Users Guide

In this configuration, the storage slots and drives in each logical library are dedicated to that library and
are not shared among other libraries. Commands issued by the applications travel to the library through
two unique control paths. Thus, the data processing for:
v Department X is confined to the storage slots and drives in Logical Library 1
v Department Y is confined to the storage slots and drives in Logical Library 2
Using Multiple Control Paths
In addition to creating multiple logical libraries, any logical library can be configured to have more than
one control path. When configuring additional control paths, additional library sharing configurations
and availability options are made possible. Access to the logical library is on a first-come, first-served
basis and each control path for a logical library can accept commands while the library is in use by
another control path. By default, only the first drive in a logical library will be LUN-1 enabled.
For a particular logical library, you can enable as many control paths as there are drives in that logical
library.
Using Multiple Control Paths for Path Failover
Command failures and timeouts are costly. You want your library to run smoothly and efficiently. To
ensure continued processing, the library offers an optional path failover feature that enables the host
device driver to resend the command to an alternate control path for the same logical library. With
control path failover installed, the alternate control path can include another HBA, SAN, or library
control path drive. The device driver initiates error recovery and continues the operation on the alternate
control path without interrupting the application.
Path Failover is a combination of two previous features: Control Path Failover (key entered at the library
user interface) and Data Path Failover (key entered at the device driver interface). Go to “Minimum
firmware levels for common library features” on page v to find the minimum firmware levels for path
failover on your library.
The Path Failover feature can be installed by the customer.
For more information about using the path failover feature, see the Dell PowerVault TL4000 Failover
Configuration Guide, included with the library documentation if purchased at point of sale and with the
customer kit if purchased later.
Library Partitioning and Element Addressing
Library 4U systems with firmware versions of .80 and higher, and containing at least 2 drives, have the
ability to configure two logical libraries (create two partitions). This partitioning has been expanded with
the new library firmware and half-high drive integration. Now it is possible to configure 1, 2, 3 or 4
partitions in the 4U library. Additionally the 2U library can now be configured into one or two partitions.
Each library must contain at least one drive per logical library (partition). In a partitioned library, the
Operator Control Panel (OCP) only reports the status of logical library 1 in the main menu due to space
limitations. The user must navigate to the logical libraries status in the OCP to get the information on the
additional library partitions.
Partitioning of 2U Libraries
When two half height drives are installed in a 2U library, the library firmware will support partitioning
in the same way that the 4U supports partitioning with two full height drives today. The first partition
will contain the first magazine and the first drive. The second partition will contain the second magazine
and the second drive. The I/O station (if configured as I/O) will be shared, as is done with the
partitioned 4U library.
26 Dell PowerVault TL2000 Tape Library and TL4000 Tape Library: User's Guide