Qualstar XLS Series Installation Manual page 115

the tape drive to the same SCSI bus. In addition, use side-by-side locations
within a drive bay if you plan to put more than one tape drive on the SCSI bus.
Important:
8.1.2
This section provides examples for installing the tape drives and connecting them to one
or more SCSI buses or Fibre Channel networks. You may find it helpful to create similar
cabling diagrams before installing the tape drives and connecting the cables.
Important:
Example 1: LTO3 SCSI Connections
Figure 8-4
containing a single LTO3 SCSI tape drive. The logical libraries are controlled as follows:
• Logical Library 1 contains one LTO3 SCSI tape drive. The software application in
the host computer communicates with the tape drive and the medium changer
over a single SCSI bus. One end of the bus is terminated by the upper port of
HBA A in the system controller (which provides active termination); the other
end is terminated by the host computer.
• Logical Library 2 also contains one LTO3 SCSI tape drive in a drive bay shared
with Logical Library 1. The software application communicates with the tape
drive and the medium changer over a single SCSI bus, terminated by the lower
port of HBA A and by the host computer.
XLS Library Installation Manual
Because the transfer rate for Ultra 160 SCSI is limited
to 160 MB/second, placing two high-speed tape drives on
a single bus may prevent both drives from streaming
data.
Example Cabling Diagrams
The example logical libraries shown use Fibre Channel
tape drives with Fibre Channel HBAs or SCSI tape
drives with SCSI HBAs. However, the communication
protocols used by the tape drives and the medium
changer do not need to be the same. A logical library can
contain Fibre Channel tape drives and a SCSI HBA or a
SCSI tape drive and Fibre Channel HBA.
shows the cabling scheme for two logical libraries, with each logical library
8
Installing the Tape Drive Assemblies
8-11