Filter
Top Products
Intel
®
NetStructure
TM
ZT 7102 Chassis Management Module
Fan Control and Monitoring
Technical Product Specification 91
17.0 Fan Control and Monitoring
The CMM controls the fan speeds and the fan tray LEDs. In a healthy state (no events) the LED
changes to a green color. If any of the fan tray sensors (temperature, voltages, fan tachs) are in an
unhealthy state, the LED changes to orange.
17.1 Setting Fan Speed
The factory default fan speed is 100 percent. The user can set the fan speed to 100 percent, 80
percent and 0 percent of the full speed through any of the supported interfaces. Setting the fan
speed from the CMM changes the fan speeds for all of the fans in the chassis. Setting the fan speeds
to 0 percent turns off the fans.
Note: The fan speed setting is persistent between CMM reboots.
The following command can be used to set the fan speed:
cmmset -l chassis -d fanspeed -v [100, 80, 0]
Where the value is 100 for 100 percent, 80 for 80 percent, or 0 for off.
Note: Querying fanspeed on the CMM will always reflect what the fan speed value was set to, not what
the actual fan speed is.
17.1.1 Considerations for Turning Off the Fans
Some fan tray designs will not allow the fans to be turned off and will override the CMM setting
with hardware on the fan trays. The CMM cannot detect fan tray hardware that provides such an
override. Consult the fan tray or chassis documentation for further information on setting fan
speeds.
For fan trays that do not allow fans to be turned off, querying the fanspeed on the CMM after
setting it to zero will still show the fanspeed as set to zero because this is what is being output by
the CMM.
Also, setting the fan speed to 0 (off) will override the automatic fan control of the CMM.
Temperature and fan tray events will no longer cause the CMM to drive the fans to full speed.
17.2 Automatic Fan Control
The CMM will drive the fans to full speed (100 percent) under any of the following conditions:
• An upper temperature threshold is violated in the platform, including blades.
• A fan tray is removed from the chassis.
• A fan tachometer crosses a lower threshold.
• A fan board controller has a failure.
The fans are also driven to full speed automatically if both CMMs are removed from the chassis.