Dell PowerVault TL4000 - Manual (Page 43)

Chapter 3. Installation Planning
Before installing your library, take time to review the following information.
Determining the Number of Logical Libraries
You can partition the library into as many logical libraries as there are drives in the
library.
Basic Guidelines
v Each logical library must contain at least one drive.
v A library configuration of exactly one logical library equals the entire physical
library.
v The library issues a warning to the user if media is moved across logical
libraries.
Library Sharing
The library's default configuration allows a single application to operate the library
through a single control path. Often, it is advantageous to be able to share a single
library between heterogeneous (dissimilar) or homogeneous (similar) applications.
Some applications (and some servers) do not allow for sharing a library between
systems. Configurations can be created that enable the library to process
commands from multiple heterogeneous applications and multiple homogeneous
applications.
From the library's Web User Interface or Operator Control Panel, the following
actions can be performed:
v Configure the library so that it is partitioned into separate logical libraries that
independently communicate with separate applications through separate control
paths. This configuration requires no special capabilities from the server or
application. (For more information, see “Using Multiple Logical Libraries for
Library Sharing” on page 3-2.)
v Configure any single logical library (including the entire physical library) so that
it is shared by two or more servers that are running the same application.
Depending on the capabilities of the server and application, there are several
ways to set up this type of configuration. Three typical ways include:
– Configuring one server (host) to communicate with the library through a
single control path; all other servers send requests to that server through a
network.
– Configuring all of the servers to communicate with the library through a
single, common control path. This configuration is used in high-availability
environments. Multi-initiator configurations are only supported by certain
adapters and independent software vendors (ISVs). Check with your ISV.
– Configuring a single logical library to communicate with multiple servers
through multiple control paths. This configuration requires that control paths
be added (see “Using Multiple Control Paths” on page 3-2).
Library configuration is not limited to the examples given above. Many
configurations are possible, and can be designed according to your business needs.
For additional information, refer to your host application documentation.
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