Virtual TapeServer 6.04.03 Installation Guide

Creating Virtual Tape Drives | 13
unique combination. For example, you cannot assign target ID 0 LUN 0 and
target ID 1 LUN 0 on the same bus; this creates a conflict. All target IDs on a bus
must be identical, and you cannot assign a LUN value more than once per bus.
The appropriate ID value depends on the host server:
• For NonStop S-series servers
IDs 4 and 5 are reserved for tape devices, while other IDs are reserved for other device
types. NonStop S servers default to target ID 5 for tape drives, therefore it is
recommended that you set the target to 5. You can set the target to 4 but you must
configure the NonStop S server by specifying “DEVICEID 4” with the SCF ADD TAPE
command. (Refer to the NonStop S server documentation for more information.)
• For NonStop Integrity (NS) and BladeSystem servers
In general, you can assign values 0–15 to the target ID. (Integrity servers support
Fibre Channel ports only.) Best practices encourage you to assign value 5 to the target
ID.
• UNIX servers
In general, any ID greater than 0 can be used for the target ID. The backup
management application determines the ID and typically assigns 0 to the robot in a
tape library. Refer to backup management application documentation and host server
to determine the target ID.
If the Fibre Channel is configured for the Arbitrated Loop topology, use the Loop ID as
the target ID here. To find the Loop ID, boot VTS while connected to the Fibre
Channel network. Then, after the startup is complete, access the VTS web interface.
Click Supervisor Functions on the navigation pane, click Examine the system
log file, and search for “Loop id.” The ID is typically set to 0 or 1 but it can be set as
high as 255.
• On an AS/400 server, check your current hardware and operating system
documentation for supported target addresses.
10. From the Lun drop-down list, select the logical unit number. This number identifies the
sub-ID on the bus, and this ID typically ranges from 0–255. The appropriate LUN value
depends on the host server. For SCSI connections, this ID is 0 typically.
• For NonStop S-series servers
Set the LUN to 0. 0 is the only value supported by NonStop S servers, which support
SCSI ports only and ignore the LUN.
• For NonStop Integrity (NS) and BladeSystem servers
Up to four tape devices are supported per port, therefore you can assign values 0–3 to
the LUN. 0 is typically assigned to the LUN for the first tape device, 1 is typically
assigned for the second tape device, 2 for the third, and 3 for the fourth.
• UNIX servers
In general, set the LUN to any value between 0 and 7. Begin with 0 and increment the
LUN for each additional VTD that is added on a bus. The backup management
application determines the number. Refer to backup management application
documentation and host server to determine the LUN.
• AS/400 servers
LUN 0 is required. If more than one VTD is created, begin with 0 and increment the
LUN for each additional VTD that is added on a bus.