DNS configuration history in RHEL 5

   18  rpm -qa |bind
   19  rpm -qa |grep bind
   20  rpm -ivh bind-9.3.3-7.el5.i386.rpm 
   21  rpm -ivh bind-devel-9.3.3-7.el5.i386.rpm 
   22  rpm -ivh bind-libbind-devel-9.3.3-7.el5.i386.rpm 
   23  rpm -ivh bind-libs-9.3.3-7.el5.i386.rpm 
   24  rpm -ivh |grep bind
   25  rpm -qa |grep bind
   26  rpm -ivh bind-libbind-devel-9.3.3-7.el5.i386.rpm 
   27  rpm -ivh bind-libs-9.3.3-7.el5.i386.rpm 
   28  cd /var/named/chroot/var/named/
   32  rpm -qa |grep bind
   33  rpm -ivh bind-sdb-9.3.3-7.el5.i386.rpm 
   36  cd /var/named/chroot/
   42  ls named .conf
   43  ls named.conf
   44  service xinetd status
   45  cd /var/named/chroot/var/named/
   46  ls
   47  service iptables stop
   48  service iptables save
   49  setenforce 0
   50  ls
   57  ifconfig 
   58  ping 172.24.0.1
   59  chcon -R -t samba_share_t /data
   71  rpm -ivh caching-nameserver-9.3.3-7.el5.i386.rpm 
   72  cd /var/named/chroot/var/named/
   73  ls
   74  vi /var/named/chroot/etc/
   75  cd /var/named/chroot/etc/
   76  ls
   77  vi named.caching-nameserver.conf 
   78  ls
   79  cd /var/named/chroot/var/named/
   80  ls
   81  cp localdomain.zone for.example.com
   82  cp named.local rev.example.com
   83  chown root:named for.example.com
   84  chown root:named rev.example.com
   85  vi /etc/resolv.conf 
   86  vi /etc/hosts
   87  vi /etc/sysconfig/network-scripts/ifcfg-eth0 
   88  cd /var/named/chroot/etc
   89  cp named.caching-nameserver.conf named.conf
   90  chown root:named named.conf
   91  vi named.conf
   92  ls
   93  vi named.rfc1912.zones 
   94  cd /var/named/chroot/var/named/
   95  ls
   96  vi for.example.com 
   97  vi named.rfc1912.zones 
   98  vi rev.example.com 
   99  service named restart
  100  chkconfig named on
  101  dig -x 172.24.0.254

RAID 5 Configuration in RHEL5.3

Step 1: Create 3 partitions by using #fdisk /dev/sda (say /dev/sda6, /dev/sda7, /dev/sda8) and change the system id as fd (Linux raid autodetect)
Step 2: #partprobe or #reboot -f
Step 3: #mdadm -C /dev/md0 -l 5 -n 3 /dev/sda6 /dev/sda7 /dev/sda8
            #mkfs.ext3 /dev/md0
Step 4: #mkdir /raid5
            mount in /etc/fstab (/dev/md0  /raid5 ext3 defaults 0 0) (add an entry in /etc/fstab)
            #mount -a
Step 5: #mdadm --detail /dev/md0 (viewing the raid device)
            #cat /proc/mdstat (viewing the raid device configuration)
Step 6: #mdadm -f /dev/md0 /dev/sda8 (disabling device from the existing RAID)
           #mdadm -a /dev/md0 /dev/sda9 (adding a new device in the existing RAID)
           #mdadm -r /dev/md0 /dev/sda8 (for removing a device from the existing RAID)

What is kernel compilation in Linux & How can do in RHEL5

What is kernel Compilation:

Linux is not a user friendly operating system, however it is more flexible than other operating systems. So you can tune the kernel to the desirable style for better performance to work with new hardware or network as well as new configurations with the existing hardware or network.

