Asus TS300-PA4 - Manual (Page 150)

6-22 Chapter 6: RAID configuration
5. When prompted, press the <SpaceBar> to select Yes from the Initialize?
dialog box, then press <Enter>. You may also press <F10> to initialize the
drive without confirmation.
6. A progress bar appears on screen. If desired, press <Esc> to abort
initialization.
7. When initialization is completed, press <Esc>.