http://wenku.baidu.com/link?url=PZlnNOhY0SjHDW-teFFnCMzPYJVjx7vj6yWY-o5HHFLuFqhLI4uFcQVu_y0_6i7vpSnzrqSRTRbwXJWeIXnzrKA1aoKTHKqFFgs2mIvktEG
http://wenku.baidu.com/link?url=CxKAKuXWMGP17_81GilGr0CNMtvf6ulzkyfeLqTjg6R51C8Bh75VcG2PosLn2wU4s2s67WGn5c4c9dels9btlfcj0bMzmYJdoUCLj_KJcPO
http://www.linuxidc.com/Linux/2012-05/59663p4.htm