User's Manual

Troubleshooting and Recovery 391
– Resolution C: Check the max power conservation setting. If this is set
then servers are allowed to power on. For more details, see the power
configuration settings.
–
Resolution D: Check the server slot power priority of the slot
associated with the newly inserted server, and ensure it is not lower
than any other server slot power priority.
•
Problem: Available power keeps changing, even when the modular
enclosure configuration hasn't changed
–
Resolution: CMC 1.2 and higher versions have dynamic fan power
management that reduces server allocations briefly if the enclosure is
operating near the peak user configured power cap; it causes the fans
to be allocated power by reducing server performance to keep the
input power draw below
System Input Power Cap . This is normal
behavior.
•
Problem: 2000 W is reported as the Surplus for Peak Performance .
–
Resolution: The enclosure has 2000 W of surplus power available in
the current configuration, and the
System Input Power Cap can be
safely reduced by this amount being reported without impacting
server performance.
•
Problem: A subset of servers lost power after an AC Grid failure,
even when the chassis was operating in the
AC Redundancy configuration
with six power supplies.
–
Resolution: This can occur if the power supplies are improperly
connected to the redundant AC grids at the time the AC grid failure
occurs. The
AC Redundancy policy requires that the left three power
supplies to be connected to one AC Grid, and right three power
supplies to be connected to other AC Grid. If two PSU are improperly
connected, such as PSU3 and PSU4 are connected to the wrong
AC grids, an AC grid failure cause loss of power to the least priority
servers.