Users Guide

This occurs if the administrator had configured power limit for the chassis lower than the full power allocation to the
servers or if insufficient power is available to servers requiring high power.
The following table provides the actions taken by CMC, when a new server is powered on in the scenario described
earlier.
Table 29. CMC Response When a Server Power-On is Attempted
Worst Case Power is Available CMC Response Server Power On
Yes No power conservation is required Allowed
No Perform power conservation:
• Power required for new server is available
• Power required for new server is not available
Allowed
Not Allowed
If a PSU stops functioning, it results in a non-critical health state and a PSU failure event is generated. The removal of a
PSU results in a PSU removal event.
If either event results in a loss of redundancy, on the basis of power allocations, a loss of redundancy event is
generated.
If the subsequent power capacity or the user power capacity is greater than the server allocations, servers have
degraded performance or, in an extrement case, servers may be turned off. Both conditions are in reverse-priority order;
that is, the low-priority servers are turned off first.
The following table provides the firmware response to a PSU turnoff, or removal as it applies to various PSU redundancy
configurations.
Table 30. Chassis Impact from PSU Failure or Removal
PSU Configuration Dynamic PSU
Engagement
Firmware Response
AC Redundancy Disabled CMC alerts you about loss of AC redundancy.
Power Supply
Redundancy
Disabled CMC alerts you about loss of power supply redundancy.
AC Redundancy Enabled CMC alerts you about loss of AC Redundancy. PSUs in standby
mode (if any) are turned on to compensate for power budget lost
from the PSU failure or removal.
Power Supply
Redundancy
Enabled CMC alerts you of loss of Power Supply Redundancy. PSUs in
standby mode (if any) are turned on to compensate for power
budget lost from PSU failure or removal.
Power Supply and Redundancy Policy Changes in System Event Log
Changes in the power supply state and power redundancy policy are recorded as events. Events related to the power
supply that record entries in the system event log (SEL) are power supply insertion and removal, power supply input
insertion and removal, and power supply output assertion and de-assertion.
The following table lists the SEL entries that are related to power supply changes:
Table 31. SEL Events for Power Supply Changes
Power Supply Event System Event Log (SEL) Entry
Insertion Power supply is present.
Removal Power supply is absent.
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