REDHAT ENTERPRISE LINUX 6.0
Index
S.NO
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CHAPTER NAME
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PAGE.NO:
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1.
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LINUX IDEAS AND HISTORY
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3-4
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2.
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Linux Usage Basics
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4-5
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3.
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Running commands
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5-8
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4.
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User And Group Permissions
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9-10
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5.
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Some important directories
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10-12
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6.
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Permissions
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12-13
|
7.
|
Using Bash shell
|
13-14
|
8.
|
Basic shell script
|
14-15
|
9.
|
Io (input and output) redirections
|
15
|
10.
|
Text processing tools
|
16
|
11.
|
vim editor
|
16-17
|
12.
|
Root password breaking
|
17
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13.
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Network configuration
|
17-18
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14.
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Create partition
|
18-20
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15.
|
Printer configuration
|
20-21
|
16.
|
Get help
|
21
|
17.
|
Using GNOME Desktop
|
21-22
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18.
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Commands About Network
|
22
|
19.
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Control The Boot Process
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22-23
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20.
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Run levels
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23-24
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21.
|
Linux path
|
24
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22.
|
Monitor System Resources
|
24-25
|
23.
|
Process Management Tools
|
25
|
24.
|
Register With Redhat Network
|
25
|
25.
|
Manage system software
|
25-26
|
26.
|
Administrator Remote Systems
|
26
|
27.
|
Deploy File Sharing Service
|
26-28
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28.
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Web server configuration
|
28-29
|
29.
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Secure Network Service
|
29-30
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30.
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Configuring The General Services
|
30-32
|
Linux 5.0 Hardware requirements:
Ø Intel P-IV Processer or above
Ø 512MB minimum of RAM (1GB required)
Ø 25GB free of HDD space
Ø VGA Monitor
Ø Mouse and keyboard
Ø DVD-ROM with bootable DVD
Linux 6.0 Hardware requirements:
Ø 64 bit operating system it is
Ø P-IV and above microprocessor
Ø 1GB minimum of Ram
Ø 25GB or above HDD free space
Ø VGA monitor
Ø Mouse and key board
Ø DVD – ROM with bootable DVD
1. LINUX IDEAS AND HISTORY
What is open source?
Ø software and source code available to all
Ø It must be freely distributed
Ø The ability to modify and create derived works.
Ø All are free to modify the software
1. The first Linux O.S released in 1984, the GNU project.
G à GNU
N à not
U à Unix
Ø Creates open source version of Unix utilities
Ø Creates the GPL [General Public License]
2. In 1991 year, Linus torvalds creates open source, Unix kernel and shell, released under the GPL, GNU project utilities.
3. Now today, it is called as Linux
Ø Unix utilities + Linux kernel +GNU utilities, all over called as Linux
About Linux:
Ø Linux is one of the clone [small part] from the Unix
Ø Backend of Linux is Unix
Ø Manufactured in AT and T Bell labs
Ø Open source
Ø It provides a very huge security
Ø ext3 file system based in RHEL 5.0
Ø In Latest RHEL 6.0, ext4 file system
Ø RHEL -> [Redhat Enterprise Linux]
Ø In Linux O.S everything is file represented including Hardware.
Ø In Linux 5 Editors are there
They are
1. vi editor à it is from Unix O.S
2. vim editor à vi improved
3. gvim editor ( graphical vi improved )
4. nano editor
5. gedit editor (Graphical edit)
Ø In Linux O.S, There is no drives like in Microsoft O.S
Ø What the partitions are while installing the O.S those are call directories
Redhat Fedora Suse Ubuntu arrya bati
Redhat Client Redhat Server
Editions Editions
7.x RHEL 1.0
8.0 RHEL 2.0
9.0 RHEL 3.0
10.0 RHEL 4.0
11.0 RHEL 5.0
RHEL 6.0 (latest)
2. Linux Usage Basics
Log in to Linux system:
Two types of login screens
1. Virtual console [text base]
2. Graphical login [display manager]
Login user name and password
Here user name: Root
Password: xxxxxx
Directories:
1. /
2. /boot
3. /home
4. /tmp
5. /usr
6. /var/ftp/pub
Ø “ / ” means file system
Ø Linux O.S is case sensitive.
