User's Manual

Power Management 255
if sufficient power is available. The System Input Power Cap can be
increased any time up to a maximum value of 7928 watts to allow the
power up of additional servers.
Changes in the modular enclosure that reduce power allocation are server
power off, server, I/O module, or iKVM removal, and transition of the chassis
to a powered off state. You can reconfigure the System Input Power Cap
when chassis is either ON or OFF.
Server Slot Power Priority Settings
The CMC allows you to set a power priority for each of the sixteen server
slots in an enclosure. The priority settings are 1 (highest) through 9 (lowest).
These settings are assigned to slots in the chassis, and the slot's priority is
inherited by any server inserted in that slot. The CMC uses slot priority to
preferentially budget power to the highest priority servers in the enclosure.
According to the default server slot priority setting, power is equally
apportioned to all slots. Changing the slot priorities allows administrators to
prioritize which servers are given preference for power allocations. If the more
critical server modules are left at their default slot priority of 1, and the less
critical server modules are changed to lower priority value of 2 or higher, the
priority 1 server modules would be powered on first. These higher priority
servers would then get their maximum power allocation, while lower priority
servers may be not be allocated enough power to run at their maximum
performance or they may not even power on at all, depending on how low the
limit is set and the server power requirements.
If an administrator manually powers on the low priority server modules before
the higher priority ones, the low priority server modules will be the first
modules to have their power allocation lowered to the minimum value.
Once the available power allocation is exhausted, CMC reclaims power
from lower or equal priority servers up to their minimum power level.
NOTE: I/O modules, fans, and iKVM (if present) are designated the highest priority.
CMC reclaims power only to meet the power needs of a higher priority module or server.