文件路径 /etc/yum.conf
[root@opvnserver ~]# grep "keepcache" /etc/yum.conf
keepcache=0
[root@opvnserver ~]# sed -i 's/keepcache=0/keepcache=1/g' /etc/yum.conf
[root@opvnserver ~]# grep "keepcache" /etc/yum.conf
keepcache=1
[root@opvnserver ~]# tree /var/cache/yum/ #<===yum安装软件包缓存路径