Dell POWEREDGE M1000E - Manual (Page 204)

DPSE can be enabled for all three power supply redundancy configurations — No Redundancy, Power Supply
Redundancy, and Grid 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 causes 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 turn on 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 turned on.
Since an enclosure in the Power Supply Redundancy configuration always has an extra PSU engaged, the enclosure
can withstand the loss of one online PSU. The enclosure can also 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 turning on.
• In Grid Redundancy configuration, all power supplies are engaged when the chassis is turned on. Power utilization
is monitored, and if system configuration and power utilization allows, PSUs are moved to the Standby state. The
Online status of PSUs in a grid mirrors that of the other grid. Hence, the enclosure can sustain the loss of power to
an entire grid without interruption of power to the enclosure.
An increase in power demand in the Grid Redundancy configuration causes 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.
Default Redundancy Configuration
The default redundancy configuration for a chassis depends on the number of PSUs it contains, as shown in the
following table.
Table 37. Default Redundancy Configuration
PSU Configuration Default Redundancy Policy Default Dynamic PSU Engagement Setting
Six PSUs Grid Redundancy Disabled
Three PSUs No Redundancy Disabled
Grid Redundancy
In Grid Redundancy mode with six PSUs, all six PSUs are active. The three PSUs on the left must connect to one input
power grid, while the three PSUs on the right connect to another power grid.
CAUTION: To avoid a system failure and for Grid Redundancy to work effectively, there must be a balanced set of
PSU properly cabled to separate grids.
If one grid fails, the PSUs on the functioning grid take over without interruption to the servers or infrastructure.
CAUTION: In Grid redundancy mode, you must have balanced sets of PSUs (at least one PSU in each grid). If this
condition is not met, Grid redundancy may not be possible.
Power Supply Redundancy
When power supply redundancy is enabled, a PSU in the chassis is kept as a spare, ensuring that the failure of any one
PSU does not cause the servers or chassis to power-down. Power Supply Redundancy mode requires up to four PSUs.
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