Transcript Linux System Configuration and Administration

Linux System
Configuration and
Administration
Lecture 6: Linux Configuration and
Administration
1
Organization of the Talk
Installation of Linux
 System Configuration

 Network
configuration
 Sharing with Windows
 Printer Configuration
 Some security configuration

Administrations
 User
Management
 User home pages
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Installing Linux: Where do you
start

Is Your Hardware Compatible?
 http://hardware.redhat.com/hcl/

Do You Have Enough Disk Space?
 You
have to decide, remove any virus if
required, use fips

Can You Install Using the CD-ROM?
 Your
BIOS may need to be changed to boot
from your CD-ROM

Alternative Boot Methods
 Boot
Diskette
 Driver Diskettes
 Network Device Drivers Diskette
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Gather more info

Use ‘other’ OS to
know more
 Personal
Desktop
Installations

Learning About
Your Hardware
with Windows
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Graphical Installation

The Graphical Installation
Program User Interface
(text mode is also
available)


Choose the language,
keyboard and mouse
Choose upgrade or new
installation

Better to choose fresh
installation
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Installation of Linux…
•Choose personal desktop installation
For the first, but next time you bet on
Custom
•After all Linux is knowing more
Choose partition
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Installation of Linux…
• Configure the partition:
• Set the mount point
• Set the SWAP size
• Set the /boot space
• Enable Ext3
formatting
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Installation of Linux…
Choose the boot loader Grub
or Lilo
• Configure the “Network
Configuration”
• DHCP, Firewall, IP address etc..
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Installation of Linux…
Choose the “Root password”
Accept the default package
selection or customize using the
“Customize option”
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Installation of Linux…
Installation starts and go on inserting the required CD when asked
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Post Installation
Create a boot diskette
Configure your video card,
monitor and screen resolution
Reboot and start your Linux….!
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System Configuration

The kickstart file is a simple text file, containing a
list of items. It allows easy installation[2] and
consistent configuration of new computer systems.

Kickstart Configurator
 Kickstart Configurator allows you to create a
kickstart file using a graphical user interface, so
that you do not have to remember the correct
syntax of the file.
 To use Kickstart Configurator, you must be
running the X Window System. To start Kickstart
Configurator, select the Main Menu Button (on
the Panel) => System Tools => Kickstart, or type
the command /usr/sbin/redhat-config-kickstart.
 As you are creating a kickstart file, you can select
File => Preview at any time to review your current
selections.
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System Configuration…

Network configuration
• Networking can always
be configured after
installation with the
Network Administration
Tool (redhat-confignetwork).
• For each Ethernet card
on the system, click Add
Network Device and
select the network device
and network type of the
device. Select eth0 as the
network device for the first
Ethernet card, select eth1
for the second Ethernet
card, and so on.
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Printer Configuration

Menu=> Printing=> New Printer => choose the printer
and printing tool (e.g. Post script printer)

Testing printer


Just do lpq to see printer status
Lpr <filename>

Should print the file
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Printer Configuration






Useful Websites
http://www.webopedia.com/TERM/p/printer.html
General denitions of printers and descriptions of
printer types.
http://www.linuxprinting.org A database of documents
about printing, along with a database of
nearly 1000 printers compatible with Linux printing
facilities.
http://www.cups.org/ Documentation, FAQs, and
newsgroups about CUPS.
http://www.tldp.org/HOWTO/PrintingHOWTO/index.html The Linux Printing-HOWTO from
the Linux Documentation Project.
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User Security
Authentication
In the Authentication section, select
whether to use shadow passwords and MD5
encryption for user passwords.
The Authentication Configuration options
allow you to configure the following methods of
authentication:
NIS, LDAP, Kerberos 5, Hesiod, SMB, Name
Switch Cache
These methods are not enabled by default. To
enable one or more of these methods,
click the appropriate tab, click the checkbox next
to Enable, and enter the
appropriate information for the authentication
method.
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Network Security

Firewalls
 Choose between
High, Medium,
and Disabled
security levels.
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Network Security

Common Access control system
/etc/hosts
 /etc/hosts.allow
 /etc/hosts.deny
 /etc/hosts.equiv


For more info refer docs on iptable,
firewall
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Sharing With Windows



