The Question is:
I have searched through all the VMS documentation and the following not clear
Some documentation refers to disk names as DKA. Other documentaion indicates
DUA. What is the naming convention for physical local disk drives in VMS?
The Answer is :
DK is a local SCSI disk prefix, DKA is the first SCSI controller,
and (somewhat counterintuitively) DKA200: is the third SCSI unit.
DU is a local or served MSCP-type disk, while DUB is the second
MSCP controller present. Disk unit numbers are typically assigned
at the MSCP storage device or MSCP controller.
DI disks are the older names for DSSI disks, these devices now
use the DU device prefix and driver stack on all current releases.
DV is one of the floppy disk device prefixes.