1，先将原来的YUM源备份
#mv /etc/yum.conf /etc/yum.conf.bak
#cp -a /etc/yum.repos.d /etc/yum.repos.d.bak
#vim /etc/yum.conf
[main]
cachedir=/var/cache/yum
debuglevel=2
logfile=/var/log/yum.log
pkgpolicy=newest
distroverpkg=redhat-release
tolerant=1
exactarch=1
obsoletes=1
# PUT YOUR REPOS HERE OR IN separate files named file.repo
# in /etc/yum.repos.d
保存
#cd /etc/yum.repos.d
#mv yum.repos.d CentOS-Base.repo
#vim CentOS-Base.repo
[base]
name=centos-5 - Base
baseurl=http://centos.ustc.edu.cn/centos/5/os/i386/
# the other site: http://centos.candishosting.com.cn/centos/5/os/i386/
# you can find more site in: http://www.centos.org/modules/tinycontent/index.php?id=13
enabled=1
gpgcheck=1
gpgkey=http://centos.ustc.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5
#released updates
[update]
name=CentOS-5 - Updates
baseurl=http://mirror.centos.org/centos/5/updates/i386/
gpgcheck=1
gpgkey=http://centos.ustc.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5
#packages used/produced in the build but not released
[addons]
name=CentOS-5 - Addons
baseurl=http://mirror.centos.org/centos/5/addons/$basearch/
gpgcheck=1
gpgkey=http://centos.ustc.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5
#additional packages that may be useful
[extras]
name=CentOS-5 - Extras
baseurl=http://mirror.centos.org/centos/5/extras/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-centos4
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-5 - Plus
baseurl=http://mirror.centos.org/centos/5/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://centos.ustc.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5
#contrib - packages by Centos Users
[contrib]
name=CentOS-5 - Contrib
baseurl=http://mirror.centos.org/centos/5/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://centos.ustc.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5
#packages in testing
[testing]
name=CentOS-5 - Testing
baseurl=http://mirror.centos.org/centos/5/testing/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://centos.ustc.edu.cn/centos/5/os/i386/RPM-GPG-KEY-CentOS-5
保存
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NOKEY, key ID的解决
rpm --import /usr/share/rhn/RPM-GPG-KEY