Kernel compilation has the following 8 steps to do:

1. Download the latest kernel from http://kernel.org

# cd /tmp
# wget http://www.kernel.org/pub/linux/kernel/v2.6/linux-x.y.z.tar.bz2

2.Extract the compressed file into the specified directory It is usually /usr/src/

  # tar -xjvf linux-2.6.25.tar.bz2 -C /usr/src
  # cd /usr/src

3.Install gcc package through yum in RHEL5

  # yum install gcc

You can use anyone of these commands for compiling the kernel in your desirable style

• # make menuconfig - Text based color menus, radiolists & dialogs. This option also useful on remote server if you wanna compile kernel remotely.
• # make xconfig - X windows (Qt) based configuration tool, works best under KDE desktop
• # make gconfig - X windows (Gtk) based configuration tool, works best under Gnome Dekstop.

  # make menuconfig

4.Compile kernel

    Start compiling to create a compressed kernel image, enter:

    # make

    Start compiling to kernel modules:

    #make modules

    Install kernel modules (become a root user, use su command):

   # make modules_install

  # make install

 5. Install kernel

    It will install three files into /boot directory as well as modification to your kernel grub configuration file:

• System.map-2.6.25
• config-2.6.25
• vmlinuz-2.6.25

6. Create on image

  # cd /boot
  # mkinitrd -o initrd.img-2.6.25 2.6.25
7. Modify Grub configuration file - /boot/grub/grub.conf

  title           Redhat Enterprise Linux, kernel 2.6.25 Default
  root            (hd0,0)
  kernel          /boot/vmlinuz root=/dev/hdb1 ro
  initrd          /boot/initrd.img-2.6.25

The following are not commands in the file.These are steps in the kernel compilation.
  savedefault
  boot

8. Reboot the system and boot into your new kernel that you have compiled just now 

    # reboot

Installation Server Setup in RHEL5

1.NFS method

1. system-config-network for setting a static ipaddress

2. Configure dhcp server with bootp option – refer dhcp installation

3. Copy the entire dvd contents to /var/ftp/pub

4. #vi /etc/exports

   /var/ftp/pub *(ro,sync)

5. #service portmap restart

6. #chkconfig portmap on

7. #service nfs restart

8. #chkconfig nfs on

9. #cd /var/ftp/pub/Server

10. #rpm -ivh tftp*

    this rpm has the dependency with xinetd rpm. So install xinetd rpm first.

11. #cp -avrf /var/ftp/pub/isolinux /tftpboot/

12. #cp /usr/lib/syslinux/pxelinux.0 /tftpboot/

13. #cd /tftpboot

14. #mkdir pxelinux.cfg

15. #cp /tftpboot/isolinux.cfg /tftpboot/pxelinux.cfg/default

16. #service xinetd restart

17. #chkconfig xinetd on

18. #chkconfig tftp on

2.FTP method

1. Same steps of NFS method

2. Create one user and make the path specified /var/ftp/pub/ as the home directory of that user.

   #useradd -d /var/ftp/pub prasanna

   #passwd prasanna

3. Choose the ftp option while installing, and choose un anonymous option, then provide the username and password that you have created.

Note:

1. Please disable the firewall if any of the methods not working properly. Follow the following steps to disable firewall in RHEL5. You can set your own firewall setup, if you know very well on that.

# iptables -F

# service iptables save

2. PXE (Pre eXecutable Environment) boot ROM required. However these methods can be used in linux askmethod installation also.

3. You cannot do the same method for creating the bootable pendrive.

Delete all other OS & no package Kickstart file

#platform=x86, AMD64, or Intel EM64T

# System authorization information

auth  --useshadow  --enablemd5 

# System bootloader configuration

bootloader --location=mbr --md5pass=$1$.9UebnNJ$hkbfHsfgw0JDYVGnVWWTq.

# Partition clearing information

clearpart --linux

# Use text mode install

text

# Firewall configuration

firewall --enabled   

# Run the Setup Agent on first boot

firstboot --disable

# System keyboard

keyboard us

# System language

lang en_US

# Installation logging level

logging --level=info

# Use NFS installation media

nfs --server=192.168.0.254 --dir=/var/ftp/pub

# Network information

network --bootproto=dhcp --device=eth0 --onboot=on

# Reboot after installation

reboot

#Root password

rootpw --iscrypted $1$bdml0V4e$dTffJK3n.0h0Slimi8XBl.

