Compaq StorageWorks TL881/TL891 Family MiniLibrary System Reference Guide (July 2000)

Installation
3-23
Compaq Confidential – Need to Know Required
Writer:
Bob Young
Project:
Compaq StorageWorks TL881/TL891 Family MiniLibrary System Reference Guide
Comments:
Part Number:
127510-002
File Name:
d-ch3 Installation.doc
Last Saved On:
7/12/00 11:24 AM
In the MiniLibrary Base Module, each drive is wired to an independent bus
with a pair of SCSI connectors. Because it can be used in free-standing
applications, the MiniLibrary Base Module has a pair of SCSI connectors for
that module’s library robotics. The library robotics SCSI interface should not
be connected when installed in a system with an Expansion Unit. The
Expansion Unit controls the library robotics for all of the modules in the
system. It has a single SCSI bus, with a pair of SCSI connectors, to enable a
host to control the library robotics.
Each of the drives in the system and the library robotics is a separate SCSI
device and is wired to a separate SCSI bus. Any of the separate buses can be
combined using a SCSI jumper cable, available from Compaq. If any two or
more devices are connected to the same SCSI bus, each must be assigned a
unique SCSI address. For information on assigning SCSI addresses, see the
section, “Configuration,” later in this chapter.
NOTE:
For reduced internal cable length the single-ended units have the robotics and
first drive daisy-chained internally.
NOTE:
For best performance, no more than two drives should be connected to a single
SCSI bus, because of the bandwidth limitations of the SCSI bus.
A terminator of the proper type (68-pin HVD, LVD/SE or SE) must be
installed on each unused connector at the end of each bus, as explained below
in the section, “Interface Cable and Terminator Installation.” Figure 3-12
shows the SCSI cable, connectors and bus terminator used on the module.
In order to connect a module to a host computer system, the host system must
have at least one SCSI controller and the appropriate driver software. As noted
earlier, higher-speed drives might require the use of separate SCSI controllers
for each drive or each pair of drives. No more than two drives should be
connected to a single SCSI bus. Your Technical Support representative is
available to answer your questions about installation procedures for specific
host systems. Before cabling the system, see the recommended SCSI cable
specifications in the following section. Also, see the section, “Interface Cable
and Terminator Installation” in this chapter.