Asus TS300-PA4 - Manual (Page 174)

6-46 Chapter 6: RAID configuration
5. The screen displays the information on the added spare drive.
Press <Esc> to exit the utility.
6.4.7 Deleting a RAID 10 set spare drive
To delete a RAID 10 set spare drive:
1. From the utility main menu, press <S>, select Delete Spare from the Options
menu, then press <Enter>.