Fdisk

fdisk allows you to manipulate slices (another word for partition) on a disk. PC hardware limits a disk to four physical slices and a number of logical slices. Most UBO fdisk utilities don't support logical slices but have their own disklabel to greatly increase the number of partitions from the fdisk's four.

Here is a sample OpenBSD fdisk where OpenBSD used exclusively on the disk.

Disk: wd0      geometry: 3133/255/63 [50331648 Sectors] Offset: 0      Signature: 0xAA55 Starting        Ending         LBA Info: #: id     C   H   S -      C   H   S [       start:        size ] --- 0: 00      0   0   0 -      0   0   0 [           0:           0 ] unused 1: 00     0   0   0 -      0   0   0 [           0:           0 ] unused 2: 00     0   0   0 -      0   0   0 [           0:           0 ] unused *3: A6     0   1   1 -   3132 254  63 [          63:    50331582 ] OpenBSD #
 * 1) fdisk wd0