centos安装virtualbox

参考： http://www.if-not-true-then-false.com/2010/install-virtualbox-with-yum-on-fedora-centos-red-hat-rhel/

如果需要wget设置proxy，参考： http://www.satwe.com/archives/355.html

参考：https://www.virtualbox.org/wiki/Linux_Downloads

安装Oracle VirtualBox的Public Key，然后使用rpm安装*.rpm包

wget http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc
sudo rpm --import oracle_vbox.asc
sudo rpm --checksig VirtualBox-4.3-4.3.12_93733_el5-1.i386.rpm 
sudo rpm -i VirtualBox-4.3-4.3.12_93733_el5-1.i386.rpm