Ø Kernel, shell are in Linux
Ø Kernel is nothing but Hardware
Ø Shell is nothing but software
Ø In Linux by defaults /bin/bash shell
Ø In Linux need not to install the antivirus
Ø RHL[Redhat Linux] it is client O.S
Ø RHEL[Redhat enterprise Linux] it is server O.S
Ø If we want to install any third party package, we should have to take .rpm extension
(rpm à Redhat package manager)
Ø If we want to install it there is no facility in CD’s, It is from Internet.
Ø There are six virtual consoles and one graphical console
To go command prompt Ctrl+Alt+F1 to F6
To go graphical prompt Ctrl+Alt+F7
Switching between consoles:
à A typical Linux O.S will run six virtual consoles.
Ctrl + Alt + F1 to Ctrl + Alt +F6
à A graphical console
Ctrl +alt + F7
Two desktop environments
1. GNU network object model environment default Desktop [GNOME]
2. KDE à Alternate K Desktop Environment.
Root user:
Ø Root user is called as “super user“ Account in Linux.
Ø It is also called as an Administrator
Ø Root has near complete control over the system
Ø There are two types of command prompts.
1. # à root user login
2. $ à normal user login
3. Running commands
Basic syntax:
All commands have following the syntax.
Command<>options<>arguments
date: This command is used to display date and time
Ex: #date
cal: This command is used to display the calendar.
Ex: #cal<>4<>1980
If we want to display the calendar page by page
Ex: #cal<>4<>1980<>|more
To display total year calendar
Ex: #cal<>1940
pwd: This command is used to display the current working directory
Ex: #pwd
Syntax: clear
Ex: #clear
cat: This command is used to create a new text file in Linux operating system
Ex: #cat<>><>ahamed.txt
- - - - - - - - - -
- - - - - - - - - -
- - - - - - - - - - -
To save the data, press Ctrl + d
Again this cat command is used to display the contents of the particular file
Ex: #cat<>ahamed.txt
To append the data in a particular file we can use this cat command.
Ex: cat<>>><>ahamed.txt
Ex: #cat<>ahamed.txt
To create hidden file in Linux operating system we can use this cat command
Ex: #cat<>> <>.ahamed.txt
ls: This command is used to list the contents of the current directory or specified directory
Syntax: ls<>options
ls<>-a: This command is used to display the file and directories including hidden files also
Syntax: ls<>-a
Blue color : directories
White color : file and normal file
ls<>-l: This command is used to display the files, directories, owner of the file, date and time, file with extension. It also displays the permissions of the files and directories.
Syntax: ls<>-l
It shows 7 columns information.
Ex:
1
|
2
|
3
|
4
|
5
|
6
|
7
|
-rw-r--r--
|
1
|
root
|
root
|
63
|
may31 12:00
|
ahamed
|
ls<>-r: This command is used to display the files and directories with a recursive.
Syntax: ls<>-r
ls<>-il: This command is used to display the in node values of directories and files.
Syntax: ls<>-il
mkdir: This command is used to make a directory
Ex: #mkdir<>ahamed
cd: This command is used to change the directory.
Ex: #cd<>ahamed
If we want to come out from the directory
Syntax: cd..
To come out from your previous working directory
Syntax: cd
cp: This command is used to copy the file and directories from one location to another location
Ex: cp<>/root/ahamed/*<>/root/nnbrothers
mv: This command is used to move the file and directories from one location to another location
Ex: mv<>/root/ahamed<>/root/nnbrothers
This command is also used to rename the files
Ex: #mv<>ahamed.txt<>nnbrothers.txt
touch: This command is used to create empty file or files
Ex: #touch<>file1<>file2<>file3
rm: This command is used to remove the file or files
Ex: #rm<>ahamed.txt
rm<>-rf: this command is used to remove the files force fully
Ex: #rm<>-rf<>ahamed.txt
rmdir: This command is used to remove the directory
Ex: #rmdir<>ahamed
But the directory must be empty
rm<>-r: This command is used to recursively remove the directory
Ex: rm<>-r<>ahamed
who: this command is used to know about that who are logged in the system
Ex: #who
4. User And Group Permissions
Ø Every user is assigned a unique user ID number(UId)
Ø UId “0“ identity root
Ø Users are assigned a home directory and program that is run when they login
syntax: useradd<>name
Ex: #useradd<> ahamed
Passwd: This command is used to set a password to the particular user account
EX: passwd<>ahamed
It is shows
New unique password:
Confirm password:
If we want to create a user account the user will be stored in four places in Linux O.S
They are
1. /etc/passwd file
2. /etc/shadow file
3. /etc/group file
4. /home directory
1. /etc/passwd: This file is used to store the user date base
2. /etc/shadow: This file is used to store the user’s password in encryption method
3. /etc/group: This file is used to store group account which is primary group
4. /etc/home: It is maintains all the user home directories, while installing the O.S. It acts as a partition
Groups
Ø user’s are assigned to groups
Ø Each group is assigned a unique group Id [GID]
Ø Group account data base stored in /etc/group file.
