Asus RS162-E4/RX4 - Manual (Page 121)

ASUS RS162-E4/RX4 -
4. Repeat step 5 to add the other disks to the volume.
5. When done, press to create the array, then select Save changes
then exit this menu.
By default, the RAID Disk field shows No before array creation. This
field is grayed out under the following conditions:
• The disk does not meet the minimum requirements for use in a RAID
array.
• The disk is not large enough to mirror existing data on the primary
drive.
• The disk has been selected as the Hot Spare for the RAID array.
• The disk is already part of another array.
6. The utility creates the array.