First problem is probably a work in progress thing, but there is no doataraid kernel to match the doatatraid isolinux boot option. Second there is no md binary that is required by mkraid to run. Which makes in impossible to install Gentoo on a raid partition from the beginning. I had the same issue with 1.4_rc2 also. Reproducible: Always Steps to Reproduce: 1.boot live cd 2.run 'mkraid --help' Actual Results: cannot determine md version: No such file or directory
the option is "gentoo doataraid" which will try to load hardware raid modules, if your just using software raid, you need to load the specific md modules. It has been reported to work by many in -rc4.
The error was on my part.