方法一
将下载下来的Linux DVD的ISO（http://ftp.cuhk.edu.hk/pub/Linux/centos/5.4/isos/i386/CentOS-5.4-i386-bin-DVD.iso）文件刻录成光盘，然后将光盘放入光驱。
mkdir /mnt/cdrom
mount /dev/hdc /mnt/cdrom
安装一个名叫createrepo的软件包，并生成一个依赖文件。具体操作如下
rpm Civh /mnt/cdrom/CentOS/createrepo-0.4.4-2.noarch.rpm
cd /mnt
createrepo .
创建客户端yum文件
cd /etc/yum.repos.d
mkdir backup
mv *.repo ./backup
vi cdrom.repo
[cdrom]
name=cdrom
baseurl=file:///mnt/cdrom
enabled=1
gpgcheck=0
方法二
[服务端]
创建基本仓库,并copy DVD或者CD文件(减少网络下载量)
Copy the RPMs from the CDs/DVD to /var/www/html/centos/5/base.
1. mount -o loop,ro CentOS-xxxxx.iso /mnt
2. cp -r /mnt /var/www/html/centos/5/base
同步远端仓库
3./usr/bin/rsync -avrt --delete rsync://rsync.muug.mb.ca/centos/5/os/i386/ /var/www/html/centos/5/os/i386/
同步update仓库
例子：
/usr/bin/rsync -avrt rsync://rsync.muug.mb.ca/centos/5/updates/i386/ /opt/repos/yum/centos/5/updates/i386/
镜像在这里的列表中选中快的
http://www.centos.org/modules/tinycontent/index.php?id=30
客户端使用仓库
[base]
name=CentOS-$releasever - Base
baseurl=http://192.168.xx.xx/centos/$releasever/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
#baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5
#released updates
[update]
name=CentOS-$releasever - Updates
baseurl=http://192.168.xx.xx/centos/$releasever/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
#baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-5