Ø Each user is given their own private group
groupadd: This command is used to create a primary group in Linux O.S
Ex: #groupadd<>marketing
Permissions:
Permissions are 3 types, in Linux
1. Read
2. Write
3. Execute
Three types of persons users
1. Owner
2. Group
3. Others
1
|
2 3 4
|
5 6 7
|
8 9 10
|
-
File or directory
|
r w -
Users
|
r - -
Groups
|
r - -
Others
|
5.Some important directories
àA collection of information is called file
àA collection of files is called as a directory
àA collection of root directories is called file system structure
/bin /sbin /boot /home /var /mnt /etc /dev /lib /usr /proc /root
Ex: #cd<>/bin
1. touch command
2. tar command
3. umount
4. vi editor
5. date
6. cat
etc…
Ex: cd<>/sbin
1. shutdown
2. fdisk
3. tune2fs
4. chkconfig
5. e2lable
etc…
Ex: cd<>/root
1. Desktop directory
2. anaconda file
3. install.log
Ex: #cd<>/boot
/mnt(mount): This directory contains the mount point for the file system. This directory is empty
#mount<>/dev/dvd<>/mnt
/lib( library ): It contains many library files used by the system
1. libsepol.so.1
2. libssl.so.0.98b
Note:lib files we can’t modify
Ex: #cd<>/etc
Ex: #cd<>/var
1. log directories
2. games directories
3. tmp directories
4. etc..
Ex: #cd<>/user
1. bin directory
2. etc directory
3. lib directory
4. etc
Ex: #cd<>/proc
1. 1
2. 10
3. 109
4. 11
5. etc
Ex: #cd<>/dev
1. audio
2. bus
3. disk
4. fd
5. net
6. etc..
Ex: cd<>/home
It shows the directories of users.
6. Permissions
In Linux there are three types of permissions
1. read permission
2. write permission
3. execute permission
In Linux two types of changing permissions
1. symbolic method
2. numeric method
syntax: chmod <>[symbolic method/numeric method]<>file name
symbolic method:
Who may be
|
Operator may be
|
Permissions may be
|
u -> user or owner
g -> group
o -> others
a -> all three categories
|
+ -> add permission
- -> remove permission
= ->assign permission
|
r -> read
w -> write
x -> execute
|
Numeric method:
User is a 3 digit mode numbers
Ø first digit specifies owner’s (user) permission
Ø second digit specifies group permission
Ø third digit specifies other’s permissions
Permissions are
4 -> for read operation
2 -> for write operation
1 -> for execute operation
Ex:
1
|
2 3 4
|
5 6 7
|
8 9 10
|
-
|
r w –
u
|
r - -
g
|
r - -
o
|
Now
r = 4
w = 2
x = 1
If we want to give the execute permissions to user, it will happen like this
Ex: chmod<>741<>filename
7. Using Bash shell
In Linux 5.0, 6.0 by default shell name is “bash shell”. It acts as user interface.
Ø Shell is nothing but software
Ø Kernel is nothing but hardware
It provides environment like settings path, home directory etc …
It provides best path like commands.
There are 4 types of features in the “bash shell”
1. History
2. Alias
3. Name completion
4. Display command
history: this command is used to see the list of remembered commands.
Ex: #history
alias: this command is used to put a duplicate name to the particular command.
Ex: #alias<>c=clear
Name completion: In Linux O.S well support to name completion of the absolute path
Syntax: cd<>filename+tab
Display command: use up and down arrow keys, it displays previous commands.
