I ran into a problem a while back because I used a manufacturer installed system without installing the OS myself and I overlooked the manufacturer defined partitioning scheme. After the system was in production I realized that the root file system was not using the entire disk and I was wasting about 400GB of disk space on the root mirror. So I had to repartition but I didnt want to reinstall. This documentation requires that the BIOS is able to choose between boot disks and may not work on all systems. Please use these instructions at your own risk, test …