Users Guide

Microsoft Windows application that is using the drive and storage slots of one logical library, while a UNIX

application uses the drive and slots of another logical library. See “Mixed drives” on page 12.

Multiple logical libraries

A library can be partitioned into multiple logical libraries to enable simultaneous data backup and restore

tasks from different applications. For example, you can create multiple logical libraries so that is

processes

• Commands from Application 1 (about Department A) in Logical Library 1

• Commands from Application 2 (about Department B) in Logical Library 2

• Commands from Application 3 (about Department C) using Sequential Mode in Logical Library 3

In this conguration, the tape drives and cartridges of each logical library are dedicated to that library and

are not shared among other libraries and applications. Commands that are issued by the applications

travel to the library through unique control paths or sequential mode processing by the library. So, the

data processing for Department A is conned to the tape drives and cartridges of Logical Library 1.

Processing for Department B is conned to the tape drives and cartridges of Logical Library 2, and so

forth.

For applications that do not support mixed drive types and media within the same logical library,

partitioning the library into multiple logical libraries provides the capability to keep them separate. For

example, you can partition the following tape drives and their media into multiple and separate logical

libraries:

• LTO 8

• LTO 7

• LTO 6

Multiple control paths

With this tape library's multipath architecture, in addition to creating multiple logical libraries, you can

congure any logical library to have more than one control path. A control path is a logical path into the

library through which the library receives standard SCSI Medium Changer commands to control the

library operations.

Note: No SCSI Medium Changer is congured when the logical library is enabled as Sequential Mode

Multiple control paths reduce the possibility of a failure in one control path to cause the entire library to

become unavailable. Also, when you congure more control paths, more library-sharing congurations

and options are possible. Access to the library is on a rst-come, rst-served basis. Each control path for

a logical library can accept commands while the library is in use by another control path.

Multiple control paths for control path failover

This tape library offers an optional control path failover feature. See “Library sharing” on page 18

and

“Control path failover, Data path failover, and load balancing” on page 18.

Use of the control path failover feature further reduces the possibility of a failure in one control path to

cause the entire library to become unavailable.

The control path failover feature (feature code 1682) enables the host device driver to resend a command

to a different control path for the same logical library.

Library partitioning

Libraries that contain at least two drives can congure two logical libraries. It is possible to congure up

to 21 logical libraries in the library (up to the number of drives installed). In a partitioned library, the

Operator Panel reports only the status of logical library 1 in the main menu because of space limitations.

The user must go to the logical libraries status in the Operator Panel to get the information about the

additional library partitions. The Management GUI provides a Logical Library Graphical View.

Chapter 3. Installing