Asus TS300-PA4 - Manual (Page 138)

6-10 Chapter 6: RAID configuration
10. When finished setting the selected logical drive configuration, select Accept
from the menu, then press <Enter>.
11. When finished setting the selected logical drive configuration, select Accept
from the menu, then press <Enter>.
12. Follow steps 5 to 10 to configure additional logical drives.
13. When prompted, save the configuration, then press <Esc> to return to the
Management Menu.