SMB protocol to share files and printers
across a network connection. Operating
systems that support this protocol include
Microsoft Windows (through its Network
Neighborhood), OS/2, and Linux.
SMB implementation in Linux is called samba
There are two things one can do
Share your files/printer with other windows
machine
 Access windows shared printer/files on linux

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Allow Windows to share

You need to start samba server and nmb
server


What ever you want to share is added in
/etc/samba/smb.conf



/etc/rc.d/init.d/smb start
Every change in conf file require restarting of server
Just browse OR find computer from windows
to see these files/folders
You can share folders, CD, printer
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To access windows share

Smbclient is a samba client
Smbclient –L myhost to see all share
 Smbclient \\\\myhost\\myshare
 This will login to share and you can access the
share
 \\\\myhost\\printer can be written to print files


Smbmount can be used to mount (map)
folders on to local host


Smbumount to unmount
There are tools (GUI) for both sharing and
accessing files
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User Management
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User Management
Simple way to add user is adduser
command
 Passwd will allow to change the passwd
 Of course there are host of GUI tools for all
these user management
 Group all common user to single group
 Be careful while editing /etc/passwd

 /etc/shadow
passwd file may also exist
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User Management

Common files to look at
 /etc/passwd
 /etc/group
 /etc/shadow
 /etc/samba/smbusers
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Web server on Linux

Apache server is mostly available on Linux
 Rpm

–q –all | grep apache to check
This can be started via init services
 /etc/rc.d/init.d/httpd
start
Configuration files are at /etc/httpd/conf/
 Normally log files at /var/log/httpd

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User home pages

Will allow user to have home pages
 http://myhost.com/~user1

Need to edit /etc/httpd/conf/httpd.conf
 Enable
UserDir public_html
 Any user can have their page at public_html
Eg. /home/user1/public_html for user1
 /home/user2/public_html for user2

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System maintenance
Using package manager
 Package Management Tool
 Because people use their
computers differently, users might
want to install or remove packages
after installation. The Package
Management Tool allows users to
perform these actions.
 RPM
is good package
management tool in RedHat
Linux
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System maintenance (redhat)




The X Window System is
required to run the
Package Management
Tool.
To start the application, go
to the Main Menu Button
(on the Panel) => System
Settings => Add/Remove
Applications,
Type the command
redhat-config-packages at
shell prompt.
Command line tool rpm
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Lost Root Passwd
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Lost Root Passwd

If you have Lilo installed, type
LILI: linux init 1
 Change the root passwd, reboot aga


If you have installed grub


Type ‘e’ to go to edit mode, add init 1 argument at the
end
Boot with knoppix or single floppy linux
Mount the disk and change root passwd
 Reboot !!

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Cost Effective Linux Solutions


You have PC, with less harddisk for dual OS
You have PC, on which you do not want to
install Linux


Good heaven's do not do that
There is a spurt of Linux PC requirements for
short duration of time

For Linux LAB in one term OR during LAB
examinations
You have old PC, with out sizable hard disk
So you need Linux host for all the above case

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Cost Effective Linux Solution

Some most easy approach
 Network
booting
 Single CD Linux
 Single floppy Linux
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Network Booting
No need for harddisk(or harddisk with
Linux) on every host
 High level work flow

 The
system boots up, may be with floppy
(could be with hard disk also)
 Sends dhcp request for IP number, gets one
 Mounts the root file system over NFS
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Requirements for Network
Booting
Setup an LAN infrastructure
 Need to setup nfs server
 Need to setup dhcp server
 Build a kernel image for network booting

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Setup an LAN infrastructure
Ethernet
Cable
Your m/c to be booted
Hub
Ethernet
Cable
NFS server
Your host, NFS server and DHCP server should be on
same LAN
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Setup nfs server
• Edit /etc/exports file before starting the nfs server.
• / 10.114.7.115(rw,no_root_squash)
• This will export all files with root r/w to host
10.114.7.115
• Save your exports file and from the prompt
execute exportfs command
• Start the nfs server (nfs daemon)
• E.g. /etc/rc.d/inid.d/nfs start
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Setup dhcp server

Add in your /etc/dhcpd.conf before starting the dhcp server.

