warning: rpmts_HdrFromFdno: Header V3 DSA signature: NOKEY, key ID e8562897
解决办法：
首先到http://mirrors.163.com/centos 下载 RPM-GPG-KEY-CentOS-5
然后在系统中导入 rpm --import RPM-GPG-KEY-CentOS-5
yum安装时报错
原文：http://rockjz.blog.51cto.com/1617227/1660611
