Centos7 modify the host name method

I want to change the host name to dwt, no longer localhost when logging in, and can distinguish other nodes.

1>Edit the contents of /etc/sysconfig/network, delete the original content, add HOSTNAME=dwt, then save and exit. Then modify the content in /etc/hosts, and add a line of content on the basis of the original content: 192.168.146.22(ip)  dwt. In general, this can be changed and restarted.

2> If the 1 step is completed, there is no success. On the basis of 1, modify the contents of /etc/hostname, delete the original content, and directly add dwt Yes, then .