Device Names in Linux
Linux disks and partition names may be different from other operating
systems. You need to know the names that Linux uses when you create
and mount partitions. Here's the basic naming scheme:
The first floppy drive is named /dev/fd0.
The second floppy drive is named /dev/fd1.
The first SCSI disk (SCSI ID address-wise) is named
The second SCSI disk (address-wise) is named
/dev/sdb, and so on.
The first SCSI CD-ROM is named /dev/scd0, also
known as /dev/sr0.
The master disk on IDE primary controller is named
The slave disk on IDE primary controller is named
The master and slave disks of the secondary controller can be called
/dev/hdc and /dev/hdd,
respectively. Newer IDE controllers can actually have two channels,
effectively acting like two controllers.
The letters may differ from what shows in the mac program pdisk
(i.e. what shows up as /dev/hdc on pdisk may show
up as /dev/hda in Debian).
The first XT disk is named /dev/xda.
The second XT disk is named /dev/xdb.
The first ACSI device is named /dev/ada, the
second is named /dev/adb.
The DASD devices are named
where xxxx is the device number in
hexadecimal notation. The kernel that ships with &debian;
uses devfs so the device nodes are created and removed automatically
when DASD are attached or detached. Please see chapter 3 in
Device Drivers and Installation Commands for more information
The partitions on each disk are represented by appending a decimal
number to the disk name: sda1 and
sda2 represent the first and
second partitions of the first SCSI disk drive in your system.
Here is a real-life example. Let's assume you have a system with 2
SCSI disks, one at SCSI address 2 and the other at SCSI address 4.
The first disk (at address 2) is then named sda,
and the second sdb. If the
sda drive has 3 partitions on it, these will be
named sda1, sda2, and
sda3. The same applies to the
sdb disk and its partitions.
Note that if you have two SCSI host bus adapters (i.e., controllers),
the order of the drives can get confusing. The best solution in this
case is to watch the boot messages, assuming you know the drive models
Linux represents the primary partitions as the drive name, plus the
numbers 1 through 4. For example, the first primary partition on the
first IDE drive is /dev/hda1. The logical partitions are
numbered starting at 5, so the first logical partition on that same
drive is /dev/hda5. Remember that the extended
partition, that is, the primary partition holding the logical
partitions, is not usable by itself. This applies to SCSI disks as
well as IDE disks.
VMEbus systems using the TEAC FC-1 SCSI floppy drive will see it as normal
SCSI disk. To make identification of the drive simpler the installation
software will create a symbolic link to the appropriate device and name
Sun disk partitions allow for 8 separate partitions (or slices). The
third partition is usually (and is preferred to have) the ``Whole Disk''
partition. This partition references all of the sectors of the disk, and
is used by the boot loader (either SILO, or Sun's).
&arch-title; disk partitions allow for 3 separate partitions. They are called