User's Manual

248 Power Management
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 mode 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, which
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.
Table 8-15. Configurable Power Budget/Redundancy Properties (continued)
Item Description