在virtualbox安装了centOS，想安装增强功能时，系统提示:
building the main Guest Additions module Failed
于是尝试了以下两步操作：
(1)yum install gcc kernel-devel kernel-headers
(2)yum update kernel
重新运行增强包中autorun.sh时，提示错误：
The missing package can be probably installed with
yum install kernel-devel-2.6.18-308.16.1.el5.i686
于是重新执行命令:
yum install kernel-devel-2.6.18-308.16.1.el5.i686
再次运行autorun.sh，操作成功。重启centOS后，增强功能生效。