> /dev/hda is being controlled by a controller that mimics an IDE > drive and is being accessed through the kernel's ide layer. /dev/ > sda is being controlled by a libata-supported controller and is > being accessed through the kernel's scsi stack with libata. As far as I know, all drives (2 hard disks and 2 optical drives) are on the same controller. Well, all 4 are plugged in to the motherboard of a Lenovo ThinkCentre M55 PC. There is no separate controller, unless there is more than one on the motherboard itself. In the BIOS, these drives all appeared together numbered 1-5 (with one of these missing because there are only 4 devices total). Alfred