Brocade FastIron SX Series Chassis Hardware Installation Guide - Manual (Page 48)

When one or more system power supplies fail
If one or more system power supplies fail and the system is left with less than the minimum number of
power supplies required for normal operation, the power supplies will go into overload and the system
will start to shut down. Several things can happen. The output voltage of the remaining good power
supplies will likely drop as they try unsuccessfully to generate more power than they are capable of.
The system will react to a drop in voltage by increasing the current draw. The hardware will shut down
due to over-current protection or under-voltage protection, whichever takes place first. One by one, the
interface modules will shut down until the power is within the power budget of the remaining power
supplies. There is no particular order in which the interface modules will shut down, as this will occur in
hardware and not in software. The management CPU requires power as well, and may also shut down
during a power supply failure.
After a power loss, if the system is left with less than the minimum number of power supplies required
for normal operation, the system will be left in an unknown state. At this point, manual recovery is
required (i.e., restore power and power cycle the device).
When one or more PoE power supplies fail
If one or more PoE power supplies fail and the system is left with less than the minimum number of
PoE power supplies, the PoE power supplies will go into overload. Non-PoE functions will not be
impacted, provided the System power supplies are still up and running. Several things can happen
with a PoE power supply failure. The output voltage of the remaining good power supplies will likely
drop as they try unsuccessfully to generate more power than they are capable of. The system will
react to a drop in voltage by increasing the current draw. The hardware will shut down PoE function
due to over-current protection or under-voltage protection, whichever occurs first. The interface
modules will start to shut down its PoE ports one by one until the over-power is within the power
budget of the remaining power supplies. There is no particular order in which the PoE ports will shut
down, as this occurs in hardware and not in software.
After a power loss, if the system is left with less than the minimum number of power supplies required
for normal operation, the system will be left in an unknown state. At this point, manual recovery is
required (i.e., restore power and power cycle the device).
Cooling system
The cooling system is contained within the system fan tray assembly and modules. The following
components comprise the cooling system:
• The FSX and FSX 800 each have six four-speed fans.
• The FSX 1600 has two five-speed fans in the rear of the device.
• One fan control module. The fan control module maintains the power to the fans, and controls the
fan speed and the reporting of the fan status to the management module.
• Two temperature sensors on each management module, and one temperature sensor on each
interface module
• One temperature sensor on each switch fabric module.
The fan tray in the FSX and FSX 800 device is located in the right side of the chassis. The FSX 1600
has two fan trays which are located in the top rear of the chassis.
Upon system startup, the fans operate at low speed, then adjust their speed based on the current
temperature of the modules and the configured temperature thresholds, or by the manually configured
fan speed.
By default, the system polls the temperature sensor on each module every 60 seconds to get a
temperature reading. For information about changing the default temperature polling interval, refer to
Changing the temperature polling interval on page 101. Depending on the temperature readings for
the modules, the system can do the following:
Cooling system
46 Brocade FastIron SX Series Chassis Hardware Installation Guide
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