Thank you for your inquiry. To properly eject the unit from the computer, you would need to properly eject the drives inside the unit from the OS. For Mac, you would eject the drives from disk utilities. For windows, you go to safely remove hardware and you be able to select the drives to eject from the computer. As for Linux, you would enter in command line "eject /dev/sdX" where x is the letter of the drive/s.
The RAID array on the MB662U3-2S R1 is a hardware RAID, so if it is in a RAID mode, the computer would only see a single drive. That single drive would be the drive to eject before disconnecting or powering off the unit.