User's Manual

Power Management 297
DPSE can be enabled for all three power supply redundancy configurations
explained above — No Redundancy, Power Supply Redundancy, and AC
Redundancy.
•In a No Redundancy configuration with DPSE, the M1000e can have up
to five power supply units in
Standby state. In a six PSU configuration,
some PSU units are placed in Standby and stay unutilized to improve
power efficiency. Removal or failure of an online PSU in this configuration
cause a PSU in
Standby state to become Online ; however, standby PSUs
can take up to 2 seconds to become active, so some server modules may
lose power during the transition in the
No Redundancy configuration.
NOTE: In a three PSU configuration, server load may prevent any PSUs from
transitioning to Standby.
•In a Power Supply Redundancy configuration, the enclosure always keeps
an additional PSU powered on and marked
Online in addition to the PSUs
required to power the enclosure. Power utilization is monitored and up to
four PSUs could be moved to
Standby state depending on the overall
system load. In a six PSU configuration, a minimum of two power supply
units are always powered on.
Since an enclosure in the
Power Supply Redundancy configuration always
has an extra PSU engaged, the enclosure can tolerate the loss of one online
PSU and still have enough power for the installed server modules. The loss
of the online PSU causes a standby PSU to come online. Simultaneous
failure of multiple PSUs may result in the loss of power to some server
modules while the standby PSUs are powering up.
•In
AC Redundancy configuration, all power supplies are engaged at chassis
power up. Power utilization is monitored, and if system configuration and
power utilization allows, PSUs are moved to the
Standby state. Since the
Online status of PSUs in a grid mirrors that of the other grid, the
enclosure can sustain the loss of power to an entire grid with no
interruption of power to the enclosure.
An increase in power demand in the
AC Redundancy configuration cause
the engagement of PSUs from the
Standby state. This maintains the
mirrored configuration needed for dual-grid redundancy.
NOTE: With DPSE Enabled, the Standby PSUs are brought Online to reclaim power
if power demand increases in all three Power Redundancy policy modes.