Specifications

PS4000 Hardware Maintenance Maintaining Control Modules
3–3
Identifying Control Module Failures
You can identify a failure in a control module by:
• LEDs. See Interpreting Control Module LEDs on page 3-2.
• Messages. A message on the LCD panel (located behind the bezel), on the
console, in the event log, or in the Group Manager GUI Alarms panel
describes a control module failure.
• Group Manager GUI and CLI output. The Member Controllers window or
the
member select show controllers command output shows the
control module status
not installed.
When viewed from the rear of the array, CM0 is on the right, and CM1 is on the
left. See Figure 1-3.
If a control module fails, see your PS Series support provider for a replacement.
Understanding Failover Behavior
In a dual control module array, only one control module is active (serving network
traffic) at one time. Each control module includes a battery-backed write cache for
storing recently-used data. For redundancy, the cache on the secondary control
module mirrors the data that is stored in the cache on the active control module.
The active control module can use a network interface only if there is a cable
connected to the port on the active control module. Therefore, you should connect
a cable to a network interface port on each control module to make sure that both
control modules can access an interface.
Table 3-2: Ethernet Port LED Descriptions
LED Location Color Description
Left side of each
port
Off No power or not connected to network.
Green Connected to network.
Right side of each
port
Off No power, not transmitting, or not receiving.
Green Transmitting or receiving.