There is disclosed a storage enclosure, a carrier, a method of receiving and/or removing disk drive units to/from a storage enclosure, methods of manufacturing a storage enclosure, and a method of mounting a disk drive unit in a storage enclosure. In an aspect of the invention, a storage enclosure (10) comprises: a housing (11); and, at least one drawer (20) movable mounted to the housing such that the drawer is able to move between a received position and a withdrawn position relative to the housing. The or each drawer has a plurality of bays (22) for receiving respective disk drive units (100) with the disk drive units being orientated on their sides. Each bay having an upwardly facing opening which is accessible for insertion and/or removal of the disk drive unit therethrough when the drawer is in the withdrawn position.