Owner's Manual

188 Power Management
Redundancy
Policy
Indicates the current redundancy configuration: AC Redundancy,
Power Supply Redundancy, and No Redundancy.
AC Redundancy — Power input is load-balanced across all PSUs.
Three of the PSUs are connected to one AC grid and the other
three are connected to another grid. When the system is running
optimally in AC Redundancy mode, power is load-balanced across
all active supplies. In case of a grid failure, the PSUs on the
functioning AC grid take over at 100% capacity.
NOTE: In AC Redundancy mode, a difference in the number of PSUs
between the two AC circuits (for example, three PSUs on one AC
circuit and two on the other AC circuit) causes a degradation in the
system redundancy.
Power Supply Redundancy — The capacity of the highest-rated
PSU in the chassis is held as spare, ensuring that a failure of any one
PSU does not cause the server modules or chassis to power down.
Power Supply Redundancy mode does not use all six PSUs; it uses a
maximum of four. PSUs in excess of four do not participate in
Power Supply Redundancy unless a PSU fails or is removed.
No Redundancy — The power from all three PSUs on one AC
circuit (grid) is used to power the entire chassis, including the
chassis, servers, I/O modules, iKVM, and CMC.
NOTICE: The No Redundancy mode uses only three PSUs at a
time, with no backup. Failure of one of the three PSUs in use
could cause the server modules to lose power and data.
Dynamic Power
Supply
Engagement
Indicates whether Dynamic Power Supply Engagement is enabled
or disabled. Enabling this feature allows the CMC to put under-
utilized PSUs into standby mode based on the redundancy policy
that is set and the power requirements of the system. Putting
under-utilized PSUs into standby mode increases the utilization,
and efficiency, of the online PSUs, saving power.
Table 7-8. System Power Policy Configuration (continued)
Item Description