安装过程中出现错误：
Bulding the VirtualBox Guest Additions Kernel modules failed
Your system does not seem to be set up to build kernel modules.
Look at /var/log/vboxadd-install.log to find out what went worg. Once you have corrected it,you run
/etc/init.d/vboxadd setup
to build them
解决办法：
yum install gcc kernel-devel
ln -s /usr/src/kernels/2.6.32-573.7.1.el6.i686/ /usr/src/linux #这步一定要，否则仍会报错
重新安装，有出现错误：
Building the OpenGL support module [FAILED]
解决办法：
cd /media/VBOXADDITIONS_4.1.8_75467/
export MAKE='/usr/bin/gmake -i'
./VBoxLinuxAdditions.run
安装成功，重启生效