Quantum Scalar Distributed Library Controller 2.7, Reference Manual

Page: 22 / 324

4 Description
Figure 1 Client Connection
The Scalar tape libraries are connected to the Scalar DLC software host via the SCSI bus or the Fibre
Channel cable. See
Figure 2 .
Figure 2 Physical Libraries connected to the Scalar DLC
For each tape library found during Scan SCSI Bus operation, the Scalar DLC software creates an object
called physical library . This object represents all aspects of the real tape device.
Logical Library Concepts
To provide clients with a flexible way of sharing common resources ( physical library ), the Scalar DLC uses
virtual objects called logical libraries to represent the real device for the client. The Management GUI is used
to create and configure these logical libraries. The connection between the logical library and the device is
implemented by means of the partitioning features that are unique to the Scalar DLC software. The
partitioning operation creates a number of element ranges called
partitions that are used by the physical
library. These partitions are then assigned to the logical libraries (see Figure 3 on page 5) so that the client
who uses a certain logical library can access the appropriate part of the physical library. This feature is
useful when clients use a single physical library while the client has access to only a certain resource. The
logical library represents these resources, and the assigned partitions provide a connection between the
logical library and its physical equivalent.