How to Set or Change Hostname in CentOS 7?

Updated: 28 September 2026 · Applies to: Ubuntu 24.04, Debian 12, AlmaLinux 9 and Rocky Linux 9

CentOS 7 is end of life. On Ubuntu 24.04, Debian 12, AlmaLinux 9 and Rocky Linux 9 the hostname is set with hostnamectl.

1. Show the current name: hostnamectl
2. Set a new one (use a fully qualified name that resolves to the server, for example server1.example.com): hostnamectl set-hostname server1.example.com
3. Add it to /etc/hosts: 192.0.2.10 server1.example.com server1
4. Log out and in again to see the new name in your prompt.

The change is permanent; no reboot is needed. Create an A record for the name in DNS, and ask support to set the reverse DNS (PTR) record if you send email from the server.

Note: On a cPanel server, change the hostname in WHM with Networking Setup › Change Hostname instead, so cPanel updates its own configuration. On some cloud images, cloud-init resets the hostname at boot: set preserve_hostname: true in /etc/cloud/cloud.cfg.

Hostname rules

• Use letters, digits and hyphens only; no underscores or spaces.
• Use a fully qualified domain name (FQDN) such as server1.example.com on servers, especially mail and cPanel servers.
• Check the result with hostname (short name) and hostname -f (full name).