Transcript Chapter 12 Installing and Maintaining Hardware in a Linux

Chapter 12
Installing and Maintaining
Hardware in a Linux Environment
12.1 - Hardware Terms, Concepts, and
Components
12.2 - Hardware Installation, Configuration,
and Maintenance
12.3 - Checking and Confirming Hardware
Configuration
12.4 - Laptop and Mobile Devices
Hardware Terms, Concepts,
and Components
Overview of Hardware Components
•
The motherboard is the central
component, which allows every other
hardware device in the system to run.
Like the central processing unit
(CPU), if the motherboard fails, so
does the system.
•
When installing RAM, users really do
not have to be concerned with
compatibility.
•
The user can install any RAM from
any manufacturer on a Linux system.
Overview of Hardware Components
• Hardware will include a
small capacity hard drive, a
CD-ROM drive, and an
inexpensive video card if
the system will only be used
for basic word processing,
e-mail, and Internet access.
Central Processing Unit (CPU)
• Originally, Linux was developed
for Intel 80x86.
• Linux was developed on the 386
system and can still run on that
system today and is also
compatible with subsequent Intel
family of processors like the 486
and entire class of Pentium
processors.
• Other x86 compatible chips by
other manufacturers such as the
AMD Athlon, Duron, and K6
processors are also compatible
with Linux.
Video Hardware
• Selecting and configuring Video
hardware is a complicated task.
• Linux systems that are only to be
used as servers do not
necessarily need to be
concerned with what video card
is installed.
• The type of video card is only a
concern when the X server
component is installed.
• The X server provides the GUI.
Miscellaneous Hardware
and Components
• Some hardware will require
special configuration if it is
installed in a Linux system.
• The following devices may
require special drivers or
configurations before they
operate properly with Linux:
– USB Devices
– Sound Cards
– Video Capture Cards
– Internal Modems
Hardware Monitoring Devices
• Some devices that can be
useful in troubleshooting
network problems include
the following:
– With a Tone Generator, the
’fox‘ portion can be
attached to one end of the
cable, and a tone is
generated. A locator, or the
’hound‘, at the other end
receives the tone.
– The crossover cable is
used to connect two
computers without going
through a hub.
Hardware Monitoring Devices
• With a Time domain
reflectometer (TDR)
a sonar-type pulse is sent
through the cable.
• The pulse is measured to
locate shorts or breaks in the
cable.
• The volt-ohm meter, or
voltmeter, is used to measure
electronic pulses through cable
and to determine if there are
shorts or breaks in the cable.
Hardware Monitoring Devices
• A cable tester is used to detect breaks and shorts.
• An oscilloscope is used in electronics calibration.
– It is also used to measure how much signal voltage passes
through a cable over a set period of time.
• A LAN meter can check for broadcasts, collisions, usage
levels, and errors on Ethernet and Token Ring LANs.
Hardware Installation,
Configuration, and Maintenance
Locating Hardware Drivers for Linux
• There are several possible
sources of hardware drivers for a
Linux system.
• In a Linux system, the kernel will
serve as the interface between
the operating system, which is
the software, and the hardware.
• Most Linux drivers are either
located in the Linux kernel
initially, or added to it in some
way.
• Some hardware such as printers,
scanners, and video card drivers
are not located in the kernel.
• These devices reside externally
in non-kernel software.
Configuring Hardware
in a Linux System
• Internal expansion cards are
installed into the system’s
motherboard.
• Soundcards, Video Cards,
Software modems, SCSI cards,
and RAID controllers are all
examples of internal expansion
cards.
• To view the resource allocations
on a Linux system view the
/proc/interrupt, /proc/dma,
/proc/ioports files.
• Using the cat command with
the files above, see what
devices are allocated.
Configuring Hardware
in a Linux System
• If using a GUI interface like
KDE for example, view the
resource allocations by
using the GUI Control
Center tool.
• Set the proper jumpers for
the device.
• The jumper is a metal cap
which is covered by plastic
that covers the jumper
pins.
Configuring Hardware
in a Linux System
• The final step of
configuring hardware on a
Linux system is being able
to load the appropriate
drivers and setting the
correct options related to
the driver.
• The two ways that options
can be set for drivers are
through kernel options
and module options.
Linux Kernel Modules
• The latest distributions of
Linux include kernel
module loader support.
• One of the latest
distributions of Linux is the
version of Red Hat Linux
that is used in this course.
• Kernel module loader
support means that the
kernel has the ability to
load and unload drivers as
it needs them.
Linux Kernel Modules
• The insmod program, is used
to insert a single module into
the kernel.
• The syntax for this command
includes adding the name of
the module that is being loaded
along with some options.
• The modprobe program,
reduces this administrative
overhead by automatically
loading any dependencies a
module has.
Linux Kernel Modules
• The rmmod program can be
used to remove drivers or
modules.
