How to set/modify hostname in RHEL/Centos 7

Upto RHEL/CentOS 6 and some version of Fedora, one has to edit /etc/sysconfig/network and restart the server to change the hostname of a server. Starting RHEL7, you now have a new command to rename a server.

To display the current hostname info

[root@c7sandbox ~]# hostnamectl
   Static hostname: c7sandbox
         Icon name: computer-vm
           Chassis: vm
        Machine ID: f4eb9a7b40cc488882191b87cdd0a6a4
           Boot ID: 4ac6b45da6c54325bfdbff821d8af31b
    Virtualization: kvm
  Operating System: CentOS Linux 7 (Core)
       CPE OS Name: cpe:/o:centos:centos:7
            Kernel: Linux 3.10.0-327.3.1.el7.x86_64
      Architecture: x86-64

To set a new hostname

[root@c7sandbox ~]# hostnamectl set-hostname c7test

This persists across reboots.

[sai@c7test ~]$ hostname
c7test
[sai@c7test ~]$ hostnamectl
   Static hostname: c7test
         Icon name: computer-vm
           Chassis: vm
        Machine ID: f4eb9a7b40cc488882191b87cdd0a6a4
           Boot ID: 2999ce807b0d4b9abcf8fe701816a006
    Virtualization: kvm
  Operating System: CentOS Linux 7 (Core)
       CPE OS Name: cpe:/o:centos:centos:7
            Kernel: Linux 3.10.0-327.3.1.el7.x86_64
      Architecture: x86-64