Informatica does not allow to backup the repository and restore directly into a higher environment as the repository version changes across major versions. This video demonstrates the migration of Repository Service from a lower version to a higher version of PowerCenter.
How to find in which host the Repository Integration service is running in a multi node domain
How to unassign services from an expired key and assign them to a valid key in 9.1.0 and 9.5.1
Converting and adding of a self signed certificate to use a Webservice Consumer transformation