Linux Slides1 to 800 [Compatibility Mode]

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index

Units:

unit-1 About the founder of Linux.

unit-2 Linux VS Windows.

unit-3 Linux Flavors.

- .

unit-5 Kernel.

-

unit-7 Dos Vs Linux.

unit-8 Redhat Linux Installation

unit-9 Hardware Requirements

unit-10 Installation Methods



Unit -1



About the founder of LINUX

•Linus Benedict Torvalds (bornDecember 28, 1969) began theeve opmen o nux, an opera ng

system kernel, and today acts as theproject coordinator.

•Inspired by Minix (a kernel and

operating system developed by AndrewTanenbaum), he felt the need for acapable UNIX operating system that hecould run on his home PC.

•Torvalds did the original developmentof the Linux kernel primarily in his owntime and on his equipment.



Evolution of Linux

•Torvalds originally used Minix on hiscomputer, a simplified kernel written

by Andrew Tanenbaum for teachingoperating system design.

•The Linux system quickly surpassed

Minix in functionality.

•The first version of the Linux kernelwas released to the Internet in

September 1991. with the secondversion following shortly thereafter inOctober



TUX - the penguin

•Penguin is the official mascot oft e nux operat ng system.

• ,looks content and satisfied.

•The concept of the Linux mascotbeing a penguin came from Linus

,kernel.



GNU’s (Not Unix)

• The GNU project was started in 1983 for developing a complete

- ,

tools and user application programs, entirely of free software.

• By the release of the first version of the Linux kernel, the GNU

project had produced all the necessary components of thissystem except the kernel.

• Torvalds and other early Linux-kernel developers adapted theirkernel to work with the GNU components and user space

ro rams to create a full functional o eratin s stem.



FEATURES OF LINUX

•

• Supports wide variety of hardware.

• Supports many networking protocols and configurations

• .

• Linux has a reputation for fewer bugs (programming

mistakes) than Windows.



Linux Vs Windows

Open Source Development Modeland so the programmer can

It is not an open source and hencecannot be redesigned by the

redesign the OS. programmer.

Linux is robust and very muchsecure from virus.

Windows gets affected by virusvery easily.

The Linux servers has surpassedwindows server operating system in

security.

Security is the main issue whichhas made windows to think to

survive.

It costs less to design andimplement a Linux Network.

It costs more to implementWindows Network administration,when compared to Linux.

There are 250000+ developersbehind Linux for open sourcedeployment.

Compared to Linux, windows isdeveloped by few thousands ofpeople.



Linux Flavors

• Red Hat Linux (Red Hat)

•

• Open Linux (Caldera)

• Mandrake Linux (Mandrake)

• ur o nux ac c - ec

• Linux PPC (MAC Power PC version)

• Info magic

• Slack ware Linux Project

• Knoppix (Live CD) etc.,



Introduction to Red Hat Linux

• Red Hat has split its Linux development into two lines :

• Red Hat Enterprise Linux and

• The Fedora Project.

• Red Hat EL features commercial enterprise products

for servers and workstations, with controlled releases

issued every two years.

• e e ora pro ect s an open source n t at ve w ose

Fedora Core release will be issued every six months.



Kernel

• The kernel is the essential center of a computer

o eratin s stem the core that rovides basic services

for all other parts of the operating system.

• A kernel can be contrasted (compared) with a shell,shell is the outermost part of an operating system thatinteracts with user commands.

• Kernel and shell are terms used more frequently in Unix

opera ng sys ems an n ma n rame or crosoWindows systems.



Shells

• Bash shell (Bourne again Shell)

– Developed for the GNU Project

– The actual standard Linux shell – Default shell for Red Hat Linux

• Borne shell (sh) – Original Unix shell written by Billoy at er e ey

• s e cs – Added many features such as command, history

Continue…



Shells

• Korn Shell (Ksh) – Written by David Korn

• Implemented many csh features such as

• e n ance s e cs –a commun y e or

• More features like command-line editing and more

sophisticated completion



Shells

prompt for bashshell

Type bash and

hit enter



Shells

command prompt

for c-shell (csh)



Shells

command prompt

or en ance

shell (tcsh)



Shells

command

bourne shell

(sh)



Shells

command promptfor korne shell



DOS Vs Linux

Commandomman c on

-

TREE ls –R List directory

recursivel

CD cd Change directory

RMDIR rmdir Remove a directory

CHDIR pwd Display directory

location

rm emove a e



DOS Vs Linuxomman

Commandct on

RMDIR /S (NT)rm -r

Remove all directories and files below

95...)

COPY cp Copy a file

XCOPY cp -r Copy all file of directory recursively

RENAME orMOVE

TYPE cat Dump contents of a file to users screen

MORE more Pipe output a single page at a time

HELP orCOMMAND /?

man Online manuals



DOS Vs Linux

Command

CommandAction

CLS clear Clear screen

EXIT exit Exit a shell

FIND find Look for a word in files given in command line

FC diff Compare two files and show differences. Also seemgdiff and tkdiff.

SET set and env Show environment variables



DOS Vs Linux

Command

SETvariable

export variable nameSet environment variables

PATH echo $PATH Display search path for

executables

DATE or date Show date. (also set date -on y

SORT sort Sort dataalphabetically/numerically

filename.txt vim

.which looks most like DOSedit is probably Pico.

\ / Director ath delimiter

.\ ./ Current directory

..\ ../ Parent directory



DOS Vs Linux

BACKUP files A:\ tar -cvf /dev/fd0 Save backup files to floppy

tar -xvf /dev/fd0 Read files from floppy.files See Using DOS floppies

ATTRIB +h or -h mv file .file Change file to a hidden file - renamee w pre x .

PRINT lpr Print a file

MEM freetop

Show free memory on system

Show s stem info Commands ev

borrowed from AIX)



DOS Vs Linuxomman omman ct on

SCANDISKfsck Check and re air hard drive file s stem

FDISK fdisk Tool to partition a hard drive.

FORMATmke2fs

See: fdformat for

Format drive file system.

For floppy drive use see YoLinux Tutorial

VER uname -a Operating system version

pkzip tar, gzip andbzip2

files/directories. Use tar to create Linuxalso has compress, gzip

HOSTNAME hostname Print host name of computer



DOS Vs Linux

DOS Command Command

Action

p ng en pac e s o a ne wor os

TRACERT tracerouteShow routes and router hops to

.

IPCONFIG (NT) ifconfig Display/configure network interface...

NBTSTAT (Netbios info: -n, -c) nslookup host-

NBTSTAT -a host-name NBTSTAT -A IP-address name

.

rou e -n r n rou ng a e.



Network CommandsDOS Command

CommandAction

TRACERT tracerouteShow routes and router hops toiven network destination.

IPCONFIG (NT)

WINIPCFG (Win 95...) ifconfig Display/configure network interface

NBTSTAT (Netbios info: -n, -c)

- -

nslookup host- Print DNS info for host.

NBTSTAT -A IP-address

ROUTE PRINT route -n Print routing table.





Hardware Requirement

32-bit Intel based processor, atleast an Intel or compatible 80386,80486, or Pentium-class

.

400 MHz Pentium is recommendedfor a ra hical interface and 200MHz for text.

Normall 64MB RAM for Text, and192 MB for graphical. (Linux canrun on as little as 12 MB RAM).

At least 2GB free hard disk spacefor a standard installation, includingapplications; 3 to 6 GB or more is

(all applications).



Installation Methods

Red Hat Installation CD-ROM.

NFS Image.

Kick Start

FTP

HTTP



Red Hat Installation through CD

• To boot from a CD-Rom or DVD-Rom ou ma first

have to change the boot sequence setting in your

computer’s BIOS so that the computer will try to boot

first from the CD-Rom.



NFS Image

• NFS (Network File Sharing): It is a common method

to s are es.

• An image of an operating system is taken already

system.

• The image system is first mounted and operating

system path is given to get into the installation.



Kick Start Installation

• Till now we have seen attended installation, where the user

ave o n erac w e sys em.

• The kick start installation is known as unattended

installation where the user appearance is not necessary.

• The system will automatically install the operating systeminto the machine including the device installation, hard disk

partition, assigning of ip address etc.,



Red Hat Installation

Press Enter, toinstall in

.




Type linux text,to install in Text

mode.




Type linux askminstall either th

FTP HTTP Haand NFS.




T e linux text

askmethod to installeither through FTP,

,NFS.



Installation Setup Screen

The Installation

Type Linux Text and

press enter for Text

mode Installation

Just press enterfor graphical

mode Installation.



Hardware Detection

Hardware

detectionprocess



Select theInstallation

.

R dh t I t ll ti



Redhat Installations

Select the t eof keyboard

layout.

R dh t I t ll ti




Select theappropriate

type ofinstallation.

R dh t I t ll ti




Select theappropriateNFS type

installation.





Select this

option to assignan dynamic ipaddress.





Enter theappropriate ip

a ress





Enter the

information ofserver ip address

.





The Anaconda-Red Hat

Installer beginse ns a a on.





Hardware

detectionprocess









The Red Hat LinuxWelcomes

ou.

Select the Partitioning T pe



Select the Partitioning Type

Select this fors mp er au oma c

partitioning.

Click here for manualpartitioning. Raid and LVM

also can be configured

used only while installation)





Click here tocreate new

partition in thefree space

Creating Partition for /boot directory



Creating Partition for /boot directory

Select the file systemmount pointshere.( /boot )

ype ere. ex , exfor normal partitionand swap for swap

artition

Enter the sizeof the

part t onshere.

Creating Partition for / directory



Creating Partition for / directory

Select the file systemmount points

here.( / )

ype ere. ex , exfor normal partition and

swap for swapartition


part t ons ere.

Creating Partition for swap directory



Creating Partition for swap directory

mount pointshere.(swap)


part t ons ere.





The final viewall the

mounting.

To Set Boot Loader



To Set Boot Loader

Click here to

change thedefault boot

loaderanare the Red Hat

Linux boot loaders.

