Device Name refers to identification of peripheral devices on OpenVMS systems and device naming conventions. For DEVICE_NAMING system parameter, see DEVICE_NAMING.
A device name is a string that uniquely identifies a device such as a disk, tape, network controller, terminal etc. on an OpenVMS system.
Parts of an OpenVMS device name include:
- allocation class or node name
- device type
- controller designation
- unit number
The same SCSI disk, DKA300:, could be represented as $1$GKA300:, TEST$DKA300:, or simply DKA300: depending on the device naming format (see below).
There are three general formats for naming devices depending on the use of clustering and multipath configurations:
- ddcu - when there is no clustering or multipath devices, e.g. DKA100:
- node$ddcu - when there is clustering, e.g. TEST$DKA100:
- $allocation-class$ddcu - when there is clustering and/or multipath devices, e.g. $30$DKA100:
If a device name is preceded by an underscore, this means that the name is a physical device name, not a logical name.
Device Naming Conventions
Allocation Class is used to uniquely identify shared devices in multipath and cluster configurations. Please see ALLOCATION_CLASS for more information. If allocation classes are used, the format for device names is as follows: $allocation-class$device-name.
An OpenVMS Cluster device name includes the name of the node to which the device is attached and the physical device name, separated by a dollar sign ($). For example, TEST$DKA1 refers to disk DKA1 on node TEST. Allocation classes should be used in multipath configurations.
|DG||Fibre Channel disk||DGA100:|
|DK||SCSI disk||DKA100: - SCSI disk|
|DS||Disk Stripe set (e.g. a shadowed disk)||DSA0:|
|DU||Disk connected to MSCP controllers||DUA0:|
|E||Ethernet Network Device|
|EC||Ethernet Network Device|
|EF||Ethernet Network Device|
|EQ||Ethernet Network Device|
|ES||Ethernet Network Device|
|ET||Ethernet Network Device|
|EX||Ethernet Network Device|
|EW||Ethernet network adapter connected to PCI||EWA0:|
|EZ||Ethernet Network Device|
|FC||Ethernet Network Device|
|FG||Fiber Channel Host Bus Adapter||FGA0:|
|FX||Ethernet Network Device|
|GH||DECwindows output device||GHA0:|
|LT||LAT Network Terminal|
|MG||Fibre Channel tape drive||MGA300|
|MK||SCSI Tape Drive|
|OP||Operator's console||OPA0: - default operator's console|
|RT||DECnet Terminal (created with the SET HOST command)|
|SE||ACPI system event||SEA0:|
|XQ||Emulated Ethernet card (DELQA-T (M7516-YM), DELQA (M7516) and DEQNA (M7504) Q-bus Ethernet cards)|
|XU||Emulated Ethernet card (Digital's DEUNA (M7792/M7793) and DELUA (M7521) Unibus Ethernet cards)|
The third letter represents controller designation (in the order detected by hardware): A - first controller, B - second controller, etc. Pseudo-controllers and indirect controllers (shadow, SAN) always use A.
SCSI disks often have unit numbers that are multiples of 100: DKA100:, DKA200:, DKA300 etc. For tapes on parallel SCSI, the device name of a directly attached tape implies the physical location of the device; for example, MKB301 resides on bus B, SCSI target ID 3, and LUN 1. Such a naming scheme does not scale well for Fibre Channel configurations, in which the number of targets or nodes can be very large.