The static hostname of a Linux ECS is user defined and injected using Cloud-Init during the ECS creation. Although the hostname can be changed by running the hostname command, the changed hostname is restored after the ECS is restarted.
To make the changed hostname take effect even after the ECS is stopped or restarted, save the changed name into configuration files.
The changed hostname is assumed to be new_hostname.
sudo vim /etc/hostname
sudo vim /etc/sysconfig/network
An example is provided as follows:
sudo vim /etc/cloud/cloud.cfg
If preserve_hostname: false is already available in the /etc/cloud/cloud.cfg configuration file, change it to preserve_hostname: true. If preserve_hostname is unavailable in the /etc/cloud/cloud.cfg configuration file, add preserve_hostname: true before cloud_init_modules.
If you use method 1, the changed hostname still takes effect after the ECS is stopped or restarted. However, if the ECS is used to create a private image and the image is used to create a new ECS, the hostname of the new ECS is the hostname (new_hostname) used by the private image, and user-defined hostnames cannot be injected using Cloud-Init.
If you use method 2, the changed hostname still takes effect after the ECS is stopped or restarted. If the ECS is used to create a private image and the image is used to create a new ECS, the changed hostname permanently takes effect, and user-defined hostnames (such as new_new_hostname) can be injected using Cloud-Init.
If the changed hostname is displayed in the command output, the hostname has been changed and the new name permanently takes effect.