8. Basic shell script
Shell scripts are text files, contains series of commands are statements to be executed shell scripts are useful for
Ø Auto mating commonly used commands.
Ø Performing system administration.
Ø Creating simple applications
Ø Manipulation of text or files
Step-1:
Syntax: #vim<>iiht.sh
Press “ i “ to insert mode
echo “the current date and time are $(date)”
Step-2:
Syntax: #chmod<>u+x<>iiht.sh
Syntax: #./iiht.sh
Change host name:
Syntax: #vim<>/etc/sysconfig/network
Press “ i “ to insert mode
To save it press esc:wq
9. Io (input and out put) redirections
There are three types of input and out put [io] redirections operators in Linux O.S
1. Standard input [STD in]
2. Standard output [STD out]
3. Standard error [STD rr]
Standard input: In Linux redirect standard input was “ < “ operator. In this standard input we can use “ tr “ command will be taken their input from a file. If “ 1 “ is given ad an argument.
1. #cat<>><>ahamed.txt
hai this is linux 6.0
2. #tr<>’a-z’<>’A-Z’<><<>ahamed.txt
It shows
HAI THIS IS LINUX 6.0.
STANDARD OUTPUT: In Linux standard output operator is “ > “
syntax: command<>><>filename
1. #touch<>file1
2.
3. #cat file1
Standard error: In Linux the standard error redirecting operator is “ 2> “.
Ex: #cat<>redhat
It shows,
file not fount error message when file was not in
1.
2.
3.
4. #cat<>file
10. Text processing tools
head: This command is used to display the first ten lines of a file
Syntax: head<>-n<>no. of lines<>filename or path
Ex: #heat<>-n<>3<>ahamed.txt<-
tail: This command is used to display the last ten lines
Syntax: tail<>-n<>no. of lines<>filename
wc(word count):
It is used to count the words, lines bytes and characters.
Syntax: wc<>options<>filename
1. #wc<>ahamed.txt<-
2. #wc<>lwc<>ahamed.txt<-
L -> lines
w -> words
c -> characters
aspell: This command is used to interactively spell check the files
syntax: aspell<>check<>filename
11. vim editor
A new version of “ vi “ editor, the standard Unix text editor.
Vim -> vi improved
Advantages:
Ø Do more with fewer key stocks.
Ø No dependence on mouse
Syntax: vim<>file name
Ex: #vim<>ahamed.txt<-
In vim editor, there are three main modes.
1. Command mode
2. Insert mode
3. Execute mode
To modify a file
(insert mode) “ i “ begins insert mode at cursor so that you can type the data.
“ A “ -> append to end of line
“ I “ -> insert at beginning the line
“ o “ -> insert new line [below]
“ O “ -> insert new line [above]
Saving a file and existing :
Press esc key -> :w <- [for writes the file to disk]
Press esc key -> :wq <- [for write and quit ]
Press esc key -> :q! <- [quits, even if changes are lost]
Manipulating text commands in “ vim “ editor :
Press “ esc “ key and then type it
Name
|
Change
|
Delete
|
Copy
|
Line
Letter
Word
Paragraph above
Paragraph bellow
|
cc
cl
cw
c{
c}
|
dd
dl
dw
d{
d}
|
yy
yl
yw
y{
y}
|
12. Root password breaking
Restart the computer and keep pressing “down arrow“ key.
Ø Select the operating system, press “ e “ (edit)
Ø Select second option, press “ e “
Ø Give space and type “ 1 “, press “ enter “
Ø Press “ b “ (boot)
13. Network configuration
48 bit length
Fixed by LAN adaptor. manually assigning IP DHCP provides IP
In CUI:
System-config-network: This command is used to assign the ip address to the particular system
Syntax: #system-config-network<-
After type this command
Select Eht0 device -> enter
-> fallow the steps
In Linux net mask will be as subnet mask in Microsoft
Service-network-restart: This command is used to start the network services.
