搜狐的开源镜像 http://mirrors.sohu.com/ 感觉蛮快的 不错！！

按以下步骤进行：
1、备份并清空 /etc/yum.repos.d/CentOS-Base.repo
echo "" > /etc/yum.repos.d/CentOS-Base.repo
或者(如果第一次使用的话)
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.DEFAULT
2、下载CentOS中文更新镜像配置文件，按照需要修改一下，如你的发行版为4那就把centos5改成centos4即可。然后：
vi /etc/yum.repos.d/CentOS-Base.repo
a
粘贴配置文件的内容
##############################################################################
以下为本人修改并校验的更新：
# CentOS-Base.repo
#
# This file uses a new mirrorlist system developed by Lance Davis for CentOS.
# 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.
#
#
# CentOS-Base.repo
[base]
name=CentOS-$releasever - Base
baseurl=http://mirrors.sohu.com/centos/5.4/os/$basearch/
http://centos.candishosting.com.cn/5.4/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.sohu.com/centos/RPM-GPG-KEY-CentOS-5
#released updates
[update]
name=CentOS-$releasever - Updates
baseurl=http://mirrors.sohu.com/centos/5.4/updates/$basearch/
http://centos.candishosting.com.cn/5.4/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.sohu.com/centos/RPM-GPG-KEY-CentOS-5
#packages used/produced in the build but not released
[addons]
name=CentOS-$releasever - Addons
baseurl=http://mirrors.sohu.com/centos/5.4/addons/$basearch/
http://centos.candishosting.com.cn/5.4/addons/$basearch/
gpgcheck=1
gpgkey=http://mirrors.sohu.com/centos/RPM-GPG-KEY-CentOS-5
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
baseurl=http://mirrors.sohu.com/centos/5.4/extras/$basearch/
http://centos.candishosting.com.cn/5.4/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.sohu.com/centos/RPM-GPG-KEY-CentOS-5
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
baseurl=http://mirrors.sohu.com/centos/5.4/centosplus/$basearch/
http://centos.candishosting.com.cn/5.4/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.sohu.com/centos/RPM-GPG-KEY-CentOS-5
#contrib - packages by Centos Users
[contrib]
name=CentOS-$releasever - Contrib
baseurl=http://mirrors.sohu.com/centos/5.4/contrib/$basearch/
http://centos.candishosting.com.cn/5.4/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.sohu.com/centos/RPM-GPG-KEY-CentOS-5
##############################################################################
软件仓库：
vi /etc/yum.repos.d/dag.repo
[dag]
name=Dag RPM Repository for Red Hat Enterprise Linux
baseurl=http://mirrors.ircam.fr/pub/dag/redhat/el$releasever/en/$basearch/dag
http://rh-mirror.linux.iastate.edu/pub/dag/redhat/el$releasever/en/$basearch/dag
http://wftp.tu-chemnitz.de/pub/linux/dag/redhat/el$releasever/en/$basearch/dag
http://archive.cs.uu.nl/mirror/dag.wieers/redhat/el$releasever/en/$basearch/dag
http://apt.sw.be/redhat/el$releasever/en/$basearch/dag
http://mirror.cpsc.ucalgary.ca/mirror/dag/redhat/el$releasever/en/$basearch/dag
http://rpmfind.net/linux/dag/redhat/el$releasever/en/$basearch/dag
http://ftp.riken.jp/Linux/dag/redhat/el$releasever/en/$basearch/dag
http://apt.sw.be/redhat/el$releasever/en/$basearch/dag
enabled=1
gpgcheck=1
gpgkey=http://dag.wieers.com/packages/RPM-GPG-KEY.dag.txt
********************************************************************
挂载/etc/fstab文件中 /dev/hda1 /mnt/win_c vfat codepage=936,iocharset=cp936 0 0
关闭、启动基本服务
执行 ntsysv 指令，只留下以下服务：
acpid
anacron
cpuspeed
crond
network
sshd
syslog
yum-updatesd
runlevel 介绍：
more /etc/inittab
ll /etc/rc.d/
more /etc/rc.d/rc.local