更换YUM及升级包方法
更换阿里yum(个人习惯) 步骤: 1)下载wget yum install -y wget 2)备份默认的yummv /etc/yum.repos.d /etc/yum.repos.d.backup 3)设置新的yum目录mkdir /etc/yum.repos.d 4)下载阿里yum配置到该目录中wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/re