Users Guide

Figure 5. PSUs per grid and a power failure on grid 1
In the event of a single PSU failure in this configuration, the remaining PSUs in the failing grid are marked
as Online. In this state, the PSUs in the Redundant Grid if not in failed state, help in functioning of the
system without interruption. If a PSU fails, the chassis health is marked non-critical. If the smaller grid
cannot support the total chassis power allocations, then grid redundancy status is reported as No
Redundancy and Chassis health is displayed as Critical.
Power Supply Redundancy Policy
The power supply redundancy policy is useful when redundant power grids are not available, but you
may want to be protected against a single PSU failure bringing down your servers in a modular enclosure.
The highest capacity PSU is kept in online reserve for this purpose. This forms a Power Supply
redundancy pool. The figure below illustrates power supply redundancy mode.
PSUs beyond those required for power and redundancy are still available and is added to the pool in the
event of a failure.
Unlike Grid Redundancy, when power supply redundancy is selected, CMC does not require the PSU
units to be present in any specific PSU slot positions.
NOTE: Dynamic Power Supply Engagement (DPSE) allows PSUs to be placed in standby. The
standby state indicates a physical state during which power is not supplied from the PSU. When you
enable DPSE, the extra PSUs may be placed in Standby mode to increase efficiency and save power.
Figure 6. Power Supply Redundancy: Totally 4 PSUs with a failure of one PSU
No Redundancy Policy
The no redundancy mode is the factory default setting for three PSU configuration and indicates that the
chassis does not have any power redundancy configured. In this configuration, the overall redundancy
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