Release Notes

Building a high-availability SAN
45 Dell PS Series Configuration Guide
Redundant SAN Connection Paths: PS4100
Redundant SAN Connection Paths: PS4110/PS6110
9.3 Controller redundancy in all models
Each array can be configured with either a single controller, or dual redundant controllers. The single
controller configuration will provide the same level of I/O performance as a dual controller configuration. The
dual controller configuration provides for redundancy. Dual controllers provide redundancy in the case of a
controller failure. Host connections will fail over to the redundant controller.
The active controller is the one processing all disk and network I/O operations for the array. A second
controller in dual controller configurations will always be in a passive operating mode. In this mode, the
secondary controller exhibits the following characteristics:
• Each of its Ethernet ports are electrically inactive (active lights are off), unless a vertical port failover
has occurred.
• The passive controller cache mirrors the cache of the active controller.