GRUB is the Default

The default boot

Loader of Red HatLinux 8.0

can be changed oradded here




eth0 means firstEthernet card itsaddress getting

from DHCP.

also gettingfrom DHCP

server..

Firewall ConfigurationFirewall Configuration



Firewall ConfigurationFirewall Configuration

No firewall optionallows all networkserv ces o your

machine

No firewall option

services to yourmachine




Enable firewall

o tion allows

Activate yourSELINUX options

specific networkservices to your

machine



http://slidepdf.com/reader/full/linux-slides1-to-800-compatibility-mode 60/798Redhat Installations



Choose thedefault languagefor the system.




Time zone is.




Enter thepassword for theroot (Super User)




Its readingpackage

information's.




Select customizeoptions to customize

the package selections

s s use to se ectthe default package.

Package Selection



The Packages to bens a e are se ec ehere. Even the office

(Like MS-Office

in windowsPackages are

available inbuiltin Red Hat

Package Selection



Checking andinstalling the

.

Beginning of Installation



g g

Click next to begin

the actual installationwhich begins writingthe operating system

in the hard drives.

Installing Packages



Creating the filesystem in the

installationpartition.

Installing Packages



The installationimage is copied to

the hard drive.

Installing Packages



Initializing theinstallation

Installing Packages



Preparing for theinstallation

Installing Packages



packages under

progress

tzdata packages

Installing Packages



packages under

progress

Installing Packages



packages under

progress



packages under

progress

Installing Packages



packages under

progress

Installing Packages



packages under

progress

Installing Packages



Performin thepost install

configuration.

Reboot the System



The Red Hat Installation iscompleted successfully.

media and boot disks.And reboot the system.

Rebooting



GRUB boot loader



Hi hli ht the o eratinsystem and press enterto boot.

Loading Kernel



Initializing hardware devices



Initializing services



Welcome to Red Hat Setup



The Red Hat

Welcometo

setup agentwill proceed

someMore basic

Setup agent

configurations

Before the systemis ready

o use.

License agreement



Setting date and time



Graphics configuration



Select the screenresolution suiting your

-the number of distinct

colours requiredsupporting the video

monitor and displaycard

card Installed

Red Hat Login



To register the system

to Red Hat enter theLogin name and

password.

Red Hat Login



If you don’t have redhatlogin select this optionto create a new login.

Red Hat Login



Enter this optionto know the

details

Red Hat Login



Click here tore ister with theThe u date a entRed Hat networkregisters the

machine withRed Hat network

Click here toski re istration

Software packages

Get updatedautomatically

System user creation.



Create nonadministrative user toaccess the system.

Sound Card Configuration



Tests sounds for the 3channels in sound card

Configuredautomatically

can be heard byselecting play test sound

To Install additional softwares



Click here to install

an additional

software.

Finishing Setup



The Red Hat

Finishes the setup

Login Screen



Login Screen



Red Hat supportsmany languages,

be selected before

login.

Login Screen



The kind of deskto can be selected here.

Login Screen



The system canbe rebooted using

the option.

Login Screen



The system canbe restarted usin

the option.

Login Screen



Enter the userName

Login Screen



Enter the userPassword.

Loading the user settings.



Red Hat Startup Screen





Now the Red HatLinux

is ready for use.

Kernel initialization

• As systems boots, kernel get initialized and thefollowing functions are occurred.



g s a

• ev ce etect on: erne w comp e t e ev ce

drivers and locate it to the corresponding devices.

• Mounts root file system: After the device detection

only.

• Load initial process: The very first process (init) is

then loaded.

Initial process

• Init :



• It is the superior of all processes.

• As soon as init process is loaded the control is

assed from kernel to this rocess.

• /etc/inittab:

should setup the system in every run level, as well.

Run levels

init 0 : Shutdown the system or halt



init 0 : Shutdown the system or halt

init 1 : Single-user mode.

n : u -user mo e w ou ne wor ng suppor .

init 3 : Multi-user mode with networking support.

init 4 : Unused.

n t : rap ca user nter ace.

init 6 : Reboot the system.

Run level configuration file



Get in to the

inittab file, the

file.

Run level configuration file



The default

be changedhere.

CONSOLES

• Text-mode login at virtual console



• Multiple non-GUI logins are possible

• Default consoles are in text mode

• Available through CTRL-ALT-F[1-6]

•

• Graphical console comes through CTRL-ALT-F7

X Window System

• It is the foundation for the graphical user Interface of



• It is the foundation for the graphical user Interface of

Red Hat Linux.

• X applications communicate with a display via. The X

protocol.

• X is OS Independent.

• It is available on many platforms.

X Protocol



• It hides the individual details of the OS and the underlying

hardware.

• X protocol is a asynchronous network protocol for the

communication between X client and X Server.

• It defines how the graphical primitives are communicated

between X client and server.

Multiple Desktop Environments



•

Environments.

• GNOME (GNU Network Object Modules Environment).

• KDE (K desktop Environment).

GNOME

• It is the default desktop environment for Red Hat



.

• It is Power full and easy-to-use desktop environment

consisting primarily of a panel and a set of GUI tools.

• GNOME is free and hence its source code can be

www.gnome.org.

GNOME Interface

• The GNOME Interface consists of a Panel and a Desktop.



• Panel appears as a long bar across the bottom of screen.

, .

• The Remainder Screen is the Deskto . Here ou can lace

directories, files or programs.

GNOME Desktop



GNOME Menus



GNOME Menus



KDE

• KDE provides an alternative desktop environment with full



.

• Along with GNOME features, It also includes

• Konsole : Highly configurable graphical terminal.

• onqueror : e manager an we rowser.

• Kmail : A graphical email client.

• Kdevelop : Integrated development.

KDE Desktop



KDE Desktop



KDE Desktop



KDE Desktop



Starting X Window

The X window start automatically, If so then a



Graphical login screen is prompted by the Display

.

Alternatively use startx to get in to X window from

non-w n ow ng conso e.

Start X



window from runlevel-3

Start X



Desktop Selection

Select failsafein case of an



previously used

desktop

graphical

failure

To get the

defaultdesktop.

To get in toGNOME To get in to

. KDE desktop.

KDE MODE

If you click yes theKDE desktop is set



for future sessions(or) login

you c c o, on ythe current session

is set to KDE.

Switchdesk



To change the desktop

environment.

Switchdesk

To switch from kde to

gnome desktop



gnome desktop

Switchdesk



Thus we switched

into GNOME

deskto

Linux File System Directories

/ Begins the file system structure – called the root.

Directory Function

/b H ld h k l i fil d i d b



/boot Hold the kernel image files and associated bootinformation and files.

’ .

/sbin Holds administration-level commands and any

commands used by the root user. /dev Holds file interface for devices such as the terminal

and the rinter.

/etc Holds system configuration files and any other

system files.

e c op o s sys em con gura on es or app ca on n /opt


/etc/X11 Holds system configuration files for the X Window

Directory Function

System and its applications.



System and its applications.

/bin Holds the essential user commands and utility

ro rams.

/lib Holds essential shared libraries and kernelmodules.

/lib/modules Holds the kernel modules.

/mnt Used to hold directories for mounting file systemslike CD-ROMs or floppy disks that are mounted

only temporarily. /o t Holds added software a lications for exam le,

KDE on some distributions).


/proc Process directory, a memory-resident directory

Directory Function

containing files used to provide information about



co ta g es used to p o de o at o aboutthe system.

/tm Holds tem orar files.

/usr Holds those files and commands used by the

subdirectories.

/var Holds files that vary, such as mailbox and FTP.



Linux Commands

• Commands have the following syntax:

• Command [options] [arguments]



[ p ] [ g ]

•

• Options modify the command’s behavior

• Arguments are filenames or other information

needed by the command

DOS Vs Linux

Command

omman c on

-



TREE ls –R List directory recursivly

CD cd Change directory

RMDIR rmdir Remove a directory

CHDIR pwd Display directory

location

rm emove a e

DOS Vs Linuxomman

Command

ct on

RMDIR /S (NT)rm -r

Remove all directories and files below

95...)



)

COPY cp Copy a file

XCOPY cp -r Copy all file of directory recursively

RENAME or

MOVE

TYPE cat Dump contents of a file to users screen

MORE more Pipe output a single page at a time

HELP orCOMMAND /?

man Online manuals

DOS Vs Linux

Command

CommandAction

CLS clear Clear screen



EXIT exit Exit a shell

FIND grep Look for a word in files given in command line

FC diff Compare two files and show differences. Also seemgdiff and tkdiff.

SET set and env Show environment variables

DOS Vs Linux

Command

SETvariable

export variable nameSet environment variables

PATH echo $PATH Display search path for



executables

DATE or date Show date. (also set date -on y

SORT sort Sort dataalphabetically/numerically

filename.txt vim

.

which looks most like DOSedit is probably Pico.

\ / Director ath delimiter

.\ ./ Current directory

..\ ../ Parent directory

DOS Vs Linux

BACKUP files A:\ tar -cvf /dev/fd0 Save backup files to floppy



tar -xvf /dev/fd0 Read files from floppy.files See Using DOS floppies

ATTRIB +h or -h mv file .file Change file to a hidden file - rename

e w pre x .

PRINT lpr Print a file

MEMfreetop

Show free memory on system

Show s stem info Commands ev

borrowed from AIX)

DOS Vs Linuxomman omman c on

SCANDISKfsck Check and repair hard drive file system



FDISK fdisk Tool to partition a hard drive.

FORMATmke2fsSee: fdformat for

Format drive file system.For floppy drive use see YoLinux Tutorial

VER uname -a Operating system version

Compress and uncompress

pkziptar, gzip andbzip2

.compilation of a directory before

compressing. Linux also has compress,gzip

HOSTNAME hostname Print host name of computer

DOS Vs Linux

DOS Command

CommandAction

p ng en pac e s o a ne wor os



TRACERT traceroute Show routes and router hops to.

IPCONFIG (NT)ifconfig Display/configure network interface

...

NBTSTAT (Netbios info: -n, -c) nslookup host- NBTSTAT -a host-name NBTSTAT -A IP-address

name .

rou e -n r n rou ng a e.

