Installation Guide

Table Of Contents
NOTE
Auto control of fan speed is not monitored when cards are in interactive mode. Set fan speed to high to prevent over-temp
condition.
NOTE
Adjusting fan controls out of the default setting can negatively affect the efficient cooling of blades and may cause a blade to
overheat and shutdown.
Changing temperature thresholds for modules and fan speeds
The cooling system includes fans that operate at four speeds: low, medium, medium-high, and high. In general, each fan speed, (except
for low), has a low and high temperature threshold associated with it, as shown in the following figure. The low fan speed has a high
temperature threshold only.
NOTE
Adjusting fan controls out of the default setting can negatively affect the efficient cooling of blades and may cause a blade to
overheat and shutdown.
FIGURE 107 Fan speeds and temperature thresholds
The low and high temperature thresholds allow the router to determine the speed at which the fans should operate. In general, the fans
operate according to these guidelines:
If the temperature of all modules falls between the low and high thresholds for a fan speed, the fan continues to operate at that
speed.
If the temperature of a management module, switch fabric module, or one interface module exceeds the high threshold
specified for a fan speed, the fan changes to the next higher speed. If the temperature of any of the modules exceeds the high
threshold for the high speed, the router shuts down the modules to prevent damage. The router also sends a warning message
to the system log and an SNMP trap. For information about viewing the warning messages, refer to Displaying temperature
warnings on page 214.
The frequency with which the temperature is checked is determined by the setting of the temp-poll-period command. For
information about temp-poll-period command, refer to Changing the temperature polling interval on page 212.
If the temperature of a management module, switch fabric module, and interface modules falls below the low threshold for a fan
speed, the fan changes to the next lower speed. If the temperature of all modules falls below the high threshold for the low
speed, the fan operates at the low speed.
Default temperature thresholds for Brocade NetIron MLX Seriesdevices are described in the following table.
Managing Routers and Modules
Brocade NetIron MLXe Series Hardware Installation Guide
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