服务器评测
CentOS6发布后，很多喜欢RedHat的朋友就迫不及待的下载安装，笔者也是一样，但笔者是将其安装在vbox中，对于vbox的增强功能和配置软件源RPMforge的过程中，也是遇到了各种各样的问题，安装了五次才解决了遇到的问题，话不多说，直面问题
1.关于在CentOS 6中安装vbox的增强功能 具体步骤：1. 切换到root用户 su -输入root密码
2. 安装gcc yum install gcc
3. 安装内核对应版本的kernel-devel
# version=`uname -a | awk ‘{print $3}’`
#yum install kernel-devel-${version}
执行结束后，点击vbox中 设备–》安装增强功能 按照提示，点击出现的光盘的自动运行后，输入root密码就可以正常安装了。
有人认为需要在第三步后，进行安装dkms（dkms==Dynamic Kernel Module Support (DKMS) ） ， 执行yum install dkms，其实并不需要，而且即便你直接安装也会提示失败的，在配置完rpmforge之后，便可以正常安装了
2.配置软件源rpmforge
在CentOS下运行yum install flash-plugin或yum installmplayer的时候，提示库里没有找到这个软件？为什么会这样？因为CentOS是RHEL编译过来的，去掉了所有关于版权问题的东西。因此，在没有使用第三方软件库的情况下，很多软件无法用yum install来直接安装。
EPEL(Extra Packages for EnterpriseLinux)软件库提供为RHEL系列(4.x、5.x、6.x等等)重新编译的Fedora组件。这个软件库在不替换系统组件方面下了功夫。在某些情况下它尝试直接针对CentOS兼容性的问题，但坚决否定软件库间的兼容性是目标之一。当它与其它第三方软件库混合使用时，问题可能会出现。故此，当你使用EPEL时，尤其是当你亦会运用其它件库的组件时，请确保你使用yum的Priorities插件。
RPMForge库现在已经拥有超过10000种的CentOS的软件包，被CentOS社区认为是最安全也是最稳定的一个第三方软件库。
下面讲解下如何使用EPEL与RPMForge、RPMFusion软件仓库：
一、安装yum-priorities插件。
这个插件是用来设置yum在调用软件源时的顺序的。因为官方提供的软件源，都是比较稳定和被推荐使用的。因此，官方源的顺序要高于第三方源的顺序。如何保证这个顺序，就需要安装yum-priorities这插件了。
[root@CentOS ~]# yum install yum-priorities
安装完后需要设置/etc/yum.repos.d/目录下的.repo相关文件（如CentOS-Base.repo），在这些文件中插入顺序指令：priority=N （N为1到99的正整数，数值越小越优先），一般的配置是这样的：
[base], [addons], [updates], [extras] … priority=1
[CentOSplus],[contrib] … priority=2
其他第三的软件源为：priority=N （推荐N>10）
如我的CentOS-Base.repo配置为（CentOS 6.0）：
# 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-$releasever – Base
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
#baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6
priority=1
#released updates
[updates]
name=CentOS-$releasever – Updates
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
#baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6
priority=1
#packages used/produced in the build but not released
[addons]
name=CentOS-$releasever – Addons
mirrorlist=http://mirrorlist.CentOS.org/?release=$releasever&arch=$basearch&repo=addons
#baseurl=http://mirror.CentOS.org/CentOS/$releasever/addons/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6
priority=1
#additional packages that may be useful
[extras]
name=CentOS-$releasever – Extras
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
#baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6
priority=1
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever – Plus
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
#baseurl=http://mirror.centos.org/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6
priority=2
[contrib]
name=CentOS-$releasever – Contrib
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib
#baseurl=http://mirror.centos.org/centos/$releasever/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6
priority=2二、下载与安装相应EPEL的rpm文件包
1、下载与安装EPEL的rpm文件包
32位系统
[root@CentOS ~]# rpm -ivh http://download.Fedora.RedHat.com/pub/epel/6/i386/epel-release-6-5.noarch.rpm
64位系统
[root@CentOS ~]# rpm -ivh http://download.Fedora.RedHat.com/pub/epel/6/x86_64/epel-release-6-5.noarch.rpm
如果您不清楚您的系统内核，请使用uname -a命令来查看您的内核信息。
2、导入DAG的PGP Key
[root@CentOS ~]# rpm –import /etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6