Network CommandsDOS Command

Command

Action



TRACERT tracerouteShow routes and router hops toiven network destination.

IPCONFIG (NT)WINIPCFG (Win 95...)

ifconfig Display/configure network interface

NBTSTAT (Netbios info: -n, -c)

- -

nslookup host- Print DNS info for host.

NBTSTAT -A IP-address

ROUTE PRINT route -n Print routing table.



Login screen



Enter the

PWD

• PWD



• Present working Directory

• Display the absolute path of the current directory.

PWD



The absolute

path of the root

directory isdisplayed.

ls

ls :

List the Files and Directories within the current directory.

Syntax:



ls o tions

Options:

- s e w perm ss on.

-a List hidden file.

-i List files and inode number.

-R List directories , sub directories and their

contents.

ls



directories in the

present directory.

ls -l

l option lists the

l li ti f



long listing of

directory.

l l command



The name of the group

which has the

Owner name, theuser who created

No of links to thedirectory

t e nes t e

permissions

assigned to theFile or directory

names.

Size of the files

or directories

permissions over the files

or directories

the directory.owners, groups and

other users

ls -a



[a] option lists all files

hidden files

ls -al



al option lists all files and

directories including

format.

ls -R



[R] option lists workingdirectory as well as

contents in the director .



mkdir



This will create a

.

cd

cd- Change directories

Syntax :

cd <directory name>



y

..

- To a directory one level up (parent directory)

cd -- To your previous working directory

cd /

- To the / slash director

cd



This commandwill take you to

the directory .

cd ~

Previous slide

we have seen cd

along with any



director name.This command

cd ~ <enter>

home directory

cd ..



cd .. Take ou to theparent directory of the

current directory.

cd ..

Now we can see that

we are in advpro

directory, the parent



director of the test

cd /

cd / will take

you to /

directory)



through pwd command





cat

cat

– it is the command to create and view files

Syntax:



>

cat [filename] To view a file

ca >> ename o appen ex o a

file

cat

As mentioned in

slide. cat is used



to create a file

The file is saved

roug c r -

after typing thetext

cat

Enter

cat < ename>

to view the



content of file.

cat

To append the

text in a file,



and file name.

cat

Th



The screenshows the

appended file

cat



The -s o tion

trims multipleadjacent blank

blank line

cat

The –b option

numbers the



of the output

cat

The –A option shows

all characters including

con ro an non



con ro an non

printing characters

Here the $ represents

the end of the line

touch

touch command is used to update the time stamps of a file.

touch is also used to create empty file.

S ntax : touch filename



– S ntax : touch filename

touch can create multiple empty file too.

– Syntax : touch [filename1] [filename2]

touch

empty file is

created



touch

Multiple files

using touch

command



Copy Command

cp : cp command is known for copying files and

– Syntax : cp [options] source destination

– p ons :



– p ons :

-r recursively copy an entire directory tree

-p preserve permissions, ownership, and timestamps

– Example :

c File1 File2

Copy Command

There is a filename a nthe directory

test



test .

Copy Command

Here we notice that

directory. Let uscopy the file ‘a’ into

s rec ory



s rec ory.

Copy Command

Cp copies the file ‘a’rom t e rectory

test to the directory

test1.



test1.

Copy Command

Thus the file ‘a’



test1 directory.

Copy Command



and old are

listed with their.

Copy Command

-r option copy



r option copythe entire

‘old’

Copy Command

us t e



contents ofold director

is copied tonew.

Copy Command

Command l lshows the



shows thepermission of



Copy Command

Now, we

one to the



one to thedirectory old

Copy Command

See thecomparisonof the file oneshown above

and old



and olddirectory

Copy Command



Now using command cpa ong w –p op on epermission is preserved.

Move Command

mv : This command is used to move and renaming filesan rec or es

Syntax:

mv <source> <destination>



mv <source> <destination>

Example

mv file1 file2 (now the file1 is changed to file2)

Move Command

A file is

the name of



the name ofone in therec ory o

Move Command

Here we see

that usin mv command the



file is moved

directory.

Move Command

Now check into the

old directory where

moved. Hence thedirectory is empty



Move Command



The file one is shownabove in the new

Move Command



created testin the old

rectory

Move Command

This exampleshows how to

fil



rename a file

Move Command



Using the l lcommand, theabove screen

shows the renamed file

rm and rmdir command

rm : This command is used to remove files

Syntax:rm < ename>

Example :



rmdir : This command is used to remove directories.

Syntax:rmdir <directory name>

Example :

rmdir linux

rm command

This screenshows the

contents of the



contents of the

The above rmcommand is

the file k

rm command



k is removed from

the directory

rmdir command



named donic which isremoved through the

comman rm r

rmdir command



The abovescreen showsthat directory

donic is

rmdir command



screen we seethat directory

tomy is unableto remove

rm command

Usin rm withoption – r, thedirectory along



directory along

be removed



rm command

The abovescreen shows



screen shows

directory jerry

rm -ri command



The rm with –ricommand is

the contents

interactively.

rm -ri command



We can see that the filefor which we have given‘ ’ ‘ ’

preserved

File command

The file command is used to check the file content.

Syntax :

file <filename>

Example:



Example:

file f1 (f1 is a file. File will show the format)

a block special file)

File format

The file along with file

name (ss) shows the



File format

This showsthe format



cat asexecutablee

more

l l command

shows thecontents at



.

more

contentquickly, which



q yma es e

viewer to seeonly last page

more

More is usedto lists the

contents one



time

more

promptedafter listing



gone y one

more

Here it is

processlisting more



contents,

shown asabove

more

Here it is

processlisting more



contents,

shown asabove

more

more

command

s over anwe are inthe end of



the end ofthe page

vi & vim editor

Vi is known as the visual editor.It is a standard editor under Linux and Unix system.

Vim is the im roved version of vi editor

Vi have three modes of operation



•Command mode

•Insert mode

•Esc mode

vi Modes

Command mode:

O erations such as cut co aste delete

undo, redo etc., are done in this mode.

Insert mode:

Type in new text



yp

Ex-mode :

Extended commands for saving, exiting, search-

and-replace can executed here

Working with vi editor

file createdor opened



editor.

Command Mode

Press ‘i’ toget into

mode



Insert Mode

insert mode



Insert Mode

After typingthe data’s hit



into commandmode

Ex- Mode

Press:wq to

write and



Ex- Mode

Press !to quitwithout



the data

Yank

Hit escape and

type 3yy to yankthree lines from

the cursor osition

Like this example,you can copy any



typing numbers oflines and yy

Text yanked

slide, we saw howto yank the text.

er yan ng we



er yan ng we

see the messageas below

Text put

Now the yankedtext is pasted fromt e cursor pos t on



t e cursor pos t on

by hitting the ‘p‘

delete

To delete text, placethe cursor in the



and give the totalnumber and dd

delete

Now 3 lines are

deleted andmessage get



fewer lines asshown below

cut and put

To cut a line

after curserposition hit 1cc.



cut and put

Get into insert modeand lace the cursor

where the data shouldbe pasted. Press esc

d



mode

cut and put

t th d t



paste the data.





Search

Then if we press ‘n’ it willshows the second match for

that data.If we continuepressing n it will show



pressing n it will show

successive matches.

Find commandFind:

To search files and directories in a specified path.

Syntax:

Condition:

-name <file name> - to search a particular file



-name <file name> - to search a particular file

-user <user name> - lists the files owned byuser.

-perm <mode> - search a file depending

.

Find command

This commandsearches the

passwor e rom



/ directory.

Find command

The abovescreen shows

the execution of



command

Locate command

Locate:

To search or locate files and directories from the

database.

It locate the files faster than the find command



Syntax:

locate [pattern]

Locate command

To search filenamed test1

from database.



Locate command



All the files anddirectories named

test1 is located and

dis la ed.

Man command

man :

Display helpful information about

commands.

Syntax:

man [option] command

Option:



Opt o

– -

command name.

Man command

It displays manualpages for ls

comman .



Man commandThe manual page

of ls command issp aye ere.



Enter q to exit frommanual a e.

useradd commanduseradd :

To create a new user account and login.

Useradd will create new entries in system files.

S ntax

useradd [options ] [user ]

Options

-c Comment field.



-d Home directory

-e Account expiration date.



useradd commandEnter thepassword.



User home directory

When new useraccount is created ,a

the user is created



in /home dir.

User configuration files

When a new user account is created, its entries

u dates the followin s stem files.

- /etc/group

- etc s a ow



Passwd fileTo view passwordconfiguration file.



Passwd file

First fieldx representsUser id.Group id.representencryp e

password is directory.

shell.



username.available inshadow file.



Shadow file

Encr tedpassword for

the user.



Groups file

To viewgroup file



Groups file

Group id forthe user

abdulkalam.



User loginAbdulkalamlogging in .



User loginUser

home dir



userdel command

User account can

userdel command



Creating groupsNew group is created by hand-editing the file /etc/group

or by using groupadd command.

groupadd groupname

groupdel command is used to remove the group.

Syntax

groupdel groupname



Groupmod is used to rename the existing groupname.

Syntax:

–

Groupadd commandA group is added inthe name of india by

groupadd.



Usermod command

Using usermodcommand the user

added to group

India



India

Groups file

To viewgroup file



Groups file

The id numberassi ned to the rou

india is 501



e as e s ows euser abdulkalam added

in India group

Groupdel command

Groupdel

window group.



Group Administration

Create a directorynamed product

sales.




ser s are a e nthe sales groupusing usermod



gcommand.


group file.




This shows that thethree users are

group.




Change the group namesales to product directoryusing chgrp command.




e screen s owsthat the changesbeen made in the



group field.


product directory.




e perm ss onfor the product

directory is



changed.


The user tom is not amember of the group.So the permission is

restricted.




suresh logs in terminal. Ashe is the member of the

group, he have the privilege.




rajesh logs in terminal. Ashe is the member of the

group, he have the privilege.




tom logs in terminal. he isnot the member of the

group so does not have the.




