All OpenBSD platforms use the disklabel to identify partitions and other information about a disk. When you label a disk (as we did in Chapter 3 and will do by hand later this chapter),
disklabel adds a disklabel unique identifier, or DUID, to the disk label. The DUID is a unique hexadecimal number that lets OpenBSD identify a specific disk.
To find a disk’s DUID, pass the device name to
disklabel and look for the
# disklabel sd0 … duid: 55128c3700af5491 …
The disk currently attached as
sd0 has a DUID of
55128c3700af5491. Even if you physically move the disk so that it becomes
sd18, OpenBSD can use the DUID to uniquely identify this disk.
OpenBSD uses the filesystem table /etc/fstab to map filesystems on ...