Users Guide

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 7. 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 status of the chassis always indicates no redundancy.
The figure below illustrates no redundancy mode is the factory default setting for three PSU configuration.
CMC does not require the PSU units to be present in any specific PSU slot positions when No Redundancy is configured.
NOTE: All PSUs in the chassis are Online if DPSE is disabled when in No Redundancy mode. When DPSE is enabled all
active PSUs in the chassis are listed as
Online and additional PSUs may be turned to Standby to increase the system's
power efficiency.
Figure 8. No Redundancy with three PSUs in the chassis
A PSU failure brings other PSUs out of Standby mode, as needed, to support the chassis power allocations. If you have four PSUs,
and require only three, then in the event that one fails, the fourth PSU is brought online. A chassis can have all six PSUs online.
When you enable DPSE, the extra PSUs may be placed in Standby mode to increase efficiency and save power. For more
information, see Default Redundancy Configuration.
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