The above screenshows the permission

been restricted to the.



Changing owner

The chowncommand

After giving thechown command

c ange t e e ordirectory owner.

changed from

root to suresh.



Changing owner

The owner andgroup name can be

c ange us ngchown command.



chage commandThe chage command let you specify an expiration limit

for a user's account and password .

– Syntax:

chage [option] username

Option

- .

-m set the min. days to change the password.

-M set the max. days to change the password.-E specific expiration date for user account



E specific expiration date for user account.

-I set inactive period (in days)

- ,expiration.

User administration

Chage –l : liststhe account andThis field sets thepassword for the

Inactive period isused to give

information of

user tom.

maximum valid

days given.

grace time tochange the

assword.



User administration

The –Mcommand with

The passwordexpires field is

100 sets as the

maximum days.

updated by +100days from usercreation date.



User administration

Allowableaccount inactivity

which password

will expire.



User administration

The -W optionshows the

message before

expiration.



User administration

The -m option forminimum number

of da s a usercan exists with

password.



User administration

-for specific

expiration datefor an account.



Set userIDIt allows an executable file to run under the user or group

security context with the permission of its owner.

SUID can be set as follows:

• chmod u+s [filename]

(or)

• chmod 4xxx [filename]



• chmod 4xxx [filename]

Set userID

The above screenThe passwd is the

password along with

the set user id

comman w c up a esthe password in the

shadow file, instead of not .having the execute



permission.

Set userID

Tom changes theassword usin

passwd command.



Set userID

The set userid

removed from the

/usr/bin/passwd.



Set userID

Now we can viewthat tom user

cannot change

the password.



Set GroupID

The user sureshlo s et into the

The user suresh

product directory

and create a file.

w o crea e a e,the group name is

assigned as suresh.



Set GroupID

The groupid isset to the

Note: the group sales

product

directory.

product directory.



Set GroupID

After setting the groupid, user suresh createsa file win98. Using thecommand ls –l showsthat the file is createdunder the group sales.



Sticky bit

The user rajesh logsThe files remove is

file bios created byposs e ecausethe sticky bit is not



ysuresh.

the sticky bit is notset to the product

directory.

Sticky bit

Using +t option thestick is set to theproduct directory.



Sticky bit

After assigning the sticky

delete the file created by

other user but he is.



Switch user

su command is used to switch to another account from

the command line.

This command is most often used b s stem

administrator to temporarily become the root user

- .

Syntax

su - [user] -c command



Switch user

Here the root user

account.(user joe)



Switch user

It executes root privileged command

from the ordinary user.



Multi user loginLike unix operating system where multi user login can

,supports multi user login.

Each user can login in each terminal and can do multi

process ng w c avo s ogg ng o rom e sys em.



Multi user

tom, is the userwho log in thefirst terminal



Multi user

Joe, is theuser who log

terminal



Multi user

harry, is theuser who log

terminal



Multi user

wilson, is theuser who log

terminal



Multi user

bill, is the userwho log in thefifth terminal



Multi userthano, is the

user who lo sin the sixthterminal

W is the command tolist the users logged



list the users logged

n

vance ses o an



File RepositioningPress G, Cursor go to last line of a file.

, .

Press Ctrl+f, Cursor forward one full screen.

Press Ctrl+b, Cursor go back one full screen.

Press Ctrl+d, Cursor go down half a screen.

ress r +u, ursor go up a a screen.



Screen Repositioning

Press H, Cursor go to first line on screen.

Press M, Cursor go to middle line on screen.

Press L, Cursor go to last line on screen.

Press Z+Enter, Make current line is first line on screen.

-

screen.



screen.

Advanced Reading and SavingIt is also possible to read a other file content in your

current files.

e o ow ng comman e p you : – Go to exmode in a vi editor

–

– Example :r /root/file1

While working in a editor we can copy the file content to

another file – Syntax : starting line, endingline w <file name>

– Example : 1,20w file2



– ,

FilteringA powerful feature of vi is the ability to include into your document

the output of Linux commands.

For example if you want to display any command output in your file

see following syntax .

!!command

The syntax will be working in exmod in editor.

For example to display date ,type following command in exmod.

!!date



Filtering

Open the file

in vi mode.



Filtering

This will replace

the current line

with output of the

date command.



Filtering

The out ut of the

date command is

written here.



Sed CommandSed command just like find and replace .

To display a file , the Sed command change the

particular word in standard input only , but notchan e ori inal content of file.

xamp e o e comman .

sed ‘s/ram/raju/g’ /root/file1



Sed Command

The output of the

named.local is

.



Sed Command

Here sed command displays the

output by replacing the localhostas www.example.com, but it wont

write output in the file.



ex mode : search and replacevi can perform search and replace operations much

e se comman .

Syntax:

ex mode:1,$s/searchname/replacename/g

, - .

s - String of character

g - replace multiple matches in a

line



ex mode : search and replace

Open the filein vi mode.




It searches and replaces

the localhost aswww.exam le.com.




Thus the localhostwas replaced as

www.example.com..



Advanced Reading and SavingIt is also possible to read a other file content in your

current files.

The following command help you :

– Go to ex mode in a vi editor

– Syntax : r <filename>

– Example :r /root/file1

While working in a editor we can copy the file content toanother file

– ,

– Example : 1,20w file2

– Exam le : 21,40w >> file2



Advanced Reading and Saving

ere you can v ew

output of test file.

mode.




To display the

output of another

the current file.




The output of testfile is displayed..




The contents of theexisting file.




To write the contents of the existing file in another

file named test1.




The contents are

appended to thetest1 file.




You can see the

in the test1 file.





Set number

File contents.



Set number

To assign numbers

editor.



Set all

To view all the

possibilities of

configurationsavailable in vi

editor.



Set all

All the available

option are

displayed here.



Redirecting Input and OutputOuput of a command is redirected to a file

– Command > filename

-

Example ls -i >> /root/file1

Output of file redirected to a command

– Command < filename

-

• Error message of a command redirected to a file- Command 2> file1

- Command 2>> file1

- – –







Redirecting Input and Output

Here the output of ls command is

appended to the

ex1 file.



Redirecting InputA command which accepts the input from a file is

known as Redirecting Input.

Syntax - command < file1

Example : tr ‘A-Z’ ‘a-z’ < file1

A file is created in the name file1 and text is

en ere n cap a e ers, w c s re rec e

through < symbol and the command translates the

a a o sma e ers.




tr translates the upper case

letters to lower case.Hereout ut of file v is

redirected as input to the tr

command.




> re rects t eerror messages to

the ex file.

Here we can see

redirected error

messa es in the exfile.



Piping

Pipes is used to execute more than one command at a time. See

following command.

Syntax : command1 | command2

Example: ls -l | more

It is also used to execute command result

Example: cat file1 | grep station



Piping

ere e ca an

grep command

are executed inpipeline

.



Redirecting Both Standard Output And Error

If find command is executed, its output can be stored in file2. if

error occurs during execution, the error message is stored in

file1.

or examp e:

find / -name passwd 2> file1 >file2



Redirecting Both Standard Output And Error

If there is anyerror messa es

If there is no error

while execution

the error message

e ou pu w e

redirected to the

ex2 file.to the file ex1.



tee Commandtee is useful to save the output at various stages from

a ong sequence o p pes.

–

The above exam le shows the t es of ls commandsand options are used to store output to the files g1,g2 and g3.



tee Command

It saves the output

of ls in file a1 and

output of ls –l in

file b2.



grep command

grep

- means general regular expression processor.

- ana yze e con en o a e a ne a a me,returning a line that matches a pattern.



grep command

Grep prints thepattern matched

with ganesh in the

file /etc/passwd.



awk command

An awk program searches for lines in a file

an per orms some ac on on ose nes.

Example:awk ‘/bash/ rint ’ /etc/ asswd



awk command

awk display first

e o e /etc/fstab file.



File CompressionsSeveral compression utilities are available for use on

Linux and Unix s stem.

But most software for Linux system use threecompression utilities.

-

2 - GNU gzip

-



Compression commandcompress:

It compresses a file and give the extension as .z forthat file.

Syntax:

compress < ename>

uncompress:

It uncompress the compressed file.

Syntax:

uncompress <filename>



Compression command

Thise actua

size of file is

107 b tes.

the file a.

The compressed file

Thus the file size

s n cate y t e .z

extension.This

is compressed to

39 bytes.

uncompress

the file a.



Compression with gzipgzip utility compresses file .

unzi decom resses them.

To compress a file, enter the command gzip and the

.

version of it,with the extension .gz.

.

Syntax:

gz p ename compress on

gunzip filename.gz (decompression)



Compression with gzip

size of file is107 bytes.gzip command

file a.

The compressed file

s n cate y t e

.gz extension.Thus the file size

is compressed to

38 bytes.

uncompress

the file a.



Compression with bzip2

It compresses files using the burrows-wheeler block-sorting text compression algorithm and huffman

coding.You compresses files using the bzip2 command and

.

The bzip2 command create a file with the extension.bz2

Syntax:

bzip2 filename (compression)

bunzip2 filename.bz2 (decompression)



Compression with bzip2

size of file is107 bytes.bzip2 command

file a.

The compressed file

This

s n cate y t e

.bz2 extension.Thus the file size

uncompress

the file a .is compressed to

51 bytes.



Creating ArchivesTar:

ar comman s use o crea e arc ves on ev ce or es.Originally, tar was used to create archives on tape devices,

.

When creating a file for a tar archive, the filename is usually. .

While tar is seldom used to back up entire file system.



Syntax for tar command

Syntax for tar command:

- -.

Options:

c - create new arc ve.

v - produce verbose message.

f - archivename,a name of new file.

x - archive will be extracted in the current directory.

t - displays a list of file in the archive





tar command

display all thefile in backup .

tvf options

displays along

with the user

and group

names.







Printer-configuration

Command to

configure the

r nter

Click Newo tion to

add printer




Now the system is

loadin rinter

information.




Click Forward

queue




Chooselocally-connected

option for localprinter






manufacture name in

he list.




