MSL5000 and 6000 Series Tape Libraries User Guide

Introduction
36 HP StorageWorks MSL5000 and MSL6000 Series Tape Libraries User Guide
Multi Unit Library Systems
MSL Series tape libraries can be stacked in a scalable combination with additional
two-drive and four-drive models to form a multi unit library configuration.
Through use of a rear-mounted Pass-Through Mechanism (PTM), all libraries in a
multi unit library configuration can operate together as a single virtual library
system. Stacked libraries are interconnected through their rear panel Ethernet
connections to a supplied LAN hub that mounts to the rack enclosure. The LAN
hub also provides a wide area network (WAN) connector when libraries are
combined in their maximum stacked height.
A maximum of four four-drive models or eight two-drive models can be
connected together in this manner. Any combination of eight libraries, not
exceeding 40 Units (40U) in total stacked height, can also be used. A multi unit
library configuration appears as a single library to the host computer system and
application software. For multi unit applications, the top library becomes the
master unit and all other libraries are slave units.
WARNING: The PTM continues to function each time a slave library is
physically removed from the rack enclosure configuration during normal
library operation. Refer to the HP StorageWorks MSL Series Pass-Through
Mechanism Reference Guide for detailed installation, configuration, and
operation information
.
The library robotics can pick and place tape cartridges into a movable elevator that
encompasses the full length of the PTM. In this manner, individual tapes can be
passed up or down between the libraries contained in the multi unit library
configuration under the master library control. Robotics access to the PTM is
located at the rear of the library beneath the PTM cover (see Figure 9 on page 37).