说明：
操作系统：CentOS 6.x
IP地址：192.168.21.188
实现目的：同步CentOS镜像站点的内容到此服务器，并且通过配置http服务器，能够向外提供yum服务
准备篇：
一、安装http服务器
这里使用Nginx服务器提供http服务
关于Nginx服务器搭建，参考：CentOS安装配置LNMP服务器（Nginx+PHP+MySQL）
http://www.osyunwei.com/archives/5910.html
二、系统约定
Nginx站点根目录:/usr/local/nginx/html
服务器执行脚本文件存放目录:/home/crontab
三、开始Nginx目录浏览功能
vi /usr/local/nginx/conf/nginx.conf #编辑配置文件，在http {下面添加以下内容：
autoindex on; #开启nginx目录浏览功能
autoindex_exact_size off; #文件大小从KB开始显示
autoindex_localtime on; #显示文件修改时间为服务器本地时间
:wq! #保存，退出
service nginx reload #重新加载配置
http://www.osyunwei.com/archives/5051.html
安装篇：
一、创建镜像文件存放目录
mkdir -p /usr/local/nginx/html/centos #CentOS官方标准源
mkdir -p /usr/local/nginx/html/repoforge #第三方rpmforge源
mkdir -p /usr/local/nginx/html/epel #第三方epel源
说明：这里创建三个文件夹，分别存放CentOS官方标准源、第三方的rpmforge源和epel源
二、确定以上三个yum源上游源的同步镜像地址
1、CentOS官方标准源：rsync://mirrors.ustc.edu.cn/centos/
2、rpmforge源：rsync://mirrors.ispros.com.bd/repoforge/
3、epel源：rsync://mirrors.ustc.edu.cn/epel/
备注：上游yum源必须要支持rsync协议，否则不能使用rsync进行同步。
参考：
CentOS官方标准源：
rsync://mirrors.kernel.org/centos
rpmforge源：
http://apt.sw.be/
rsync://ftp-stud.fht-esslingen.de/dag
epel源：
http://mirrors.fedoraproject.org/publiclist/EPEL/
rsync://mirrors.kernel.org/fedora-epel
三、创建以上三个yum源同步脚本，并且设定脚本自动执行
mkdir -p /home/crontab #创建目录
vi /home/crontab/yum_rsync.sh #添加以下代码
#!/bin/sh
/usr/bin/rsync -avrt rsync://mirrors.ustc.edu.cn/centos/ --exclude-from=/usr/local/nginx/html/exclude_centos.list /usr/local/nginx/html/centos/
/usr/bin/rsync -avrt rsync://mirrors.ispros.com.bd/repoforge/ --exclude-from=/usr/local/nginx/html/exclude_repoforge.list /usr/local/nginx/html/repoforge/
/usr/bin/rsync -avrt rsync://mirrors.ustc.edu.cn/epel/ --exclude-from=/usr/local/nginx/html/exclude_epel.list /usr/local/nginx/html/epel/
:wq! #保存退出
chmod +x /home/crontab/yum_rsync.sh #添加脚本执行权限
备注：运行此脚本前，先要创建好同步目录及不需要同步的目录列表文件
cd /usr/local/nginx/html/ #进入目录
touch exclude_centos.list #创建文件
touch exclude_repoforge.list #创建文件
touch exclude_epel.list #创建文件
把不需要同步的目录写到上面对应的文件中，每行一个目录
例如：
vi exclude_epel.list
4/
4AS/
4ES/
4WS/
:wq! #保存退出
四、添加脚本定时执行任务
vi /etc/crontab #在最后一行添加以下代码
0 1 * * * root /home/crontab/yum_rsync.sh #设置每天凌晨1点整开始执行脚本
:wq! #保存退出
service crond restart #重启
测试篇：
一、安装rsync同步软件
yum install rsync xinetd #安装
vi /etc/xinetd.d/rsync #编辑配置文件，设置开机启动rsync
disable = no #修改为
/etc/init.d/xinetd start #启动（CentOS中是以xinetd 来管理Rsync服务的）
:wq! #保存退出
二、执行同步脚本
sh /home/crontab/yum_rsync.sh
注意：等待脚本执行完毕，首次同步，耗费的时间比较长！
三、根据不同版本创建三个yum源的repo配置文件
cd /etc/yum.repos.d/ #进入目录
mv /etc/yum.repos.d/CentOS-Base.repo CentOS-Base.repo-bak
1、CentOS官方标准源：
CentOS 5.x系列：
vi /etc/yum.repos.d/CentOS-Base.repo #添加以下代码
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-$releasever - Base - huanqiu.com
baseurl=http://192.168.21.188/centos/$releasever/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
gpgcheck=1
gpgkey=http://192.168.21.188/centos/RPM-GPG-KEY-CentOS-5
#released updates
[updates]
name=CentOS-$releasever - Updates - huanqiu.com
baseurl=http://192.168.21.188/centos/$releasever/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
gpgcheck=1
gpgkey=http://192.168.21.188/centos/RPM-GPG-KEY-CentOS-5
#packages used/produced in the build but not released
[addons]
name=CentOS-$releasever - Addons - huanqiu.com
baseurl=http://192.168.21.188/centos/$releasever/addons/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=addons
gpgcheck=1
gpgkey=http://192.168.21.188/centos/RPM-GPG-KEY-CentOS-5
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras - huanqiu.com
baseurl=http://192.168.21.188/centos/$releasever/extras/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
gpgcheck=1
gpgkey=http://192.168.21.188/centos/RPM-GPG-KEY-CentOS-5
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus - huanqiu.com
baseurl=http://192.168.21.188/centos/$releasever/centosplus/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
gpgcheck=1
enabled=0
gpgkey=http://192.168.21.188/centos/RPM-GPG-KEY-CentOS-5
#contrib - packages by Centos Users
[contrib]
name=CentOS-$releasever - Contrib - huanqiu.com
baseurl=http://192.168.21.188/centos/$releasever/contrib/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib
gpgcheck=1
enabled=0
gpgkey=http://192.168.21.188/centos/RPM-GPG-KEY-CentOS-5
:wq! #保存退出
#########################
CentOS 6.x系列：
vi /etc/yum.repos.d/CentOS-Base.repo #添加以下代码
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-$releasever - Base - huanqiu.com
baseurl=http://192.168.21.188/centos/$releasever/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
gpgcheck=1
gpgkey=http://192.168.21.188/centos/RPM-GPG-KEY-CentOS-6
#released updates
[updates]
name=CentOS-$releasever - Updates - huanqiu.com
baseurl=http://192.168.21.188/centos/$releasever/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
gpgcheck=1
gpgkey=http://192.168.21.188/centos/RPM-GPG-KEY-CentOS-6
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras - huanqiu.com
baseurl=http://192.168.21.188/centos/$releasever/extras/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
gpgcheck=1
gpgkey=http://192.168.21.188/centos/RPM-GPG-KEY-CentOS-6
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus - huanqiu.com
baseurl=http://192.168.21.188/centos/$releasever/centosplus/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
gpgcheck=1
enabled=0
gpgkey=http://192.168.21.188/centos/RPM-GPG-KEY-CentOS-6
#contrib - packages by Centos Users
[contrib]
name=CentOS-$releasever - Contrib - huanqiu.com
baseurl=http://192.168.21.188/centos/$releasever/contrib/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib
gpgcheck=1
enabled=0
gpgkey=http://192.168.21.188/centos/RPM-GPG-KEY-CentOS-6
:wq! #保存退出