Choose the serialnumber of the printer




for

What you have

selected




Now the printerconfiguration

applying the

changes to the

system




Choose yes you will be

getting an test page form

the printer




lpq is a command to view




lpr is a command given

to print particular file.




lpq is a command to view

t e queue n pr nter




lpq is a command to

v ew t e num er o

queue in printer



Introduction to process

Linux treats each task performed on your system as a, .

You can examine this rocess and even sto them.

Red Hat provides several tools for examining processesas well as your system performances.

e process s easy mon or ng s prov e y severaGUI tools,like Red Hat Procman System Monitor.



ps Command• .

• To display a information about process specific to

the active terminal.

• Syntax: ps [option]• Options available:

-a : o sp ay a process, not nc u ng

process not controlled by a terminal

-

a terminal, such as daemon process.

-l : To long list including more information such

as process owner's user id.

-u : To display user name of the process

owner.

-e : To view the all process id



pstree command

s ows e

process ancestry

for all process

running on the

system.



ps –a command

sp ay a

processes

excluding

processes not

controlled by..



ps –l command

It list the

rocesses alon

with the owners

id.



ps –x command

sp ay a

processes

including

processes

controlled by.



ps –u command

It list theprocesses along

with the user

name.



kill process

• Kill command is used to send a particular process to

get clear.

• S ntax : Kill -9 < rocess id>

• ps - aux is the command to view all process name

and id

• -command, option and the process id to kill.)



kill process

It kills the tty2

term na as

processes .



Altering process schedule

• renice is the command to set the priority of a process.

• The priority value can range from -20 (highest priority)to 19 (Lowest priority)

• Syntax : renice - +(minus symbol or plus symbol)

<priority number> -p <process id>

• xamp e : ren ce - -p



Foreground and Background process

• Fg command is used to run the background process in

the fore round Front End

• jobs command helps you to view the background

processes.

• Step 1: jobs <enter> to view the process

running and job numbers

• • bg command is used to resume the suspended

command in the back grounded.




‘&’ makes the

in background.Jobs displays the

processes runningin the background.




Fg bring back the

back grounded

rocesses to the

foreground.




Here the

command is

suspendedwhile

pressing ctrl+z.Bg resumes the

stopped jobs tothe

background.



Bash Shell Scripting

Scripting basics

– A shell script is a text file containing set of commands.

– Scripts are useful for automating process that you perform

repeatedly at the command line.

– ,

through scripts.

– For example : Every morning when you login you can

perform following operations.

• Checking system date and time

• Checking email

• How many users have logged in the server.



Creation of shell scripts

Shell script are written in vi editor

,

– For example:

• #!/bin/bash used for bash shell script

• #!/bin/sh used for borne shell script

• #!/bin/csh used for C shell script

• # usr n per use or er s e scr pt

• #!/usr/bin/python used for Python shell script



Basic bash shell script

How to print a data in a console

– ec o e at <enter>

How to execute a command in echo statement

– echo “hostname `hostname` “ <enter>

How to execute a variable in echo statement

– =

– echo “A value: $A” <enter>



Execute bash shell script file

Two methods available to execute a script file are

– First method is

• Syntax :

» bash filename

– Second method is

• Syntax :

»Give the execute permission the script file

through chmod command

»Run the file by ./<file name>




Get in toe v e or

to createscript file




It denotes weare usingas s e

scripts

This script executes

hostname and date



Executing script - First Method

Bashexamp e

(file name)to execute

Output is

shown in theterminal



Executing script - Second Method

No executepermissionfor a file in

default

Permission is,

asexecutable



Second Method

./ example(file name)to execute

the file



Arithmetic Calculation

Exam lescript file forcalculation



Arithmetic Calculation

Using read

read the valuefor A and B

Using exprwe can add

va ues



The values areentered for input

The output is





Partitions

The Linux supports four primary partitions and many

logical partitions in the extended partition.

The Linux kernel supports maximum number of 63

artitions on each IDE disk.

And maximum of 15 partitions on each SCSI device.



Partition Types

Linux-specific partitions would normally be one of the

.

0 X 5 - Extended

0 X 82- Linux swap

-

0 X fd - Linux RAID

0 X 8e- Linux LVM



Partitioning

In Linux, partitions can be created by either of the

o ow ng ree u es

– fdisk

– sfdisk

– disk druid (only available during installation)

–



fdisk

fdisk

- Fixed Disk

- Menu driven programs to create and

Before starting fdisk, identify the hard disk type that is

whether primary master or slave and secondary

master or slave by using command fdisk -l.



Partitioning with fdisk

l option list the

available

partitions

space with totalheads, sectors and

cy n ersAvailable partitions, hdb

represents that the hard

Star indicates

the boot

Starting and ending

cylinder for each

Size of the partitions

in blocksdisk is connected as

primary slavepartition.

cylinder = 8.3MB




To create partition in

the device hdb




Type h or help to

shows list of

available commands




Type p to display the

available partitions




Enter the starting

ype n to create a

new partition

enter to take the

default cylinder




Enter the ending

cylinder or type thesize in MB.

Type w to save and.




nstea o restart ng to

update the partition tableust enter the command

partprobe.




Thus a new partition

created







minux & reiserFS

Minux : This file system is small , simple and mostlyused for floppy disk .It support filenames up to 30characters.

e ser : s a vance ourna ng esys em sunder development for Linux.

Its main difference between ext3 and reiserFS .Its usedisk resource efficiently and is particularly effective

w e sys em con a n ng many sma es an argedirectories



Creating file system

Once you create a partition, you have to create a file

.

To do this, use the mkfs command. To build the Linux

file system and pass the name of the harddisk

artition as a arameter.

Syntax:

mkfs -t <filesystem type> <partitioname>



Creation of file system

Current partitions

are displayed here




Hdb6,7and 8 arenewly created

partitions.




It creates ext2file system for

the device hdb6.



To view the file system type

Dumpe2fs : this command is used to view which file

system we are us ng.

S ntax :

dumpe2fs <partitions>

Example:



To view the file system type

It displays the

file system

information's.

Sparse_super

represents theext2 file system.



Mke2fs command

Mke2fs : This command is used to create file system.

mke2fs [options] device

Example:

mke2fs /dev/hda1 (it will create ext2 filesystem forhda1 partition)

mke2fs – /dev/hda1 it will create ext3 files stem

for hda1 partition)

C i f fil




It creates ext2

file systems for

device hdb7.

Vi h fil



View the file system type

S arse su er_represents the

ext2 file system.

C i 2 3 fil



Converting ext2 to ext3 file system

It converts the file

system of hdb7 from

ext2 to ext3

Vi th fil t t




has_journal

represents the ext3file system thus the

ext2 is converted to

ext3

M t d



Mount command

n nux, e any

other device the

artitions should be

Mount the partitions

hda6 in data1

director and hda7 inmounted.data2 directory.

T 2f d



Tune2fs command

tune2fs : It is a command used to converting from

ext2 to ext3 file system without un mounting..

tune2fs –j <partitions>

Example:

tune2fs -j /dev/hda1




View the file system type.

Ext2 is the current

device hdb6.

Tune2fs command



Tune2fs command

Here it converts the

file system for hdb6



Repair Filesystem



Repair Filesystem

e2fsck : This command checks the consistency of the

,

file system checking tools.

fsck : This command checks and repair a Linux file

sys em.

Example : fsck /dev/hda1

The main difference is e2fsck it will work in ext2 andext3 filesystem and fsck will work only in ext3 file

system.

Repair Filesystem



Repair Filesystem

fsck and e2fsck arethe command used

to check and repair

the file s stem.

Disk usage



Disk usage

df and du are used to check the disk usage.

df : It reports the amount of space used and

available on a mount file system as reported.

du : It displays directories entries and the number of

.

df command



df command

df commanddisplays the space

in the mounted filesystems

df -h, displays size

in human readable

-

of 1024

size in the power1000 instead of

.

du command



du command

du command displaysthe estimate file space

usa e available

df -h & H, displays size in

human readable format in

the power of 1024 and

.

Performance tools



Performance tools

free command lists the free ram memory and as well as

.

top command lists the most CPU intensive processes.

Vmstat shows the performance of system components.

free command



free command

free commanddisplay

information

about free and

used memoron the system.

vmstat



vmstat

Report virtualmemory statistics

top



top

Displays top CPUprocesses

top



top

It displays the

CPU-intensive

tasks on the system.

Daemon Process



Daemon Process

Some process start at boot time and continue runninguntil the system is shutdown. Such process are

known as daemon processes.

Two types of daemon process:

standalone daemon

Transient daemon

Daemon Process



Daemon Process

Standalone daemon are a program that run all the time

and are started up either directly by init or by a startup

script under /etc/rc.d.

rans en aemon are on y s ar e up w en ey are

needed, and are controlled by a standalone daemon

called xinetd.

checkconfig command



g

The chkconfig command can also be used to activateand deactivate services.

The chkconfig --list command displays a list of systemservices and whether they are started (on) or stopped

- .

At the end of the list is a section for the servicesmanaged by xinetd.

checkconfig command



g

chkconfig can also be used to configure a service to

be started (or not) in a specific run level. For

example, to turn httpd off in runlevels 3, 4, and 5,

chkconfig --level 345 httpd off

checkconfig command



g

--list options

used to list theservice.

checkconfig command



--list option

lists xinetdservices also.

checkconfig command



--list option list

httpd serviceThis command

htt d service is

--list options

used to list htt drunlevel 0-6.

stop on runlevel

3-5.

service status .


http://slidepdf.com/reader/full/linux-slides1-to-800-compatibility-mode 459/798Standard Boot loader



• There are two standard boot loader are used inLinux

• GRUB

• Grand unified boot loader

•

GRUB



• GRUB Grand Unified Boot Loader

and default boot loader for Redhat Linux.

• Using GRUB user can select operating systems to

run from a menu interface displayed when a systemboot up

,

editing mode and a shell like command line interface

ava a e a oo me.

