We have a RHEL 7.2 EC2 instance and we are trying to install Oracle 12C EE server. We have assigned an Elastic IP to the instance to make sure that the Public IP address does not change when we restart the server. But we saw that the hostname of the instance gets changed on a server restart.
Problem: There are a few steps in oracle installation where we need to mention the hostname of the EC2 instance (i.e. private DNS), so we are hardcoding the hostname during oracle installation. But the problem is if in case the hostname gets changed in every server restart then the installed software wont work (since it holds previous host name) - how to resolve this issue?
Please let us know on the best practices to resolve this issue.
IP addresses do not change in EC2 with a simple restart. They only change with a complete stop, followed later by a start. If you are using a VPC, which you most likely are, then the private IP address will not change even with a stop/start.
If you want a solution that will work even if you move the installation to a different EC2 instance, then you should create a Route53 private hosted zone, attach it to your VPC, and then create a custom DNS name for this server.