You need first to mirror the recovery partition, then the EFI system partition, and then the operating system partition. Make sure you understand the disk management commands entirely before we go ...

Each disk drive is connected to its own controller. See disk mirroring and RAID. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction requires permission.

and Mirror was on the Supplemental Disk. Mirror was eliminated in Windows 95. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction requires permission.