1、查看当前主机名

[root@localhost ~]# hostname
localhost

[root@localhost ~]# hostnamectl
   Static hostname: localhost
         Icon name: computer
           Chassis: n/a
        Machine ID: 9e3877e4c127481eb6f1170fcf1be9e2
           Boot ID: 52bc258264a643e788afc8b0afc261d7
    Virtualization: vmware
  Operating System: CentOS Linux 7 (Core)
       CPE OS Name: cpe:/o:centos:centos:7
            Kernel: Linux 3.10.0-123.el7.x86_64
      Architecture: x86_64
      [root@localhost ~]#

2、临时修改主机名

[root@localhost ~]# hostname local     //临时修改主机名，关机后失效
[root@localhost ~]# hostname
local
[root@localhost ~]#

3、永久修改主机名

[root@localhost ~]# vim /etc/hostname     //vim进入主机配置文件
localhost     //删除旧主机名，输入新主机名，
                                                                                 
:wq     //esc后，：wq保存退出
[root@localhost ~]# reboot