IBM System Storage DS3300 Installation, User's, And Maintenance Manual page 112

6. Reinstall the hard disk drives in the bays from which they were removed. See
7. If you turned off the DS3300 in step 2 on page 93, turn it on.
94
System Storage DS3300 Storage Subsystem: Installation, User's, and Maintenance Guide
flush with the side wall, the tab is covered, and the front of the key extends
approximately 1 mm [0.04 in.] in front of the short metal upper guide).
"Replacing a hot-swap hard disk drive" on page 72.