Syntax: #service-network-restart<-
Eth -> Ethernet
Eth0 -> on board
Eth1 -> additional
Process: #system-config-network<-
Select Eth0 device -> press “ enter “<-
Now it will show, one configuration table, then follow the steps like this
Divert configuration
Name: eth0
Device: eth 0
Use DHCP: [*]->[remove the as trick, press space bar]
Static IP: 192.168.1.1
Net mask: 255.255.255.0
Default gateway:
Ø Press [tab] key, to select [ok]
Ø Again press [tab], quit
Ø Enter
Ø Command [#service-network-restart]
Ø Enter
Ping: This command is used to check the connectivity of the system
Syntax: #ping<>ip address
Ex: #ping<>192.168.1.2<-
14. Create partition
fdisk: This command is used to create a partition and deleting partition on the particular Linux system
Syntax: fdisk<>option
Ex: #fdisk<>-l<-
It shows details about devices in their
Example total cylinders -> 82699 [ex only]
Last device endpoint -> 80194
There is “2505” free space available
To create partition: follow the steps
step-1:
#fdisk<>-l<-
See the details, if free space is available then
#fdisk<>/dev/sda<-
Command: n<-
First cylinder [57432-82700, default 57432] <-
Last cylinder <-
Command: w<-
Step-2:
#fdisk<>-l to view our new partition
Step-3:
#partprobe ->(it is only in RHEL5)
[In RHEL 6, the command is #kpartx<>/dev/sda]
To restart the partition tab
Step-4:
#init<>6<-
To restart the computer
Step-5:
To format the partition to access [compulsory do it]
#mkfs<>-t<>ext3<>/dev/sda10<-
ext3 ->our file system RHEL5
ext4 -> file system supported in RHEL6, ext3 also supported [ our wish ]
/dev/sda10 -> it is our new creating partition number
Step-6:
create a directory to make mount to partition to we access
#mkdir<>/redhat [ give “ / “ before the name of directory ]
#mount<>/dev/sda10<>/redhat<-
again to see
#mount <-
Step-7:
Go to the file system table to permanent the mount partition [device]
#vim<>/etc/fstab<-
Go to the last line, press “i“ to insert mode
Now type it
/dev/sda10 press “ tab “ /redhat press “ tab” ext3 press “ tab “ defaults press “ tab “ 0 press “ space bar “ 0<-
Save it esc:wq<-
#mount<>-0<>remount<>/dev/sda10 or /redhat<-
Step-8:
Now to conform this device is as permanent device
#cd<>/redhat<-
It shows [last + found ] directory. Now it is permanent device [partition]
To delete the partition:
Step-1: #unmount<>/redhat<-
Step-2: #vim<>/etc/fstab<-
Press “ i “
Delete the last line
Save it, esc:wq<-
Step-3: #rm<>-r<>/redhat<- [to remove the directory]
Step-4: #fdisk<>/dev/sda<-
Command: d<-
Partition (1 – 10): 10<-
Command: w <-
Step-5: init<>6<- [restart the computer]
15. Printer configuration
Go to GUI mode
Select system -> administration
->printing
->click new printer
->give the printer name
->click forward
->lpt port [line printer terminal]
->click forward
->printer selection Ex:(HP)
->click forward
->model number Ex:[deskjet 660c]
->click forward
->apply
->now select our printer
->click make default printer
If we want to make this system a printer server, now follow the steps
ð Select server settings
ð It shows some options
ð Select all
ð Apply
Printer commands:
lpq: This command is used to display, whether the printer is ready to install or not
Syntax: lpq<-
(view the contents of the print queue)
lpr: This command is used to sends a print job to the printer queue to be print.
Syntax: lpr<-
Ex:lpr<>-p<>linux printer<>-#5<>Prasad.txt<-
lpq<- (to check the print queue)
lprm: To remove the print jobs from the queue
Syntax: lprm<>job number<-
Ex: #lprm<>1<-
If we want to remove the print connection then go to the [GUI]
Click system -> administration
-> Printing
-> Select the printer
->Click delete
In command prompt
System-config-printer<-
[to view the wizard of printer configuration]
Printer configuration data is stored in /etc/cups/printer.conf
To open this
#vim<>/etc/cups/printer.conf<-
Cups: -. Common UNIX Printer
16. Get help
Many soft help, here in Linux O.S
Command prompt:
1. whatis: To display the shortcut description about particular command
Syntax: whatis<>command
Ex: #whatis<>cat<-
2. --help: To display the summary of particular command
Syntax: command<>--help
Ex: #cat<>--help<-
3. info: To gives the information about particular command.
