CentOS5本地光盘作为yum源
yum安装时遇到
warning:rpmts_HdrFromFdno: Header V3 DSA signature: NOKEY, key ID e856297
解决：
$rpm import /etc/pki/rpm-gpg/RPM-GPG-KEY-CentIS-5
$rpm import /etc/pki/rpm-gpg/RPM-GPG-KEY-beta
