User`s guide

4. Add a passthrough container, the bridge between the physical loader and

the virtual unit.

5. Add the passthrough container as a virtual unit visible to the host.

The following example shows the CLI commands necessary to add a tape library

device to your conﬁguration using a command disk. Note that the PTL addresses

for devices in your storage subsystem will probably be different.

CLI> ADD TAPE320 3 2 0

CLI> ADD UNIT T322 TAPE320

CLI> ADD LOADER LDR321 3 2 1

CLI> ADD PASSTHROUGH PASS1 LDR321

CLI> ADD UNIT D332 LDR321

The commands in the example do the following:

Adds the tape drive at PTL 320tothelist of known tape drives with the

name TAPE320.

Creates a host-visible unit called T322 that consists of TAPE320.

Adds the tape laoder at PTL 3 2 1 to the list of known loaders with the name

LDR321. Note that for this tape library device, both the drive from step 1 and

the loader have the same Port and Target number; only the LUN is different.

Creates a passthrough container (command disk) associated with LDR321 to

allow the host direct access to the loader. The passthrough container is called

PASS1.

Creates a host-visible unit called D332 that consists of passthrough PASS1.

The host operating system will use disk unit 332 to exercise loader functions,

and tape unit 332 for backups, and so forth.

7.3.13.4 Host Setup

To communicate with a loader through a command disk, you must have the

following available at the host level:

• You must have special host-level application software for controlling the

particular loader. The application software can vary and is not provided with

the HS array controller or ﬁrmware. Simply stated, the application software

will manage the command disk protocol to control the loader in conjunction

with the drives served by it.

• You must install the OpenVMS operating system’s JU driver. When you

install JU driver, you must assign a JU device to the the correct unit number

(the unit number established through the CLI when you created the command

disk):

7–102 Diagnostics and Utilities