Syntax: info<>command
Ex: #info<>cat<-
4. man: The “ man “ command is used to provides a full of documentation for the particular command
Syntax: man<>command<-
Ex: man<>cat<-
In GUI click on system menu-> click help
17. Using GNOME Desktop
GNOME -> GNU network object model environment
Ø GNOME is the powerful default graphical desktop environment for redhat enterprise Linux
Ø It provides an integrated, attractive desktop for users and developers on top of the graphical environment provides by (X Windows system)
Ø X windows system called as display manager
Ø In Linux system administration is known as for the power and flexible of command line interface
Only
18. Commands About Network
1. System-config-network: -> To assign ip address
2. ifconfig-> To display the network configuration
#ifconfig<>|more<-
3. ifdown-> To display the network adaptor
#ifdown<>eth0<-
4. ifup-> To enable the network adaptor
#ifup<>eth0
5. service-network-restart: After assigning ip we must have to restart the service
#service-network-restart<-
6. Global network setting:
#vim<>/etc/sysconfig/network<-
To change host name
Device and networking settings are stored in
#vim<>/etc/sysconfig/network-scripts/ifcfg-eth0<-
In this configuration file, we can change network address also
arpa<>-a: To display the MAC address of other network system
Ex: arpa<>-a<>192.168.1.20<-
If our system ip is 192.168.1.10<- (same network)
In GUI
Click -> system
->administration
->network
19. Control The Boot Process
Lilio GRUB
(Linux loader) (grand unified boot loader)
lilo: A boot loader is a small program that exits in the system and loads the operating system in to the system’s memory (RAM) at system boot
lilo is a flexible boot loader for Linux which is independent of a file system
MBR(HDD has)
Small logical program
Fixed by manufacture of HDD in logical circuit board
lilo loads computer memory in two stages
Stage-1:
Ø Iit is called as primary boot loader
Ø It checks the “ BIOS “ wither the “ HDD “ detected or not
Ø And will be check the MBR and loads in to the memory
Stage-2:
Ø It is called as secondary boot loader
Ø It reads into memory and display the redhat entraprise linux screen
The configuration file was /etc/lilo.conf
GRUB:
It provides the bridge in the boot process between the hardware and Linux kernal
In the Linux GRUB stage supports 446 bytes of disk space.
The boot loader will be stored in /boot partition
GRUB configuration file was stored in /boot/grub/grub.conf
Making presentence grub changes:
Comment line begins with the symbol [#]
ð Default = number, number is the default boot stanza
ð Timeout = number, it specifies how long the O.S countdown occurred
Note: when our the configuration of grub is edited or modified there is no need to restart the grub or computer
20.Run levels
The run level determines which service are started automatically on your Linux system
Init<>1 -> To login as single user mode
Init<>2 -> To login as multi user mode without network supporting
Init<>3 -> To login as multi user with network support
Init<>4 -> Not used
Init<>5 -> Graphical login mode
Init<>6 -> system restart
Init<>0 -> System shutdown
The configuration file of run levels is /etc/init/tab<-
Manage files from the command line:
Linux file hierarchy concepts:
1. Files and directories are organized into a single-root inverted tree structure
2. File system begins at the root directories, represented by a “ / “ (forward slash )
3. Name are case sensitive
4. Path are delimited by “ / “
ex: /hom, /boot, /tmp etc
Graphical navigation
|
Command line equivalent
|
1. Click from folder to folder to move around
2. Open a folder to view its contents
3. List of folders in the location bar
|
1. Cd<>[directory name]
2. Ls<>[directory]
3. pwd
|
21. Linux path
There are two types of paths in Linux operating system
1. absolute path
2. relative path
absolute path :
Ø Begins with forward slash
Ø complete “root map” to file location
Ø can be used anytime you wish to specify a filename
relative path:
Ø Do not begins with slash
Ø specify location relative to your current working directory
Ø can be used as a shorter way to the specify file name
22. Monitor System Resources
process scheduling:
The “cron” mechanism is controlled by a process named “crond”. This process runs every minute and determines if any entry in used cron table need to be executed.
