Somehow in an unlucky moment(s) you’ll find that your yum command stop working, I have experienced it a couple of time, never find out how it happen.

It is quite simple to re install yum in an rpm base linux distros, specifically CentOS in my case. What you need to do first is to download the source file (rpm) from CentOS repo.

Check your current kernel, make sure you download the correct package later;

uname -a
Linux xxx.yyy.com 2.6.18-128.7.1.el5 #1 SMP Mon Aug 24 08:21:56 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux

Go to the correct repo url, and search for yum rpm link url. For x86_64 Kernel, go to http://mirror.centos.org/centos-5/5.3/os/x86_64/CentOS/ (assuming that you are using the latest version of CentOS), copy the link of yum package, and download them into your server, you must at this point have wget installed.

cd /usr/local/src/
wget http://mirror.centos.org/centos-5/5.3/os/x86_64/CentOS/yum-3.2.19-18.el5.centos.noarch.rpm

Check yor current version of installed yum

rpm -qa | grep yum
yum-metadata-parser-1.1.2-2.el5
yum-updatesd-0.9-2.el5
yum-utils-1.1.16-13.el5.centos
yum-3.2.19-18.el5.centos
yum-fastestmirror-1.1.16-13.el5.centos

The result confirmed that you have yum-3.2.19-18, erase it using rpm and no dependencies check option.

rpm -e --nodeps yum-3.2.19-18.el5.centos

Reinstall with rpm from yum rpm you just downloaded;

rpm -ivh yum-3.2.19-18.el5.centos.noarch.rpm

Update

This repo is no longer available, use http://mirror.biz.net.id/ it is the best one available right now (IMO).

Required Pack

Install the required package using yum;

yum install gettext httpd mysql mysql-server perl

yum install php php-mysql php-xml php-imap php-mbstring php-mcrypt php-pecl-Fileinfo php-pecl-memcache php-pear-DB php-pear-File php-pear-Log php-pear-Mail-Mime php-pear-Auth-SASL php-pear-Date php-pear-HTTP-Request php-pear-Mail php-pear-Net-Sieve php-pear-Net-Socket php-pear-Net-SMTP

yum install openssl perl-Net-SSLeay

yum install php-devel gcc

Start the Service

Start Apache and MySQL daemon, and add them to startup script so it will survive reboot.

service httpd restart
chkconfig httpd on

service mysqld restart
chkconfig mysqld on

Standard MySQL First Step After Install

Run the mysql_secure script to do basic securing MySQL and give root password to your MySQL databases;

mysql_secure_installation

Apache and Basic Virtual Host Configuration

Edit the apache configuration file to fit your requirement.

vi /etc/httpd/conf/httpd.conf

###Modify

Listen vvv.xxx.yyy.zzz:80  <--Put your IP Address here

###Add

<Directory “/path/to/rootwwwdir/public_html”>
Options Indexes FollowSymLinks SymLinksifOwnerMatch ExecCGI MultiViews
AllowOverride None
</Directory>

<Directory “/path/to/rootwwwdir/public_html”>
Options Indexes FollowSymLinks SymLinksifOwnerMatch ExecCGI MultiViews
AllowOverride None
</Directory>

Virtual Host Configuration

NameVirtualHost vvv.xxx.yyy.zzz:80

<VirtualHost vvv.xxx.yyy.zzz:80>
ServerAdmin hostmaster@magnet-id.com
DocumentRoot /path/to/rootwwwdir/public_html
ServerName virt1.magnet-id.com
ErrorLog logs/virt1.magnet-id.com-error_log
CustomLog logs/virt1.magnet-id.com-access_log common
</VirtualHost>

<VirtualHost vvv.xxx.yyy.zzz:80>
ServerAdmin hostmaster@magnet-id.com
DocumentRoot /path/to/rootwwwdir/public_html
ServerName virt2.magnet-id.com
ErrorLog logs/virt2.magnet-id.com-error_log
CustomLog logs/virt2.magnet-id.com-access_log common
</VirtualHost>

###Empty the file
/etc/httpd/conf.d/welcome.conf

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

DEVICE=eth0
BOOTPROTO=static
BROADCAST=xxx.xxx.xxx.255
IPADDR=xxx.xxx.xxx.12
NETMASK=255.255.255.0
NETWORK=xxx.xxx.xxx.0
ONBOOT=yes
TYPE=Ethernet
USERCTL=no
IPV6INIT=no
PEERDNS=yes

cat /etc/sysconfig/network

NETWORKING=yes
HOSTNAME=xxx.magnet-id.com
GATEWAY=xxx.xxx.xxx.1

Put the resolver DNS IP Address on your /etc/resolv.conf (get them from your ISP or Data Center)

cat /etc/resolv.conf

nameserver 117.103.57.4
nameserver 117.103.56.5

If you want to make an alias IP Address, do this step;

Copy the ifcfg startup script

cp /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth0:0

Edit the newly created ifcfg script, customize to your other IP Address (aliased to the same network interface). Change the Device and IP Address Informations.
Restart Network Service

service network restart

cp /usr/share/zoneinfo/Asia/Jakarta /etc/localtime

That is if your box ran CentOS and you want the Time Zone in WIT (GMT+7)