How do I assign a static hostname to an Amazon EC2 instance that runs RHEL 5 or 6, CentOS 5 or 6, or Amazon Linux?

Short description

To make a hostname persist when you reboot or stop and start your EC2 instance, add the hostname to the instance's relevant configuration files.

The following steps apply to Amazon Linux and RHEL 5 or 6, and CentOS 5 or 6. For instructions that apply to other distributions, see the following resources:

• Change the system hostname
• How do I assign a static hostname to an Amazon EC2 instance that runs SLES?
• How do I assign a static hostname to an Amazon EC2 instance that runs Ubuntu Linux?
• How do I assign a static hostname to an Amazon EC2 instance that runs RHEL 7, 8, or 9, or CentOS 7, 8, or 9?

Important: RHEL 5 or 6 and CentOS 5 or 6 are end of life (EOL) distributions. This means that they no longer receive active support, such as security updates. It's a best practice to use operating system distributions that still receive regular updates.

Resolution

1. Open /etc/sysconfig/network in vim:

   sudo vim /etc/sysconfig/network

2. Change the value of the HOSTNAME parameter (replace persistent_hostname with your preferred hostname):

   HOSTNAME=persistent_hostname

3. Set NETWORKING to yes:

   NETWORKING=yes

4. Save and exit the vim editor.

   Note: After making this change, press SHIFT + : to open a new command entry box in the vim editor. Type wq, and then press Enter to save your changes and exit vim.

5. Open /etc/hosts in vim:

   sudo vim /etc/hosts

6. Change the entry beginning with 127.0.0.1 to the following, replacing persistent_hostname, localdomain, and localhost with your preferred hostname, local domain, and localhost:

   127.0.0.1 persistent_hostname.localdomain localhost localhost.localdomain

7. Save and exit the vim editor.

8. To verify that you successfully changed the hostname, reboot your instance, and then run the hostname command:

   sudo reboot
   hostname

   The command returns the new hostname.

Related information

Change the hostname of your Amazon Linux instance