# SELinux configuration

selinux --enforcing

# System timezone

timezone --isUtc Asia/Calcutta

# Install OS instead of upgrade

install

# X Window System configuration information

xconfig  --defaultdesktop=GNOME --depth=24 --resolution=800x600

# Disk partitioning information

part / --fstype ext3 --size=10000 --asprimary

part swap --size=512 --asprimary

No Packages Kickstart files

#platform=x86, AMD64, or Intel EM64T

# System authorization information

auth  --useshadow  --enablemd5

# System bootloader configuration

bootloader --location=mbr --md5pass=$1$.9UebnNJ$hkbfHsfgw0JDYVGnVWWTq.

# Partition clearing information

clearpart --none

# Use text mode install

text

# Firewall configuration

firewall --enabled

# Run the Setup Agent on first boot

firstboot --disable

# System keyboard

keyboard us

# System language

lang en_US

# Installation logging level

logging --level=info

# Use NFS installation media

nfs --server=192.168.0.254 --dir=/var/ftp/pub

# Network information

network --bootproto=dhcp --device=eth0 --onboot=on

# Reboot after installation

reboot

#Root password

rootpw --iscrypted $1$bdml0V4e$dTffJK3n.0h0Slimi8XBl.

# SELinux configuration

selinux --enforcing

# System timezone

timezone --isUtc Asia/Calcutta

# Install OS instead of upgrade

install

# X Window System configuration information

xconfig  --defaultdesktop=GNOME --depth=24 --resolution=800x600

# Disk partitioning information

part / --bytes-per-inode=4096 --fstype="ext3" --size=6000

part swap --bytes-per-inode=4096 --fstype="swap" --size=1000

Minimal Packages Kickstart file

#platform=x86, AMD64, or Intel EM64T

# System authorization information

auth  --useshadow  --enablemd5 

# System bootloader configuration

bootloader --location=mbr --md5pass=$1$.9UebnNJ$hkbfHsfgw0JDYVGnVWWTq.

# Partition clearing information

clearpart --none  

# Use text mode install

text

# Firewall configuration

firewall --enabled   

# Run the Setup Agent on first boot

firstboot --disable

# System keyboard

keyboard us

# System language

lang en_US

# Installation logging level

logging --level=info

# Use NFS installation media

nfs --server=192.168.0.254 --dir=/var/ftp/pub

# Network information

network --bootproto=dhcp --device=eth0 --onboot=on

# Reboot after installation

reboot

#Root password

rootpw --iscrypted $1$bdml0V4e$dTffJK3n.0h0Slimi8XBl.

# SELinux configuration

selinux --enforcing

# System timezone

timezone --isUtc Asia/Calcutta

# Install OS instead of upgrade

install

# X Window System configuration information

xconfig  --defaultdesktop=GNOME --depth=24 --resolution=800x600

# Disk partitioning information

part / --bytes-per-inode=4096 --fstype="ext3" --size=6000

part swap --bytes-per-inode=4096 --fstype="swap" --size=1000

%packages

@admin-tools

@base

@base-x

@core

@dialup

@editors

@games

@gnome-desktop

@graphical-internet

@java

@office

@printing

@sound-and-video

@text-internet

Full Packages Kickstart file

#platform=x86, AMD64, or Intel EM64T

# System authorization information

auth  --useshadow  --enablemd5 

# System bootloader configuration

bootloader --location=mbr --md5pass=$1$.9UebnNJ$hkbfHsfgw0JDYVGnVWWTq.

# Partition clearing information

clearpart --none  

# Use text mode install

text

# Firewall configuration

firewall --enabled   

# Run the Setup Agent on first boot

firstboot --disable

# System keyboard

keyboard us

# System language

lang en_US

# Installation logging level

logging --level=info

# Use NFS installation media

nfs --server=192.168.0.254 --dir=/var/ftp/pub

# Network information

network --bootproto=dhcp --device=eth0 --onboot=on

# Reboot after installation

reboot

#Root password

rootpw --iscrypted $1$bdml0V4e$dTffJK3n.0h0Slimi8XBl.

