On Thu, Jan 21, 2010 at 8:42 PM, Song Li <email@example.com> wrote:Read intro(4), sd(4), wd(4) and disklabel(5)/disklabel(8). The naming comes from the driver itself: sd is scsi disk, wd is "WD100x compatible hard disk driver." It depends on the upper level driver to determine the device name. The 'r' prefix, "rsd0" for example, is the raw device. It's rare you'll need to access it, but it does happen occasionally.