/hdb8 b 3 72
41 chown root:disk /dev/hd*
42
44 /dev/hd*
45
47 chown(1), mknod(1), sd(4), mount(8)
48
50 This page is part of release 5.12 of the Linux man-pages project. A
51 description of the project, information about reporting bugs, and the
52 latest version of this page, can be found at
53 https://www.kernel.org/doc/man-pages/.
54Linux 2017-09-15 HD(4)