Owner's Manual

file:///T|/htdocs/SOFTWARE/smdrac3/cmc/cmc1.20/en/readme/CMC_120_A00_README_final.txt[10/26/2012 2:28:35 PM]
* System Input Power Cap: System Input Power Cap is the max AC power that the system
is allowed to allocate to servers and chassis infrastructure. It can be configured
by the user to any value that exceeds the minimum power needed for Servers that
are powered on and the chassis Infrastructure. If an attempt is made to configure
a value that falls below the minimum power needed for Servers and Chassis Infrastructure,
the attempt would fail. The power allocated to Servers and Chassis Infrastructure can
be found in the User Interface on the Chassis -> Power Management-> Power Budget status
page under Power Budgeting section or via CLI RACADM utility command (racadm getpbinfo).
Users can power OFF one or more server(s) to lower the current Power allocation, and
re-attempt setting a lower value for System Input Power Cap (if desired) or simply configure
the cap prior to powering on the servers.
To change this setting, it is possible to enter a value in any of the units. The interface
ensures that the unit field that was last changed will be the value that is submitted
when those changes are applied.
NOTE: Refer to the Datacenter Capacity Planner (DCCP) tool at www.dell.com/calc for
capacity planning.
NOTE: When value changes are specified in watts, the submitted value will exactly
reflect what is actually applied. However, when the changes are submitted in either
of the BTU/h or percent units, the submitted value may not exactly reflect what is
actually applied. This is because these units are converted to watts and then applied
and the conversion will be susceptible to some rounding error.
* Redundancy Policy This option will allow you to select one the following options:
* No Redundancy: Power from all three power supplies on one AC circuit (grid) is used to power-on
the entire chassis, including the chassis, servers, I/O modules, iKVM, and CMC.
NOTE: The No Redundancy mode uses only three power supplies at a time. If 3 PSUs are installed,
then there is no backup available. Failure of one of the three power supplies being used could
cause the servers to lose power and/or data. If PSUs 4-6 are present, then these will become
redundant and will become available in the event of an online PSU going down.
* Power Supply Redundancy: The capacity of the highest-rated power supply in the chassis is kept as a
spare, ensuring that a failure of any one power supply will not cause the server modules or chassis
to power-down (hot spare).
Power Supply Redundancy mode does not utilize all six power supplies, but rather a maximum of
four and a minimum of two power supplies. Power Supply Redundancy mode prevents server modules from
powering up if the power consumption of the chassis exceeds the rated power. Failure of two power
supplies may cause some or all server modules in the chassis to power-down. Server modules are not
throttled in this mode.
* AC Redundancy: This divides the 6 PSUs into two power grids (PSUs 1-3 making up power grid 1 and
PSUs 4-6 making up power grid 2). 6 PSUs are required to have a fully redundant AC Redundancy power
policy. In this configuration 3 PSUs in one grid will be online and 3 PSUs in the other grid will be
redundant. Failover will occur when any of the 3 PSUs in the online grid fail. This will cause the
redundant PSUs to convert to online and will report the redundancy policy as degraded.
NOTE: In AC Redundancy mode, a difference in the number of power supplies between the two AC
circuits (for example, three power supplies on one AC circuit and two on the other AC circuit)
will cause a degradation in the redundancy.