Need some help with partitions MBL

This thread contains some pointers about partition sizes: http://community.wd.com/t5/My-Book-Live/GUIDE-How-to-unbrick-a-totally-dead-MBL/m-p/435724

I would expect it to be possible to run the OS on a 500 GB drive, since the OS itself is small (2GB), but that’s based on guessing.