3Com 3CB9E7 - CoreBuilder 9000 Chassis Switch Getting Started Manual page 110

110 A C: I
PPENDIX NTELLIGENT
Operate the CoreBuilder 9000 Enterprise Switch in
power fault-tolerant mode to ensure that power that
is equivalent to at least one power supply is available
to replace power that is lost if a single power supply
fails.
To set the CoreBuilder 9000 Enterprise Switch to
power fault-tolerant mode or to power
non-fault-tolerant mode, enter the
command at the EME prompt.
When you attempt to set the CoreBuilder 9000
Enterprise Switch to power fault-tolerant mode, EMEs
determine if there is sufficient unallocated power
budget available to place power that is equivalent to
one power supply in reserve.
If there is sufficient unallocated power budget, the
CoreBuilder 9000 Enterprise Switch sets to power
fault-tolerant mode.
If there is insufficient unallocated power budget,
the CoreBuilder 9000 Enterprise Switch remains in
power non-fault-tolerant mode.
To prevent management modules from automatically
disabling power fault-tolerant mode in response to a
power supply failure, ensure that the number of
installed power supplies is equal to or greater
than n-2 (two extra power supplies). In a
CoreBuilder 9000 Enterprise Switch with at least two
extra installed power supplies, n-1 power supplies
continue to be available to run the system in power
fault-tolerant mode, even after a single power supply
fails.
If a power supply failure occurs under any condition,
an alert is sent to the management application.
P S
OWER UBSYSTEM
set power mode
Non-fault tolerant mode — A user-selectable mode
in which 100 percent of the power that can be
allocated to all modules is available to them (no
power is held in reserve). This is the default mode for
power supplies as shipped.
While the Switch is running in power
non-fault-tolerant mode, the amount of power that is
available to modules is determined by the number
and type of power supplies that are installed.
If a power supply fails while the chassis is running in
power non-fault-tolerant mode:
Installed management modules may shut down
selected CoreBuilder 9000 interface modules and
switch fabric modules in an attempt to bring
installed module power consumption under the
now-reduced power budget.
Installed interface modules and switch fabric
modules continue to operate without interruption
if the output of remaining installed power supplies
is sufficient to provide adequate power to all
installed modules.