Hard disk drive system and keying method

A hard disk drive system includes a plurality of hard disk drive carriers and a hard disk drive chassis. Each of the plurality of hard disk drive carriers has a body and an ejector rotatably connected to the body. The ejector includes a first alignment member on a first side of the ejector and a second alignment member on a second side of the ejector. The second side of the ejector is opposite the first side of the ejector. The hard disk drive chassis includes a plurality of receiving slots for receiving the plurality of hard disk drive carriers. Two of the plurality of hard disk drive carriers may be fully inserted, next to each other, into the plurality of receiving slots.