linux yum更新好慢，设置下yum更新源就好~~

CentOS默认的yum源在国外，速度极其缓慢，如下设置为国内资源（清华大学资源）
1.修改/etc/yum.repos.d/CentOS-Base.repo为:

[base]
name=CentOS-5 - Base
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever5&arch=$basearch&
repo=os
#baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
baseurl=http://mirror.lib.tsinghua.edu.cn/centos/5.3/os/$basearch/
baseurl=http://ftp.twaren.net/Linux/CentOS/5.3/os/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5

#released updates
[update]
name=CentOS-5 - Updates
#mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=updates
baseurl=http://mirror.lib.tsinghua.edu.cn/centos/5.3/updates/$basearch/
baseurl=http://ftp.twaren.net/Linux/CentOS/5.3/updates/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5

#packages used/produced in the build but not released
[addons]
name=CentOS-5 - Addons
#mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=addons
baseurl=http://mirror.lib.tsinghua.edu.cn/centos/5.3/addons/$basearch/
baseurl=http://ftp.twaren.net/Linux/CentOS/5.3/addons/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5

#additional packages that may be useful
[extras]
name=CentOS-5 - Extras
#mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=extras
baseurl=http://mirror.lib.tsinghua.edu.cn/centos/5.3/extras/$basearch/
baseurl=http://ftp.twaren.net/Linux/CentOS/5.3/extras/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5

#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-5 - Plus
#mirrorlist=http://mirrorlist.centos.org/?release=4&arch=$basearch&repo=centosplus
baseurl=http://mirror.lib.tsinghua.edu.cn/centos/5.3/centosplus/$basearch/
baseurl=http://ftp.twaren.net/Linux/CentOS/5.3/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos5

[fasttrack]
name=CentOS-$releasever - fasttack
baseurl=http://mirror.lib.tsinghua.edu.cn/centos/5.3/fattrack/$basearch/
baseurl=http://ftp.twaren.net/Linux/CentOS/5.3/fattrack/$basearch/
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5

2.执行如下命令:

64位:

rpm --import http://mirror.lib.tsinghua.edu.cn/centos/5/os/x86_64/RPM-GPG-KEY-CentOS-5

32位:
rpm --import http://mirror.lib.tsinghua.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5

3.执行升级命令，看看速度如何：

yum update

4.建立定义非官方库
# vi /etc/yum.repos.d/dag.repo
[dag]
name=Dag RPM Repository for Red Hat Enterprise Linux
baseurl=http://apt.sw.be/redhat/el$releasever/en/$basearch/dag
gpgcheck=1
enabled=1

5.导入导入非官方库的GPG
#rpm --import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt