Oracle currently ships 12cR1 (12.1.0.2) as the preferred install.
Being the R1 release it needs a lot of patching, and now many patches require OPatch 12.1.0.2, although the OPatch shipped with Grid 12.1.0.2 is in fact OPatch 12.1.0.1.3.
So you need to patch OPatch, before you can apply the patches you need to make 12cR1 work. Follow?
On this blog and elsewhere you will find UDEV rules examples for setting device ownership and naming consistency on older versions of Linux.
With RHEL7 some of the syntax has changed slightly.
This example was created using OEL7 with the Red Hat kernel, but should also work on Red Hat and CentOS.
The following shows how to clean up a failed 12cR1 RAC install on Linux, so that you can launch the runInstaller executable again.
Note. This approach assumes you have a single Oracle Home. If you have multiple versions of Oracle installed this approach may need to be adapted.
USE AT YOUR OWN RISK.
the gruffdba 