The installation needs to be done in a particular order. More information about the steps to follow can be found in Section 5 of our NetIQ Identity Manager 4.5 Service Pack 2 Release Notes.
A listing of Known issues can be found in Section 6.0 "Known Issues" of the release notes. In particular, section 6.10 lists issues that are specific to the installation of Identity Manager on RHEL 7.x and SLES 12.x. This can be found at: NetIQ Identity Manager 4.5 Service Pack 2 Release Notes.
System Requirements for the Identity Vault: https://www.netiq.com/documentation/idm45/setup_guide/data/b189nap8.html
System Requirements for the Identity Manager Engine: https://www.netiq.com/documentation/idm45/setup_guide/data/b194dddx.html
System Requirements for Identity Reporting (EAS): https://www.netiq.com/documentation/idm45/setup_guide/data/b1dft23e.html