LILO



• means nux oa er

• LILO is a program written to boot sector of a disk that loads

the OS and starts execution.

• It is an older version of boot loader of Red Hat Linux.

• LILO loads the Kernel based on its actual sector location on

the disk , rather than its file name

LILO



• /etc/lilo.conf - Configuration file

• o -v - o ns a or up a e e o

boot loader.

• lilo -t - Test the configuration beforeinstallation.

• lilo -u - To restore the MBR backup.

• - -the a current boot loader.

Lilo installation



Check the

the lilo

package.

Copy the

lilo.conf.anaconda

to lilo.conf lilo

lilo –v

installs lilo

configuration file).

oot oa er.

Lilo installation



Thus the lilo

boot loader

is installed.

This command displays

the current boot loader,thus we can see the lilo

.

Lilo installation



Open the lilo

configuration file.









GRUB Configuration



Open the grub

file.

GRUB Configuration



The options rhgb quiet

will start xserver while

bootin .

emove s op ons o

boot through textmode.

Grub Configuration



Save the file

.

GRUB Configuration



ow re oot t e

system.

GRUB Configuration



Now system is booting

in text mode .

GRUB Configuration




in text mode .

GRUB Configuration




in text mode .

GRUB Configuration




in text mode .

GRUB Configuration




in text mode .

GRUB Configuration




in text mode .

GRUB Configuration




in text mode .

GRUB Configuration



Open the grub

file.

GRUB Configuration



The options rhgb quiet

will start xserver whilebootin .

GRUB Configuration



ow re oot t e

system.

GRUB Configuration



Now system isbooting in

graphical mode.



In EL-4 redhat-config-*

tools are renamed as

system-config-*.

GRUB installation

N th b t



Now the boot

loader is lilo.

To install grub loader use

the command

- .

GRUB installation



Open the

configuratio

n file.

GRUB installation



If default isLabel for firstFlash screen to beThis represents that theBoots the kernelIt loads the initial

se o zero

then it boot

through first

.displayed at boot

time.

partition of the hard disk on

hd0.

image.s .

stanza.Loads the

dual OS.

second

stanza.

GRUB installation



To set password to

loader.

It gives us the encrypted format of the

.be entered in the grub.conf file. This can

be done by the following method.

GRUB installation



type the password two times,

this will append the encrypted

password to the grub.conf file.

GRUB installation



Open the

configuration

file.

GRUB installation



Here we cansee the

appended

assword.

GRUB installation



Just cut and

password

here.

Save the file and

system.

GRUB installation



Here you can see the

Type p to enter grub

password if you

want to o to sin le

for the OS to boot.user mode.

GRUB installation



password

here.

GRUB installation



Change the command

prompt to get in to

that press ‘e.’

GRUB installation



to run level 1.

GRUB installation



Press b to



Using rpm command

• rpm command is used to manage and install



software packages.

• This command performs installation, removal and

.

• Each package is actually an rpm packages.

• rpm consists of an archive of software file and

information to install.

• Each archive is resides as a single file with a name.

Using rpm commandrpm command is used either for installing or uninstalling

package.



Syntax:

rpm [parameter] package name [options]

parameter:- - .

-U - Updates package.

-e - Remove a package.

-q - sp ays n orma on or an ns a epackage.

-ql - Displays file list for installed package.

-qpi - Displays information from an rpm package file.

(used for uninstalled packages)-qpl - Displays file list from an rpm package file. (used

for uninstalled packages)

Using rpm command

Options:



--force - Forces installation des ite conflicts.

--nodeps - Install or remove without doing any

dependency checks.

--aid - Automatic dependency to install a package.

(While available of package rpmdb-redhat

aid option will work)

Querying the packing



rpm –q a

querying a

particular package

Using rpm command

rpm –q checkswhether the above



whether the above.

r m –e commandwill remove thehttp package.

Using rpm command



For installing the

the mount the

operating system

cd-rom of RHELand then only we

can install the

packages.

Using rpm command



Go to

Redhat

rectory.

Using rpm command



Go to

RPMS

directory.

Using rpm command



List the files in

RPMS directory

and we can seethat the packages

end with an

extension .rpm.

Using rpm command



rpm –qpi shows

about the packagebefore installation.

Using rpm command



shows the

list of files ina pac age

beforeinstallation.

Using rpm command



r m –ivh is

to install a

package.

Using rpm command



- ,

a package.

Using rpm command



rpm –qi

shows theinformationabout the

acka e afterinstallation.

Using rpm command



– the list of files in

a package afterns a a on.

To view an IP-addressTwo methods available in linux to view the ip address

ifconfig :



g

-shows the ip address of the active interfaces withhardware address.

-it can show ip address of a particular interface by takinge n er ace name as argumen

example:

ifconfig eth0

ip a :

- simply shows the ip address of all interface.

Ifconfig command



Displays

information ona current y

active interfaces.

Ifconfig command



Here it displays

the information

of eth0 interface.

ip a command



Here it displays the

information about allthe interfaces.

ifup / ifdown commandIfup:

-ifup command is used to activate the interfaces.



Syntax:

Ifdown:

-ifdown command is used to deactivate the interface

Syntax:

ifdown <interfacename>

ifup / ifdown command



It deactivate the

.




Now you can notice

the interface eth0 isdeactivated.




interface eth0.




Now you can notice

the interface eth0 isactivated.

Assigning ip addressIn linux ip address can be assigned by the following methods.

netconfig:- to assign permanent ip address to the interface



Ifconfig:

- to assign temporary ip address to the interface.Syntax:

ifconfig <interfacename> <ipaddress> subnetmask<subnetmaskaddress> broadcast <broadcastaddress>

Ip a a :

- to assign additional ip address temporarily

Syntax:

ip a a <ip/subnetmaskaddress> dev <interfacename>

Assigning ip address



To assign permanent

i address usinnetconfig command.






To assign ip

automatically

from dhcp server.




To assign ip

.




Using ifconfig

command ip

address can beassigned.

ip a command

s ows e

assigned ipaddress.




When network

service is restarted,

As said earlier,

the ipaddress

assigned through

con g s use oassign ip address

temporarily.

device is removed.




To update ip

address thenetwork service is

restarted.

ip a command

assigned ip

address.




ip address can beassigned

temporary using

.




I address canbe removed

using

command, once

network service

s restarte t get

removed.

Router configuration



The ip_forward file is

assigned 1 for enabling

the router or 0 for

disabling.( Thisprocess for temporary.)



To enable the router

in permanent way get

into the s sct1.conf.



The 1 is assigned to

enable the router and

this file is for setting

router in permanentmanner.



Gateway can be added

using the command

route add.





ping command

It is used to detect whether a system is up andrunning.

Syntax:



ping [options] <domainname>

ping [options] <ipaddress>

O tions:

a - audible pingb - to ping the broadcast address

c - s op sen ng pac e s a er coun .

ping command



It checks whether

www.examp e.com

is up and connected

to the network.

ping command



It checks whether192.168.0.253 machine

is u and connected to

the network.

ping command

-b option used



p

to ping aroa cast

address.

ping command

-c options stops

sending packets

ft th



after the

LVM Structure

• LVM structure



•

also known as extents, are organized into logical

groups, which are in turn used by logical volumes.

Physical volume



• It is nothing but hard disk partition that you create

with artition creation tools such as arted or fdisk.

• The partitions type can be any standard Linux

par ons ype, suc as ex or ex .

Volume groups

• Ph sical volumes are or anized into lo ical rou s,known as Volume groups



• Volume groups that operate much like logical hard.

• You assign collection of physical volume to different

logical groups.



lvm



LVM Configuration

Create partitionType p to check how

many partitions



using fdisk

many partitions

command

disk

LVM Configuration

Here 4 partitionis created with

equal sizes of

100mb through



100mb through

.

LVM Configuration

Newly created

partition is

listed below as



To know the

partition id, use

the option l.

LVM Configuration



lvm partition id.

LVM Configuration

Here below after‘ ’

the partition id is

changed to lvmTo change the



changed to lvmWe have topartition id as lvmmention the

hex code of

the artition

id, use T option.

LVM Configuration

Now

partition id is

changed to



changed to

LVM Configuration

We save the lvm



artition throu hw option.

Previous versions of

redhat needed to restartsystem after creating

.

version to avoid restart

we use partprobe.

LVM Configuration

Physical volume is



yPvdisplay command

partition(hda6.7.8&9)show the details of

physical volume

LVM Configuration



pvdisplay command

dis la s the h sical

volume size.

LVM Configuration

Vgcreate creates

group as test0 forvgdisplay command



g p a 0displays thevm part t oninformation about

volume group test0.

LVM Configuration

vcrea e crea es a

logical volume and we



assign name as data inthe test0 grouplvdisplay,

displays the

about logicalvolume.

LVM Configuration

,

an ext3 file

system for data.



y

og ca vo ume

LVM Configuration

The logical volume



/data directory.

Open fstab file forpermanently mounted

the logical volume data.

LVM Configuration



See thecontent of

fstab file.

LVM Configuration



Logical volume name isdata is mounted on /data

directory permanently .

LVM Configuration



Here we can see free

space of logical volume

data.

LVM Configuration



Create a bi file of size

40mb in /data directory.Here we can see there isno free space available in

/data directory .

LVM Configuration



Extend the logical volume

size u to 45mb usinNow create filesystem for

If the spacelvextend command.

e ex en e vo ume us ng

ext2online.After extending volume now

we see the free space

is not sufficient,

we can resize the

available in /data directory.

logical volume .

LVM Configuration



Here we can see only 12mb

free space ia available in

.

LVM Configuration

Now the screen

shows that test



increased to 200mb.Note that the total

allocated size for

,the space from

hdb7.

100 mb.

LVM Configuration

The abovecommand shows

the increased

space of logical



.

LVM Configuration

Extend the lo ical volume



Extend the lo ical volumesize upto 50mb using

lvextend command.Now create filesystem for

e ex en e vo ume us ng

ext2online.After extending volume nowwe see the free space

available in /data directory.

LVM Configuration



We can remove logicalvolume first we must

(/data directory).

