hadoop安装步骤:

1. 系统需要安装的包
   ssh，rpm，gcc，make
   yum -y install openssh-server openssh-clients

2. 检测ssh安装和rpm安装
   a. ssh localhost
   b. yum install rpm

3. 安装java
   a. 安装java-7
   rpm -Uvh java

   b. 添加并配置新的jdk系统命令

   update-alternatives –install “/usr/bin/java” “java” “/usr/java/jdk1.7.0_45/bin/java” 16001
   update-alternatives –install “/usr/bin/java” “javac” “/usr/java/jdk1.7.0_45/bin/javac” 16001
   alternatives –config java
   alternatives –config javac
   c. 检查并测试
   update-alternatives –display java
   java -version

4. 添加hduser用户
   a. groupadd hdgroup
   b. useradd -g hdgroup hduser
   c. passwc hduser
   d. chown -R hduser .
   e. chmod 755 hduser
   f. chgrp -R hdgroup hduser

5. 将da-master上的公钥拷贝到新机器上
   ssh-copy-id -i id_rsa.pub hadoop@cloud011

6. 修改主机名称和hosts文件
   127.0.0.1 localhost
   172.21.36.4 da-slave05
   172.21.101.7 web2
   172.21.101.30 da-master
   172.21.101.31 da-slave01
   172.21.101.32 da-slave02
   172.21.101.33 da-slave03
   172.21.101.34 da-slave04
   ::1 localhost6.localdomain6 localhost6

7. 进入hduser用户环境
   a. su - hduser
   b. tar -zxf hadoop.2.2.0.tar.gz
   c. ln -s hadoop-2.2.0 /

8. 编辑环境变量
   vim ~/.bahsrc

9. 修改系统参数
   a.关闭防火墙
   service iptables stop
   chkconfig iptables off
   vim /etc/selinux/config

   改成disabled

   setenforce 0
   service iptables status

   b.修改最大文件打开数
   1）vim /etc/security/limits.conf

   • • nofile 204800
       2）vim /etc/security/limits.d/90-nproc.conf
     • soft nproc new-max-user-processes-value

   c.调整交换分区大小
   vim /etc/sysctl.conf
   vm.swappiness = 0
   vm.dirty_ratio = 5

   1. 安装LZO包
      cd lzo-2.06
      ./configure –enable-shared
      make
      make install
      #编辑/etc/ld.so.conf，加入/usr/local/lib/后，执行/sbin/ldconfig
      或者cp /usr/local/lib/liblzo2.* /usr/lib64/

   10.将master上的数据库配置参数文件拷贝到该机器上来

   11.同步时间： http://www.cnblogs.com/panfeng412/p/drop-caches-under-linux-system.html
   http://blog.sina.com.cn/s/blog_79fded950101gfc7.html

介绍得比较简略，待有时间贴上图文演示，敬请期待！