linuxidc@ubuntu:/usr/lib/jvm/java$ sudo groupadd hadoop [sudo] password for linuxidc: jerry@ubuntu:/usr/lib/jvm/java$ useradd hadoop -g hadoop useradd: Permission denied. useradd: cannot lock /etc/passwd; try again later. linuxidc@ubuntu:/usr/lib/jvm/java$ sudo useradd hadoop -g hadoop linuxidc@ubuntu:/usr/lib/jvm/java$
3. 修改/etc/hosts文件，配置master, slave1, slave2的主机IP地址和主机名的映射关系。修改/etc/hostname文件，配置本机的电脑名。