Why to use Yum if I can install RPM using rpm command?
Well if you want to install RPM you have to make sure that its dependencies are also installed . But this is not in the case of YUM you can simply install package with its dependencies. YUM take care of your all install things . Also update feature is not available in the rpm installation method but it is available in yum.

Here are some key features of “Yum”:
• Multiple Repositories
• Simple config file
• Correct dependency calculation
• Fast operation
• rpm-consistent behavior
• comps.xml group support, including multiple repository groups
• Simple interface

Starting With Creating Your Own Repository [Server Side Configuration]

Step First : Check Prequisites
-Have Your Distro CD/DVD

-Check if you have free space on your Hard Disk or not [Total space required vary from Distro to Distro]

Step Two : Copy Disc to Hard Disk
First mount your CD/DVD and copy it to hard disk
cp -avr /cd/dvd/mount/point/ /destination/directory/

Step Three : Intalling CreateRepo Package
Now go to your directory where you copied the files and search for createrepo-*.rpm file * may be different from version to version and system architecture
Install that rpm using rpm command
install using following command
rpm -ivh –aid createrepo-*.rpm

Repeat this step with your all you cd .
Note:- If you want install Repository on your network thrugh ftp or http upload in their respective default directories i.e /var/ftp/pub for ftp server and /var/www/html for http server.

Step four: Run createrepo
Go to the directory where you copied the file and run the createrepo command
createrepo -v .
[please note that “.” {dot} after that command as we are in present directory ]

Now you have done all thing.
Now we will see Client side setting

Client Side Setting For YUM

Create a repo file in /etc/yum.repos.d/ directory [ you can name anything to ur file make sure a .repo extension is added later on]
vim /etc/yum.repos.d/my.repo

add following date in that file

[Myrepo]
name=Any name you want to put
baseurl=file:///destination/directory/
enabled=1
gpgcheck=0

The first line is alias given for your repository . This help to indicate/find that from which repository the package is available.
Second line is name which you can put any thing
Next comes baseurl
base url supports different protocols like file:// ftp:// httpd:// etc. if you are running repository from local pc then give absolute path after file:// . for ftp give ftp://server_ip_or_domain/pub_dir_or_accessable_dir or http://server_ip_or_domain/dir
next line is enabled this specify if yum should enable that repo server for installtion or not 1 is for enable and 0 is for disable
gpgcheck is for checking gpg key. as I don’t required it so I disabled it if you enabled it then you hav to add one more line after that
gpgkey=/your/path/to/key

after this save that repo file and run following command
yum clean all [ will clean yum database ]
yum list [will list the files / packages available on that directory ]

If you find some difficulty in using it please feel free to contact us

Note:- SElinux or Firewall may conflict sometimes [ for ftp and http service ]
Note:- I used RHEL server 5 edition . This process is same for RHEL 4,5 FC [versions I don’t know]