# SELinux configuration

selinux --enforcing

# System timezone

timezone --isUtc Asia/Calcutta

# Install OS instead of upgrade

install

# X Window System configuration information

xconfig  --defaultdesktop=GNOME --depth=24 --resolution=800x600

# Disk partitioning information

part / --bytes-per-inode=4096 --fstype="ext3" --size=6000

part swap --bytes-per-inode=4096 --fstype="swap" --size=1000

%packages

@admin-tools

@authoring-and-publishing

@base

@base-x

@core

@development-libs

@development-tools

@dialup

@dns-server

@editors

@engineering-and-scientific

@ftp-server

@games

@gnome-desktop

@gnome-software-development

@graphical-internet

@graphics

@hindi-support

@java

@java-development

@kannada-support

@kde-desktop

@kde-software-development

@legacy-network-server

@legacy-software-development

@legacy-software-support

@mail-server

@mysql

@network-server

@news-server

@office

@printing

@ruby

@server-cfg

@smb-server

@sound-and-video

@sql-server

@system-tools

@tamil-support

@text-internet

@web-server

@x-software-development

kernel-devel

DHCP & NFS Configuration in RHEL5

RHEL 5   DHCP Server Configuration   Step1  :           # rpm –q dhcp*                         # rpm –ivh dhcp* Step 2 :           # cd /usr/share/doc/dhcp-3.0.1 # ls                         # dhcpd.conf.sample                         # cp dhcpd.conf.sample /etc/dhcpd.conf Step 3 :           # vi /etc/dhcpd.conf                                                 option domain-name           dns      server ip                         range  172.24.0.10     172.24.0.20 Step 4 :                       # vi /etc/sysconfig/network-scripts/ifcfg-eth0                         onbootpro=static Step 5 :           # service dhcpd restart                         # chkconfig dhcpd on   Client Configuration   # vi /etc/sysconfig/network-script/ifcfg-eth0 onbootpro=dhcp                                                                      NFS Server Configuration   Step1  :           # rpm –ivh nf* Step 2 :           # vi /etc/exports /test *(rw,sync) :wq                         Step3  :           # exportfs –av                         Step4  :           # service portmap restart                                                 # chkconfig portmap on                         Step 5 :           # service nfs restart                                                 # chkconfig nfs on Client Configuration   Step1  :           # mount 172.24.0.254:/test /mnt                         # cd /mnt

YUM Server Configuration in RHEL5 (Yellow Dog Updater Modified)

YUM Server Configuration in RHEL5 (Yellow Dog Updater Modified) -for increasing the package integrity.

Step 1: install createrepo.rpm from the DVD for creating repository.

# rpm -ivh createrepo.rpm

Step 2: copy all rpms form the DVD and past over the hard disk share them up in NFS.

#createrepo /path-to-rpms

eg: createrepo /var/ftp/pub

It will take several minutes that depends upon the number of rpms that you have copied from the DVD specified and the configuration of your machine.

Step 3: Touch the following file with the contents specified.

#vi /etc/yum.repos.d/somename.repo

[base]

name=friendly name

baseurl=file:///var/ftp/pub

enabled=1

gpgcheck=0

Step 4: Use the yum server in the same machine because server is the first client of the same service most of the times

the following command is used for install gcc compiler

#yum install gcc

Note: Remember ftp or http service has to be running in the yum server.

