[oracle@hadoop ~]$ hostnamectl status
   Static hostname: hadoop
         Icon name: computer-vm
           Chassis: vm
        Machine ID: 52f2b03b2afb46be8b195895d9025dd3
           Boot ID: e948f0f5e7524fb38c56f36dfbe4abb7
    Virtualization: vmware
  Operating System: CentOS Linux 7 (Core)
       CPE OS Name: cpe:/o:centos:centos:7
            Kernel: Linux 3.10.0-514.2.2.el7.x86_64
      Architecture: x86-64

[oracle@hadoop ~]$ hostnamectl --transient set-hostname centos7

[oracle@hadoop ~]$ hostnamectl --static set-hostname centos7