Disklabel

Disklabel sits on the physical disk (wd0c, sd0c, or da0s1c) and has an internal table of partitions on this disk. Disklabel itself is a command to create these partitions.

In OpenBSD disklabel can be used interactively with disklabel -E option. This is also the same as the OS install.

OpenBSD allows 16 partitions using "disklabel wd0" shows the partition table

{drive data cut} 16 partitions: a:         2104452               63  4.2BSD   2048 16384    1 b:         2104515          2104515    swap c:        50331648                0  unused      0     0 d:         2104515          4209030  4.2BSD   2048 16384    1 e:        44018100          6313545  4.2BSD   2048 16384    1
 * 1)                size           offset  fstype [fsize bsize  cpg]

This is a sample OpenBSD disklabel on a 24 GB drive. Partition a is the root disk, historically the root drive is always on a. Partition b is for swap, partition c represents the entire disk and d is /var filesystem. The rest (partition e) is for the /usr filesystem.