Asus KFN5-Q/SAS - Manual (Page 123)

5-16 Chapter 5: RAID configuration
2. When the array details appear, select the hard disk drive you want to
clear, then press <C>. A confirmation message appears.
3. Press <Y> to clear the disk data, or press
<N> to cancel. Press <C> to clear disk. The
following confirmation message appears.
5.2.7 Clearing the disk data
You will lose all data when you clear a disk!
To clear the disk data:
1. From the Array List, use the up or down arrow keys to select a RAID
set, then press <Enter>. The RAID set details appear.
Clear disk data?
[Y] Yes [N] Cancel
For RAID0, clearing one member disk would erase all data in the array.