1.安裝 yum-priorities
yum install yum-priorities
2.priorities的配置文件是/etc/yum/pluginconf.d/priorities.conf，確認其是否存在。內容為：
[root@chy002 yum.repos.d]# cat !$ cat /etc/yum/pluginconf.d/priorities.conf [main] enabled = 1
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的值為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)