出現的問題：
1. 開啓Hadoop2.6.0出現ssh無法解析主機名
Starting namenodes on [Java HotSpot(TM) Client VM warning: You have loaded library /hadoop/hadoop-2.6.0/lib/native/libhadoop.so.1.0.0 which might have disabled stack guard. The VM will try to fix the stack guard now.
It's highly recommended that you fix the library with 'execstack -c <libfile>', or link it with '-z noexecstack'.
hd-m1]
Client: ssh: Could not resolve hostname Client: Temporary failure in name resolution
You: ssh: Could not resolve hostname You: Temporary failure in name resolution
warning:: ssh: Could not resolve hostname warning:: Temporary failure in name resolution
...
解決方法參考：http://shisiyou.blog.51cto.com/9864147/1608060
#vi /etc/profile或者vi ~/.bash_profile
export HADOOP_COMMON_LIB_NATIVE_DIR=$HADOOP_HOME/lib/native
export HADOOP_OPTS="-Djava.library.path=$HADOOP_HOME/lib"
2. JAVA_HOME not set
hadoop-env.sh, 等配置文件中的JAVA_HOME必須配置成絕對路徑。
export JAVA_HOME=${JAVA_HOME}是不行的。
參考文獻：
http://hadoop.apache.org/docs/current/hadoop-mapreduce-client/hadoop-mapreduce-client-core/MapReduceTutorial.html
http://hadoop.apache.org/docs/current/hadoop-project-dist/hadoop-common/SingleCluster.html
http://www.cnblogs.com/xia520pi/archive/2012/05/16/2504205.html