CentOS 7 Hostname Resetting on Reboot - SOLVED

Problem

Setting the hostname was working without problems in CentOS 7 (including latest updates), but the hostname would revent back to the old hostname on every reboot. Nothing I read about worked, and I see lots of other people with the same problems (although RackSpace could not reproduce the problem on a newly spun up CentOS 7).

Solution

Assumes you're running as root. Otherwise, sudo the commands

• Backup /etc/hosts, /etc/sysconfig/network, /etc/sysconfig/network-scripts/ifcfg-eth0 and /etc/cloud/cloud.cfg
• execute "hostnamectl set-hostname yourdomain.com"
• execute "hostnamectl set-hostname --static yourdomain.com"
• Change old hostname to yourdomain.com in /etc/hosts
• In /etc/sysconfig/network, add
  HOSTNAME=yourdomain.com
• In /etc/sysconfig/network-scripts/ifcfg-eth0, add
  HOSTNAME=yourdomain.com
  DHCP_HOSTNAME=yourdomain.com
• in /etc/cloud/cloud.cfg, set
  preserve_hostname=true
• Reboot
• hostname and hostname -f should now correctly give yourdomain.com