Brocade FastIron X Series Chassis Hardware Installation Guide
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Managing the cooling system
4
•
Thermal Plane 2 (also called Rule 2/2) – This thermal plane includes all of the temperature
sensors on all of the Interface modules. Each Interface module has one temperature sensor.
The
FSX 800
and
FSX 1600
have three thermal planes:
•
Thermal Plane 1 (also called Rule 1/3) – This thermal plane includes the temperature sensors
on the management module or modules only. Each management module has two temperature
sensors.
•
Thermal Plane 2 (also called Rule 2/3) – This thermal plane includes all of the temperature
sensors on all of the Interface modules. Each Interface module has one temperature sensor.
•
Thermal Plane 3 (also called Rule 3/3) – This thermal plane includes all of the temperature
sensors on the switch fabric modules. Each switch fabric module has one temperature sensor.
All thermal planes, along with temperature thresholds, help determine at which speed the fans
should operate. For each thermal plane, you can define separate temperature thresholds for fan
speeds. Each thermal plane can have different temperature thresholds.
For each thermal plane, the Brocade device records the highest temperature based on the
temperature reading of all of the modules in the thermal plane. The system uses this information
and the current configured temperature thresholds to adjust the fan speed. You can view the
temperature of each thermal plane using the show chassis command.
Fan speed modes
The fans can operate in automatic or manual mode. The default is automatic mode. This section
describes both methods.
Automatic mode
By default, the fans operate in automatic mode, self-adjusting their speed based on both of the
following factors:
•
the current temperature of each thermal plane
•
the current configured temperature threshold ranges for all fan speeds
The Brocade device has default temperature threshold ranges for fan speeds (
you can change these settings.
The software regularly polls the chassis to obtain the temperature of each thermal plane, then
uses this information to decide whether or not to switch the fan speed. By default, the Brocade
device polls the chassis every 60 seconds for temperature data. You can change this interval using
the CLI command chassis poll-time.
If the temperature of a thermal plane exceeds the high temperature level of the temperature range
associated with the current fan speed in the associated plane, the system will switch the fan speed
to the next higher level. For example, let’s say the current fan speed is 3 (medium), and the
configured operating temperature range for fan speed 3 is 40 to 50 degrees Centigrade for
Thermal Plane 2. Based on this configuration, if the temperature of Thermal Plane 2 rises to 51
degrees Centigrade, the system will automatically increase the fan speed to fan speed 4.
Manual mode
Typically, the fans operate in automatic mode, as described above. If desired, you can manually set
the speed at which the fans will operate. For more information, refer to