D-Link xStack Storage DSN-5210 Hardware Reference Manual page 17

Figure 2-5. Close-up View of DSN-5000 series Controller Rear Panel
Redundant Controller or Filler Plate in Slot #1
Rear Panel Switches & LED's
10G Data Port
Management Port
Primary Controller in Slot #0
Two Expansion Ports
Figure 2-6. Rear View of the DSN-5410 with two controllers installed
Figure 2-7. Close-up View of DSN-5000 series-10G Controller Rear Panel
The DSN-5000 series primary array is "HA-capable" (High Availability) and
can be equipped with dual controllers for automatic failover in the event of
a hardware or software failure on the primary controller. For systems with
dual controllers, both controllers must have the same number and type of
data ports.
To allow the automatic re-direction of the network connections to the
redundant controller when a failure occurs on the primary controller, the
network cables for the Management Port and each of the Data Ports must be
connected to both controllers before the system starts up.
The network connections for the Management Port and each of the Data
Ports must be connected to the same network switch to allow the failover
mechanism to function correctly. For example, the Management Port of
both controllers must be connected to the same switch, and Data Port 0 on
both controllers must be connected to the same switch, although that switch
can be different than the one used for the Management Port. The same
method should be used for all other data ports.
DSN-5000 series Hardware Reference Guide 9