將yum的目標伺服器更改為中國大陸伺服器鏡像
修改/etc/yum.repos.d/CentOS-Base.repo，將鏡象站點地址改為在中國的鏡象站點地址。不然我們通過yum安裝軟體速度會比較慢。
以下的URL地址我都驗證過了在當前完全可以下載，而且速度挺快。
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak
vi /etc/yum.repos.d/CentOS-Base.repo
# 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.
#
#
name=CentOS-$releasever - Base
baseurl=http://mirror.be10.com/centos/$releasever/os/$basearch/
http://ftp.iasi.roedu.net/mirrors/centos.org/$releasever/os/$basearch/
http://ftp.ncnu.edu.tw/Linux/CentOS/$releasever/os/$basearch/
http://ftp.hostrino.com/pub/centos/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
#released updates
name=CentOS-$releasever - Updates
baseurl=http://mirror.be10.com/centos/$releasever/os/$basearch/
http://ftp.iasi.roedu.net/mirrors/centos.org/$releasever/os/$basearch/
http://ftp.ncnu.edu.tw/Linux/CentOS/$releasever/os/$basearch/
http://ftp.hostrino.com/pub/centos/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
#packages used/produced in the build but not released
name=CentOS-$releasever - Addons
baseurl=http://mirror.be10.com/centos/$releasever/os/$basearch/
http://ftp.iasi.roedu.net/mirrors/centos.org/$releasever/os/$basearch/
http://ftp.ncnu.edu.tw/Linux/CentOS/$releasever/os/$basearch/
http://ftp.hostrino.com/pub/centos/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
#additional packages that may be useful
name=CentOS-$releasever - Extras
baseurl=http://mirror.be10.com/centos/$releasever/os/$basearch/
http://ftp.iasi.roedu.net/mirrors/centos.org/$releasever/os/$basearch/
http://ftp.ncnu.edu.tw/Linux/CentOS/$releasever/os/$basearch/
http://ftp.hostrino.com/pub/centos/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
#additional packages that extend functionality of existing packages
name=CentOS-$releasever - Plus
baseurl=http://mirror.centos.org/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
#contrib - packages by Centos Users
name=CentOS-$releasever - Contrib
baseurl=http://mirror.centos.org/centos/$releasever/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
《解決方案》
哦 ，的5不知道怎麼搞的死活不能用？用4的正常？鬱悶
