What is Yum?
” Yum is an automatic updater and package installer/remover for rpm systems. It automatically computes dependencies and figures out what things should occur to install packages. It makes it easier to maintain groups of machines without having to manually update each one using rpm.

Features include:

* Multiple Repositories
* Simple config file
* Correct dependency calculation
* Fast operation
* rpm-consistent behavior
* comps.xml group support, including multiple repository groups
* Simple interface”

1. Installation

The best part of this howto is you have to just install the necessary softwares and everything will be ready after install. The following packages will be needed to install YUM software successfully.

* yum
* python-elementtree
* python-iniparse
* python-sqlite
* rpm-python
* python-urlgrabber
* yum-metadata-parser
* m2crypto

It may be possible that some of the above software are already installed and may be some more depended software needed. For more software you just have to add any other depended software full URL to the following command which i will used to install yum.

rpm -Uvh http://mirror.centos.org/centos/5/os/i386/CentOS/yum-3.2.8-9.el5.centos.1.noarch.rpm http://mirror.centos.org/centos/5/os/i386/CentOS/python-elementtree-1.2.6-5.i386.rpm http://mirror.centos.org/centos/5/os/i386/CentOS/python-iniparse-0.2.3-4.el5.noarch.rpm http://mirror.centos.org/centos/5/os/i386/CentOS/python-sqlite-1.1.7-1.2.1.i386.rpm http://mirror.centos.org/centos/5/os/i386/CentOS/rpm-python-4.4.2-48.el5.i386.rpm http://mirror.centos.org/centos/5/os/i386/CentOS/python-urlgrabber-3.1.0-2.noarch.rpm http://mirror.centos.org/centos/5/os/i386/CentOS/yum-metadata-parser-1.1.2-2.el5.i386.rpm http://mirror.centos.org/centos/5/os/i386/CentOS/m2crypto-0.16-6.el5.2.i386.rpm

As soon as installation completed, you have fully functional YUM is available and now you can use any command to test successfull installation, usually i used

yum list

How to install YUM on centOS 4

Login to your server as root and create yum directory
# cd /usr/local/src/
# mkdir yum
# cd yum

Now download some rpms that yum needs:
# wget http://centos.cs.ucr.edu/centos/4/apt/i386/RPMS.os/python-urlgrabber-2.9.6-2.noarch.rpm
# wget http://centos.cs.ucr.edu/centos/4/apt/i386/RPMS.os/python-sqlite-1.1.6-1.i386.rpm
# wget http://centos.cs.ucr.edu/centos/4/apt/i386/RPMS.os/python-elementtree-1.2.6-4.i386.rpm
# wget http://centos.cs.ucr.edu/centos/4/apt/i386/RPMS.os/python-urlgrabber-2.9.6-2.noarch.rpm
# wget http://centos.cs.ucr.edu/centos/4/apt/i386/RPMS.os/sqlite-3.2.2-1.i386.rpm
# rpm -Uvh *rpm

Download and install yum:
# wget http://centos.cs.ucr.edu/centos/4/apt/i386/RPMS.os/centos-yumconf-4-4.3.noarch.rpm
# wget http://centos.cs.ucr.edu/centos/4/apt/i386/RPMS.os/yum-2.4.0-1.centos4.noarch.rpm
# rpm -Uvh *rpm

Thats it.. yum installation is complete.