本文尝试在CentOS上搭建10台HDFS集群，不会搭建YARN和Hive, 因为之后会采用Spark。先安装jdk 1.8, 此处不细说。

下载

首先下载hadoop binary包

wget http://apache.mesi.com.ar/hadoop/common/hadoop-2.7.1/hadoop-2.7.1.tar.gz

解压后放在/data/slot0/目录下，并建立软链接/data/slot0/hadoop

创建帐号

创建管理hadoop集群的帐号

useradd lisa

会出现/home/lisa目录，lisa帐号无需密码，因为不能直接登录。

可以用批处理的方式对10台服务器都创建lisa帐号，主要通过ssh -t 这里不再细说

修改目录拥有者

chown -R lisa:lisa hadoop-2.7.1/
chown -R lisa:lisa hadoop
ll
total 8
drwxr-xr-x 3 root root 4096 Sep 25 18:02 download
lrwxrwxrwx 1 lisa lisa   13 Sep 25 17:42 hadoop -> hadoop-2.7.1/
drwxr-xr-x 9 lisa lisa  139 Jun 29 14:15 hadoop-2.7.1
lrwxrwxrwx 1 root root   24 Sep 25 16:50 java -> /data/slot0/jdk1.8.0_45/
drwxr-xr-x 8 root root 4096 Sep 25 14:01 jdk1.8.0_45

打通帐号间SSH认证

切换到hadoop系统使用的帐号，然后生成ssh key

su - lisa
ssh-keygen -t rsa -P ''
Generating public/private rsa key pair.
Enter file in which to save the key (/home/lisa/.ssh/id_rsa): 
Created directory '/home/lisa/.ssh'.
Your identification has been saved in /home/lisa/.ssh/id_rsa.
Your public key has been saved in /home/lisa/.ssh/id_rsa.pub.
The key fingerprint is:
15:44:c6:4e:bb:cd:b9:09:e7:50:c7:ae:dd:92:56:57 lisa@10-149-11-152
The key's randomart image is:
+--[ RSA 2048]----+
|         +=      |
|         .o.     |
|         o.. .   |
|         .o . o E|
|        S  = +  .|
|          + = . o|
|           = = +.|
|            = = .|
|             . . |
+-----------------+