LVM Configuration



Remove the

mounted entr of

logiacl volume

(data) in fstab file

LVM Configuration



After removing

lo ical volume save

and exit the file.

LVM Configuration



Remove the logicalWe can remove volumeAfter deactivated the

rou will be removedvo ume name s a a

using lvremove

command.

decativate the volume

group using vgchange

using vgremove

command.comman .

RAID

• RAID means Redundant Arrays of Independent

• RAID is a method of storing data across several



redundancy.

• ,

as just as one hard disk by your operating system.

Types of RAID

• RAID can be implemented on a

• Hardware level



or

• Software level

Hardware RAID

• On a hardware level, you can have hard disk

connected to a RAID controller, usually a special

PC card.



PC card.

•

though the RAID hardware controller.

Software RAID

• You can implement RAID as software controller,

letting a software RAID controller program.



ett g a so t a e co t o e p og a

• The controller program manage access to hard

disks treated as RAID device.

RAID disk.

Software RAID Levels

RAID levels Capabilities Description

Linear Appending Simply treat RAID hard drives as one virtualdrive with no striping, mirroring.

0 Striping Implements disk stripping across drives with



p g p pp gno redundancy.

1 Mirroring Implements a high level of redundancy. Each

drive is treated as mirror for all data.

5 Distributed Parity Implements data reconstruction capabilityusing parity information. Parity information is

distributed across all drives.

RAID

rpm -q command



p q

checks, whether the

mdadm installed

RAID

The partition is

created using

fdisk command.



Now the screen lists

.

Raid Configuration

The partition is

created usingNow the screen lists

the artitions.fdisk command.



Raid Configuration

4 Partitions is

option with equal

size of 100 mb



Raid Configuration

‘ ’

check created

partitions.



The l option, lists the

file system. The fd

Raid Configuration



,

file system. The fddenotes linux raid







Raid Configuration

Using mdadm tool

creatin raid level 5 it usefour partition



/dev/hda6,7,8&9 and

/dev/md0.

Raid Configuration

Watch command

shows the online

status of raid

d i



devices.

Raid Configuration

Here we see statusof each raid disk.



Raid Configuration

Creating ext3 file

system for raid device

/dev/md0 using mke2fs

d



command.

Raid Configuration

Here we see the

ext3 file system is

created.



Raid Configuration

mdadm –detail

command show the

detail information

about the raid



about the raid

.

Raid Configuration

Here we see each

raid disk major &Its show the raid

minor no. .raid disk active or



not active ).

Raid Configuration

Now raid device

(/dev/md0) is

mounted on /data

directory



directory.



Raid Configuration

Now go to /data

directory and



directory and

name is file1 usingdd command.df command show

ree use space

for the raid devices

& partitions.

Raid Configuration

Mdadm –query

command show the

information about

particular raid device &



particular raid device &

.

Raid Configuration



Raid Configuration

Mdadm – manage

command set fault or

fail particular partitions

(/dev/hda9).Cat /proc/mdstat

d h di k



( 9)command show disk

t e s s a e .

Raid Configuration

Here see mdadm –

show disk /dev/hda9

is faulty



is faulty.

Raid Configuration

Now remove the

from the raid device

/dev/md0 using



/dev/md0 using

a m –manage

command .





Raid Configuration

Watch command

shows the online

status of raiddevices.



Raid Configuration

Here we can see the

status of online

synchronization of raid



y

.

Raid Configuration

Now the faulty

and we can

see the data.



Raid Configuration

Here you can see

–command show disk

/dev/hda9 is active.



Disk quota

Disk quota is used to control how much disk space a particular

user can access.

Quota tools:

uotacheck

quotaon



edquota

Quota tools

Quotacheck:

It scans the file system for the current disk usage and

update the aquota.user file.

Quotaon:

t turns on t e quota.

Quotaoff



.

Edquota:It is used to set disk uotas for a user.

Repquota:

It displays summary of disk quotas and and the quotausage .



Implementing quota

pen t e

fstab file.



Implementing quota

Replace this



defaults as

usrquota.

Implementing quota

Now usr uota



Now usr uota

is assigned to

the /home

.

Implementing quota

Here you can see thatRemount the

updated for the /home

directory.

ome rectory

to update.

Now ou can see the



Now ou can see the

user quota got

assigned to /home

Implementing quota

Create quota

database file named

aquota.user to holdthe quota information

for all users.

It checks thevalidity of quota



/home directory.

Implementing quota

Turn on the

quota.



Implementing quota

Let us set disk

quota for the



Implementing quota

To assign the

uota for the



user jack.

Implementing quota

The maximum memoryThis soft limit will justf Thi illh d



represents disk

space in KB.

space for a user. This will

deny the user to access, if he exceeds the uota limit.

issue a warning if he

exceeds soft limit.Inode represents

number of files andfor the inode .To set hard

limit for inode.

rec or es can e

accessed by the user.

Implementing quota



Here we set softlimit as 40 KB Here we setHere we set hardlimit as 50 KB

Here we set hard limitas 20 inodes .so that

memory space .inodes .memory space .user can access only

max of 20 inodes.

Implementing quota

It dis la s

summary of

disk usage.



User jack has a hardlimit(block limits) of 50KBUser jack has a hard limit (filelimits) of 20 inodes and soft

and soft limit of 40 KB, he

already used 10KB.

limit of 15 inodes , he already

used 10 inodes.



Implementing quota

Now, when the jack attemptto create more than ten files

. .,



write failed message occurs.

Implementing quota

command to create a file

named ‘1’ of 30KB.



Since the user exceeds

the soft limits a warning

messages s occurre .

Implementing quota

a file named ‘2’ of 10KB .

But since, he has exceeded

hard limit write failed



hard limit write failed

error occurred.

Implementing quota

ere we can no ce a



the jack had used all thisquota. So he is restricted

to create files.

mount command

Mount

It takes two argument : the storage

ev ce an e moun ng po n .The device is a special device file that

connects the system to the hardware device.



co ects t e syste to t e a d a e de ce

Mounting point is directory on which the

storage device is to be mounted.

mount command

Syntax:

mount [options] <device> <mountpoint>

Options:

-w mount the file system with read/write permission.

-r mount the file system with read permission.

t t if th t f fil t t b t d



-t to specify the type of file system to be mounted.

-a mounts all the file systems listed in /etc/fstab.

umount command

It un mounts the mounted file system.

The removable media like floppy disk, and cd are un

mounted after use, by using umount command.

S t



Syntax:

umount <mount oint>

mounting CD-ROM

To mount the

CDROM on themounting point

/mnt/cdrom



mounting CD-ROM

Now we can access



Now we can access

the CDROM contentsrom e moun ng

point.



Unmounting cd-ROM

To eject the

CD from the



CD Drive.

Mount /unmount floppy

To mount the

floppy on themounting point

/mnt/flo .

Unmount the



Unmount the

floppy after

access.

Mounting Hard drive partitions

To mount a hard drive artition

The hard disk partition also can be mounted like

any other file systems.



mount –t ext3 /dev/hda4 /mnt/data

Mounting Hard drive partitions

To mount the hard disk

partition (hda3 of ext3file system) in /data

lists the mounted

device..



Mounting NFS

Mounting NFS (network file sharing) :

– Before mountin we must know the files stem are ex orted b a

remote system. The following command is used to know the

directory shared.

showmount –e remote_server



– When the host and share name are known, the following command

is used to connected the network file system to the local file system

tree

mount remoteserver:/shareddir /mnt/newdir1

Mounting NFS

Showmount command

displays the shareddirectory on

. . . . .



Mounting NFS

We mount the el



directory from remotemac ne n o our mn

directory .

Mounting NFS

Mount command



shows information'sabout mounted

devices.

Mounting NFS

to unmount remote

machine directory.



Mounting smbfs

This command hel s to

view windows sharedfiles.



Mounting smbfs

The above screensdisplays window shared

director .



Mounting smbfs



umount command used

to unmount remote

machine directory.

Auto mount /etc/fstab:

information in this file.

Using entries in this file the file system can be automatically

mounted whenever the system boots.

It consists of six field per line for each file system as follows



<device> <mountpoint> <fs_type> <options> <dump_freq>

<fsck_order>

Auto mount

pen t efstab file.



Auto mount

It representsIt representsIt represents fileIt representsIt represents the

.t e mount

i

systems.different options

f i h

ump

f

the fsck.



points.for mounting thefile s stem.frequency.

AutofsAutofs service mounts the file system automatically

when the user access the mountin oint.

The autofs to supports the removable media without

recurr ng e user o o any ng more an nserthe media

Autofs configurations file are



/etc/auto.master

/etc/auto.misc

Autofs configurations files /etc/auto.master:

used for a file systems and that mounts will time out

a er secon s o nac ve.

/etc/auto.misc:



file system is configured in this file.

Autofs configurations files

auto.master

fil



file.


Mounting

'

should be entered

here



here.


the mounting

point

information's about

the file systems to be

to unmounted the

auto mounted file



point.the file systems to beauto mounted filemounte .system.


auto.misc file.






Mounting device

information's are

entered here.


K th fI h



Key, the name of It re resents thethe subdirectory

where the datasystem type.device to be

mounted.

.


Now autofs serviceis restarted.




The contents of the

cdrom is now

available in the

mounting point



mounting point.



Scheduling Task: cron

Cron Schedules one-time maintenance tasks.

Cron is ideal for setting up jobs that execute regularly atspec e mes or n erva s.

,up and configuring jobs.



Creating cron

cron tab files are stored in /var/spool/cron.

s e s accesse on y y e roo user, w ereas eother users cannot access.

User can access this file by using crontab command.






Root user has the

privilege to open

this file.




Now open

t e e.



Scheduling Task: cronIf any

values isnot

represented

First fieldSecondThis filesThis fieldThis fieldComman

mention *

represents

minutes(0

-59 .

field

indicates

hours 0-

indicates,

day of the-

indicates

the month-

indicates

the day of

d can be

given inThe above command gets

executed at 13 hours, 34



--23)

31)

week(0-6)

minutes as daily basis at

same time.


e serv ce s

restarted using

service crond

Chkconfig commandenables the crond

restart.

in next boot time.




