How to change the host name in Linux

[root@fangjian ~]# hostnamectl
  Static hostname: brace
  Pretty hostname: Brace
     Icon name: computer-vm
      Chassis: vm
    Machine ID: 20191225111607875619293640639763
      Boot ID: 25ac5021d229471382a26bea3d351de3
  Virtualization: kvm
 Operating System: CentOS Linux 7 (Core)
    CPE OS Name: cpe:/o:centos:centos:7
      Kernel: Linux 3.10.0-1062.9.1.el7.x86_64
   Architecture: x86-64

[root@fangjian ~]# hostname yin # Temporarily modify the host name, which will become invalid after shutdown [root@fangjian ~]# hostname
yin

[root@fangjian ~]# hostnamectl set-hostname Brace #Permanently set the user name, which will not expire after shutdown [root@fangjian ~]# hostname
brace

[root@fangjian ~]# vi /etc/hostname # Enter vi, delete the old host name, enter the new host name, Esc followed by a colon wq to exit and save the file. # reboot to take effect.