# hd - MFM/IDE hard disk devices - man(4) - [phpMan]

[_hd_(4)](https://www.chedong.com/phpMan.php/man/hd/4/markdown)                                 Kernel Interfaces Manual                                 [_hd_(4)](https://www.chedong.com/phpMan.php/man/hd/4/markdown)

## NAME
       hd - MFM/IDE hard disk devices

## DESCRIPTION
       The **hd* **devices are block devices to access MFM/IDE hard disk drives in raw mode.  The master
       drive  on  the primary IDE controller (major device number 3) is **hda**; the slave drive is **hdb**.
       The master drive of the second controller (major device number 22) is **hdc **and  the  slave  is
       **hdd**.

       General  IDE  block device names have the form **hd_**X_, or **hd_**XP_, where _X_ is a letter denoting the
       physical drive, and _P_ is a number denoting the partition on that physical drive.   The  first
       form,  **hd_**X_,  is used to address the whole drive.  Partition numbers are assigned in the order
       the partitions are discovered, and only nonempty, nonextended partitions get a number.   How‐
       ever,  partition numbers 1–4 are given to the four partitions described in the MBR (the "pri‐
       mary" partitions), regardless of whether they are unused or extended.  Thus, the first  logi‐
       cal  partition  will  be **hd_**X_**5**.  Both DOS-type partitioning and BSD-disklabel partitioning are
       supported.  You can have at most 63 partitions on an IDE disk.

       For example, _/dev/hda_ refers to all of the first IDE  drive  in  the  system;  and  _/dev/hdb3_
       refers to the third DOS "primary" partition on the second one.

       They are typically created by:

           mknod -m 660 /dev/hda b 3 0
           mknod -m 660 /dev/hda1 b 3 1
           mknod -m 660 /dev/hda2 b 3 2
           ...
           mknod -m 660 /dev/hda8 b 3 8
           mknod -m 660 /dev/hdb b 3 64
           mknod -m 660 /dev/hdb1 b 3 65
           mknod -m 660 /dev/hdb2 b 3 66
           ...
           mknod -m 660 /dev/hdb8 b 3 72
           chown root:disk /dev/hd*

## FILES
       _/dev/hd*_

## SEE ALSO
       [**chown**(1)](https://www.chedong.com/phpMan.php/man/chown/1/markdown), [**mknod**(1)](https://www.chedong.com/phpMan.php/man/mknod/1/markdown), [**sd**(4)](https://www.chedong.com/phpMan.php/man/sd/4/markdown), [**mount**(8)](https://www.chedong.com/phpMan.php/man/mount/8/markdown)

Linux man-pages 6.7                          2023-10-31                                        [_hd_(4)](https://www.chedong.com/phpMan.php/man/hd/4/markdown)