unable to find the sources of your current Linux kernel.

運行

sh ./VBoxLinuxAdditions.run

時FAILED，查看日誌：

/tmp/vbox.0/Makefile.include.header:97: *** Error: unable to find the sources of your current Linux kernel. Specify KERN_DIR=<directory> and run Make again.  Stop.
Creating user for the Guest Additions.
Creating udev rule for the Guest Additions kernel module.

意思是說沒有內核源文件，解決的辦法是運行

yum instal gcc.i686 kernel.i686 kernel-devel.i686
reboot

分別是編譯器，內核，內核頭文件以及Makefile，而後再重啓，讓系統重新的內核文件選項啓動。再運行

sh ./VBoxLinuxAdditions.run

就能夠編譯成功了。