Dell EqualLogic PS Series Hardware Owner's Manual page 22

PS6610 Hardware Owner's Manual
Dual Controller Configuration
A dual control module configuration eliminates a single point of failure in the array. If the active
control module fails, the secondary control module takes over automatically with no interruption of
service. This automatic transition gives you time to replace the failed control module while your
volumes and data remain accessible.
In addition, a dual control module configuration supports a feature called vertical failover. An Ethernet
port on the active control module can fail over to the same Ethernet port on the secondary control
module if a network path fails.
Both Ethernet ports on the control module can fail over.
configuration for vertical failover.
Figure 11: Recommended Network Configuration to Support Vertical Failover
If a network port is available for failover on either control module, but is not currently in use,
Note:
its LEDs will not be lit.
Note: Vertical failover is transparent to applications.
Interpreting Control Module LEDs
Control modules have the following LEDs:
• The Ethernet ports and the management port each have LEDs that indicate the port's status and
activity. See Table
16
8.
3 Control Module Maintenance
Figure 11 shows a recommended