Client configuration:

Step 1: Touch the following file with the contents specified in case of ftp server is running in the server machine

#vi /etc/yum.repos.d/somename.repo

[base]

name=friendly name

baseurl=ftp://192.168.0.254/pub

enabled=1

gpgcheck=0

Step 2:

the following command is used for install gcc compiler

#yum install gcc

these are the commands for removing the service specified

#yum erase gcc

#yum remove gcc

for mail server

#yum install sendmail

DNS Configuration in RHEL 5

DNS Configuration in RHEL 5

Step 1:

set static ipaddress by using these commands

system-config-network

or

ifconfig eth0 192.168.0.254

Step 2:

Install all these following rpms

rpm -ivh bind-9.3.3-7.el5.i386.rpm

rpm -ivh bind-chroot-9.3.4-9.P1.el5.i386.rpm

rpm -ivh bind-devel-9.3.3-7.el5.i386.rpm

rpm -ivh bind-libbind-devel-9.3.3-7.el5.i386.rpm

rpm -ivh bind-libs-9.3.3-7.el5.i386.rpm

rpm -ivh bind-sdb-9.3.3-7.el5.i386.rpm

rpm -ivh caching-nameserver-9.3.3-7.el5.i386.rpm

Step 3:

cd /var/named/chroot/var/named/

cp localdomain.zone for.prasanna.com

cp named.local rev.prasanna.com

chown root:named for.prasanna.com

chown root:named rev.prasanna.com

Step 4:

Edit the following files and add the respective lines in those

vi /etc/sysconfig/network

hostname=server.prasanna.com

vi /etc/sysconfig/network-scripts/ifcfg-eth0

peerdns=no

vi /etc/resolv.conf

search prasanna.com

nameserver 192.168.0.254

vi /etc/hosts

192.168.0.254

cd /var/named/chroot/etc

cp named.caching-nameserver.conf named.conf

chown root:named named.conf

vi named.conf

option{

listen-on pot 53{127.0.0.1; 192.168.0.254;};

allow-query{ localhost; 192.168.0.0/24;}

match-clients {localhost; 192.168.0.0/24;};

match-destination {localhost; 192.168.0.0/24;};

vi /etc/named.rfc1912.zones

zone "prasanna.com" IN {

type master;

file "for.prasanna.com";

allow-update {none;};

};

zone "0.168.192.in-addr.arpa" IN {

type master;

file "rev.prasanna.com";

allow-update { none; };

};

Step 5:

Edit for.prasanna.com and rev.prasanna.com in the respective location /var/named/chroot/var/named

in the following way.

for.prasanna.com

$TTL 86400

@ IN SOA server.prasanna.com. root.server.prasanna.com. (

42 ; serial (d. adams)

3H ; refresh

15M ; retry

1W ; expiry

1D ) ; minimum

IN NS server.prasanna.com.

server IN A 192.168.0.254

client8 IN A 192.168.0.108

client1 IN A 192.168.0.101

client2 IN A 192.168.0.102

client3 IN A 192.168.0.103

client4 IN A 192.168.0.104

client5 IN A 192.168.0.105

client6 IN A 192.168.0.106

client7 IN A 192.168.0.107

rev.prasanna.com

$TTL 86400

@ IN SOA server.prasanna.com. root.server.prasanna.com. (

42 ; serial (d. adams)

3H ; refresh

15M ; retry

1W ; expiry

1D ) ; minimum

IN NS server.prasanna.com.

254 IN PTR server.prasanna.com.

101 IN PTR client1.prasanna.com.

102 IN PTR client2.prasanna.com.

103 IN PTR client3.prasanna.com.

104 IN PTR client4.prasanna.com.

105 IN PTR client5.prasanna.com.

106 IN PTR client6.prasanna.com.

107 IN PTR client7.prasanna.com.

108 IN PTR client8.prasanna.com.

Step 6:

service named restart

chkconfig named on

dig -x 192.168.0.254

if you get all the four sections question, answer,additional, authority as 1, you got it. Otherwise, some check the steps properly.

Step 7:

Client side: in station1.prasanna.com

just touch these files with the existing details

vi /etc/resolv.conf

search prasanna.com

nameserver 192.168.0.254

vi /etc/hosts

192.168.0.254 server.prasanna.com

192.168.0.1 station1.prasanna.com

dig -x 192.168.0.254

you should get the same sections like the server, Otherwise check the steps properly.

