（1）默认配置文件：存放在hadoop相应的jar包中
[core-default.xml]
hadoop-common-2.8.2.jar → core-default.xml
[hdfs-default.xml]
hadoop-hdfs-2.8.2.jar → hdfs-default.xml
[yarn-default.xml]
hadoop-yarn-common-2.8.2.jar → yarn-default.xml
[mapred-default.xml]
hadoop-mapreduce-client-core-2.8.2.jar → mapred-default.xml
（2）自定义配置文件：存放在$HADOOP_HOME/etc/hadoop
[victor@node1 hadoop]$ pwd
/opt/module/hadoop-2.8.2/etc/hadoop
[victor@node1 hadoop]$ ls
core-site.xml
hdfs-site.xml
yarn-site.xml
mapred-site.xml
（3）Hadoop官网默认配置
http://hadoop.apache.org/docs/r2.8.2/hadoop-project-dist/hadoop-common/core-default.xml
http://hadoop.apache.org/docs/r2.8.2/hadoop-project-dist/hadoop-hdfs/hdfs-default.xml
http://hadoop.apache.org/docs/r2.8.2/hadoop-yarn/hadoop-yarn-common/yarn-default.xml
http://hadoop.apache.org/docs/r2.8.2/hadoop-mapreduce-client/hadoop-mapreduce-client-core/mapred-default.xml
