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<html> <head> <title>hd</title> <META NAME="KEYWORDS" CONTENT="hd"> </head> <body BGCOLOR="#ffffff" LINK="#0000ff" VLINK="#0000ff" ALINK="#0000ff" TEXT="#000000"> <center> <h1><b>hd</b></h1></center> <PRE> <STRONG><A HREF="/man4/HD">HD(4)</A></STRONG> Linux Programmer's Manual <STRONG><A HREF="/man4/HD">HD(4)</A></STRONG> 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 sec- ond controller (major device number 22) is hdc and the slave is hdd. General IDE block device names have the form hdX, or hdXP, where X is a letter denoting the physical drive, and P is a number denoting the par- tition on that physical drive. The first form, hdX, is used to address the whole drive. Partition numbers are assigned in the order the par- titions are discovered, and only nonempty, nonextended partitions get a number. However, partition numbers 1-4 are given to the four parti- tions described in the MBR (the "primary" partitions), regardless of whether they are unused or extended. Thus, the first logical partition will be hdX5. Both DOS-type partitioning and BSD-disklabel partition- ing 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 sys- tem; 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 <STRONG><A HREF="/man1/chown">chown(1)</A></STRONG>, <STRONG><A HREF="/man1/mknod">mknod(1)</A></STRONG>, <STRONG><A HREF="/man4/sd">sd(4)</A></STRONG>, <STRONG><A HREF="/man8/mount">mount(8)</A></STRONG> COLOPHON This page is part of release 5.05 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/. Linux 2017-09-15 <STRONG><A HREF="/man4/HD">HD(4)</A></STRONG></PRE> <center> <h6>Man Pages Copyright Respective Owners. Site Copyright (C) 1994 - 2025 <a href="http://www.he.net">Hurricane Electric</a>. All Rights Reserved.</h6></center> </body> </html>