由於redhat的yum在線更新是收費的，如果沒有注冊的話不能使用，如果要使用，需將redhat的yum卸載后，安裝CentOS yum工具，再配置其他源，以下為詳細過程：
- 刪除redhat原有的yum及RedHat訂閱軟件包
# rpm -qa | grep subscription-manager-* | xargs rpm -e # rpm -e yum-3.4.3-132.el7.noarch --nodeps
- 安裝163 yum軟件包
# rpm -ivh http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-3.4.3-132.el7.centos.0.1.noarch.rpm \
http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-34.el7.noarch.rpm
- 創建163 repo文件
# vi /etc/yum.repos.d/CentOS-Base-163.repo
[base] name=CentOS-7 -Base baseurl=http://mirrors.163.com/centos/7/os/$basearch/ gpgcheck=1 gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7 #released updates [updates] name=CentOS-7 - Updates baseurl=http://mirrors.163.com/centos/7/updates/$basearch/ gpgcheck=1 gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7 #additional packages that may be useful [extras] name=CentOS-7 - Extras baseurl=http://mirrors.163.com/centos/7/extras/$basearch/ gpgcheck=1 gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7 #additional packages that extend functionality of existing packages [centosplus] name=CentOS-7 - Plus baseurl=http://mirrors.163.com/centos/7/centosplus/$basearch/ gpgcheck=1 enabled=0 gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7
- 更新倉庫緩存
# yum clean all
# yum makecache
- 列出所有倉庫
# yum repolist
如果你運行yum update命令時，遇到以下錯誤，是因為你安裝的是最小化系統，有些包缺失了 Delta RPMs disabled because /usr/bin/applydeltarpm not installed. 你需要安裝deltarpm軟件包，使用下面命令查看這個包的名稱 yum provides '*/applydeltarpm' 然后安裝它 # yum install deltarpm