We need several packages to create yum repository, you can install them from CD/DVD disks or ISO images.
# yum install createrepo wget
# cd /mnt # createrepo .
Mount your CD/DVD or ISO images
DVD Disk or DVD ISO image
* If you have DVD disk, please mount dvd-rom first, and then create yum repository:
# mkdir /mnt/dvd/
# mount /dev/cdrom /mnt/dvd/
* If you use DVD iso, please copy it to the system, and then create yum repository:
# mkdir /mnt/dvd/
# mount -o loop /root/rhel5.1-dvd.iso /mnt/dvd
CD images
If you have multiple CD image files, you should mount all iso images and then create yum repository.
* Mount all iso images:
# mkdir -p /mnt/{1,2,3,4,5}
# mount -o loop rhel5.1-disc1.iso /mnt/1
# mount -o loop rhel5.1-disc2.iso /mnt/2
# mount -o loop rhel5.1-disc3.iso /mnt/3
# mount -o loop rhel5.1-disc4.iso /mnt/4
# mount -o loop rhel5.1-disc5.iso /mnt/5
Install necessary package
* Find and install ‘createrepo’ package in /mnt directory:
# find /mnt -iname ‘createrepo*’
/mnt/dvd/Server/createrepo-0.4.11-3.el5.noarch.rpm
# rpm -ivh /mnt/dvd/Server/createrepo-0.4.11-3.el5.noarch.rpm
Create yum repository
Create metadata
* Create yum repository:
# cd /mnt/
# createrepo .
Define yum repository
Create yum repository define file /etc/yum.repos.d/dvdiso.repo:
[MailRepo]
name=MailRepo
baseurl=file:///mnt/
enabled=1
gpgcheck=0
Test it
# yum clean all
# yum list
If ‘yum list’ list all packages in DVD/CD disks or ISO images, it works. 
Share the repo via NFS:
Copy the yum repository define file /etc/yum.repos.d/dvdiso.repo on the second machine:
scp server1:/etc/yum.repos.d/dvd.repo /etc/yum.repos.d/
[root@server1 ~]# echo "/mnt 192.168.1.0/24(ro,async)' >>/etc/exports
[root@server1 ~]# exportfs -r
access_log /usr/local/squid/var/logs/access.log common