更改CentOS镜像为国内镜像

国内镜像地址：

http://mirrors.163.com/centos/ 。（网易）

我们就用 http://mirrors.163.com/centos/ 网易）来修改配置文件

方法一：

#先备份配置文件

cp /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.save

#修改配置文件（安（i）键 进入插入模式进行修改）
vi /etc/yum.repos.d/CentOS-Base.repo
#配置文件如下修改：

# 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-$releasever - Base - 163.com
  mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
  baseurl=http://mirrors.163.com/centos/$releasever/os/$basearch/
  gpgcheck=1
  gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
  
  #released updates 
  [updates]
  name=CentOS-$releasever - Updates - 163.com
  mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
  baseurl=http://mirrors.163.com/centos/$releasever/updates/$basearch/
  gpgcheck=1
  gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
  
  #packages used/produced in the build but not released
  [addons]
  name=CentOS-$releasever - Addons - 163.com
  mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=addons
  baseurl=http://mirrors.163.com/centos/$releasever/addons/$basearch/
  gpgcheck=1
  gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
  
  #additional packages that may be useful
  [extras]
  name=CentOS-$releasever - Extras - 163.com
  mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
  baseurl=http://mirrors.163.com/centos/$releasever/extras/$basearch/
  gpgcheck=1
  gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
  
  #additional packages that extend functionality of existing packages
  [centosplus]
  name=CentOS-$releasever - Plus - 163.com
  mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
  baseurl=http://mirrors.163.com/centos/$releasever/centosplus/$basearch/
  gpgcheck=1
  enabled=0
  gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
  
  #contrib - packages by Centos Users
  [contrib]
  name=CentOS-$releasever - Contrib - 163.com
  mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib
  baseurl=http://mirrors.163.com/centos/$releasever/contrib/$basearch/
  gpgcheck=1
  enabled=0
  gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5
    
 #修改完成后 安 （ESC）键 退出 插入模式 输入 (:wq) 保存退出

  
上面的修改就是把mirrorlist注释掉，将baseurl改成ustc.edu.cn的镜像地址。

方法二：

#先备份配置文件

cd /etc/yum.repos.d/

mv CentOS-Base.repo CentOS-Base.repo.save

wget http://mirrors.163.com/.help/CentOS-Base-163.repo

mv CentOS-Base-163.repo   CentOS-Base.repo

yum clean all
yum makecache