Hd* 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 hdd.
General IDE block device names have the form
hd X\c
, or
hd XP\c
, 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 non-empty, non-extended partitions
get a number. However, partition numbers 1-4 are given to the
four partitions described in the MBR (the `primary' partitions),
regardless of whether they are unused or extended.
Thus, the first logical partition will be
hd X 5\c
.
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*