Swat in Samba

SCENARIO: Configure a SAMBA Server on RHEL5 with a NETBIOS name STATION2-NIX. Create a SHARE in it having name STATION2-RHEL5-VM and mapped to the directory /network-places/station2. Windows Machine workgroup being WORKGROUP. The share should be writeable to the user "root"

STEPS

Before you configure SAMBA SERVER make sure following packages are installed:
system-config-samba-
samba-common-
samba-
samba-swat-
samba-client-

The easiest way to configure SAMBA server is to use samba-swat utility. By default it is turned off. First check whether it has been bind to port 901 or not using:
#cat /etc/services | grep swat

After this you need to start the swat service. Use #system-config-services and check mark "swat". Save the changes and closed the window.

Open a web-browser and type the link given below:
http://localhost:901/

It will ask for username and password. It's always advisable to login with root credentials. You will presented with a Web Based GUI.

Configuring a SAMBA server is just a 3 step process:

STEP 1: Go to "GLOBAL" section. Change the workgroup to the workgroup being used by Windows Machine. It can be anything like MSHOME, MYWORKGROUP,MYGROUP etc. But both Windows and Linux should use the same workgroup name. In my case workgroup="WORKGROUP". Change the netbios name to "STATION2-NIX". Change the security to "USER". Commit the changes.

STEP 2: Go to "SHARES" tab. Create a new share having the name "STATION2-RHEL5-VM". Set the path to "/network-places/station2". Make sure this directory path exits. Also make sure "browsable" and "available" options are set to yes. Add the user "root" to "write list". Commit the changes.

STEP 3: Go to the "PASSWORD" section. For the user "root" set the password and click "Add New User". You can now verify that a new entry must have been added to /etc/samba/smbpasswd. Start the smb service.
#service smb start

You all set to access the Linux Machine from Windows. Just go to Windows Box and your share would be browsable in "My Network Places"(XP) or "Network"(VISTA). Just double click the icon having you netbios name and login using "root" credentials.

Procdure to configure dhcp and nfs servers in RHEL5

RHEL 5

DHCP Server Configuration

Step1 : # rpm –q dhcp*
# rpm –ivh dhcp*
Step 2 : # cd /usr/share/doc/dhcp-3.0.1
# ls
# dhcpd.conf.sample
# cp dhcpd.conf.sample /etc/dhcpd.conf
Step 3 : # vi /etc/dhcpd.conf

option domain-name dns server ip
range 172.24.0.10 172.24.0.20
Step 4 : # vi /etc/sysconfig/network-scripts/ifcfg-eth0
onbootpro=static
Step 5 : # service dhcpd restart
# chkconfig dhcpd on

Client Configuration

# vi /etc/sysconfig/network-script/ifcfg-eth0
onbootpro=dhcp


NFS Server Configuration

Step1 : # rpm –ivh nf*
Step 2 : # vi /etc/exports
/test *(rw,sync)
:wq
Step3 : # exportfs –av
Step4 : # service portmap restart
# chkconfig portmap on
Step 5 : # service nfs restart
# chkconfig nfs on

Client Configuration

Step1 : # mount 172.24.0.254:/test /mnt
# cd /mnt

RHEL5 DHCP Configuration file

ddns-update-style interim;
ignore client-updates;

subnet 172.24.0.0 netmask 255.255.0.0 {

# --- default gateway
option routers 172.24.0.1;
option subnet-mask 255.255.0.0;

option nis-domain "domain.org";
option domain-name "prasanna.org";
option domain-name-servers 172.24.0.1;

option time-offset -18000; # Eastern Standard Time
# option ntp-servers 192.168.1.1;
# option netbios-name-servers 192.168.1.1;
# --- Selects point-to-point node (default is hybrid). Don't change this unless
# -- you understand Netbios very well
# option netbios-node-type 2;

range dynamic-bootp 172.24.0.10 172.24.0.20;
default-lease-time 21600;
max-lease-time 43200;

# we want the nameserver to appear at a fixed address
host ns {
next-server marvin.redhat.com;
hardware ethernet 12:34:56:78:AB:CD;
fixed-address 207.175.42.254;
}
}