第一步：安装Linux
第二步：安装JDK
javac查是否安装配置好了JDK，若未安装，以JAVA 7为例：
#Centos yum install java-1.7.0-openjdk-devel #Ubuntu apt-get install openjdk-7-jdk -y
再次输入javac若出现类似下面的提示则表明安装成功
Usage: javac <options> <source files>
where possible options include:
-g Generate all debugging info
-g:none Generate no debugging info
-g:{lines,vars,source} Generate only some debugging info
-nowarn Generate no warnings
-verbose Output messages about what the compiler is doing
-deprecation Output source locations where deprecated APIs are used
-classpath <path> Specify where to find user class files and annotation processors
-cp <path> Specify where to find user class files and annotation processors
-sourcepath <path> Specify where to find input source files
-bootclasspath <path> Override location of bootstrap class files
-extdirs <dirs> Override location of installed extensions
-endorseddirs <dirs> Override location of endorsed standards path
-proc:{none,only} Control whether annotation processing and/or compilation is done.
-processor <class1>[,<class2>,<class3>...] Names of the annotation processors to run; bypasses default discovery process
-processorpath <path> Specify where to find annotation processors
-d <directory> Specify where to place generated class files
-s <directory> Specify where to place generated source files
-implicit:{none,class} Specify whether or not to generate class files for implicitly referenced files
-encoding <encoding> Specify character encoding used by source files
-source <release> Provide source compatibility with specified release
-target <release> Generate class files for specific VM version
-version Version information
-help Print a synopsis of standard options
-Akey[=value] Options to pass to annotation processors
-X Print a synopsis of nonstandard options
-J<flag> Pass <flag> directly to the runtime system
-Werror Terminate compilation if warnings occur
@<filename> Read options and filenames from file
要在整个系统中使用JDK，还需要配置环境变量，首先打开/etc/profile下
#centos export JAVA_HOME=/usr/lib/jvm/java-1.7.0-openjdk.x86_64/ #ubuntu export JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64 export JRE_HOME=$JAVA_HOME/jre export CLASSPATH=$JAVA_HOME/lib:$JER_HOME/lib:$CLASSPATH export PATH=$JAVA_HOME/BIN:$JRE_HOME/bin:$PATH
通过source /etc/pofile设置生效
第三步：配置Hadoop
首先需要下载Hadoop安装包，以1.2.1版本为例，比如：
wget http://apache.mesi.com.ar/hadoop/common/hadoop-1.2.1/hadoop-1.2.1.tar.gz
mv hadoop-1.2.1.tar.gz /opt/
cd /opt/
tar -xzvf hadoop-1.2.1.tar.gz
cd hadoop-1.2.1/conf/
nano hadoop-env.sh
#找到 # export JAVA_HOME=/usr/lib/j2sdk1.5-sun，去除注释交将JAVA_HOME修改为
/usr/lib/jvm/java-1.7.0-openjdk.x86_64/
nano core-site.xml
#在configuration标签内添加
<property>
<name>hadoop.tmp.dir</name>
<value>/hadoop</value>
</property>
<property>
<name>dfs.name.dir</name>
<value>/hadoop/name</value>
</property>
<property>
<name>fs.default.name</name>
<value>hdfs://localhost:9000</value>
</property>
nano hdfs-site.xml
<property>
<name>dfs.data.dir</name>
<value>/hadoop/data</value>
</property>
nano mapred-site.xml
<property>
<name>mapred.job.tracker</name>
<value>localhost:9001</value>
</property>
nano /etc/profile
添加export HADOOP_HOME=/opt/hadoop-1.2.1
PATH内添加一条$HADOOP_HOME/bin
source /etc/profile
cd ..
hadoop namenode -format
些时在命令窗口输入hadoop来检查配置是否成功