Set the correct MAC address in /etc/dhcpd.conf as follows:
subnet <subnet address e.g.10.3.31.0> netmask 255.255.255.0 {
}
subnet 10.10.10.0 netmask 255.255.255.0 {
host master {
hardware Ethernet <Mac address of your Ethernet card>;
fixed-address <IP address of your machine e.g.10.10.10.1>;
option root-path <your root path>”;
}
}
 Save your /etc/dhcpd.conf file
 start the dhcpd dameon by “/etc/rc.d/init.d/dhcpd start” command
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Build a kernel image for
network booting

Linux Kernel compilation steps:
 Assumptions: machine x86 (i386); boot loader lilo.
 Get plain vanilla kernel from www.kernel.org
 Explode it into a directory (better if can do it in /usr/src/) => tar -zxvf linux2.x.xx.tar.gz
 Optional: create a symbolic link ln -s linux-2.x.xx linux
 cd to linux directory
 cd /usr/src/linux or cd /usr/src/linux-2.x.xx
 Select the components support by make menuconfig or make xconfig save the configuration



Select IP:BOOTP support from Networking options
In File system -> Network File System -> Select
 NFS File system support and
 Root file system on NFS
Do


Make dep bzImage
Make modules modules_install
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Build a kernel image for
network booting…
Copy the
/usr/src/linux/arch/i386/boot/bzImage
to /boot
 Do mkbootdisk with new kernel as
argument
 Optional take a coffee or tea break ?

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Putting all together..
 Make
sure you are running dhcp
server
 Make sure you are running nfs
server
 On any PC that need Linux for
temporary time
Boot with new
That’s it !!!
floopy you just made
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Knoppix Single CD Linux




Knoppix is full Linux on a single CD
Can be freely downloaded from
www.knoppix.com
Just make your PC to boot from
CD, that is all required
Your current software (OS) on your
system will not be lost
If there is less memory, you can create
temporary swap on dos partation
 You can access dos partation
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Knoppix more info

Hardware Requirements
Minimum of 486 PC, 20M ram for text mode, 90M for
graphics mode and128M for office suite
 Bootable CD drive + key board, mouse, multimedia


Software available
2.4 kernel, standard drivers, development tools,
Internet applications, multimedia applications
 Upto 2GB worth software in total


How to load/install start
Step 1 put the 'cd' in drive, switch on the power
 All the configuration is “auto”
 Step 2 Enjoy working on Linux

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Knoppix can be handy

The fact is you need not install Knoppix on
harddisk
So can be used in Demo of linux or software on
Linux
 So you need extra Linux machine lab ?? 2 minutes !!
 No extra space on harddisk on old PC's, just use
knoppix
 Got a new laptop, just boot Linux on that in a jiffy

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Knoppix in Emergency
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Knoppix at emergency

Lost root passwd, boot knoppix, mount the
harddisk, edit /mnt/etc/passwd, reboot old linux


Linux do not boot, boot with knoppix and
recover the important files


Can be dangerous, spurious user can do the same
Best part is you also recover lost dos/windows files
as well
You have screwed up your configuration

Boot with knoppix and bring back to default
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Single Floppy Linux

Similar to Knoppix, but over a floppy
Will have much lesser applications
 Some distributions come with two or more floppy


MuLinux quite esay to use


http://mulinux.nevalabs.org/
Coyote linux: mostly for network applications

http://www.coyotelinux.com/
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References


Chetan Kumar S “Power Linux – Unleash the full potentials of Linux”, BIET,
Davangere, Wipro Technologies
http://www.tldp.org/ (The Linux Documentation Project) : It contains a lots and lots
of well documented and timely documents to learn and trouble shoot your Linux
system (it’s free)


The Linux System Administrators' Guide



Michael Stutz
It’s free and available at http://www.tldp.org/guides.html
The Linux Network Administrator's Guide, Second Edition



Lars Wirzenius, Joanna Oja, Stephen Stafford, and Alex Weeks
It’s free and available at http://www.tldp.org/guides.html
The Linux Cookbook: Tips and Techniques for Everyday Use



http://www.tldp.org/guides.html
Olaf Kirch and Terry Dawson
It’s free and available at http://www.tldp.org/guides.html
http://www.redhat.com/docs/
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Thanks
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