Users Guide

• Power Budgeting For Hardware Modules
• Server Slot Power Priority Settings
• Viewing Power Consumption Status
• Viewing Power Budget Status
• Redundancy Status and Overall Power Health
• Configuring power budget and redundancy
• Executing Power Control Operations
Redundancy Policies
Redundancy policy is a configurable set of properties that determine how CMC manages power to the chassis. The following
redundancy policies are configurable with or without dynamic PSU engagement:
● Grid Redundancy
● Power Supply Redundancy
● No Redundancy
Grid Redundancy Policy
The purpose of the Grid Redundancy policy is to enable a modular enclosure system to operate in a mode in which it can tolerate
power failures. These failures may originate in the input power grid, the cabling and delivery, or a PSU itself.
When you configure a system for Grid Redundancy, the PSUs are divided into grids: PSUs in slots 1, 2, and 3 are in the first grid
while PSUs in slots 4, 5, and 6 are in the second grid. CMC manages power so that if there is a failure of either grid the system
continues to operate without any degradation. Grid Redundancy also tolerates failures of individual PSUs.
NOTE:
Grid Redundancy provides seamless server operation despite failure of a whole power grid. Hence, the maximum
power is available to maintain Grid Redundancy when the capacities of the two grids are approximately equal.
NOTE: Grid Redundancy is only met when the load requirements do not exceed the capacity of the weakest power grid.
Grid Redundancy Levels
To configure Grid Redundancy, at least one PSU must be present in each grid. Additional configurations are possible with every
combination that has at least one PSU in each grid. However, to make the maximum power available for use, the total power of
the PSUs in each grid should be as close to equal as practical. The upper limit of power while maintaining Grid Redundancy is the
power available on the weakest of the two grids. The following figure illustrates 2 PSUs per grid and a power failure on grid 1.
If CMC is unable to maintain Grid Redundancy, an email or SNMP alerts are sent to administrators if the Redundancy Lost
event is configured for alerting.
Figure 14. 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.
Managing and Monitoring Power
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