• The modprobe program with
the -r or --remove option will
also remove modules.
• ismod reveals what modules are
currently being used and what
device is using them, as well as
other information.
• ismod also lists the sizes of the
modules and the dependency
modules.
Checking and Confirming
Hardware Configuration
Power Cables
• The first power cable is the
one that connects the wall
outlet.
• This cable is external and is
not necessarily the power
cable of concern when
installing a hardware device.
• The other type of power cable
is internal.
• This cable connects the
internal power supply to one of
the hardware devices.
Power Cables
• Internal cables enable the
devices to send data from
one device to another.
• Usually the cables will
extend from a controller card
or the motherboard to a disk
or tape drive, which stores
the data.
• The most common form of
data cable that is used is
ribbon cable.
Power Cables
• When installing SCSI
devices, keep in mind some
of the data cables will not
connect to a device at all
because there might be
more cables than available
devices.
• External Cables are
referred to as the cables
that connect the computer
to the external devices such
as keyboards, mice,
monitor, printers, scanners,
and network connections.
IRQ, DMA, and I/O Settings
• Most hardware, specifically ISA and PCI controller cards,
that are inserted into the motherboard use hardware
resources located on the motherboard.
• These resources are called the Interrupt Request (IRQ),
Direct Memory Access Channel (DMA), and the
Input/Output (I/O) Port.
• There are more I/O ports available
than DMA channels or IRQs.
EIDE Devices
• EIDE devices are usually
hard drives, floppy drives,
CD-ROMs, and other types
of disk and tape drives.
• The differences are in the
data transfer speeds.
• When installing EIDE devices
confirm that they are set to
the proper Master or Slave
setting.
• In Linux, the master drive
takes on the lower device
letter in its /dev/hdx
filename, where x is the
device letter.
SCSI Devices
1. Check the SCSI
variant.
2. Each SCSI device that
is installed needs to be
assigned a number, or
SCSI ID.
3. Check that there is a
terminating device.
4. Check cable quality.
5. Check cable length.
BIOS Settings
• The BIOS plays a big role in
configuration and installation of
hardware.
• Another aspect of the BIOS that
will differ from one system to
another is the Complementary
Metal Oxide Semiconductor
(CMOS) setup utility.
• The CMOS is the memory
component of the BIOS where
low-level configurations and
options for certain hardware are
saved so that they can be
retrieved every time the system
is booted.
Diagnosing and
Troubleshooting Devices
• In some cases EIDE/ATA
devices can produce very
slow data transfer speeds in
Linux systems.
• One possible reason is the
use of wrong drivers.
• The hdparm utility can be
used to test disk speeds as
well as set several options.
• Read the hdparm man page
to find out more information
about the complete set of
options that can be used
with this utility.
SCSI Devices
• In any SCSI chain there needs
to be a terminator put in place
at each end to keep the signal
from continuously bouncing
back.
• Some SCSI devices are
capable of self-termination by
setting the proper jumper or
switch.
• SCSI adapters typically have 3
adapters.
• There is one external and two
internal adapters.
• The two internal adapters are
for wide or narrow internal
SCSI adapters.
Peripheral Devices
• Peripheral Devices are
devices that connect to the
computer through an
external or internal port and
are controlled by the
computer.
• There are several
peripheral interfaces which
need to be covered to be
able to fully diagnose and
troubleshoot peripheral
device problems.
– Floppy, Monitor, Keyboard,
Mouse, Parallel ports, RS232 serial, USB, cables
Core System Hardware
• The core system hardware refers to the RAM, CPU, and
motherboard, the most critical hardware on a system.
• If any of these devices are not working properly or are
damaged then they entire system may not work
• In a Linux system, some problems associated with core
system hardware do not make themselves known until
after the system boots up.
• Another helpful indicator to properly diagnose and
troubleshoot core system hardware problems is to identify
when the error occurs.
• Does the problem occur right when the system starts up
or does the problem come up after the system has been
running for a period of time?
Laptop and Mobile Devices
Power Management
• Installing Linux on laptops is another area that
requires special attention.
• Linux was not initially designed to run on a system in
which things like power management or swapping PC
cards was needed.
• The most challenging part of using Linux on a laptop
is the installation.
• It can be difficult to get the XFree86 configuration to
work properly with the liquid crystal displays (LCDs)
that the laptops use.
• The biggest problem to be concerned with when
installing Linux on a laptop is getting the GUI to
display properly.
PC Card Devices
• A standard for expansion cards that
can be easily inserted and removed
form the laptop is the PCMCIA card.
• The main problem of using PCMCIA
Cards on a Linux system is that these
PCMCIA cards are designed to be
inserted, or removed at will.
• This forces the driver to be mounted
and unmounted whenever the card is
inserted and removed from the laptop.
• The PCMCIA card driver package
includes the Card Services feature,
which helps to smoothly mount and
unmount drivers from the kernel in a
way that is safe for the system.