Release Notes

Building a high-availability SAN
47 Dell PS Series Configuration Guide
Note how IP addresses are reassigned to their corresponding ports during the failover processes shown in
Figure 9 and Figure 10.
Fully connected controller failover
9.4.2 Controller failover behavior for: PS42x0/PS41x0/PS62x0/PS61x0/PS6610
In the event of a controller failure the following changes occur:
• The passive controller immediately activates and continues to process all data requests to the array.
• Vertical port failover ensures that IP addresses assigned to each of the failed controller Ethernet ports
apply to the corresponding ports on the second controller.
As stated in Section 9.4.1, controller models prior to the PS4100/PS6100 required having cabled connections
present on corresponding controller ports for controller failover to work correctly. The vertical port failover
feature in PS42x0/PS41x0/PS62x0/PS61x0/PS6610 controllers eliminates this requirement, enabling partially
cabled configurations to support controller failover too.
It is important to ensure that ports from each controller are connected to at least two different switches. This
will prevent a switch failure from also disabling all paths between a host and its connected volumes. We
illustrate controller failover behavior for the PS4200/PS4100 family controller in Figure 11. Controller failover
behavior for the PS6200/PS6100 (4 port) controller family is identical.