执行安装 rpm -ivh lib64stdc++6-4.6.1-2-mdv2011.0.x86_64.rpm 时提示以下错误：

warning: lib64stdc++6-4.6.1-2-mdv2011.0.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 70771ff3: NOKEY

Preparing...                ########################################### [100%]

    file /usr/lib64/libstdc++.so.6 from install of lib64stdc++6-4.6.1-2.x86_64 conflicts with file from package libstdc++-4.4.7-11.el6.x86_64

    file /usr/lib64/libstdc++.so.6 from install of lib64stdc++6-4.6.1-2.i686 conflicts with file from package libstdc++-4.4.7-11.el6.i686

是安装包冲突，把冲突的包卸载

yum -y remove libstdc++-4.4.7-11.el6.i686

yum -y remove libstdc++-4.4.7-11.el6.x86_64