http://docs.oracle.com/cd/E37670_01/E37355/html/ol_create_repo.html

http://wiki.centos.org/TipsAndTricks/YumAndRPM

1. Mount repository media:

# mount -o loop,ro /ISOs/V33411-01.iso /var/OSimage/OL6.3_x86_64

Entry in fstab looks like this:

/ISOs/V33411-01.iso /var/OSimage/OL6.3_x86_64 iso9660 loop,ro 0 0

2. Disable network yum repositories:

In the /etc/yum.repos.d directory, edit the existing repository files, and disable all entries by setting enabled=0

3. Enable local repository

Create the following entries in a new repository file (for example, /etc/yum.repos.d/OL63.repo).

[OL63]
name=Oracle Linux 6.3 x86_64
baseurl=file:///var/OSimage/OL6.3_x86_64
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY
gpgcheck=1
enabled=1

4. Flush yum cache:

# yum clean all

# yum repolist