yum源優先級設置

1.安裝 yum-priorities //事先查看是否已安裝  rpm -q yum-priorities
#yum install yum-priorities -y

2.priorities的配置文件是/etc/yum/pluginconf.d/priorities.conf，確認其是否存在。內容為：
#cat /etc/yum/pluginconf.d/priorities.conf
[main]
enabled = 1 # 0禁用 1啟用

3.編輯 /etc/yum.repos.d/目錄下的*.repo 文件來設置優先級。參數為：

　　priority=N # N值為1-99，數字越大,優先級越低

★推薦的設置為：
[base], [addons], [updates], [extras] … priority=1
[centosplus],[contrib] … priority=2
Third Party Repos such as rpmforge … priority=N (where N is > 10 and based on your preference)
例：
echo "priority=1" >> CentOS7.repo

例：編輯 /etc/yum.repos.d/目錄下的*.repo 文件來設置優先級

[base]
name=CentOS-$releasever – Base
baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
gpgcheck=0
priority=1