Hostnames of some ECSs have the suffix .novalocal.
For example, the hostname is set to abc during ECS creation. Table 1 lists the hostnames (obtained by running the hostname command) of ECSs created using different images and those displayed after the ECSs are restarted.
Hostnames of ECSs created from some types of images have the suffix .novalocal, while others do not.
This is a normal phenomenon.
The static hostname of a Linux ECS is user defined and injected using Cloud-Init during the ECS creation. According to the test results, Cloud-Init adapts to OSs differently. As a result, hostnames of some ECSs have suffix .novalocal, while others do not.
If you do not need suffix .novalocal in obtained host names, change the host names. For details, see section How Can a Changed Static Hostname Take Effect Permanently?