User's Manual

Carrier Grade Chassis Management Controller User’s Guide Addendum 7
for some reason CMC is unable to maintain grid redundancy, then E-mail
and/or SNMP alerts are sent to administrators if the Redundancy Lost event
is configured for alerting.
Figure 1-1. 2 PSUs per grid and a power failure on grid 1
NOTE: 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, any of the remaining PSUs can
fail without interrupting operation of the system. 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 Mode
The power supply redundancy mode 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. Figure 1-2 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.
Power
Supply
#1
Power
Supply
#2
Empty
Slot
#3
Power
Supply
#4
Power
Supply
#5
Empty
Slot
#6
DC Power Grid #1
DC Power Grid #2
Chassis DC Power Bus
DC Power Grid #1