I believe the easiest approach would be:
- Install the same OS on the new servers
- Install OS pre-req software and packages for your EBS instance
- Restore from cold backup (if the crash happened directly after this backup and you haven't lost any data)
- Restore from hot backup (if the crash happened after your cold backup and you have data that wasn't part of the cold backup)
I assume that no changes to the hostname, domainname, IP Address, port numbers, directory structure, ..etc is taking place in this restore.
Assuming that the new server is configured exactly as the old server (IP, hostname, port pool, directories...), what you mean by restoring is that I will just have to copy the cold/hot backup from the external drive to the new server? Is that all that needs to happen? Can you please go into more details?