HD(4)                      Linux Programmer's Manual                     HD(4)



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
       chown(1), mknod(1), sd(4), mount(8)

COLOPHON
       This page is part of release 4.16 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                             HD(4)