3、设置/etc/yum.repos.d/epel.repo文件中源的级别，就是添加priority=11这句。
如我的epel.repo文件内容：
[epel]
name=Extra Packages for Enterprise Linux 6 – $basearch
#baseurl=http://download.Fedoraproject.org/pub/epel/6/$basearch
mirrorlist=https://mirrors.Fedoraproject.org/metalink?repo=epel-6&arch=$basearch
failovermethod=priority
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6
priority=11
[epel-debuginfo]
name=Extra Packages for Enterprise Linux 6 – $basearch – Debug
#baseurl=http://download.Fedoraproject.org/pub/epel/6/$basearch/debug
mirrorlist=https://mirrors.Fedoraproject.org/metalink?repo=epel-debug-6&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6
gpgcheck=1
name=Extra Packages for Enterprise Linux 6 – $basearch – Source
#baseurl=http://download.Fedoraproject.org/pub/epel/6/SRPMS
mirrorlist=https://mirrors.Fedoraproject.org/metalink?repo=epel-source-6&arch=$basearch
failovermethod=priority
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6
gpgcheck=1三、下载与安装相应rpmforge的rpm文件包
1、下载rpmforge的rpm文件包
32位系统
[root@CentOS ~]# wget http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.i686.rpm
64位系统
[root@CentOS ~]# wget rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm
2、安装DAG的PGP Key
[root@CentOS ~]# rpm –import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt
3、验证rpmforge的rpm文件包
[root@CentOS ~]# rpm -K rpmforge-release-0.5.2-2.el6.rf.*.rpm
如果报XXX not an rpm package的错，查看是否wget下载的包不完整，包的大小是12K
4、安装rpmforge的rpm文件包
[root@CentOS ~]# rpm -ivh rpmforge-release-0.5.2-2.el6.rf.*.rpm
5、设置/etc/yum.repos.d/rpmforge.repo文件中源的级别，就是添加priority=12这句，如我的rpmforge.repo文件内容：
### Name: RPMforge RPM Repository for RHEL 6 – dag
### URL: http://rpmforge.net/
[rpmforge]
name = RHEL $releasever – RPMforge.net – dag
baseurl = http://apt.sw.be/RedHat/el6/en/$basearch/rpmforge
mirrorlist = http://apt.sw.be/RedHat/el6/en/mirrors-rpmforge
#mirrorlist = file:///etc/yum.repos.d/mirrors-rpmforge
enabled = 1
protect = 0
gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-rpmforge-dag
gpgcheck = 1
priority=12
[rpmforge-extras]
name = RHEL $releasever – RPMforge.net – extras
baseurl = http://apt.sw.be/RedHat/el6/en/$basearch/extras
mirrorlist = http://apt.sw.be/RedHat/el6/en/mirrors-rpmforge-extras
#mirrorlist = file:///etc/yum.repos.d/mirrors-rpmforge-extras
enabled = 0
protect = 0
gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-rpmforge-dag
gpgcheck = 1
[rpmforge-testing]
name = RHEL $releasever – RPMforge.net – testing
baseurl = http://apt.sw.be/RedHat/el6/en/$basearch/testing
mirrorlist = http://apt.sw.be/RedHat/el6/en/mirrors-rpmforge-testing
#mirrorlist = file:///etc/yum.repos.d/mirrors-rpmforge-testing
enabled = 0
protect = 0
gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-rpmforge-dag
gpgcheck = 1
四、测试
1、测试升级
[root@CentOS ~]# yum check-update
输出信息应该会有以下两行：
Loading “priorities” plugin
…
XX packages excluded due to repository priority protections
2、测试各插件是否生效
[root@CentOS ~]# yum check-update
如果出现类似以下输出，则表示配置成功。
Loaded plugins: fastestmirror, priorities, refresh-packagekit
Loading mirror speeds from cached hostfile
下面是一长串软件列表，最后一列形如：
epel
rpmforge
base
说明各个软件包的来源。