Command: crontab
Syntax: crontab<>-e<-
Ex: # crontab<>-e<-
Crontab fileds:
Minute 0-59
Hour 0-23
Day of month 0-31
Month 0-12
Day of week 0-6 ( Sunday)
Crontab<>-l: To show the crontab details
Crontab<>-r: To remove the crontab list
23. Process Management Tools
The GNOME system monitor is a utility which make it easy to observe which process are running on the system and what resource they are currently running
Desktop -> right click
-> open terminal
-> #cd <-
#gnome-system-monitor<-
Or
Click applications -> system tools
->system monitor
In system monitor
System, process, resources, file systems are the options in this
24. Register With Redhat Network
Redhat network is centrally managed service that makes it easy to display software and software updates to RHEL systems and to remotely managed and monitor those systems
click system -> administration
->RHN
25. Manage system software
Command: rpm<>-ivh
This command is used to install the redhat packages on the particular Linux system.
Syntax: #rpm<>-ivh<>package name
i -> install
v -> verbose
h -> percentage of installation
Ex: login to root
#rpm<>-ivh<>vsftpd-2.2.2-6.e/6.i686.rpm<-
To uninstall the package:
Click system -> administration
->add/remove programs
->click continue any way
->click on all packages
->search our software which we want to remove
->remove tick mark
->apply
->click remove
->ok
->close
In command rpm<>-e<>package name to uninstall
26. Administrator Remote Systems
1. ssh(secure shell): This command is used to connect the systems remotely
Syntax: ssh<>other system ip
Ex: #ssh<>1.0.0.2<-
2. scp(secure copy): This command is used to copy the file or directories through network
Root 1 packages
System 1 System 2
Login to root user
In system – 1:
Create new directory to store packages
#mkdir<>packages<-
#scp<>192.168.1.20: /root/packages/*<>/root/packages
27. Deploy File Sharing Service
FTP server configuration (FTP): The file transfer protocol is one of the oldest network protocols still in common use on the internet. It provides a simple way for systems to transfer files to and from a remote server over the network
There are four steps for deploy a network FTP service
1. Package install
2. Start the service
3. Enable the configuration
4. We can use firefox browser or command line
Package name : vsftpd
Service name : vsftpd
Port number : 20,21
192.168.1.10 192.168.1.20
System 1 System 2
System-1:
Login into root user account #cd<>packages<-
#rpm<>-ivh<>vsftpd…..rpm<-
When we install the package, configuration file also installed automatically
To open the configuration file
#vim<>/etc/vsftpd/vsftpd.conf<-
Then we check 12th line in configuration table
Anonymous<>enable=yes
Save it, Esc :wq<-
To put some data that what we want to show to others
#cd<>/var/ftp/pub<-
Create one or more directories or not. (It is our wish )
#mkdir<>RHEL6<-
#cd<>RHEL6<-
#cat<>><>linux.txt<-
- - - - - - -
- - - - - - -
-- - - - - - - <-
Save it , Ctrl+d<-
To check config
#chkconfig<>vsftpd<>--list<-
#chkconfig<>vsftpd<>on<-
#service<>-vsftpd<>restart<- (2time)
And, do FTP firewall on
System-2:
Check the communication in between system 1and System 2
#ping<>192.168.1.10<-
#ftp<-
It shows
ftp>
then type ftp>0<>192.168.1.10<-
type, anonymous <-
#ls<-
Cd<>pub<-
#ls<-
It shows the directories
RHEL6
To download files
Get<>linux.txt<-(file name)
To exit type, quit<-
To check the downloading file in our system in root
#ls<>-l<-
28. Web server configuration
Display a web server:
Package name: httpd
Service name: httpd
192.168.1.10 192.168.1.20
System 1 System 2
System-1: login into root user
Step-1:
#cd<>packages<-
#rpm<>-ivh<>httpd-------.rpm<- (4 packages are compulsory install)
To check the information about packages are installed or not
# rpm<>-q<>package name
Step-2 : Now create a web page
#cd<>/var/www/html<-
#vim<>index.txt [compulsory type [index.txt] only]
Press “ i “ to insert mode
<html>
<head>
<body bgcolor=”blue”>
<font size=”12”>
Font color=”red”>
<marqueue>
Hai this is NN brothers
</marqueue>
</font>
</body>
</head>
</html>
Now open the configuration file
#vim<>/etc/httpd/conf/httpd.conf<-
Press “i” to insert mode
Now type it
<VirtualHost<>192.168.1.10>
Press “enter” and also press “tab”
Type it
Server admin<>192.168.1.10
Enter + tab, type it
Document root <>/var/www/html
Enter</virtual host>
After completing configuration start service
#chkconfig<>httpd<>--list<-
#chkconfig<>httpd<>on<-
#service<>httpd<>restart<- (2times)
Now go to GUI
è Applications
è Internet
è Firefox
è Now type
è (http://192.168.1.10)
è Enter
Note: after completing service
Click system
->administration
->firewall
->you can select trusted service
->www (select)
->click apply
Then you get the service
29. Secure Network Service
Activate And Deactivate Firewall Protection:
In Linux firewall are names as (ip tables)
Where there are many independent layers of security policy. In Linux the firewall is a layer of protection implanted by the kernel which sits between network application and the network.
