http://www.chinaunix.net/jh/4/904906.html
http://www.linuxsky.org/doc/admin/200803/288.html
http://www.ibm.com/developerworks/cn/linux/cluster/cluster_system/balance/part6/index.html#
http://blog.sina.com.cn/s/blog_466c66400100bi2n.html
http://hi.baidu.com/willor/blog/item/fd9f9183d3ce99b56c811986.html
http://www.linuxsir.org/main/node/271