Automatically

“ ”

gets displayed in

terminal.




The permission is

denied to the normaluser joe when the

user attempts to the

As said before the root user

.

only has the privilege to

access the file.






Now open

t e e.




The above command gets

executed at 13 hours, 40

i d il b i



minutes as daily basis at

same time.


Crontab –l command

used to display content of t b fil



crontab file.



DNS• DNS - Domain naming system.

• serv ce oca es an rans a es oma n namesinto corresponding associated IP addresses.

• DNS configuration.

• It requires the following software packages to be

installed.• n



n

• Caching-name server

• -

Service profile

- , - ,

caching-nameserver

Configuration files - /etc/named/named.conf

/var/named/named.local

Daemons - namedPort number 53



Port number - 53

DNS Configuration

Install bind, thisInstall bind-utils

which rovides

package includesweb page manualsmany utilities likehost, dig and

Install caching-

name server which

provides a working



provides a working

named.conf

DNS Configuration

Open this file for

mentioning the homedirectory for DNS.



DNS Configuration

Here DNS home

directory is

/var/named/chroot.



DNS Configuration

directory files.



DNS Configuration

Open the

file named.conf.



DNS Configuration

Now ou are seeing the

contents of

.

file.



DNS Configuration

Forward zone mapping

This file

contains the ip

between fully qualified

domain to particular ip

address and

the locations

of all the dot

servers.



DNS Configuration









DNS Configuration

forward file.



DNS Configuration

Enter the fully

qualified name of It is interpreted as

the name of the

originating domain.Enter the authorisedEnter the fully

name server for this

zone.

qualified name of

host.Enter the last numbersegment of the host

dd i th



address in the reverse

zone file.

DNS Configuration

fully qualified nameusing as given

e ow.



DNS Configuration

Now the localhost is

replaced as

server1.example.com.



DNS Configuration

Enter the ip address for

s ecified domain name.

Canonical name, is used

to define an alias for aos name. e www as

the cname for



the cname for




DNS Configuration



DNS Configuration

Replace localhost to

server1.example.comusin as below.



DNS Configuration

Now the localhost is

replaced by




DNS Configuration

In a PTR record, you can

s ecif ust that last

number segment of the

address.



DNS Configuration

Open the

resolve.conf file.



DNS Configuration

Mention the nameserver

ipaddress and domain

name here.





DNS Configuration

Thus the DNS makes it possible toping an host by its domain name

by resolving the domain name




.

DNS Configuration

Thus the DNS makes it possible toping an host by its domain name




y g

.

DNS Configuration

g comman s ows p

address of the specified

f ll lifi d d i



fully-qualified domain

name .

DNS Configuration

Nslookup is a dns

query a dns server.Using nslookup you canidentifies nameserver forUsing nslookup you can

.identifies address for

particular FQDN.Using nslookup you can

identifies FQDN forparticular IP address.



DNS Configuration

ping an host by its domain name





into IP address.



DNS Configuration

In client side open

.

file.



DNS Configuration

Mention the nameserver

ipaddress and domain

name here.



DNS Configuration

Thus the DNS makes it possible to

ping an host by its domain namey reso v ng e oma n name

into IP address.



DNS Configuration

It shows the simple

lookup of host,thus its

show the correspondingi address to the

s ng ns oo up you can

identifies MX record forparticular domain.

specified fully quailed

domain name.

identifies nameserver for

particular domain.



p

DNS Configuration

forward file.



DNS Configuration

In this file we can add

additional entry MX(mail

In this file we can add

additional entr station105exc ange recor an s

corresponding ip address

192.168.0.100.

machine and its

corresponding ip address



192.168.0.100.. . .

DNS Configuration

pen t e

reverse file.



DNS Configuration

Similarly we can add

another pointer record105 for

station105.example.com.



DNS Configuration

Now named

service is

restarted.



DNS Configuration

s ng ns oo up you can

identifies MX record forparticular domain.Using nslookup you can

en es a ress or

particular FQDN.

Using nslookup you canen es recor or

particular FQDN.



DNS Configuration

Open the

configurationfile named.conf.



DNS Configuration

orwar zone sts t e

name servers outside the

network that should besearched when the

networks name server



.



Apache Web Server• Apache web server:

• e pac e e server s a ree eserver developed by the Apache Server Project.

• It is a reliable, efficient , and easily extensible WebServer

• Free open source code



Apache Web Servermportant rector es an con gurat on es



Service profile

ac ages - p

- .

Daemons - htt d

Portnumber - 80



Web server configuration

Query a httpd packagewhether installed or not

but the screen shows

httpd packages is not

.




httpd package isinstalled usinNow query thepackage it show

rpm command.package is

installed.




Open the httpd

configuration file.



Web server configurationYou can see the first

,need to edit the end part

of the, so press shift+G

in command mode the

cursor will bottom of a e.



Web server configurationThis screen show

end of httpd.conf

file.

Copy the last

seven lines .




Paste the copied

lines here .




In virtual host field we

enter ipaddress or fully

qualified domain

ere spec y e e-maaddress of the

administrator for the web

Here specify the basedirectory from which

Here specify the

hostname for yourNow save and quit the

the htt d.conf file..

server. ..server.




After editing the

service httpd is

restarted.




Creating index.html page

and lace this file in the /var/www/html/ directory.




Let us createAfter typing save

tm e . .




browser and type thefully qualified domain

name in address bar and

press enter, it will open

corres ondin web a e.




To allow only aDirectives that can beparticular user to access

our web site we can adddirector session inside

Setting up /var/www/html/ access

overridden by the entries

in an .htaccess file.

virtualhost session.control directive .




.

/var/www/html/

directory and open the

e

.



Web server configurationThe authorization realm is

iven to the client so the

Type of user

authentication forSelects the authenticated

user knows which

username and password to

directory. only Basic and

Digest are currentlyThis file contain list of directory.

. .users and passwords for

user authentication.




Set the httpd

passwor or t e user

joe .




httpd password isstored in htpasswd




Set full ermission for

the htpasswd file to

make sure that the user

permission .




the htpasswd file.




Restart the httpd

service.




Enter the fully qualifieddomain name in address

bar.




When we access the webpage the mozilla will

prompts for the

.




n er e username anthe password.




Now you can see theweb page.



Access ControlThe web access can be controlled by using accesscontrol directives such as allow and deny.

Directive Description

deny from host Determines hosts that can access ahost …. given directory: all, or partial or full

domain name or ip address.

allow from hosthost ….

Determines which hosts can access agiven directory: all, or partial or fulldomain name or ip address.




This indicates that we

can access e we pagefrom any network.




o access e we pageonly from the above

specified network.



Virtual host

Virtual hosts allow you to host multiple domains from a

single machine.

pac e suppor s wo eren ype o v r ua os s.

-

I -based virtual hosts



Ip and Named-based Virtual Hosts

IP-based virtual hosts

- p- ase v r ua os s are use w en a s ng emachine has several different IP address.

-To run a virtual host on each IP address.

Named-based virtual hosts

-It allow you to host many virtual hosts from asingle IP address.



Name-based virtual hosts

Here we place twoTwo domains are

oma ns n a s ng e p

address and we canplace number of

used in the name of

example and test.com

domains using single

IP address.

192.168.0.20.




An i address is

mentioned in the

virtualhost field.




The server fully

qualified

described here.




A Directory is created

in the s ecified ath as above here copy

test.com webpage..




ttp serv ce srestarted.




This is the webpage for

t e test.com .




This is the webpage forexample.com.



Proxy Server: SquidSquid

.

Handles the request from the local clients for

web access.

including FTP, Gopher ad HTTP.



Service profile

Packages - Squid

Configuration files - /etc/squid/squid.conf

Daemons - Squid

-





Squid Configuration

configuration file if we

want to change the

e au s en we can ethe file.





Squid Configuration

Search for the acl

access control list



Squid Configuration

Create another acl named

ano o res r c e we

access by time. Thus here the

web server can be accessed

during 18:30-19:30 only.Search for

http_access incomman mo e.

IP address are allowed to

access the web server by

ass gn ng em n acnamed thano.



Squid Configuration

This deny other IP

addresses except the IP

access lists

o a ow e access s sthano and thano1



Squid Configuration

Now restart the

squidservice.











Squid Configuration

Now the time is in

between the access timeiven in the acl so we

can access web server.



Squid Configuration

Here you can see that

the access is denied

since the we are not

allowed to access the.



Apache Encrypted Web Server

A ache can rovide encr ted communications usin

the mod_ssl apache module.

To make use of encrypted communications, a client

must request the https protocol.

Encryption is based on either the RSA or DSA

.








To generate the

certificate signature

request.




The self signed certificate

can be installed using the

commandmake testcert.




When we restart the

httpd service it will

prompts for the

password.




Open the mozilla

browser and type fullyualified name in the

address bar using https

protocol.




Click here to

view the

certificate.




Here you can view thecertificate informations.




After examining accept the

certificate tem oraril or

permanent and then click

ok.




You can see a warning

this page can not be read

by a third party.




ow you can accessthe web page securely.



Sendmail ConfigurationSendmail:

e a nux uses en ma as s o e vermessages.

It listens for any mail messages received from other

hosts and address to user on the network host itserves.

,to be sent.



Sendmail Service Profile

- -,

configuration file - /etc/mail/sendmail.mc

m4 macro config. file - /etc/mail/sendmail.cf

demon service - sendmail

ort number - 25 smt 110 o



Sendmail Configuration

Query is made to

check whether the

sendmail package is

installed. if not install

the packages.




using rpm command.




Open the sendmail

configuration file .




Sendmail

con gurat on e.








e wor n s a e nthe beginning of this line

to comment.

commen ng s nevoids to send mail to the

other systems






Open the

Virtusertable file, for

domain addresses.




The virutusertable

configuration helps to

along with fully

qualified domain name.




pen a oca -host-file.

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