The firewall can easily managed using system -> administration ->firewall
Or
In command prompt
#system-config-firewall<-
SE linux with ssl:
(ssl) -> (security Shell layer)
Note: web server must be run in the system (http)
Security Authentication:
Can access the website with user name and password only
Step-1
Ø #cd<>/var/www/html<-
Ø #vim<>.htaccess<-
Press “ i “ to insert mode
Type it
auth name<>”only for members”<-
auth type<>basic<-
auth userfile<>/var/www/html/.htpasswd<-
require<>valid-user
Save it esc:wq<-
Ø Create one user and exist user
->useradd ahmed<-
->passwd ahamed<-
To create password for the web site
#htpasswd<>-cm<>/var*www*html/.htpasswd<>ahamed<-
Ø To open the configuration file
#vim<>/etc/httpd/conf/httpd.conf<-
Go to the last line, type it
<directory<>/var/www/html>
auth name “secret stuff”
auth type basic
auth user file /var/www/html/.htpasswd
Require valid-user
</directory>
Save it, esc:wq<-
30. Configuring The General Services
Secure access to remote desktop:
While many date centers, will standardize on ssh [secure shell] for remote administration of Unix and Linux system[it is in command line]. Some will use VNC [virtual network computing] for remote administration for networking.
Redhat enterprise Linux 6 supports the implementation of VNC server, that can allow one or more remote graphical desktop . This can also found by
Click -> applications
->Internet
->tigervnc viewer
If it is not available, then install the packages
#rpm<>-ivh<>tigervnc<-
After installing the packages the configuration file was
#vim<>/etc/sysconfig/vncservers
To enable the remote desktop
System->preference
->remote desktop
->select allow other users
->select password
->apply
VNC Server Configuration
192.168.1.10 192.168.1.20
System 1 System 2
System-1: go to GUI
Desktop->right click
->open terminal
#cd<-
#cd<>packages<-
#rpm<>-ivh<>tigervnc-1----------.rpm<-
#rpm<>-ivh<>tigervnc-2----------.rpm<-
Create two user accounts
#user add<>ahamed<-
#passwd<>ahamed<-
Redhat
#user<>Prasad<-
Passed<>Prasad<-
Redhat
To open the configuration file
#vin<>/ect/sysconfig/vncservers<-
Goto the last line, type it
VNCSERVERS=2:prasad<>/:ahamed
VNCSERVERARGS[1]=”-geometry 800*600”
VNCSERVERARGS[2]=”-geometry 800*600”
VNCSERVERARGS[2]=”-localhost”
Save it esc:wq<-
Now, to set the VNC password for the particular user i.e., ahamed, Prasad
#su - prasa<-
$vncpasswd<-
Redhat123
$exit<-
#su - ahamed<-
$vncpasswd<-
Redhat123<-
$exit<-
#chkconfig<>vncserver<>--list<-
#chkconfig<>vncserver<>on<-
#service<>vncserver<>restart<- (2times)
System-2: Goto GUI
Open terminal
#vncviewer <>-via<>prasad@192.168.1.10<>localhost:2<-
It shows, are you sure you want (yes/no): yes
Prasad@192.168.1.10 passwd : redhat<-
vnc password : redhad123
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