注意一下操作都是在hadoop用户下操作的也就是hadoop-2.7.1的所有者是hadoop.如下所示：
total 120 drwxr-xr-x 19 hadoop hadoop 4096 Feb 1 02:28 . drwxr-xr-x 4 root root 4096 Jan 31 14:24 .. -rw------- 1 hadoop hadoop 1297 Feb 1 03:37 .bash_history -rw-r--r-- 1 hadoop hadoop 220 Jan 31 14:24 .bash_logout -rw-r--r-- 1 hadoop hadoop 3771 Jan 31 14:24 .bashrc drwx------ 3 root root 4096 Jan 31 22:49 .cache drwx------ 5 root root 4096 Jan 31 23:59 .config drwx------ 3 root root 4096 Jan 31 23:59 .dbus drwxr-xr-x 2 hadoop hadoop 4096 Feb 1 00:55 Desktop -rw-r--r-- 1 hadoop hadoop 25 Feb 1 00:55 .dmrc drwxr-xr-x 2 hadoop hadoop 4096 Feb 1 00:55 Documents drwxr-xr-x 2 hadoop hadoop 4096 Feb 1 00:55 Downloads -rw-r--r-- 1 hadoop hadoop 8980 Jan 31 14:24 examples.desktop drwx------ 2 hadoop hadoop 4096 Feb 1 00:56 .gconf drwx------ 3 hadoop hadoop 4096 Feb 1 00:55 .gnupg drwxrwxrwx 11 hadoop hadoop 4096 Feb 1 00:30 hadoop-2.7.1 drwxrwxrwx 8 hadoop hadoop 4096 Feb 1 02:44 hbase-1.2.4 -rw------- 1 hadoop hadoop 318 Feb 1 00:56 .ICEauthority drwxr-xr-x 3 root root 4096 Jan 31 22:49 .local drwxr-xr-x 2 hadoop hadoop 4096 Feb 1 00:55 Music drwxr-xr-x 2 hadoop hadoop 4096 Feb 1 00:55 Pictures -rw-r--r-- 1 hadoop hadoop 675 Jan 31 14:24 .profile drwxr-xr-x 2 hadoop hadoop 4096 Feb 1 00:55 Public drwx------ 2 hadoop hadoop 4096 Feb 1 00:02 .ssh drwxr-xr-x 2 hadoop hadoop 4096 Feb 1 00:55 Templates drwxr-xr-x 2 hadoop hadoop 4096 Feb 1 00:55 Videos -rw------- 1 hadoop hadoop 51 Feb 1 00:55 .Xauthority -rw------- 1 hadoop hadoop 1492 Feb 1 00:58 .xsession-errors（2）配置 hadoop 的环境变量
sudo gedit /etc/profile