A disk controller connected to a set of disks in a data storage system is configured to mirror a first class of data on multiple disks while storing a second class of data without mirroring. The swirl chamber is etched in a first side of the plate and the spray orifice is etched through a second side to the center of the swirl chamber. According to another aspect, the device includes a non-circular filter element disposed between an air inlet and an air outlet.