Chapter 2 — Architecture Overview Fibre Channel Connectivity
December 2019 User Guide—Spectra T200, T380, and T680 Libraries
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Robotic Controller Connectivity
The robotics requires a direct-attached LTO drive, a RIM, or an F-QIP to
provide the robotic control path. When configuring a storage partition, the
device you select to provide the robotic control path is referred to as the
“exporting controller” for the partition. The exporting controller makes the
partition accessible to the hosts as a media changer (a library). It receives
the media changer commands sent from the host to the library and relays
them to the LCM, which in turn processes them into the motion commands
used to control the robotics.
You can select multiple exporting controllers (drives or RIMs and F-QIPs)
for a partition and use your host software to export the same changer
interface over the controllers to provide redundancy.
When a RIM or an F-QIP is not present, a direct-attached Fibre Channel
or SAS drive provides the robotic control path, as described in Control
Path Through a Direct-Attached Drive, below.
When a RIM or an F-QIP is present, it can be used to provide the robotic
control path, as described in Control Path Through a RIM or F-QIP on
page 61.
Control Path Through a Direct-Attached Drive
In a direct-attached drive configuration, one or more drives in a storage
partition are designated as the exporting drive (also known as the
exporting controller). The commands from the host to control the motion
of the robotics within the partition are routed to the exporting drive’s
logical unit number 1 (LUN 1). Commands to control the operation of the
exporting drive are sent from the host to LUN 0 of the drive.
Notes: If you have multiple storage partitions, you must designate
an exporting drive for each partition.
A drive can only provide the robotic control path for the
partition to which it is assigned.
If you have LTO-5 or later generation drives, you can select
multiple drives as controllers, and export the same changer
interface over the drives to provide redundancy, as long as
your storage management software can support this. These
multiple paths cannot be used at the same time.
Assigning multiple drive exporters to one partition reduces the
total number of partitions that can be configured in the library.
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