CenOS 6.0更新镜像站点

在网上找了不少东西，有的就是贴了个repo的文件，还是自己整理下，软件源设置好了，才可以快速的安装软件呀！

1. 首先介绍一下CentOS的repo文件的结构：
   
   [base]
   name=CentOS-$releasever - Base
   mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
   #baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
   gpgcheck=1
   gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6
   
   

   【base】：代表容器的名字，中括号一定要存在，里面的名字可以任取，不可重名；

    name:说明一下这个容器的意义，不是很重要；
   mirrorlist=: 列出这个容器可以使用的镜像站点，如果不想使用，可以注释掉（默认用'#'）；
   baseurs=: 这个很重要,后面接的是容器的实际网址，mirrorlist是由yum程序自行去找镜像站点，baseurl则是指定固定的一个容器网址，我们要添加的网址就在这里；
   gpgcheck=: 这个是RPM的数字证书了，指定对应安装文件的数字证书，也就是类似于电驴的校验码了，和每个文件的大小内容有关的签证，可以用来验证文件是否更改，下载是否成功等，有了这个你就不怕你安装的东西是骇客植入了病毒的文件了。
   gpgkey=: 这个是数字证书的公钥文件所在的位置。

2. 现在根据我们的国情(china)设置我们的文件，我们用的比较多的就是中科大的源

   http://centos.ustc.edu.cn/centos/
   （教育网爽了），163
   http://mirrors.163.com/centos/
   中国移动
   http://mirrors.ta139.com/centos

    

3. 修改repo文件，总结来说就是注释mirrorlist,添加baseurl，如下是我的：
   

    1 [base]
    2 name=CentOS-$releasever - Base
    3 #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
    4 #baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
    5 baseurl=http://centos.ustc.edu.cn/centos/$releasever/contrib/$basearch/
    6 http://mirrors.163.com/centos/$releasever/contrib/$basearch/
    7 http://mirrors.ta139.com/centos/$releasever/contrib/$basearch/
    8 http://mirror.neu.edu.cn/centos/$releasever/contrib/$basearch/
    9 gpgcheck=1
   10 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
   11 
   12 #released updates
   13 [updates]
   14 name=CentOS-$releasever - Updates
   15 #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
   16 #baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/
   17 baseurl=http://centos.ustc.edu.cn/centos/$releasever/contrib/$basearch/
   18 http://mirrors.163.com/centos/$releasever/contrib/$basearch/
   19 http://mirrors.ta139.com/centos/$releasever/contrib/$basearch/
   20 http://mirror.neu.edu.cn/centos/$releasever/contrib/$basearch/
   21 gpgcheck=1
   22 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
   23 
   24 #additional packages that may be useful
   25 [extras]
   26 name=CentOS-$releasever - Extras
   27 #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
   28 #baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/
   29 baseurl=http://centos.ustc.edu.cn/centos/$releasever/contrib/$basearch/
   30 http://mirrors.163.com/centos/$releasever/contrib/$basearch/
   31 http://mirrors.ta139.com/centos/$releasever/contrib/$basearch/
   32 http://mirror.neu.edu.cn/centos/$releasever/contrib/$basearch/
   33 gpgcheck=1
   34 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
   35 
   36 #additional packages that extend functionality of existing packages
   37 [centosplus]
   38 name=CentOS-$releasever - Plus
   39 #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
   40 #baseurl=http://mirror.centos.org/centos/$releasever/centosplus/$basearch/
   41 baseurl=http://centos.ustc.edu.cn/centos/$releasever/contrib/$basearch/
   42 http://mirrors.163.com/centos/$releasever/contrib/$basearch/
   43 http://mirrors.ta139.com/centos/$releasever/contrib/$basearch/
   44 http://mirror.neu.edu.cn/centos/$releasever/contrib/$basearch/
   45 gpgcheck=1
   46 enabled=0
   47 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
   48 
   49 #contrib - packages by Centos Users
   50 [contrib]
   51 name=CentOS-$releasever - Contrib
   52 #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib
   53 #baseurl=http://mirror.centos.org/centos/$releasever/contrib/$basearch/
   54 baseurl=http://centos.ustc.edu.cn/centos/$releasever/contrib/$basearch/
   55 http://mirrors.163.com/centos/$releasever/contrib/$basearch/
   56 http://mirrors.ta139.com/centos/$releasever/contrib/$basearch/
   57 http://mirror.neu.edu.cn/centos/$releasever/contrib/$basearch/
   58 gpgcheck=1
   59 enabled=0
   60 gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6

4. 测试一下：
   yum repolist all    #列出现在yum server所使用的容器有哪些

    [root@localhost yum.repos.d]# yum repolist all
    2 Loaded plugins: fastestmirror, refresh-packagekit
    3 Loading mirror speeds from cached hostfile
    4 base                                                     |  951 B     00:00     
    5 base/primary                                             |  201 B     00:00     
    6 extras                                                   |  951 B     00:00     
    7 Not using downloaded repomd.xml because it is older than what we have:
    8   Current   : Mon Sep 26 21:11:35 2011
    9   Downloaded: Sun Jul 10 21:28:07 2011
   10 updates                                                  |  951 B     00:00     
   11 updates/primary                                          |  201 B     00:00     
   12 repo id                       repo name                               status
   13 base                          CentOS-6 - Base                         enabled: 0
   14 c6-media                      CentOS-6 - Media                        disabled
   15 centosplus                    CentOS-6 - Plus                         disabled
   16 contrib                       CentOS-6 - Contrib                      disabled
   17 debug                         CentOS-6 - Debuginfo                    disabled
   18 extras                        CentOS-6 - Extras                       enabled: 1
   19 updates                       CentOS-6 - Updates                      enabled: 0
   20 repolist: 1

5. 如果有问题可以使用清除功能：
   yum clean all  #所有容器的数据删除

6. 更新一下全系统：
   yum -y update #系统整体升级
   

7. 查看所有的内核
   rpm -q kernel  #查询存在的内核版本

8. 删除新的内核（应该要重启进入新的内核版本再删吧，呵呵，没有试过当前版本删除！）
   rpm -e  kernel-2.6.32-71.29.1.el6.i686 #删除你查询到的旧内核，复制粘贴就比较方便了！