The block device name has the following form: sdlp, where l is a letter denoting the physical drive, and p is a number denoting the partition on that physical drive. Often, the partition number, p, will be left off when the device corresponds to the whole drive.
SCSI disks have a major device number of 8, and a minor device number of the form (16 * drive_number") + "partition_number, where drive_number is the number of the physical drive in order of detection, and partition_number is as follows:
partition 0 is the whole drive
partitions 1-4 are the DOS "primary" partitions
partitions 5-8 are the DOS "extended" (or "logical") partitions
For example, /dev/sda will have major 8, minor 0, and will refer to all of the first SCSI drive in the system; and /dev/sdb3 will have major 8, minor 19, and will refer to the third DOS "primary" partition on the second SCSI drive in the system.
At this time, only block devices are provided. Raw devices have not yet been implemented.
The following ioctls are provided: