Direct-Attached Shared Libraries - Prerequisites
To help you get the most out of your tape libraries, the software allows you to attach the media changer and the drives within a library to different MediaAgents within the CommCell. The system creates a drive pool for all of the drives within a given library that are attached by a specific MediaAgent. (Although the library's media changer is attached to one MediaAgent, all MediaAgents that are attached to the library have access to the media changer through centralized software.)
Follow these guidelines if your libraries are shared among and are attached directly to two or more MediaAgents.
- If you configure a MediaAgent that controls the media changer of a shared library, follow the guidelines described in Single SCSI Configuration Guidelines.
- If you configure a MediaAgent that is attached to drives within a library, but not the library's media changer, assign the lowest available SCSI targets to these drives. We recommend that you assign SCSI targets in ascending order in accordance with drive position. If possible, the SCSI target numbers should match the physical drive location. This facilitates library and drive administration.
In this configuration, one SCSI port connects the first MediaAgent to the library and its media drives. The port number can vary from system to system and depends on whether any other SCSI devices are already installed. For example, your system might have internal disk drives assigned to targets on SCSI port 0.
When we assigned SCSI targets in this example, we assigned the lowest target number to the media changer, and then proceeded in ascending order, which keeps all of the targets unique across the library. The SCSI targets correspond to the physical drive number.