The Rear Panel; Dual Controller Models - Infortrend EonStor DS 1000 Gen2 Series Hardware Manual

The Rear Panel

Dual Controller Models

Dual controller systems are indicated by an "R" in their model number (please refer
to Model Naming
bottom for dual controller models. In dual controller configuration, if one controller
fails, the second controller module will take over in a manner that is transparent to
application servers.
The top controller (Controller A) is the primary controller. The bottom controller
(Controller B) is the secondary (= redundant) controller which is idle during normal
operation and takes over the management role when Controller A cannot function
properly due to hardware error, controller module removal, etc.
If the failed Controller A restarts or a replacement is installed, Controller A will
temporarily assume the role of the secondary controller.
When the storage system is rebooted, all system configurations will revert back to
the default state and Controller B returns the primary role back to Controller A.
Conventions). Controller A is located on top and controller B at the
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