Virtual TapeServer 6.04.02 Operations and Administration Guide

Modifying Virtual Tape Drives | 19
7. Select the media format from the Tape Type drop-down list. This property defines the
type of tape that the VTD emulates.
Note Do not select RAID; this option is provided for physical tapes only.
8. From the Bus drop-down list, select the bus ID to which the host server is connected. To
determine the bus ID, you must find the PCI slot number on the back of the VTS server
module where the SCSI or Fibre Channel cable connects from the card to the target.
Labels indicate the bus number for each port.
9. If you are editing a SCSI VTD, select the ID on which the VTD will respond from the
Target drop-down list. This is the ID that the host uses to identify its target, and the ID
typically ranges from 0–15.
Note Fibre Channel devices use LUN-based addressing. SCSI devices use target-based
addressing. For Fibre Channel devices, the LUN determines the unique address of
the device on the bus. When assigning the target ID and LUN, be sure to assign a
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.
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.